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The commonly used lipopolysaccharide (LPS)-induced depression models often evaluate depression-like behaviors in the acute phase after a single intraperitoneal injection of LPS, and are not suitable for examining long-term depression-like behaviors. To overcome this limitation, we developed a mice LPS model for elucidating the long-term pathophysiology of depression. Using the tail-suspension test, we show that a single intraperitoneal injection of a high dose (1.66 mg/kg) of LPS prolonged depression-like behavior to 14 days after LPS administration unlike 4 days after administration for the most commonly used LPS dose (0.83 mg/kg). Upon high-LPS dose administration, TNF-α levels in the cerebrospinal fluid were increased only on the first day after administration. Moreover, LPS-induced depression-like behavior on day 10 after LPS administration was prevented by imipramine or minocycline. Immunohistochemical analysis revealed reduced neurogenesis in the hippocampal dentate gyrus of LPS-treated mice on day 10 of LPS administration. The LPS model, in which a single intraperitoneal administration of LPS at a dose double of the standard dose used currently, exhibits depression-like behavior via reduced neurogenesis mediated by neuroinflammation, and should be useful for elucidating the long-term pathophysiology of depression and for studying antidepressant drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Introduction and Hypothesis: Despite the high prevalence of fecal incontinence, existing treatment options may be inadequate. Drugs that enhance the tone of the anal sphincter complex could potentially be an effective pharmacological approach. This study investigated the effect of the tricyclic antidepressant imipramine on anal sphincter tone in healthy women, employing anal acoustic reflectometry as the evaluating method., Methods: In a double-blind, randomized, placebo-controlled crossover study, 16 healthy female volunteers were randomized to one of two treatment sequences. The participants attended two study visits separated by at least 7 days' washout. At each visit, they received a single dose of 50 mg imipramine or matching placebo, in alternating order. We assessed the anal opening pressure under the resting state and during voluntary squeezing of the pelvic floor. Measurements were performed pre-dose and 1 h after drug administration, corresponding to the estimated time of peak plasma concentration of imipramine., Results: All participants completed the study. In total, 44% of the participants reported at least one adverse effect, primarily anticholinergic. Compared with placebo, imipramine increased anal opening pressure by 15.2 cmH 2 O (95% confidence interval [CI] 2.0-28.2 cmH 2 O, p = 0.03) in the resting state and 15.1 (95% CI 4.2-26.0 cmH 2 O, p = 0.01) cmH 2 O during squeezing., Conclusions: The findings indicate that imipramine increases anal sphincter tone in healthy women. However, further research is required to evaluate its clinical impact on individuals with fecal incontinence. This research also demonstrates the effectiveness of using anal acoustic reflectometry for assessing pharmacological effects on anal sphincter function., (© 2024. The Author(s).)

Introduction and Objective: Desmopressin is well accepted as first-line medical therapy for enuresis. If ineffective, combination therapy of desmopressin + oxybutynin or desmopressin + imipramine has been used. This study assessed the efficacy of adjunct therapy with either imipramine or oxybutynin in the management of enuresis patients who failed desmopressin treatment., Study Design: A retrospective chart review of our database for patients with enuresis was performed. Patients who were prescribed desmopressin, oxybutynin, and imipramine over 14 years for enuresis were included. Two cohorts of patients were examined; group OXY was treated with desmopressin and oxybutynin, and group IMP received desmopressin and imipramine. Pretreatment measurement of Vancouver Symptom Scores (VSS) were used to compare groups using the VSS question "I wet my bed at night" where 4: every night, 3: 4-5 nights per week, 2: 1-2 nights per week, 1: 3-4 nights per month, and 0: never. International Children's Continence Society (ICCS) criteria for continence success was utilized to determine outcomes., Results: 2521 patients prescribed one of the 3 medications were identified. Among them, 81 patients (mean age: 10.5 ± 2.8 years) received combination therapy. Of which, 55 were male and 26 female. Specifically, 58 were prescribed both desmopressin and imipramine (group IMP), 23 desmopressin and oxybutynin (group OXY), and 4 transitioned from OXY to IMP. Mean pretreatment VSS showed no difference between groups. Both groups experienced minimal drops in wet nights with desmopressin alone. A comparison revealed that group IMP reduced wet nights significantly more than group OXY (VSS wet night score 0.7 ± 1.2 vs. 2.3 ± 1.1 respectively, p < 0.0001). Non-intent-to-treat complete response rate was 68% vs 5% (OR = 42.5, p < 0.001) (IMP vs. OXY respectively). Intent-to-treat response rates were 58%., Discussion: Although first-line desmopressin treatment for enuresis is effective, it does not work for all patients, and many parents and children desire nighttime dryness. Clinicians have combined desmopressin with oxybutynin or imipramine for improved results, but research comparing these modalities is scarce. Our study suggests that the desmopressin and imipramine combination is superior at reducing nights wet compared to desmopressin and oxybutynin, attributed to imipramine's probable central mechanism rather than its secondary anticholinergic properties. Limitations include a modest sample size, retrospective design, and subjective responses to the Vancouver questionnaire., Conclusion: A combination of desmopressin and imipramine was more effective in reducing wet nights and had a complete response rate that was 42.5 times greater than desmopressin and oxybutynin., Competing Interests: Conflicts of interest This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2024 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)

Major depressive disorder (MDD) stands as a significant cause of disability globally. Cannabidiolic Acid-Methyl Ester (CBDA-ME) (EPM-301, HU-580), a derivative of Cannabidiol, demonstrates immediate antidepressant-like effects, yet it has undergone only minimal evaluation in psychopharmacology. Our goal was to investigate the behavioral and potential molecular mechanisms associated with the chronic oral administration of this compound in the Wistar Kyoto (WKY) genetic model of treatment-resistant depression. Male WKY rats were subjected to behavioral assessments before and after receiving chronic (14-day) oral doses of CBDA-ME (0.5 mg/kg), 15 mg/kg of imipramine or vehicle. At the end of the study, plasma corticosterone levels and mRNA expression of various genes in the medial Prefrontal Cortex and Hippocampus were measured. Behavioral outcomes from CBDA-ME treatment indicated an antidepressant-like effect similar to imipramine, as oral ingestion reduced immobility and increased swimming duration in the Forced Swim Test. Neither treatment influenced locomotion in the Open Field Test nor preference in the Saccharin Preference Test. The behavioral impact in WKY rats coincided with reduced corticosterone serum levels, upregulated mRNA expression of Cannabinoid receptor 1, Fatty Acid Amide Hydrolase, and Corticotropin-Releasing Hormone Receptor 1, alongside downregulation of the Serotonin Transporter in the hippocampus. Additionally, there was an upregulation of CB1 mRNA expression and downregulation of Brain-Derived Neurotrophic Factor in the mPFC. These findings contribute to our limited understanding of the antidepressant effects of CBDA-ME and shed light on its potential psychopharmacological mechanisms. This discovery opens up possibilities for utilizing cannabinoids in the treatment of major depressive disorder and related conditions., Competing Interests: Declaration of Competing interest The authors have nothing to declare., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: The present study aimed to elucidate the transport properties of imipramine and paroxetine, which are the antidepressants, across the blood-brain barrier (BBB) in rats., Methods: In vivo influx and efflux transport of imipramine and paroxetine across the BBB were tested using integration plot analysis and a combination of brain efflux index and brain slice uptake studies, respectively. Conditionally immortalized rat brain capillary endothelial cells, TR-BBB13 cells, were utilized to characterize imipramine and paroxetine transport at the BBB in vitro., Results: The in vivo influx clearance of [ 3 H]imipramine and [ 3 H]paroxetine in rats was determined to be 0.322 mL/(min·g brain) and 0.313 mL/(min·g brain), respectively. The efflux clearance of [ 3 H]imipramine and [ 3 H]paroxetine was 0.380 mL/(min·g brain) and 0.126 mL/(min·g brain), respectively. These results suggest that the net flux of paroxetine, but not imipramine, at the BBB in vivo was dominated by transport to the brain from the circulating blood. The uptake of imipramine and paroxetine by TR-BBB13 cells exhibited time- and temperature-dependence and one-saturable kinetics with a K m of 37.6 μM and 89.2 μM, respectively. In vitro uptake analyses of extracellular ion dependency and the effect of substrates/inhibitors for organic cation transporters and transport systems revealed minor contributions to known transporters and transport systems and the difference in transport properties in the BBB between imipramine and paroxetine., Conclusions: Our study showed the comprehensive outcomes of imipramine and paroxetine transport at the BBB, implying that molecular mechanism(s) distinct from previously reported transporters and transport systems are involved in the transport., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Discovery of the rapid antidepressant effect of ketamine has been considered one of the most important advances in major depressive disorder treatment. Several studies report a significant benefit to patients that lasts up to 19 days after treatment. However, concerns arise from the long-term use of ketamine, thus a safe and effective strategy for maintaining its antidepressant effect is still necessary. To this end, our work assessed the effects of imipramine and fluoxetine after repeated ketamine treatment in male mice. Ketamine (30 mg/kg/day for 14 days) induced an anti-immobility effect in the forced swimming (FS) paradigm, detected 1 and 3 days after treatment. Seven days after the last ketamine injection, mice received imipramine (20 mg/kg) or fluoxetine (30 mg/kg). Imipramine and fluoxetine did not change mice's immobility time, regardless of the pre-treatment (saline or ketamine). Since both drugs' anti-immobility effect was demonstrated in the classical FS test, we can assume that repeated exposure to intermittent stress inhibited the antidepressant drugs' anti-immobility effects. Moreover, pre-exposure to ketamine did not counteract stress-induced changes in mice response to antidepressants. Since exposure to forced swim and i.p. injections are stressful to rodents, each stressor's contribution to the blunted response to antidepressants was investigated. Our data demonstrated that both stressors (FS and i.p. injections) influenced the reported effect. In summary, our results showed that exposure to intermittent repeated stress inhibited the anti-immobility effect of imipramine and fluoxetine in mice and corroborated findings demonstrating that exposure to stress can blunt patients' response to antidepressants., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The contribution of metabotropic glutamate receptors (mGlu receptors) in depression is well known and tested worldwide. Our previous study showed the involvement of the cyclooxygenase-2 (COX-2) pathway in behavioral changes mediated by an antagonist of metabotropic glutamate receptor subtype 5 (mGlu5 receptor) 3-[(2-methyl-1,3-tiazol-4-yl)ethynyl]-pyridine (MTEP). Among others, we have found that chronic concomitant administration of a COX-2 inhibitor and sub-effective dose of MTEP accelerates antidepressant-like activity of MTEP. This paper seeks to explore whether the same effect would be observed with the use of a non-selective COX inhibitor 2-[1-(4-chlorobenzoyl)-5-methoxy-2-methylindol-3-yl]acetic acid (indomethacin). To that end, we have employed experimental procedure implemented in the earlier research. MTEP and indomethacin or MTEP + indomethacin were used chronically for 7 or 14 days. Then, the Porsolt test, tail suspension test and locomotor activity test were performed. Imipramine was used as a reference compound, as its action is connected with mGlu5 receptor. We found that, in contrast to COX-2 inhibition, indomethacin - acting both through COX-1 and COX-2 - did not release antidepressant-like potential of MTEP. The opposite effect was shown when imipramine was used., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: Doxorubicin (DOX) is a chemotherapeutic agent widely used to treat cancers, particularly breast cancer. DOX has side effects, including cardiotoxicity, hepatotoxicity, and nephrotoxicity. Imipramine is an antidepressant that increases the release of neurotransmitters. This study aimed to investigate the effect of co-administration of imipramine and DOX on DOX-induced toxicity., Materials and Methods: Forty female mice (10-12-weeks-old, 30-38 g) were divided into four groups (n = 10 per group). The animals in the control group received a single-dose saline injection. The animals in the DOX group received a single dose of DOX (20 mg/kg) by intraperitoneal (i.p.) injection. The animals in the imipramine group received the drug daily in their drinking water (0.13 mg/mL) for 9 days, starting 1 day before the DOX injection received by the DOX group. The animals in the combination group (DOX+imipramine) received a single dose of DOX (20 mg/kg, i.p. injection), and a daily dose of imipramine in their drinking water (0.13 mg/mL) for 9 days starting 1 day before the DOX injection. The animals were observed daily to record mortality, and their body weights were recorded every alternate day., Results: DOX treatment increased the rate of mortality compared with that for control animals. Imipramine co-administration with DOX increased the rate of mortality significantly (p < 0.05) compared with DOX treatment alone. The mortality rate in both the control and imipramine-treatment groups was zero. DOX co-administered with imipramine resulted in significantly reduced body weight compared with control animals., Conclusions: The combination of DOX and imipramine reduced the survival rate of female mice, suggesting that imipramine increases the toxic effects of DOX.

Zinc (Zn) was found to enhance the antidepressant efficacy of imipramine (IMI) in human depression and animal tests/models of depression. However, the underlying mechanism for this effect remains unknown. We measured the effect of intragastric ( p.o. ) combined administration of IMI (60 mg/kg) and Zn (40 mg Zn/kg) in the forced swim test (FST) in mice. The effect of Zn + IMI on serum, brain, and intestinal Zn concentrations; Zn transporter (ZnT, ZIP) protein levels in the intestine and ZnT in the brain; including BDNF (brain-derived neurotrophic factor) and CREB (cAMP response element-binding protein) protein levels in the brain were evaluated. Finally, the effect of IMI on Zn permeability was measured in vitro in colon epithelial Caco-2 cells. The co-administration of IMI and Zn induced antidepressant-like activity in the FST in mice compared to controls and Zn or IMI given alone. This effect correlated with increased BDNF and the ratio of pCREB/CREB protein levels in the prefrontal cortex (PFC) compared to the control group. Zn + IMI co-treatment increased Zn concentrations in the serum and brain compared to the control group. However, in serum, co-administration of IMI and Zn decreased Zn concentration compared to Zn alone treatment. Also, there was a reduction in the Zn-induced enhancement of ZnT1 protein level in the small intestine. Zn + IMI also induced an increase in the ZnT4 protein level in the PFC compared to the control group and normalized the Zn-induced decrease in the ZnT1 protein level in the hippocampus (Hp). The in vitro studies revealed enhanced Zn permeability (observed as the increased transfer of Zn through the intestinal cell membrane) after IMI treatment. Our data indicate that IMI enhances Zn transfer through the intestinal tract and influences the redistribution of Zn between the blood and brain. These mechanisms might explain the enhanced antidepressant efficacy of combined IMI/Zn treatment observed in the FST in mice.

Deficient learning and memory are well-established pathophysiologic features of depression, however, mechanisms of the enhanced learning of aversive experiences associated with this disorder are poorly understood. Currently, neurobiological mechanisms of enhanced retention of aversive memories during depression, and, in particular, their relation to neuroinflammation are unclear. As the association between major depressive disorder and inflammation has been recognized for some time, we aimed to address whether neuroinflammatory changes are involved in enhanced learning of adversity in a depressive state. To study this question, we used a recently described mouse model of enhanced contextual conditioning of aversive memories, the modified forced swim model (modFST). In this model, the classic two-day forced swim is followed by an additional delayed session on Day 5, where increased floating behaviour and upregulated glycogen synthase kinase-3 (GSK-3) are context-dependent. Here, increased time spent floating on Day 5, a parameter of enhanced learning of the adverse context, was accompanied by hypercorticosteronemia, increased gene expression of GSK-3α, GSK-3β, c-Fos, cyclooxygenase-1 (COX-1) and pro-inflammatory cytokines interleukin-1 beta (IL-1β), tumor necrosis factor (TNF), and elevated concentrations of protein carbonyl, a marker of oxidative stress, in the prefrontal cortex and hippocampus. There were significant correlations between cytokine levels and GSK-3β gene expression. Two-week administration of compounds with antidepressant properties, imipramine (7 mg/kg/day) or thiamine (vitamin B1; 200 mg/kg/day) ameliorated most of the modFST-induced changes. Thus, enhanced learning of adverse memories is associated with pro-inflammatory changes that should be considered for optimizing pharmacotherapy of depression associated with enhanced learning of aversive memories., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Antidepressants are the first-choice for pharmacological treatment of panic disorder. However, they present disadvantages, such as delayed therapeutic effect, many side effects and a considerable rate of non-responders. These shortcomings prompt the development of new therapeutic strategies. Among these are the adjunctive use of enkephalinase inhibitors, such as opiorphin, which supposedly acts by increasing the availability of brain enkephalins and other endogenous opioids., Aims: We here evaluated whether opiorphin in the dorsal periaqueductal grey matter (dPAG), a key panic-related area, accelerates and/or facilitates the antipanic-like effect of fluoxetine or imipramine. We also verified whether the panicolytic effect of imipramine depends on activation of μ-opioid receptors (MORs)., Methods: Male Wistar rats were submitted to the escape task of the elevated T-maze, an index of panic attack, after treatment with imipramine (3, 7 or 21 days) or fluoxetine (3, 7, 14 or 21 days), combined with an intra-dPAG injection of opiorphin., Results: Opiorphin facilitated and accelerated the panicolytic-like effect caused by imipramine, but not with fluoxetine. The antipanic-like effect caused by chronic imipramine did not depend on MOR activation in the dPAG., Conclusion: Combined treatment of antidepressant drugs with opiorphin for hastening or potentiating the effects of the former compounds may not be generally effective, with the results varying depending on the type/class of these panicolytic drugs., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Although a lot of information can be found on the specific dual role of the endocannabinoid system in the emotional-related responses, little is known whether stimulation or inhibition of the cannabinoid (CB) receptors may affect the activity of the frequently prescribed antidepressant drugs. Our interests have been particularly focused on the potential influence of the CB 2 receptors, as the ones whose central effects are relatively poorly documented when compared to the central effects of the CB 1 receptors. Therefore, we evaluated the potential interaction between the CB 2 receptor ligands (i.e., JWH133 - CB 2 receptor agonist and AM630 - CB 2 receptor inverse agonist) and several common antidepressant drugs that influence the monoaminergic system (i.e., imipramine, escitalopram, reboxetine). In order to assess the antidepressant-like effects we used two widely recognized behavioural tests, the mouse forced swim test (FST) and the tail suspension test (TST). Brain concentrations of the tested antidepressants were evaluated by the HPLC method. Intraperitoneal co-administration of per se ineffective doses of JWH133 (0.25 mg/kg) or AM630 (0.25 mg/kg) with imipramine (15 mg/kg), escitalopram (2 mg/kg), and reboxetine (2.5 mg/kg) significantly shortened the immobility time of mice in the FST and the TST, whereas it did not disturb their spontaneous locomotor activity. Furthermore, the brain levels of antidepressants were not changed. Summarizing, the results of the present study revealed that both activation and inhibition of the CB 2 receptor function have a potential to strengthen the antidepressant activity of drugs targeting the monoaminergic system. Most probably, the described interaction has a pharmacodynamic background., (Copyright © 2019 Elsevier B.V. All rights reserved.)

To assess the influences of blood sampling volumes or sites on toxicological and toxicokinetic (TK) evaluations, 4-week duration animal studies and a single-dose TK study of imipramine were conducted. In the toxicological evaluation, six-week-old Sprague-Dawley rats were divided into no blood and blood sampling groups. Fifty microliters (microsampling) or 100 μL (larger sampling) of blood/time point was collected from the jugular vein (50 μL of data was reported previously as Yokoyama et al., 2020) or the tail vein 6 to 7 times on days 1/2 and in week 4. Although no parameters were affected by the 100 μL sample from the tail vein, the 100 μL jugular vein sampling decreased the red blood cell parameters in females, possibly due to hemorrhage at the sampling site. Regarding the TK assessment, 50 μL of blood/site/time point was collected at 6 time points from the tail and jugular vein of the same male rats after single oral administration of 10 or 100 mg/kg imipramine, which was selected as a representative drug with high distribution volume. Although there were no differences in the AUC 0-24hr and C max values between the sites, the plasma concentrations at the early time points were significantly lower from the tail vein than the jugular vein. From our studies, 50 μL of jugular and tail vein microsampling did not affect the toxicity parameters or AUC/C max . However, appropriate toxicity considerations and/or selection of the blood sampling site may be important in the case of larger sampling volumes or blood concentration assessment.

Objective: To analyse the use, indications and potential risks of tricyclic antidepressants (TCAs), using a technological system of clinical alerts at the time of prescription., Methods: Observational, descriptive, retrospective study on a population covered by a Colombian health insurance plan with an average of 2,333,582 members/month. The information was generated in the PBM (Pharmacy Benefit Management) MC21 Colombia technological platform., Results: Of the total members, 368,298 (16%) patients/month on average were prescribed medicines; 3,640 (1%) were prescribed TCAs: 2,573 amitriptyline (70%) and 1.062 imipramine (29%); 817 (22.5%) were over 65 years of age. The median daily dose of amitriptyline and imipramine was 25 mg. A total of 17,153 alerts were reported: 8,685 (51%) for drug-drug interactions, 7,354 (43%) for drug-age interactions and 543 (3%) for duplicate therapy., Conclusions: Risks were identified in the prescription of tricyclic antidepressants, especially in the over-65 population, where these drugs are used in particular for the management of neuropathic pain. The clinical alert system at the time of medicinal product formulation can make an important contribution to the prevention of potential adverse events associated with the use of medicinal products., (Copyright © 2018 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España, S.L.U. All rights reserved.)

Tricyclic antidepressives, such as imipramine, indirectly induce ejaculation by increasing the noradrenaline concentration, which triggers an α-adrenergic response, whereas α-adrenergic agonists, such as xylazine and detomidine, directly trigger ejaculation by activating the α-1 adrenergic receptors. Furthermore, serum oxytocin concentrations in stallions increase drastically before ejaculation, but decline immediately thereafter, implicating the role of this hormone in emission. The objectives of the present study were to: 1) compare the efficiency of various protocols for inducing ex copula ejaculation in stallions, 2) evaluate the benefits of including oxytocin in the protocols, and 3) compare the semen characteristics of ex copula versus in copula ejaculates. Nine protocols were used to induce ex copula ejaculation using various combinations of xylazine (X; 0.66 mg/kg, iv); oxytocin (O; 20 IU, iv), imipramine (I; 3 mg/kg, orally), and detomidine (D; 0.02 mg/kg, iv). Imipramine was given 2 h prior to the administration of α-adrenergic agonist (detomidine or xylazine) and oxytocin. If ejaculation did not occur within 10 min after treatment with an α-adrenergic agonist, a half-dose of the same product was injected. Twelve sexually mature stallions (6-26 y) were used; 9 of 12 stallions responded to the treatment. Two stallions responded to X or XO, four stallions responded to IX and IXO, one stallion responded to DO, and five responded to IDO. Stallions that responded to detomidine did not respond to xylazine. No stallion ejaculated in response to D, ID, or IO. Erections and masturbation occurred only in imipramine-treated stallions. Sperm quality was similar among all the protocols and was not significantly different from those in in copula ejaculates collected with an artificial vagina. In a separate trial, none of these protocols induced ex copula ejaculation in 2-3 y old stallions. The side effects included sialorrhea after imipramine administration in all the stallions and sedation after administration of xylazine or detomidine. In conclusion, the new protocol, IDO, and the traditional protocol, IX, had similar results, with IDO being a useful alternative protocol in stallions for which IX was not effective. Therefore, attempts using both the protocols are encouraged, as stallions that ejaculated upon administration of detomidine did not ejaculate when xylazine was administered, whereas those that responded to xylazine did not respond to detomidine., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Rationale: Some antidepressants have been previously found to produce anti-parkinsonian effect; nicotine was known to mitigate experimental neurotoxic lesions. The anticataleptic efficacy of antidepressant-nicotine co-administration is unstudied., Objectives: This work aimed to evaluate anticataleptic action of imipramine-nicotine combination in rotenone model., Methods: Catalepsy was measured by the bar test. Concentrations of tyrosine hydroxylase, dopamine, and DOPAC were determined in the substantia nigra and dorsal striatum using ELISA and HPLC techniques; additionally, dopamine/DOPAC ratio was calculated for both areas., Results: Imipramine and nicotine alone were ineffective; however, co-administration of the drugs significantly (p < 0.01) inhibited rotenone-induced catalepsy and mitigated neurochemical changes in the nigrostriatal system. Anticataleptic effect of the combination exceeded that of levodopa, a standard drug for anti-parkinsonian treatment., Conclusion: The combined use of imipramine and nicotine at relatively low doses inhibits neurotoxin-induced catalepsy and nigrostriatal neurochemical changes. The co-administration of these drugs might be a new approach to the treatment of extrapyramidal dysfunctions.

The two-factor theory predicts that the acquisition of avoidance responses is dependent on fear reduction; as such, drugs that reduce or increase fear or anxiety states should alter inhibitory avoidance (IA) acquisition. The present experiment used white spaces as aversive unconditioned stimuli in IA in zebrafish. Adult zebrafishes were tested in three experiments: validation of white compartment as aversive in IA; open field test; and effect of antidepressant (fluoxetine, imipramine) and anxiolytic (diazepam, clonazepam). The data show the effectiveness of the white compartment as an aversive stimulus in IA. Antidepressant fluoxetine did not alter and imipramine impairs avoidance acquisition in higher doses. Imipramine also produced a sedative effect in lower doses. Anxiolytic and stimulant drugs facilitated learning at doses which did not impair locomotion, suggesting that pharmacological manipulation of other factors in addition to fear/anxiety can impact aversive learning in zebrafish.

Swiss mice may be valuable for the screening of antidepressants in preclinical trials. Acute treatment with antidepressants may affect the behaviour of Swiss mice, but the effects on their hippocampal neurogenesis remain unknown. The present work aims to assess the influence of acute treatment with antidepressants on cell proliferation in the dentate gyrus of the hippocampus of adult Swiss mice. Cell proliferation was estimated by ex vivo counting of Ki-67 immunoreactive nuclei (Ki-67-ir) in the dentate gyrus of Swiss mice housed in standard or enriched environments, at survival-times 2 or 24 h after imipramine injection Independent of the experimental group, intraperitoneal imipramine (0 or 30 mg/kg) failed to change the number of Ki-67-ir in the hippocampus of mice. Through intracerebroventricular route, imipramine reduced the number of Ki-67-ir in the hippocampus of Swiss mice at the dose of 0.06 nmol and increased it at the dose 0.2 nmol. At the dose 0.2 nmol, not 0.06 nmol, imipramine increased the immunoreactivity to doublecortin (a marker for immature neurons) in the hippocampus of mice. The effects of intracerebroventricular injection of imipramine on neurogenesis markers were seen 24 h after the injection in mice housed in standard conditions. The effects of intracerebroventricular injection of imipramine on neurogenesis markers were absent in mice housed in enrichment or 2 h after the injection. These data suggest that acute treatment with imipramine may affect proliferation in the hippocampus of adult Swiss mice depending on the route of administration, doses, survival time and lodging conditions., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objectives: Treatment-resistance to antidepressants is a major problem in the pharmacotherapy of major depressive disorder (MDD). Unfortunately, only a few animal models are suitable for studying treatment-resistant depression, among them repeated treatment with Adrenocorticotropic hormone (ACTH) appears to be useful to mimic treatment-resistance to monoaminergic antidepressants. Therefore, the present work aimed to investigate the effectiveness of s-ketamine and rapastinel (formerly GLYX13), modulators of the glutamatergic N-methyl-D-aspartate receptor in ACTH-treated animals., Methods: Naïve male Sprague Dawley rats were subjected to repeated subcutaneous injections with ACTH (100 µg/0.1 ml/rat/day) for 14 days and drug treatment on the test day (open field and forced swim test) with imipramine, s-ketamine or rapastinel. In addition, assessment of plasma levels of corticosterone and ACTH was carried out., Results: We found that rats repeatedly treated with ACTH for 14 days responded to single injections with s-ketamine (15 mg/kg) and rapastinel (10 mg/kg), but failed to respond to imipramine (15 mg/kg). In the plasma, the levels of corticosterone and ACTH were increased after 14 days of daily treatment with ACTH, independently of the treatment., Conclusion: The present data confirm development of a resistance to treatment following chronic ACTH administration. In addition, the study confirms the possible effectiveness of s-ketamine and rapastinel as treatment options in treatment-resistant depression. Moreover, it highlights the importance of the glutamatergic system in the neurobiology of depression. Further studies are necessary to evaluate how repeated treatment with ACTH leads to a depressed condition resistant to monoaminergic antidepressants.

Background: This study investigated the effects of fish oil and olive oil in improving dysbiosis and depressive-like symptoms., Methods and Results: Male rats were fed normal, fish oil-rich or olive oil-rich diets for 14 weeks. Chronic mild stress (CMS) was administered from week 2. The sucrose preference test (SPT) and forced swimming test (FST) were used to determine depressive-like behavior. The SPT results revealed that the CMS, CMS with imipramine (CMS+P) treatment, and CMS with olive oil diet (CMS+O) groups exhibited significantly reduced sucrose intake from week 8, whereas the fish oil diet (CMS+F) group exhibited significantly reduced sucrose intake from week 10. The FST results showed that the immobile time of the CMS+F group was significantly less than that of the CMS-only group. Next generation sequencing (NGS) results showed CMS significantly reduced the abundance of Lactobacillus and increased that of Marvinbryantia and Ruminiclostridium&#95;6 . However, the CMS+F group showed an increase in the abundance of Eisenbergiella , Ruminococcaceae&#95;UCG&#95;009 , and Holdemania , whereas the CMS+O group showed an increase in the abundance of Akkermansia ., Conclusions: CMS stimuli altered the gut microbiome in depressed rats. Fish oil and olive oil exerted part of a prebiotic-like effect to ameliorate dysbiosis induced by CMS. However, only fish oil ameliorated depressive-like symptoms.

The circadian system regulates sleep/wake cycles, metabolism, mood, and other functions. It also influences medication efficacy. In this study, we studied the chronopharmacological profiles of antidepressants with various modes of action. We also investigated the effects of dosing time on the pharmacological activity of several antidepressants acting on serotonergic, noradrenergic, and/or dopaminergic neurons. C57BL/6 mice were intraperitoneally administered fluoxetine, imipramine, venlafaxine, or bupropion at 08:00 h (morning), 14:00 h (mid-day), 20:00 h (evening), or 02:00 h (mid-night). Antidepressant activity was evaluated by the tail suspension test. All antidepressants reduced immobility, and their activities varied according to the dosing time. Fluoxetine and imipramine induced relatively strong rhythms with high amplitudes. Their maximal effects were observed in the morning and evening, respectively. Venlafaxine and bupropion induced weak rhythms with maximal effects in the evening and dawn, respectively. These results suggest that the antidepressant activity is associated with circadian fluctuation, and antidepressants with different modes of action have different chronopharmacological profiles. They affect locomotor activity in animals placed in novel (unfamiliar) environments. Fluoxetine, imipramine, and venlafaxine reduced locomotor activity, whereas bupropion increased it. The effects on locomotor activity also vary with circadian rhythm, and the tested drugs showed a maximal effect during the light phase. The peak time was different from that in TST. Plasma and brain levels of all drugs were slightly higher in the morning than in the evening. The dosing time dependency of the antidepressant activity did not correlate with the sedative/stimulatory activity or tissue drug level. Therefore, these latter two factors may have only a small impact on circadian antidepressant activity fluctuations. The relative activity of the serotonergic, noradrenergic, and dopaminergic systems may determine the chronopharmacological profiles of each drug. These results suggest the possibility that drug therapy be optimized by considering the dosing time when the antidepressant activity is high and other pharmacological activities leading to adverse effects are low. Further studies using animal models of depression and in clinical settings are necessary to confirm the effects of dosing time on depressed subjects.

Sexual side-effects are common among those using antipsychotic medication and may result in poor compliance and reduced quality of life. Retrograde ejaculation (RE) has been described occurring with a number of antipsychotic medications (thioridazine, risperidone, iloperidone and clozapine) but there are no guidelines regarding management of antipsychotic-associated RE. Imipramine has been suggested as a treatment for antipsychotic-associated RE in one small study of patients prescribed thioridazine and a case series of patients prescribed iloperidone. Quetiapine is a commonly used antipsychotic and is thought to be associated with less sexual side-effects relative to other antipsychotic medications. This case report describes a 25-year-old man with first episode psychosis who developed RE during treatment with quetiapine which improved with low-dose imipramine. This is the first description of RE occurring with quetiapine and successful treatment of quetiapine-associated RE with imipramine., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Nocturnal enuresis is a condition, which can affectthe quality of life in children. The present study was designed toinvestigate the efficacy of low-dose imipramine combined withdesmopressin on treatment of patients with primary nocturnalenuresis who were defined as desmopressin non-responders., Methods: A randomized clinical trial was carried out on patientswith primary nocturnal enuresis. Forty children with enuresisranging from 5 to 12 years old were randomly divided into theintervention (n = 20) and control groups (n = 20). The subjects inthe intervention group were treated with desmopressin combinedwith 5 mg imipramine at bedtime, and those in the control groupwere given desmopressin alone. The patients were followed upweekly for one month. The number of wet nights was recorded., Results: Two individuals in the intervention and three individualsin the control group were excluded from the study. Our findingsindicated that the age and gender showed no significant difference.Furthermore, a significant better recovery in the enuresis wasobserved in 18 of 20 patients who were treated with combinationtherapy after 1 month (P < .05). In addition, the frequency ofrecovery was significantly higher (83.3%) in the intervention group,compared with the control group (29.4%)., Conclusion: The analysis showed that low-dose imipramine is welltolerated in clinical practice and may represent a good short-termtreatment option in combination therapy where desmopressinalone is not efficient enough.

Purpose/background: According to available international clinical guides, tricyclic antidepressants are our first- or second-line treatment of choice for severe unipolar major depression. However, the therapeutic option after an unsuccessful response to a tricyclic antidepressant drug in unipolar major depression is still unclear., Methods/procedures: This 10-week randomized open-label study assessed the effectiveness of add-on lithium (adjusted to plasma levels) compared with add-on citalopram (30 mg/d) in 104 severe unipolar major depressive patients after a 10-week unsuccessful imipramine (adjusted to plasma level). Efficacy analyses examined changes in the severity of depression symptoms from baseline visit to endpoint and the comparative remission rate between treatment subgroups., Findings/results: The randomized sample consisted of 104 imipramine-resistant severe unipolar major depressed patients. Both, the percentage of remitters (40.4% vs 21.1%, P = 0.034) and the mean reduction of the Hamilton Depression Rating Scale score (58.8% vs 42.5%, P = 0.005) were significantly greater in the add-on citalopram subgroup at endpoint visit., Implications/conclusions: Although we should be cautious about generalizing these results to patients with a less severe unipolar major episode, results from the present study suggest that add-on citalopram is a very effective treatment option in unipolar major depressive episodes after an unsuccessful imipramine regimen.

Maternal hypercaloric exposure during pregnancy and lactation is a risk factor for developing diseases associated with inflammation such as obesity, diabetes and, neurological diseases in the offspring. Neuroinflammation might modulate neuronal activation and flavonoids are dietary compounds that have been proven to exert anti-inflammatory properties. Thus, the aim of the present study is to evaluate the effect of maternal supplementation with flavonoids (kaempferol-3- O -glucoside and narirutin) on the prevention of depression-like behaviour in the female offspring of dams fed with an obesogenic diet during the perinatal period. Maternal programming was induced by high fat (HFD), high sugar (HSD), or cafeteria diets exposure and depressive like-behaviour, referred to as swimming, climbing, and immobility events, was evaluated around postnatal day 56⁻60 before and after 30 mg/kg i.p. imipramine administration in the female offspring groups. Central inflammation was analyzed by measuring the TANK binding kinase 1 (TBK1) expression. We found that the offspring of mothers exposed to HSD programming failed to show the expected antidepressant effect of imipramine. Also, imipramine injection, to the offspring of mothers exposed to cafeteria diet, displayed a pro-depressive like-behaviour phenotype. However, dietary supplementation with flavonoids reverted the depression-like behaviour in the female offspring. Finally, we found that HSD programming increases the TBK1 inflammatory protein marker in the hippocampus. Our data suggest that maternal HSD programming disrupts the antidepressant effect of imipramine whereas cafeteria diet exposure leads to depressive-like behaviour in female offspring, which is reverted by maternal flavonoid supplementation.

Background: Guidelines recommend the use of neuromodulators in patients with functional dyspepsia not responding to proton pump inhibitors (PPIs) and prokinetics; however, there is a lack of data from randomised controlled trials supporting their use. We aimed to assess the safety and efficacy of imipramine, a tricyclic antidepressant (TCA), in treatment-refractory functional dyspepsia., Methods: In this single-centre, double-blind, randomised controlled trial, we enrolled consecutive patients with Rome II functional dyspepsia aged 18-80 years. Eligible patients were Helicobacter pylori-negative, had a normal upper gastrointestinal endoscopy and abdominal ultrasound, and remained symptomatic after open-label treatment with 8 weeks of esomeprazole and 4 weeks of domperidone. Patients completed questionnaires assessing dyspepsia symptoms, mood, and insomnia, and were then randomly assigned (1:1) via a computer-generated list of random numbers to receive imipramine (at a dose of 25 mg once nightly for the first 2 weeks, and then 50 mg thereafter) or placebo for 12 weeks. The primary endpoint was overall satisfactory relief of global dyspepsia symptoms at 12 weeks, via patient-reported assessment in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00164775, and is completed., Findings: Between Sept 11, 2005, and Aug 20, 2010, 107 patients with treatment-refractory functional dyspepsia were randomly assigned to receive imipramine (n=55) or placebo (n=52). Relief of global dyspepsia symptoms at 12 weeks occurred in 35 (63·6%, 95% CI 50·4-75·1) of 55 patients on imipramine compared with 19 (36·5%, 95% CI 24·8-50·1) of 52 on placebo (p=0·0051). Ten (18%) patients on imipramine discontinued the study due to adverse events (three dry mouth, two constipation, two drowsiness, and one each insomnia, palpitations, and blurred vision), compared with four (8%) on placebo (one dry mouth and constipation, and one each palpitations, worsening of gastro-oesophageal reflux, and limb paraesthesia). There were no serious adverse events., Interpretation: Low-dose imipramine should be considered as a possible therapy for patients with functional dyspepsia refractory to both PPIs and prokinetics, although patients should be cautioned about the adverse event profile., Funding: None., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: A significant proportion of depressed patients fail to respond to treatment with antidepressant drugs. Such patients might nonetheless respond to deep brain stimulation of the prefrontal cortex. Deep brain stimulation has also been shown to normalize behaviour in the chronic mild stress (CMS) model of depression. However, these studies have involved animals that are in general treatment responsive. Thus, this is not the ideal situation in which to investigate how deep brain stimulation is effective where antidepressant drugs are not., Aims: Here, we studied the behavioural effects of deep brain stimulation in treatment-resistant animals., Methods: Wistar rats were exposed to chronic mild stress and concurrent treatment with saline or one of three antidepressant drugs, imipramine, citalopram and venlafaxine. Individuals were selected from the CMS-exposed drug-treated groups that had failed to increase their sucrose intake by week 5 of drug treatment. All animals were then implanted with deep brain stimulation electrodes in the ventro-medial prefrontal cortex, and tested for sucrose intake and in the elevated plus maze and novel object recognition test, following 2 × 2 h of deep brain stimulation., Results: The selected drug-treated animals were found to be antidepressant-resistant in all three tests. With a single exception (sucrose intake in imipramine-treated animals), deep brain stimulation reversed the anhedonic, anxiogenic and dyscognitive effects of CMS in all four conditions, with no significant differences between saline- and drug-treated animals., Conclusions: These data provide a proof of principle that deep brain stimulation of the prefrontal cortex can be effective in a rat model of resistance to chronic antidepressant treatment, replicating the clinical effect of deep brain stimulation in treatment-resistant depression.

This study aimed at evaluating the antidepressant-like action of the marine alga Solieria filiformis lectin (SfL) and to investigate the participation of the monoaminergic system in this action. For this, male Swiss mice (n=10) were pretreated with intravenous injections (i.v.) of SfL (1, 3 or 9mg/kg) and submitted to open field (OFT), tail suspension (TST), forced swimming (FST), elevated plus-maze (EPMT) and hole-board tests (HBT). As controls, mice received sterile saline (i.v.), imipramine (10 or 30mg/kg; intraperitoneally - i.p.) or diazepam (1 mk/kg; i.p.). To assess the involvement of the monoaminergic system in SfL effects, the FST was conducted in mice pretreated with PCPA, an inhibitor of serotonin synthesis, or noradrenergic and dopaminergic receptors specific antagonists. The results showed that SfL has an antidepressant-like effect, with no psychostimulant and anxiolytic-like effects. When denatured or combined with mannan, SfL lost the ability to reduce the immobility time in the FST. In addition, SfL antidepressant-like effect was inhibited by the pretreatment of mice with SCH 23390, a dopamine D 1 receptor antagonist, and by sulpiride, a dopamine D 2 receptor antagonist. Thus, SfL produced an antidepressant-like effect, which is probably dependent on its interaction with the dopaminergic system., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Drugs are prescribed for chronic low back pain without knowing in advance whether a patient will respond to them or not. Quantitative sensory tests (QST) can discriminate patients according to sensory phenotype, possibly reflecting underlying mechanisms of pain processing. QST may therefore be a screening tool to identify potential responders to a certain drug. The aim of this study was to investigate whether QST can predict analgesic effects of oxycodone, imipramine and clobazam in chronic low back pain., Methods: Oxycodone 15 mg (n = 50), imipramine 75 mg (n = 50) and clobazam 20 mg (n = 49) were compared to active placebo tolterodine 1 mg in a randomized, double-blinded, crossover fashion. Electrical, pressure and thermal QST were performed at baseline and after 1 and 2 h. Pain intensity was assessed on a 0-10 numeric rating scale every 30 min for up to 2 h. The ability of baseline QST to predict pain reduction after 2 h was analysed using linear mixed models. Genetic variants of drug-metabolizing enzymes and genes affecting pain sensitivity were examined as covariables., Results: No predictor of analgesic effect was found for oxycodone and clobazam. Thermal QST was associated with analgesic effect of imipramine: patients more sensitive to heat or cold were more likely to experience an effect of imipramine. Pharmacogenetic variants and pain-related candidate genes were not associated with drug efficacy., Conclusions: Thermal QST have the potential to predict imipramine effect in chronic low back pain. Oxycodone and clobazam effects could not be predicted by any of the selected QST or genetic variants., Significance: Predicting drug efficacy in chronic low back pain remains difficult. There is some evidence that patients more sensitive to heat and cold pain respond better to imipramine., (© 2018 European Pain Federation - EFIC®.)

Time dependent sensitization (TDS) - phenomenon described originally by Chiodo and Antelman (1980) in context of dopamine receptors, refers to cascade of events that continue to develop in the organism, after the initiating stimulus is no longer available. Treatment could be recognized as such a initiating stimulus (in case of depression, example of electroconvulsive therapy would be obvious, but some aspects of pharmacotherapy too). The process leads to improvement, but, on the other hand, phenomena of kindling in recurrent depression is well known (more relapses and therapies make heavier and longer lasting subsequent episodes). Hence our interest in delayed effects of treatment. Here we report alterations in rat immune system after Imipramine (IMI) treatment cessation. Wistar male rats were treated with IMI (10 mg/kg i.p. in 2 ml/kg of saline) repeatedly for 21 days or once - on the last day of drug administration period. Then the 3 weeks discontinuation phase begun, during which, at certain time points (3 h, 72 h, 7days, 21days) the trunk blood was collected. Tissue concentrations of IMI and its metabolite desipramine (DMI), as well as ACTH and various cytokines were measured. The IMI and DMI was detectable only 3 h after the last i.p. injection of the drug. Ever since the second time point (72 h of discontinuation) the levels of either compound were below detection threshold.There was no significant changes in ACTH levels between rat groups, although IMI seemed to attenuate alterations of the hormone level comparing to control groups. We observed differences between groups regarding certain cytokines at certain time points. Namely: at 72 h of discontinuation IL-2 and IL-4 were elevated in sera of rats treated with IMI acutely; at 7d of discontinuation levels of IL-1α, IL-5, IL-10 and IL-12 were affected in both acutely and chronically treated animals. Presented data support, regarding some cytokines in serum, the TDS theory. Furthermore they refer to important aspect of antidepressants (ADs) action - antidepressant discontinuation syndrome (ADS). The most frequently, ADS has been described in context of ADs-disrupted monoamine homeostasis. Here, the other principle (i.e. immunomodulation) of the syndrome is proposed., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Preclinical Research The effects of methyl jasmonate (MJ; 5, 10, 20 mg/kg, i.p), a natural product widely used for the relief of stress, depression, and exhaustion on unpredictable chronic mild stress (UCMS)-induced depression-like behaviors in mice was assessed and compared to those of imipramine (IMP; 10 mg/kg, i.p). MJ and IMP were given 30 min before exposure to UCMS with the procedure repeated daily for 2 weeks; 24 h after the stress session, the tail suspension test (TST) and sucrose preference test were assessed. MJ decreased immobility time in the TST and reversed impaired intake of sucrose relative to the stressed control suggesting antidepressant-like activity. MJ also reduced UCMS-induced increases in corticosterone and MDA (malondialdehyde) levels and attenuated UCMS-induced decreases in GSH and TNF-α levels and SOD activity. These findings suggest that MJ attenuated UCMS-induced depressive-like behaviors through decreased levels of corticosterone and decreasing oxidative stress and neuroinflammation in mouse brain.Drug Dev Res 78 : 381-389, 2017. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Objective: Co-morbid depression with post-traumatic stress disorder (PTSD) is often treatment resistant. In developing a preclinical model of treatment-resistant depression (TRD), we combined animal models of depression and PTSD to produce an animal with more severe as well as treatment-resistant depressive-like behaviours., Methods: Male Flinders sensitive line (FSL) rats, a genetic animal model of depression, were exposed to a stress re-stress model of PTSD [time-dependent sensitisation (TDS)] and compared with stress-naive controls. Seven days after TDS stress, depressive-like and coping behaviours as well as hippocampal and cortical noradrenaline (NA) and 5-hydroxyindoleacetic acid (5HIAA) levels were analysed. Response to sub-chronic imipramine treatment (IMI; 10 mg/kg s.c.×7 days) was subsequently studied., Results: FSL rats demonstrated bio-behavioural characteristics of depression. Exposure to TDS stress in FSL rats correlated negatively with weight gain, while demonstrating reduced swimming behaviour and increased immobility versus unstressed FSL rats. IMI significantly reversed depressive-like (immobility) behaviour and enhanced active coping behaviour (swimming and climbing) in FSL rats. The latter was significantly attenuated in FSL rats exposed to TDS versus unstressed FSL rats. IMI reversed reduced 5HIAA levels in unstressed FSL rats, whereas exposure to TDS negated this effect. Lowered NA levels in FSL rats were sustained after TDS with IMI significantly reversing this in the hippocampus., Conclusion: Combining a gene-X-environment model of depression with a PTSD paradigm produces exaggerated depressive-like symptoms that display an attenuated response to antidepressant treatment. This work confirms combining FSL rats with TDS exposure as a putative animal model of TRD.

Objective: Post-traumatic stress disorder (PTSD) displays high co-morbidity with major depression and treatment-resistant depression (TRD). Earlier work demonstrated exaggerated depressive-like symptoms in a gene×environment model of TRD and an abrogated response to imipramine. We extended the investigation by studying the behavioural and monoaminergic response to multiple antidepressants, viz. venlafaxine and ketamine with/without imipramine., Methods: Male Flinders sensitive line (FSL) rats, a genetic model of depression, were exposed to a time-dependent sensitisation (TDS) model of PTSD and compared with stress naive controls. 7 days after the TDS procedures, immobility and coping (swimming and climbing), behaviours in the forced swim test (FST) as well as hippocampal and cortical 5-hydroxyindoleacetic acid (5HIAA) and noradrenaline (NA) levels were analysed. Response to imipramine, venlafaxine and ketamine treatment (all 10 mg/kg×7 days) alone and in combination were subsequently studied., Results: TDS exacerbated depressive-like behaviour of FSL rats in the FST. Imipramine, venlafaxine and ketamine were ineffective as monotherapy in TDS-exposed FSL rats. However, combining imipramine with either venlafaxine or ketamine resulted in significant anti-immobility effects and enhanced coping behaviours. Only ketamine+imipramine (frontal-cortical 5HIAA and NA), ketamine alone (frontal-cortical and hippocampal NA) and venlafaxine+imipramine (frontal-cortical NA) altered monoamine responses versus untreated TDS-exposed FSL rats., Conclusion: Exposure of FSL rats to TDS inhibits antidepressant response at behavioural and neurochemical levels. Congruent with TRD, imipramine plus venlafaxine or ketamine overcame treatment resistance in these animals. These data further support the hypothesis that exposure of FSL rats to a PTSD-like paradigm produces a valid animal model of TRD and warrants further investigation.

Preclinical Research Neurotensin is a nonbrain penetrant neuropeptide neurotransmitter that alters dopaminergic and serotonergic neurotransmission. Previous animal behavioral studies have demonstrated that intra-ventral tegmental administration of neurotensin and system administration of the selective neurotensin NTS 1 receptor agonist, PD149163 produce antidepressant-like effects in a forced swim test and a differential reinforcement of low rate task, respectively. The present study sought to expand upon these past findings by assessing systemic administration of PD149163 in a forced swim test, a primary antidepressant preclinical screening model, in mice. The tricyclic antidepressant drug imipramine was tested for comparison, and both compounds were also assessed in an open field test. Both PD149163 and imipramine reduced time spent immobile, an antidepressant-like effect, in the forced swim test. The highest dose of each compound significantly reduced locomotor activity. These findings provide further evidence for the putative antidepressant effects for PD149163 and suggest that NTS 1 receptor activation may be a novel pharmacologic strategy for antidepressant drug development. Drug Dev Res 78 : 196-202, 2017. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Objective: To compare the efficacy of two antidepressant treatment strategies in severely depressed in-patients, that is, imipramine vs. venlafaxine, both with subsequent lithium addition in non-responders., Method: In-patients (n = 88) with major depressive disorder were randomized to 7-week treatment with imipramine or venlafaxine (phase I). All non-responders (n = 44) received 4-week plasma level-targeted dose lithium addition (phase II). Efficacy was evaluated after 11 weeks of treatment., Results: Analyzing phases I and II combined, non-inferiority was established and the difference in the proportion of responders (HAM-D score reduction ≥50%) by the end of phase II demonstrated the venlafaxine-lithium treatment strategy to be significantly superior to the imipramine-lithium treatment strategy (77% vs. 52%) (χ 2 (1) = 6.03; P = 0.01). Regarding remission (HAM-D score ≤ 7), 15 of 44 (34%) patients in the imipramine-lithium treatment group were remitters compared to 22 of 44 (50%) patients in the venlafaxine-lithium treatment group, a non-significant difference. Patients in the venlafaxine-lithium treatment group had a non-significant larger mean HAM-D score reduction compared with patients in the imipramine-lithium treatment group (16.1 vs. 13.5 points, respectively; Cohen's d = 0.30)., Conclusion: The venlafaxine-lithium treatment strategy can be considered a valuable alternative for the imipramine-lithium treatment strategy in the treatment of severely depressed in-patients., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Although a role for alpha-2 adrenoceptors (alpha-2 ARs) in alcohol use disorder (AUD) and depression is suggested, very little information on a direct interaction between alcohol and these receptors is available., Methods: In this study adult female Wistar and Wistar-Kyoto (WKY) rats, a putative animal model of depression, were exposed to alcohol vapor 3h daily for 10days (blood alcohol concentration ∼150mg%) followed by daily injection of 10mg/kg of imipramine (IMP, a selective norepinephrine NE/serotonin reuptake inhibitor) or nomifensine (NOMI, a selective NE/dopamine reuptake inhibitor). On day 11 animals were tested for open field locomotor activity (OFLA) and forced swim test (FST) and were sacrificed 2h later for measurement of alpha-2 ARs densities in the frontal cortex and hippocampus using [3H]RX 821002 as the specific ligand., Results: Chronic alcohol treatment increased the immobility in the FST, without affecting OFLA in both Wistar and WKY rats, suggesting induction of depressive-like behavior in Wistar rats and an exacerbation of this behavior in WKY rats. Alcohol treatment also resulted in an increase in cortical but not hippocampal alpha-2 ARs densities in both Wistar and WKY rats. The behavioral effects of alcohol were completely blocked by IMP and NOMI and the neurochemical effects (increases in alpha-2 ARs) were significantly attenuated by both drugs in both strains., Conclusions: The results suggest a role for cortical alpha-2 ARs in alcohol withdrawal-induced depression and that selective subtype antagonists of these receptors may be of adjunct therapeutic potential in AUD-depression co-morbidity., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Functional somatic syndromes, including chronic fatigue syndrome or irritable bowel syndrome, often co-exist. Treatment guidelines supported by high quality evidence exist for most functional somatic syndromes, but are lacking for multiple comorbid functional somatic syndromes. We aimed to assess the effect of the tricyclic antidepressant, imipramine, in patients with multiple functional somatic syndromes defined by the criteria for multiorgan bodily distress syndrome, a unifying diagnosis that encompasses most functional somatic syndromes and somatoform disorders., Methods: In this single-centre, double-blind, randomised trial done in a Danish university hospital setting, participants were patients consecutively referred (age 20-50 years) fulfilling criteria for multiorgan bodily distress syndrome with no concurrent comorbid depression or anxiety disorder. Participants were randomly assigned (1:1) to receive either 10 weeks of low-dose imipramine or placebo (oral daily doses of 25-75 mg). The hospital pharmacy handled randomisation (computer-generated) and masking, providing sequentially numbered packs of study drug that were given serially to the participants. All others involved were masked to allocation. Primary outcome was patient-rated overall health improvement on a 5-point clinical global improvement scale. Improvement was defined as patients responding "better" or "much better" as opposed to "unchanged" and "worse" or "much worse" when rating their overall health status after 10 weeks of minimum 25 mg study drug. Analyses included patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01518634., Findings: Between Jan 30, 2012, and Nov 24, 2014, 138 patients were randomly assigned; 70 to receive imipramine and 68 to receive placebo. The study was completed on May 1, 2015. 125 patients received at least one dose of study drug: 65 received imipramine and 60 received placebo. Treatment was terminated prematurely for eight (12%) patients receiving imipramine and seven (12%) patients receiving placebo. Data were missing for two (3%) patients receiving imipramine and three (5%) patients receiving placebo. Of the 120 patients (96%) who provided primary outcome data, 33 (53%) receiving imipramine reported their overall health status as "better" or "much better" compared with 14 patients (25%) receiving placebo. The improvement after imipramine was significantly greater than after placebo (odds ratio 3·3 [95% CI 1·6-6·8]; p=0·001). Number needed to treat was 3·6 (95% CI 2·3-8·9). Analysis of the worst-case scenario for patients with missing outcome did not change the interpretation of the results. 32 patients (49%) receiving imipramine and 10 patients (17%) receiving placebo had at least one adverse event of moderate intensity (p=0·0001); eight patients (12%) receiving imipramine and three patients (5%) receiving placebo had at least one adverse event of severe intensity (p=0·1496). One patient (1%) receiving placebo experienced a serious adverse event (a subdural haematoma sustained after an accident). Adverse events caused dropout in four patients (6%) receiving imipramine and three patients (5%) receiving placebo., Interpretation: Imipramine treatment compared with placebo significantly improved overall health in patients with multiple functional somatic syndromes when both treatments were supported by regular contacts with clinicians. Adverse events were more common in the imipramine group, but only rarely led to discontinuation of treatment., Funding: The Danish Foundation, Trygfonden., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Evidence is growing that vulnerability to depression may be characterized by strong negative feedback loops between mental states. It is unknown whether such dynamics between mental states can be altered by treatment. This study examined whether treatment with imipramine or treatment with Mindfulness-Based Cognitive Therapy (MBCT) reduces the connectivity within dynamic networks of mental states in individuals with depressive symptoms. In the Imipramine trial, individuals diagnosed with major depression were randomized to imipramine treatment or placebo-pill treatment (n = 50). In the Mind-Maastricht trial, individuals with residual depressive symptoms were randomized to Mindfulness-Based Cognitive Therapy (MBCT) or to a waiting-list control condition (n = 119). Lagged associations among mental states, as assessed with the Experience Sampling Method (ESM), were estimated at baseline and post-intervention. The results show that few of the dynamic network connections changed significantly over time and few of the changes after MBCT and imipramine treatment differed significantly from the control groups. The decrease in average node connectivity after MBCT did not differ from the decrease observed in the waiting-list control group. Our findings suggest that imipramine treatment and MBCT do not greatly change the dynamic network structure of mental states, even though they do reduce depressive symptomatology.

Accumulation of respiratory drugs in human alveolar macrophages (AMs) has not been extensively studied in vitro and in silico despite its potential impact on therapeutic efficacy and/or occurrence of phospholipidosis. The current study aims to characterize the accumulation and subcellular distribution of drugs with respiratory indication in human AMs and to develop an in silico mechanistic AM model to predict lysosomal accumulation of investigated drugs. The data set included 9 drugs previously investigated in rat AM cell line NR8383. Cell-to-unbound medium concentration ratio (K p,cell ) of all drugs (5 μM) was determined to assess the magnitude of intracellular accumulation. The extent of lysosomal sequestration in freshly isolated human AMs from multiple donors (n = 5) was investigated for clarithromycin and imipramine (positive control) using an indirect in vitro method (±20 mM ammonium chloride, NH 4 Cl). The AM cell parameters and drug physicochemical data were collated to develop an in silico mechanistic AM model. Three in silico models differing in their description of drug membrane partitioning were evaluated; model (1) relied on octanol-water partitioning of drugs, model (2) used in vitro data to account for this process, and model (3) predicted membrane partitioning by incorporating AM phospholipid fractions. In vitro K p,cell ranged >200-fold for respiratory drugs, with the highest accumulation seen for clarithromycin. A good agreement in K p,cell was observed between human AMs and NR8383 (2.45-fold bias), highlighting NR8383 as a potentially useful in vitro surrogate tool to characterize drug accumulation in AMs. The mean K p,cell of clarithromycin (81, CV = 51%) and imipramine (963, CV = 54%) were reduced in the presence of NH 4 Cl by up to 67% and 81%, respectively, suggesting substantial contribution of lysosomal sequestration and intracellular binding in the accumulation of these drugs in human AMs. The in vitro data showed variability in drug accumulation between individual human AM donors due to possible differences in lysosomal abundance, volume, and phospholipid content, which may have important clinical implications. Consideration of drug-acidic phospholipid interactions significantly improved the performance of the in silico models; use of in vitro K p,cell obtained in the presence of NH 4 Cl as a surrogate for membrane partitioning (model (2)) captured the variability in clarithromycin and imipramine K p,cell observed in vitro and showed the best ability to predict correctly positive and negative lysosomotropic properties. The developed mechanistic AM model represents a useful in silico tool to predict lysosomal and cellular drug concentrations based on drug physicochemical data and system specific properties, with potential application to other cell types.

Background: Examining transcriptional regulation by antidepressants in key neural circuits implicated in depression and understanding the relation to transcriptional mechanisms of susceptibility and natural resilience may help in the search for new therapeutic agents. Given the heterogeneity of treatment response in human populations, examining both treatment response and nonresponse is critical., Methods: We compared the effects of a conventional monoamine-based tricyclic antidepressant, imipramine, and a rapidly acting, non-monoamine-based antidepressant, ketamine, in mice subjected to chronic social defeat stress, a validated depression model, and used RNA sequencing to analyze transcriptional profiles associated with susceptibility, resilience, and antidepressant response and nonresponse in the prefrontal cortex (PFC), nucleus accumbens, hippocampus, and amygdala., Results: We identified similar numbers of responders and nonresponders after ketamine or imipramine treatment. Ketamine induced more expression changes in the hippocampus; imipramine induced more expression changes in the nucleus accumbens and amygdala. Transcriptional profiles in treatment responders were most similar in the PFC. Nonresponse reflected both the lack of response-associated gene expression changes and unique gene regulation. In responders, both drugs reversed susceptibility-associated transcriptional changes and induced resilience-associated transcription in the PFC., Conclusions: We generated a uniquely large resource of gene expression data in four interconnected limbic brain regions implicated in depression and its treatment with imipramine or ketamine. Our analyses highlight the PFC as a key site of common transcriptional regulation by antidepressant drugs and in both reversing susceptibility- and inducing resilience-associated molecular adaptations. In addition, we found region-specific effects of each drug, suggesting both common and unique effects of imipramine versus ketamine., (Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Industrialisation greatly increased human night-time exposure to artificial light, which in animal models is a known cause of depressive phenotypes. Whilst many of these phenotypes are 'direct' effects of light on affect, an 'indirect' pathway via altered sleep-wake timing has been suggested. We have previously shown that the Period3 gene, which forms part of the biological clock, is associated with altered sleep-wake patterns in response to light. Here, we show that both wild-type and Per3 -/- mice showed elevated levels of circulating corticosterone and increased hippocampal Bdnf expression after 3 weeks of exposure to dim light at night, but only mice deficient for the PERIOD3 protein (Per3 -/- ) exhibited a transient anhedonia-like phenotype, observed as reduced sucrose preference, in weeks 2-3 of dim light at night, whereas WT mice did not. Per3 -/- mice also exhibited a significantly smaller delay in behavioural timing than WT mice during weeks 1, 2 and 4 of dim light at night exposure. When treated with imipramine, neither Per3 -/- nor WT mice exhibited an anhedonia-like phenotype, and neither genotypes exhibited a delay in behavioural timing in responses to dLAN. While the association between both Per3 -/- phenotypes remains unclear, both are alleviated by imipramine treatment during dim night-time light.

Cholestasis is one of the major causes of drug-induced liver injury (DILI), which can result in withdrawal of approved drugs from the market. Early identification of cholestatic drugs is difficult due to the complex mechanisms involved. In order to develop a strategy for mechanism-based risk assessment of cholestatic drugs, we analyzed gene expression data obtained from the livers of rats that had been orally administered with 12 known cholestatic compounds repeatedly for 28 days at three dose levels. Qualitative analyses were performed using two statistical approaches (hierarchical clustering and principle component analysis), in addition to pathway analysis. The transcriptional benchmark dose (tBMD) and tBMD 95% lower limit (tBMDL) were used for quantitative analyses, which revealed three compound sub-groups that produced different types of differential gene expression; these groups of genes were mainly involved in inflammation, cholesterol biosynthesis, and oxidative stress. Furthermore, the tBMDL values for each test compound were in good agreement with the relevant no observed adverse effect level. These results indicate that our novel strategy for drug safety evaluation using mechanism-based classification and tBMDL would facilitate the application of toxicogenomics for risk assessment of cholestatic DILI.

Background: Although depression is the leading cause of disability worldwide, its pathophysiology is poorly understood. Recent evidence has suggested that sirtuins (SIRTs) play a key role in cognition and synaptic plasticity, yet their role in mood regulation remains controversial. Here, we aimed to investigate whether SIRT function is associated with chronic stress-elicited depression-like behaviors and neuronal atrophy., Methods: We measured SIRT expression and activity in a mouse model of depression. We injected mice with a SIRT1 activator or inhibitor and measured their depression-like behaviors and dendritic spine morphology. To assess the role of SIRT1 directly, we used a viral-mediated gene transfer to overexpress the wild-type SIRT1 or dominant negative SIRT1 and evaluated their depression-like behaviors. Finally, we examined the role of extracellular signal-regulated protein kinases 1 and 2, a potential downstream target of SIRT1, in depression-like behavior., Results: We found that chronic stress reduced SIRT1 activity in the dentate gyrus of the hippocampus. Pharmacologic and genetic inhibition of hippocampal SIRT1 function led to an increase in depression-like behaviors. Conversely, SIRT1 activation blocked both the development of depression-related phenotypes and aberrant dendritic structures elicited by chronic stress exposure. Furthermore, hippocampal SIRT1 activation increased the phosphorylation level of extracellular signal-regulated protein kinases 1 and 2 in the stressed condition, and viral-mediated activation and inhibition of hippocampal extracellular signal-regulated protein kinase 2 led to antidepressive and prodepressive behaviors, respectively., Conclusions: Our results suggest that the hippocampal SIRT1 pathway contributes to the chronic stress-elicited depression-related phenotype and aberrant dendritic atrophy., (Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

This report describes a 63-year-old woman, who had experienced 3 previous episodes of severe major depressive disorder. The first 2 episodes responded to treatment with antidepressants, whereas the third episode was accompanied by psychotic features and responded well to treatment with electroconvulsive therapy (ECT). After a severe relapse, the patient responded very slowly to a second course of ECT and failed to achieve full remission. Within a few weeks, she had another severe relapse and responded very rapidly to a combination of ECT and imipramine. The possible enhancement of the antidepressant efficacy of ECT by combining it with a tricyclic antidepressant (TCA) has received little study, although the literature provides some evidence for a synergy between ECT and TCAs. Combining ECT with a TCA may be a useful strategy in patients who fail to achieve full remission or who experience a rapid relapse.

Introduction and Hypothesis: Epidemiological studies demonstrated that patients suffering from overactive bladder often present with different mental problems, amongst which depression is the most frequently observed. The main goal of our study was to check if the repeated administration of corticosterone (CORT) is able to evoke the depressive-like behaviour and detrusor overactivity (DO) symptoms in rats. Moreover, we investigated whether the acute administration of common antidepressants (imipramine, 30 mg/kg, and fluoxetine, 15 mg/kg), antimuscarinic (oxybutynin chloride, 0.5 mg/kg) or CRF 1 (SN 003, 1 mg/kg) antagonists has an impact on the cystometric parameters, behaviour in the Porsolt test, and overall locomotor activity of animals exposed to CORT., Methods: The experiments were carried out on female Wistar rats. All applied surgical and histopathology procedures, cystometric investigations, locomotor activity and forced swim measurements have been fully described in the published literature., Results: Fourteen-day administration of CORT may induce both depressive and DO symptoms in rats, which are reversed by the inhibition of CRF 1 receptors., Conclusions: It seems that the CRF 1 receptor could be an interesting target for overactive bladder pharmacotherapy, particularly in patients with co-existing depression., Competing Interests: Compliance with ethical standards Funding This study was supported by Funds for Statutory Activity of the Medical University of Lublin, Poland. Conflicts of interest The authors declare that they have no conflicts of interest. Financial disclaimers None.

In order to relieve anxiety and depression accompanying stress, physicians resort to tricyclic antidepressants, such as imipramine. We had previously shown that imipramine reversed stress-induced social avoidance behavior, and down-regulated microglial activation 24days after stress cessation. To further characterize the effects of imipramine on stress induced neuroimmune dysregulation and associated changes in behavior, the aims of this study were to determine if imipramine 1) ameliorated stress-induced inflammation in the periphery and central nervous system, and 2) prevented stress related anxiety- and depressive-like behaviors. C57BL/6 mice were treated with imipramine (15mg/kg) in their drinking water, and exposed to repeated social defeat (RSD). Imipramine attenuated stress-induced corticosterone and IL-6 responses in plasma. Imipramine decreased the percentage of monocytes and granulocytes in the bone marrow and circulation. However, imipramine did not prevent splenomegaly, stress-related increased percentage of granulocytes in this organ, and the production of pro-inflammatory cytokines in the spleen, following RSD. Moreover, imipramine abrogated the accumulation of macrophages in the brain in mice exposed to RSD. Imipramine blocked neuroinflammatory signaling and prevented stress-related anxiety- and depressive-like behaviors. These data support the notion that pharmacomodulation of the monoaminergic system, besides exerting anxiolytic and antidepressant effects, may have therapeutic effects as a neuroimmunomodulator during stress., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Major circulating drug metabolites can be as important as the drugs themselves in efficacy and safety, so establishing methods whereby exposure to major metabolites following administration of parent drug can be predicted is important. In this study, imipramine, a tricyclic antidepressant, and its major metabolite desipramine were selected as a model system to develop metabolite prediction methods. Imipramine undergoes N-demethylation to form the active metabolite desipramine, and both imipramine and desipramine are converted to hydroxylated metabolites by the polymorphic enzyme CYP2D6. The objective of the present study is to determine whether the human pharmacokinetics of desipramine following dosing of imipramine can be predicted using static and dynamic physiologically-based pharmacokinetic (PBPK) models from in vitro input data for CYP2D6 extensive metabolizer (EM) and poor metabolizer (PM) populations. The intrinsic metabolic clearances of parent drug and metabolite were estimated using human liver microsomes (CYP2D6 PM and EM) and hepatocytes. Passive diffusion clearance of desipramine, used in the estimation of availability of the metabolite, was predicted from passive permeability and hepatocyte surface area. The predicted area under the curve (AUCm/AUCp) of desipramine/imipramine was 12- to 20-fold higher in PM compared with EM subjects following i.v. or oral doses of imipramine using the static model. Moreover, the PBPK model was able to recover simultaneously plasma profiles of imipramine and desipramine in populations with different phenotypes of CYP2D6. This example suggested that mechanistic PBPK modeling combined with information obtained from in vitro studies can provide quantitative solutions to predict in vivo pharmacokinetics of drugs and major metabolites in a target human population., (Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.)

Previous studies have shown that intracellular calcium ion dysfunction may be an etiological factor in affective illness. Nimodipine (NMD) is a Ca(2+) channel blocker that has been extensively investigated for therapy of central nervous system (CNS) disorders. In this work, we have evaluated the antidepressant-like activity of nimodipine encapsulated into liposomes (NMD-Lipo) in mice through tail suspension and forced swim assays, as well as MAOB activity. During the tail suspension test, the administration of NMD-Lipo at 0.1, 1 and 10mg/kg was able to promote a reduction in the immobility time of animals greater than the positive control (imipramine). In the forced swim test, the immobility time of mice treated with NMD-Lipo was reduced. This reduction was significantly greater than that found in the animals treated with imipramine and paroxetine. This may suggest that NMD-Lipo provides more antidepressant-like activity than in positive controls. The groups that received a combination of liposomal NMD and antidepressant drugs showed lower immobility time than the groups, which were treated only with imipramine or paroxetine. The mice treated with the combination of NMD-Lipo and reserpine presented an increase in the time of immobility compared with animals treated only with NMD-Lipo. There was a significant decrease in MAOB activity in animals treated with NMD-Lipo compared with untreated animals. The results of the tail suspension test, forced swim test and MAOB activity suggested that the antidepressant activity of NMD-Lipo may be related to an increase in the cerebral monoamine concentrations., (Copyright © 2016 Elsevier B.V. All rights reserved.)