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Noradrenaline (NA) levels are altered during the first hours and several days after cortical injury. NA modulates motor functional recovery. The present study investigated whether iron-induced cortical injury modulated noradrenergic synthesis and dopamine beta-hydroxylase (DBH) activity in response to oxidative stress in the brain cortex, pons and cerebellum of the rat. Seventy-eight rats were divided into two groups: (a) the sham group, which received an intracortical injection of a vehicle solution; and (b) the injured group, which received an intracortical injection of ferrous chloride. Motor deficits were evaluated for 20 days post-injury. On the 3rd and 20th days, the rats were euthanized to measure oxidative stress indicators (reactive oxygen species (ROS), reduced glutathione (GSH) and oxidized glutathione (GSSG)) and catecholamines (NA, dopamine (DA)), plus DBH mRNA and protein levels. Our results showed that iron-induced brain cortex injury increased noradrenergic synthesis and DBH activity in the brain cortex, pons and cerebellum at 3 days post-injury, predominantly on the ipsilateral side to the injury, in response to oxidative stress. A compensatory increase in contralateral noradrenergic activity was observed, but without changes in the DBH mRNA and protein levels in the cerebellum and pons. In conclusion, iron-induced cortical injury increased the noradrenergic response in the brain cortex, pons and cerebellum, particularly on the ipsilateral side, accompanied by a compensatory response on the contralateral side. The oxidative stress was countered by antioxidant activity, which favored functional recovery following motor deficits., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The effect of [bis-(4-methyl-1-homopiperazinylthiocarbonyl)-disulfide] (FLA-63) (40 mg/kg, i.p.) on acquisition and retention in four different avoidance tasks was evaluated in mice. In all tasks animals were submitted to a training session on one day and to a retest session 24 h later. The drug or its vehicle were given either 2 h prior to training and/or retest (pretrial treatments) or immediately after the end of the training session (posttrial treatments). Two hours after injection, FLA-63 was found to lower brain norepinephrine (NE) levels by 51% without affecting those of dopamine (DA). Pretrial administration of the drug resulted in poorer performance of step-through and step-down passive avoidance as well as of step-up active avoidance in retest sessions. There was no apparent posttrial effect of the drug nor any effect on acquisition in these tasks. The drug was without influence on either acquisition or retention in an any-way passive avoidance task in which the response required from the animals was immobility. No evidence for statedependent learning was detected in any of the tasks. The data are consistent with the hypothesis of an involvement of NE either in memory processes or in events parallel and related to memory processes. The present results rule out, however, several such possible parallel events (effects on acquisition, motor disturbances, and effects on reactivity to shocks). [ABSTRACT FROM AUTHOR]

Clioquinol (5-chloro-7-indo-8-quinolinol), a chelator and ionophore of copper/zinc, was extensively used as an amebicide to treat indigestion and diarrhea in the mid-1900s. However, it was withdrawn from the market in Japan because its use was epidemiologically linked to an increase in the incidence of subacute myelo-optic neuropathy (SMON). SMON is characterized by the subacute onset of sensory and motor disturbances in the lower extremities with occasional visual impairments, which are preceded by abdominal symptoms. Although pathological studies demonstrated axonopathy of the spinal cord and optic nerves, the underlying mechanisms of clioquinol toxicity have not been elucidated in detail. In the present study, a reporter assay revealed that clioquinol (20-50 µM) activated metal response element-dependent transcription in human neuroblastoma SH-SY5Y cells. Clioquinol significantly increased the cellular level of zinc within 1 h, suggesting zinc influx due to its ionophore effects. On the other hand, clioquinol (20-50 µM) significantly increased the cellular level of copper within 24 h. Clioquinol (50 µM) induced the oxidation of the copper chaperone antioxidant 1 (ATOX1), suggesting its inactivation and inhibition of copper transport. The secretion of dopamine-β-hydroxylase (DBH) and lysyl oxidase, both of which are copper-dependent enzymes, was altered by clioquinol (20-50 µM). Noradrenaline levels were reduced by clioquinol (20-50 µM). Disruption of the ATOX1 gene suppressed the secretion of DBH. This study suggested that the disturbance of cellular copper transport by the inactivation of ATOX1 is one of the mechanisms involved in clioquinol-induced neurotoxicity in SMON.

Dysfunction of the central noradrenergic and dopaminergic systems is the primary neurobiological characteristic of Parkinson's disease (PD). Importantly, neuronal loss in the locus coeruleus (LC) that occurs in early stages of PD may accelerate progressive loss of dopaminergic neurons. Therefore, restoring the activity and function of the deficient noradrenergic system may be an important therapeutic strategy for early PD. In the present study, the lentiviral constructions of transcription factors Phox2a/2b, Hand2 and Gata3, either alone or in combination, were microinjected into the LC region of the PD model VMAT2 Lo mice at 12 and 18 month age. Biochemical analysis showed that microinjection of lentiviral expression cassettes into the LC significantly increased mRNA levels of Phox2a, and Phox2b, which were accompanied by parallel increases of mRNA and proteins of dopamine β-hydroxylase (DBH) and tyrosine hydroxylase (TH) in the LC. Furthermore, there was considerable enhancement of DBH protein levels in the frontal cortex and hippocampus, as well as enhanced TH protein levels in the striatum and substantia nigra. Moreover, these manipulations profoundly increased norepinephrine and dopamine concentrations in the striatum, which was followed by a remarkable improvement of the spatial memory and locomotor behavior. These results reveal that over-expression of these transcription factors in the LC improves noradrenergic and dopaminergic activities and functions in this rodent model of PD. It provides the necessary groundwork for the development of gene therapies of PD, and expands our understanding of the link between the LC-norepinephrine and dopamine systems during the progression of PD.

This work is aimed at studying the mechanisms of reciprocal humoral regulation of noradrenaline-producing organs in rats in the perinatal period of development. The activity of noradrenaline synthesis enzymes tyrosine hydroxylase and dopamine-beta-hydroxylase was measured in the brain and adrenal glands 48 and 72 h after the injection of immunotoxin (anti-dopamine-beta-hydroxylase-saporin) into the rat brain ventricles. It was shown that, 48 h after the immunotoxin injection into the brain, the activity of tyrosine hydroxylase in the brain decreased; however, 72 h after the injection it reached the control levels. This fact indicates that noradrenaline synthesis in the survived neurons increases. In the adrenal glands, 72 h after the immunotoxin injection into the brain, the activity of dopamine-beta-hydroxylase increased. This points to a compensatory increase in the rate of noradrenaline synthesis in the adrenal glands when the synthesis of noradrenaline in the brain is inhibited.

Maternal-fetal crosstalk has been implicated in long-term control of the health of offspring, including transgenerational hypertension. However, current knowledge is limited regarding maternal influences on the gut and its microbiome in blood pressure control in offspring. Therefore, the current study was designed to test the hypothesis that maternal factors influence the gut-brain axis impacting hypertension in offspring. We elected to use captopril, an antihypertensive angiotensin-converting enzyme inhibitor that possesses antibacterial properties, for the study. Pregnant female spontaneously hypertensive rats and normotensive Wistar Kyoto rats were treated with captopril water (100 mg/[kg·day]) or sterile water throughout pregnancy and lactation. At weaning, the pups from dams drinking sterile water were continued with sterile water until 12 weeks of age. The male pups from dams drinking captopril water were divided at weaning into 2 groups: offspring drinking captopril water and offspring withdrawn from captopril water, then drinking sterile water until 12 weeks of age. Captopril changed gut microbiota of spontaneously hypertensive rat dams, and some of these changes were reflected in their 12-week-old male offspring. These 12-week-old spontaneously hypertensive rat male offspring exposed to captopril via dams demonstrated persistently decreased systolic blood pressure, decreased number of activated microglia and neuroinflammation, as well as improvement of gut inflammation and permeability. Therefore, maternal captopril treatment improves the dysregulated gut-brain axis in spontaneously hypertensive rat male offspring, providing conceptual support that targeting the gut-brain axis via the mother may be a viable strategy for control of hypertension in the offspring.

Vesicular monoamine transporters (VMAT) 1 and 2 are responsible for monoamine transportation into secretary vesicles and are tissue-specifically expressed in central and peripheral monoaminergic tissues, including the carotid body (CB). The aim of the present study was to examine the expression of catecholamine-synthesizing enzymes in VMAT1- and VMAT2-immunoreactive glomus cells in the rat CB using multiple immunolabeling. The expression of VMAT1 and VMAT2 mRNA in the CB was confirmed by RT-PCR. Immunohistochemistry revealed that VMAT1 immunoreactivity was predominant in glomus cells rather than VMAT2 immunoreactivity. Glomus cells with VMAT1 immunoreactivity exhibited weak/negative VMAT2 immunoreactivity, and vice versa. Immunoreactivities for VMAT1 and tyrosine hydroxylase, the rate-limiting enzyme for catecholamine biosynthesis, were co-localized in the same glomus cells and a positive correlation was confirmed between the two immunoreactivities (Spearman's coefficient = 0.82; p <  0.05). Although some glomus cells showed co-localization of VMAT2 and dopamine β-hydroxylase immunoreactivity, the biosynthetic enzyme for noradrenaline, VMAT2 immunoreactivity appeared to be less associated with both catecholamine-synthesizing enzymes as indicated by a correlation analysis (TH: Spearman's coefficient = 0.38, DBH: Spearman's coefficient = 0.26). These results indicate that heterogeneity on functional role would exist among glomus cells in terms of VMAT isoform and catecholamine-synthesizing enzymes expression., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Goal-directed behavior requires the ability to resolve subliminally or consciously induced response conflicts, both of which may benefit from catecholamine-induced increases in gain control. We investigated the effects of presynaptic differences in dopamine and norepinephrine synthesis with the help of the tyrosine hydroxylase (TH) rs10770141 and the dopamine-β-hydroxylase (DBH) rs1611115, rs6271, and rs1611122 polymorphisms. Conscious and subliminal response conflicts were induced with flanker and prime distractors in (n = 207) healthy young participants while neurophysiological data (EEG) was recorded. The results demonstrated that the increased presynaptic catecholamine synthesis associated with the TH rs10770141 TT genotype improves cognitive control in case of consciously perceived (flanker) conflicts, but not in case of subliminally processed (prime) conflicts. Only norepinephrine seemed to also modulate subliminal conflict processing, as evidenced by better performance of the DBH rs1611122 CC genotype in case of high subliminal conflict load. Better performance was linked to larger conflict-induced modulations in post-response alpha band power arising from parietal and inferior frontal regions, which likely helps to suppress the processing of distracting information. In summary, presynaptic catecholamine synthesis benefits consciously perceived conflicts by improving the suppression of distracting information following a conflict. Subliminal conflicts were modulated via the same mechanism, but only by norepinephrine.

In the sympatho-adrenal system, angiotensin II (Ang II) acts as a key neuromodulatory component. At sympathetic nerve terminals, Ang II influences sympathetic transmission by enhancing norepinephrine (NE) synthesis, facilitating NE release and inhibiting NE uptake. Previously, it was demonstrated that tyrosine hydroxylase (TH) mRNA is trafficked to the distal axons of primary superior cervical ganglia (SCG) neurons, directed by a cis-acting regulatory element (i.e. zipcode) located in the 3'UTR of the transcript. Results of metabolic labeling studies established that the mRNA is locally translated. It was further shown that the axonal trafficking of the mRNA encoding the enzyme plays an important role in mediating dopamine (DA) and NE synthesis and may facilitate the maintenance of axonal catecholamine levels. In the present study, the hypothesis was tested that Ang II induces NE synthesis in rat primary SCG neurons via the modulation of the trafficking of the mRNAs encoding the catecholamine synthesizing enzymes TH and dopamine β-hydroxylase (DBH). Treatment of SCG neurons with the Ang II receptor type 1 (AT1R) agonist, L-162,313, increases the axonal levels of TH and DBH mRNA and protein and results in elevated NE levels. Conversely, treatment of rat SCG neurons with the AT1R antagonist, Eprosartan, abolished the L-162,313-mediated increase in axonal levels of TH and DBH mRNA and protein. In a first attempt to identify the proteins involved in the Ang II-mediated axonal transport of TH mRNA, we used a biotinylated 50-nucleotide TH RNA zipcode as bait in the affinity purification of TH zipcode-associated proteins. Mass spectrometric analysis of the TH zipcode ribonucleoprotein (RNP) complex immune-purified from SCG neurons led to the identification of 163 somal and 127 axonal proteins functionally involved in binding nucleic acids, the translational machinery or acting as subunits of cytoskeletal and motor proteins. Surprisingly, immune-purification of the TH axonal trafficking complex, results in the acquisition of DBH mRNA, suggesting that these mRNAs maybe transported to the axon together, possibly in the same RNP complex. Taken together, our results point to a novel mechanism by which Ang II participates in the regulation of axonal synthesis of NE by modulating the local trafficking and expression of TH and DBH, two key enzymes involved in the catecholamine biosynthetic pathway., (© Published 2019. This article is a U.S. Government work and is in the public domain in the USA.)

Dysfunction of noradrenergic (NA) neurons is associated with a number of neuronal disorders. Diverse neuronal subtypes can be generated by direct reprogramming. However, it is still unknown how to convert non-neuronal cells into NA neurons. Here, we show that seven transcription factors (TFs) (Ascl1, Phox2b, AP-2α, Gata3, Hand2, Nurr1, and Phox2a) are able to convert astrocytes and fibroblasts into induced NA (iNA) neurons. These iNA neurons express the genes required for the biosynthesis, release, and re-uptake of noradrenaline. Moreover, iNA neurons fire action potentials, receive synaptic inputs, and control the beating rate of co-cultured ventricular myocytes. Furthermore, iNA neurons survive and integrate into neural circuits after transplantation. Last, human fibroblasts can be converted into functional iNA neurons as well. Together, iNA neurons are generated by direct reprogramming, and they could be potentially useful for disease modeling and cell-based therapies., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

This work represents one part of our research project, in which we attempted to prove that a humoral regulation between noradrenaline-producing organs exist in the perinatal period. In this study, we used a rat model that allowed blocking the synthesis of noradrenalin in the brain and evaluated gene expression and protein levels of noradrenaline key synthesis enzymes such as tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) in peripheral noradrenaline-producing organs. As a result, we showed an increased gene expression of TH and DBH in adrenal glands. These data indicate that, if neonatal rat brain lacks the ability to produce noradrenaline, then the synthesis of noradrenaline in adrenal glands increased as a compensatory process, so that the concentration levels in blood are maintained at normal levels. This indicates that there is a humoral regulation between brain and adrenal glands, which is not fully understood yet.

Classical brown adipocytes, characterized by interscapular depots, have multilocular fat depots and are known to release excess energy. Recent studies have shown that induction of brown-like adipocytes, also referred to as beige or brite cells, in white adipose tissue (WAT) results in the release of excess energy through mitochondrial heat production via uncoupling protein 1. This has potential a therapeutic strategy for obesity and related diseases as well as classical brown adipocytes. In our previous studies, we found that artepillin C (ArtC, 10 mg/kg body weight), a characteristic constituent of Brazilian propolis, significantly induced the development of brown-like adipocytes in inguinal WAT (iWAT) of mice. Furthermore, we recently demonstrated that curcumin (Cur, 4.5 mg/kg) also significantly induced the development of brown-like adipocytes in mice. The combined administration of several food-derived factors can enhance their bioactivity and reduce their required functional doses. In this study, we showed that co-administration of Cur and ArtC at lower doses (Cur, 1.5 mg/kg; ArtC, 5 mg/kg) additively induce brown-like adipocyte development in mouse iWAT. Moreover, this induction is associated with the localized production of norepinephrine following accumulation of alternatively activated macrophages in iWAT. These findings suggest that co-administration of Cur and ArtC is significantly effective to reduce the dose and enhance the formation of brown-like adipocyte via a unique molecular mechanism.

Objectives: This article investigates the anxiolytic activity of Terminalia chebula tannin-rich extract against picrotoxin (PTX; GABA antagonist)-induced anxiety in mice model., Methods: Anxiolytic activity was studied by elevated plus maze (EPM), open field test (OFT), light/dark box test (LDT) and Vogel's conflict test (VCT). Electroencephalogram (EEG) was performed to know the changes in brain activity instigated by GABA antagonist. 5-hydroxytryptamine (5-HT), dopamine and norepinephrine levels in brain tissues were estimated by HPLC. The mRNA (CREB, BDNF, GABA, and 5-HT 1A ) and protein expression (CREB, p-CREB, BDNF, ERK ½, p-ERK ½, GABA A Rα1, 5-HT 1A and GAPDH) levels in brain tissue were determined by RT-PCR and Western blot analysis, respectively., Key Findings: Terminalia chebula tannin-rich extract (TCHE) supplementation increased locomotion in mice towards open arm (EPM), time spent in illuminated area (LDT), rearing frequency (OFT) and number of shocks (VCT) compared to PTX (P < 0.05). Furthermore, TCHE down-regulated serum cortisol levels and showed increased levels of 5-HT, DA and NE. Gene expressions such as BDNF, CREB, GABA A and 5-HT 1A were up-regulated by TCHE treatment compared to PTX., Conclusions: Terminalia chebula tannin-rich extract showed significant anxiolytic activity against picrotoxin and could be used as natural therapy in neurodegenerative disorders., (© 2018 Royal Pharmaceutical Society.)

Background: The role of autonomic nervous system in the development and maintenance of portal hypertension is not fully elucidated. It is known that the gene expression of norepinephrine in the superior mesenteric artery varies with time, and it may contribute for splanchnic vasodilation and its consequent hemodynamic repercussions. It is still not known exactly how the adrenergic expression behaves at the heart level in the initial stages of this process., Aim: To evaluate the immunohistochemical expression of the enzyme tyrosine hydroxylase (tyrosine 3-monooxygenase), involved in the synthesis of norepinephrine, in the myocardium of rats submitted to partial ligation of the portal vein., Methods: Twenty-four Wistar rats were divided into two groups: Sham Operated and Portal Hypertension. The partial ligation was performed in the Portal Hypertension group, and after 1/6/24 h and 3/5/14 days the animals were euthanized. Immunohistochemical analysis was performed to quantify the expression of the stained enzyme using the ImageJ program., Results: The Portal Hypertension group expressed percentages between 4.6-6% of the marked area, while the Sham Operated group varied between 4-5%. Although there was no statistical significance, the percentage stained in the Portal Hypertension group followed an increasing pattern in the first 6 h and a decreasing pattern after 24 h, which was not observed in the Sham Operated group., Conclusion: The expression of noradrenaline in rat myocardium during the first two weeks after partial ligation of the portal vein, with tyrosine hydroxylase as marker, did not show differences between groups over time.

The endogenous neurotransmitter, noradrenaline, exerts anti-inflammatory and neuroprotective effects in vivo and in vitro. Reduced noradrenaline levels results in increased inflammation and neuronal damage. The primary source of noradrenaline in the central nervous system is tyrosine hydroxylase (TH)‑positive neurons, located in the locus coeruleus (LC). TH is the rate‑limiting enzyme for noradrenaline synthesis; therefore, regulation of TH protein expression and intrinsic enzyme activity represents the central means for controlling the synthesis of noradrenaline. Catalpol is an iridoid glycoside purified from Rehmannia glutinosa Libosch, which exerts a neuroprotective effect in multiple sclerosis (MS). The present study used an experimental mouse model of autoimmune encephalomyelitis to verify the neuroprotective effects of catalpol. Significant improvements in the clinical scores were observed in catalpol‑treated mice. Furthermore, catalpol increased TH expression and increased noradrenaline levels in the spinal cord. In primary cultures, catalpol exerted a neuroprotective effect in rat LC neurons by increasing the noradrenaline output. These results suggested that drugs targeting LC survival and function, including catalpol, may be able to benefit patients with MS.

It is becoming increasingly clear that neurotransmitters impose direct influence on regulation of the immune process. Recently, a simple but sophisticated neuroendocrine-immune (NEI) system was identified in oyster, which modulated neural immune response via a "nervous-hemocyte"-mediated neuroendocrine immunomodulatory axis (NIA)-like pathway. In the present study, the de novo synthesis of neurotransmitters and their immunomodulation in the hemocytes of oyster Crassostrea gigas were investigated to understand the autocrine/paracrine pathway independent of the nervous system. After hemocytes were exposed to lipopolysaccharide (LPS) stimulation, acetylcholine (ACh), and norepinephrine (NE) in the cell supernatants, both increased to a significantly higher level (2.71- and 2.40-fold, p  < 0.05) comparing with that in the control group. The mRNA expression levels and protein activities of choline O-acetyltransferase and dopamine β-hydroxylase in hemocytes which were involved in the synthesis of ACh and NE were significantly elevated at 1 h after LPS stimulation, while the activities of acetylcholinesterase and monoamine oxidase, two enzymes essential in the metabolic inactivation of ACh and NE, were inhibited. These results demonstrated the existence of the sophisticated intracellular machinery for the generation, release and inactivation of ACh and NE in oyster hemocytes. Moreover, the hemocyte-derived neurotransmitters could in turn regulate the mRNA expressions of tumor necrosis factor (TNF) genes, the activities of superoxide dismutase, catalase and lysosome, and hemocyte phagocytosis. The phagocytic activities of hemocytes, the mRNA expressions of TNF and the activities of key immune-related enzymes were significantly changed after the block of ACh and NE receptors with different kinds of antagonists, suggesting that autocrine/paracrine self-regulation was mediated by transmembrane receptors on hemocyte. The present study proved that oyster hemocyte could de novo synthesize and release cholinergic and adrenergic neurotransmitters, and the hemocyte-derived ACh/NE could then execute a negative regulation on hemocyte phagocytosis and synthesis of immune effectors with similar autocrine/paracrine signaling pathway identified in vertebrate macrophages. Findings in the present study demonstrated that the immune and neuroendocrine system evolved from a common origin and enriched our knowledge on the evolution of NEI system.

Amitraz is a formamidine insecticide/acaricide that alters different neurotransmitters levels, among other neurotoxic effects. Oral amitraz exposure (20, 50 and 80 mg/kg bw, 5 days) has been reported to increase serotonin (5-HT), norepinephrine (NE) and dopamine (DA) content and to decrease their metabolites and turnover rates in the male rat brain, particularly in the striatum, prefrontal cortex, and hippocampus. However, the mechanisms by which these alterations are produced are not completely understood. One possibility is that amitraz monoamine oxidase (MAO) inhibition could mediate these effects. Alternatively, it alters serum concentrations of sex steroids that regulate the enzymes responsible for these neurotransmitters synthesis and metabolism. Thus, alterations in sex steroids in the brain could also mediate the observed effects. To test these hypothesis regarding possible mechanisms, we treated male rats with 20, 50 and 80 mg/kg bw for 5 days and then isolated tissue from striatum, prefrontal cortex, and hippocampus. We then measured tissue levels of expression and/or activity of MAO, catechol-O-metyltransferase (COMT), dopamine-β-hydroxylase (DBH), tyrosine hydroxylase (TH) and tryptophan hydroxylase (TRH) as well as estradiol levels in these regions. Our results show that amitraz did not inhibit MAO activity at these doses, but altered MAO, COMT, DBH, TH and TRH gene expression, as well as TH and TRH activity and estradiol levels. The alteration of these enzymes was partially mediated by dysregulation of estradiol levels. Our present results provide new understanding of the mechanisms contributing to the harmful effects of amitraz., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Tyrosine hydroxylase (TH) is the enzyme that catalyzes the rate-limiting step in the biosynthesis of the catecholamine neurotransmitters. In a previous communication, evidence was provided that TH mRNA is trafficked to the axon, where it is locally translated. In addition, a 50-bp sequence element in the 3'untranslated region (3'UTR) of TH mRNA was identified that directs TH mRNA to distal axons (i.e., zip-code). In the present study, the hypothesis was tested that local translation of TH plays an important role in the biosynthesis of the catecholamine neurotransmitters in the axon and/or presynaptic nerve terminal. Toward this end, a targeted deletion of the axonal transport sequence element was developed, using the lentiviral delivery of the CRISPR/Cas9 system, and two guide RNA (gRNA) sequences flanking the 50-bp cis- acting regulatory element in rat superior cervical ganglion (SCG) neurons. Deletion of the axonal transport element reduced TH mRNA levels in the distal axons and reduced the axonal protein levels of TH and TH activity as measured by phosphorylation of SER40 in SCG neurons. Moreover, deletion of the zip-code diminished the axonal levels of dopamine (DA) and norepinephrine (NE). Conversely, the local translation of exogenous TH mRNA in the distal axon enhanced TH levels and activity, and elevated axonal NE levels. Taken together, these results provide direct evidence to support the hypothesis that TH mRNA trafficking and local synthesis of TH play an important role in the synthesis of catecholamines in the axon and presynaptic terminal.

Gene expression and content of the key enzymes involved in the synthesis of noradrenaline-tyrosine hydroxylase and dopamine beta-hydroxylase-was evaluated in the organ of Zuckerkandl of rats in the critical period of morphogenesis. High levels of mRNA and protein of both enzymes in the perinatal period of development and their sharp decline on day 30 of postnatal development were detected. These data indicate that the synthesis of noradrenaline in the organ of Zuckerkandl is maximum during the critical period of morphogenesis and decreases during the involution of this paraganglion.

To examine whether edible peptide intake affects neurotransmitter metabolism in the brain, we evaluated the effect of peptides derived from soy proteins or fish collagen on free amino acids and monoamines in the mouse brain. Ingestion of soy peptides led to markedly higher levels of tyrosine, a catecholamine precursor, in the serum, and cerebral cortex compared to those following ingestion of vehicle alone or collagen peptides. Soy peptide ingestion also effectively increased 3-methoxy-4-hydroxyphenylethyleneglycol and normetanephrine, the principal metabolites of noradrenaline, in the cerebral cortex, hippocampus, and brainstem, whereas collagen peptides did not exert such effects. Further, soy peptide ingestion led to a significant increase in noradrenaline itself in the brainstem, where noradrenergic neurons are present. Noradrenergic turnover was also markedly stimulated in these regions after soy peptide ingestion. These in vivo observations suggest that soy peptide ingestion can maintain and promote the synthesis and metabolism of noradrenaline in the brain.

Background: Extremely preterm infants frequently have patent ductus arteriosus (PDA). Recent recommendations include immediately beginning amino acid supplementation in extremely preterm infants. However, the effect of amino acids on closure of the ductus arteriosus (DA) remains unknown.Methods and Results:Aminogram results in human neonates at day 2 revealed that the plasma glutamate concentration was significantly lower in extremely preterm infants (<28 weeks' gestation) with PDA than in those without PDA and relatively mature preterm infants (28-29 weeks gestation). To investigate the effect of glutamate on DA closure, glutamate receptor expression in fetal rats was examined and it was found that the glutamate inotropic receptor, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) type subunit 1 (GluR1), mRNA was highly expressed in the DA compared to the aorta on gestational day 19 (preterm) and gestational day 21 (term). GluR1 proteins were co-localized with tyrosine hydroxylase-positive autonomic nerve terminals in the rat and human DA. Intraperitoneal administration of glutamate increased noradrenaline production in the rat DA. A whole-body freezing method demonstrated that glutamate administration induced DA contraction in both preterm (gestational day 20) and term rat fetuses. Glutamate-induced DA contraction was attenuated by the calcium-sensitive GluR receptor antagonist, NASPM, or the adrenergic receptor α1 blocker, prazosin., Conclusions: These data suggest that glutamate induces DA contraction through GluR-mediated noradrenaline production. Supplementation of glutamate might help to prevent PDA in extremely preterm infants. (Circ J 2016; 80: 2388-2396).

The hippocampus is sensitive to stress which activates norepinephrine terminals deriving from the locus coeruleus. Melatonin exerts positive effects on the hippocampal neurogenic process and on depressive-like behaviour. Thus, in the present study, an examination was made of the effect of chronic melatonin treatment on norepinephrine content, synthesis, uptake, vesicular transport and degradation in the hippocampus of rats exposed to CUMS. This entailed quantifying the norephinephrine, mRNA and protein levels of DBH, NET, VMAT 2, MAO-A and COMT. The results show that CUMS evoked prolonged immobility. Melatonin treatment decreased immobility in comparison with the placebo group, reflecting an antidepressant-like effect. Compared with the placebo group, a dramatic decrease in norepinephrine content, decreased VMAT2 mRNA and protein and increased MAO-A protein levels in the hippocampus of the CUMS rats were observed. However, no significant differences in the levels of DBH, NET, COMT mRNA and protein and MAO-A mRNA levels between the placebo and the stressed groups were found. The results showed the restorative effects of melatonin on the stress-induced decline in the norepinephrine content of the hippocampus. It was observed that melatonin treatment in the CUMS rats prevented the stress-induced decrease in VMAT2 mRNA and protein levels, whereas it reduced the increase of the mRNA of COMT and protein levels of MAO-A. Chronic treatment with melatonin failed to alter the gene expression of DBH or NET in the hippocampus of the CUMS rats. Additionally, the results show that melatonin enhances VMAT2 expression and norepinephrine storage, whilst it reduces norepinephrine degrading enzymes., (Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.)

Limiting enzymes in the synthesis of brain monoamines seems to be susceptible to oxidative damage, one of the most important factors in aging. It has been suggested that the use of anti-oxidants can reduce the rate of free radical production related with aging and the associated damage. Therefore, this study aims to analyze the effects of the chronic treatments with the anti-oxidant α-tocopherol (vitamin E) on central monoamines (high-performance liquid chromatography [HPLC] analysis) mediating cognitive functions, as well as on the evaluation of memory and motor abilities in old rats measured by radial maze, Barnes maze, novel object recognition test, and rotarod test. Results show that α-tocopherol significantly increased in a dose- and/or time-dependent manner the synthesis rate and the levels of monoaminergic neurotransmitters (serotonin, dopamine, and noradrenaline) in the hippocampus and striatum, brain regions involved in memory processing and motor coordination. These positive neurochemical effects, largely due to an increased activity of the limiting enzymes in monoamines synthesis, tryptophan hydroxylase and tyrosine hydroxylase, were accompanied by an improvement in cognitive and motor abilities in old rats. Altogether these findings suggest that α-tocopherol exhibits neuroprotective actions in old rats; thus, diets with α-tocopherol might represent a promising strategy to mitigate or delay the cognitive and motor decline associate with aging and related-diseases.

Severe systemic inflammatory response to infection results in severe sepsis and septic shock, which are the leading causes of death in critically ill patients. Septic shock is characterised by refractory hypotension and is typically managed by fluid resuscitation and administration of catecholamine vasopressors such as norepinephrine. Vasopressin can also be administered to raise mean arterial pressure or decrease the norepinephrine dose. Endogenous norepinephrine and vasopressin are synthesised by the copper-containing enzymes dopamine β-hydroxylase and peptidylglycine α-amidating monooxygenase, respectively. Both of these enzymes require ascorbate as a cofactor for optimal activity. Patients with severe sepsis present with hypovitaminosis C, and pre-clinical and clinical studies have indicated that administration of high-dose ascorbate decreases the levels of pro-inflammatory biomarkers, attenuates organ dysfunction and improves haemodynamic parameters. It is conceivable that administration of ascorbate to septic patients with hypovitaminosis C could improve endogenous vasopressor synthesis and thus ameliorate the requirement for exogenously administered vasopressors. Ascorbate-dependent vasopressor synthesis represents a currently underexplored biochemical mechanism by which ascorbate could act as an adjuvant therapy for severe sepsis and septic shock.

Genome-wide association studies implicate a variant in the neuronal nitric oxide synthase adaptor protein (CAPON) in electrocardiographic QT variation and sudden cardiac death. Interestingly, nitric oxide generated by neuronal NO synthase-1 reduces norepinephrine release; however, this pathway is downregulated in animal models of cardiovascular disease. Because sympathetic hyperactivity can trigger arrhythmia, is this neural phenotype linked to CAPON dysregulation? We hypothesized that CAPON resides in cardiac sympathetic neurons and is a part of the prediseased neuronal phenotype that modulates calcium handling and neurotransmission in dysautonomia. CAPON expression was significantly reduced in the stellate ganglia of spontaneously hypertensive rats before the development of hypertension compared with age-matched Wistar-Kyoto rats. The neuronal calcium current (ICa; n=8) and intracellular calcium transient ([Ca(2+)]i; n=16) were significantly larger in the spontaneously hypertensive rat than in Wistar-Kyoto rat (P<0.05). A novel noradrenergic specific vector (Ad.PRSx8-mCherry/CAPON) significantly upregulated CAPON expression, NO synthase-1 activity, and cGMP in spontaneously hypertensive rat neurons without altering NO synthase-1 levels. Neuronal ICa and [Ca(2+)]i were significantly reduced after CAPON transduction compared with the empty vector. In addition, Ad.PRSx8-mCherry/CAPON also reduced (3)H-norepinephrine release from spontaneously hypertensive rat atria (n=7). NO synthase-1 inhibition (AAAN, 10 μmol/L; n=6) reversed these effects compared with the empty virus alone. In conclusion, targeted upregulation of CAPON decreases cardiac sympathetic hyperactivity. Moreover, dysregulation of this adaptor protein in sympathetic neurons might further amplify the negative cardiac electrophysiological properties seen with CAPON mutations., (© 2015 American Heart Association, Inc.)

Background & Purpose: Toll-like receptor 4 (TLR4) signaling induces tissue pro-inflammatory cytokine release and endoplasmic reticulum (ER) stress. We examined the role of TLR4 in autonomic dysfunction and the contribution of ER stress., Experimental Approach: Our study included animals divided in 6 experimental groups: rats treated with saline (i.v., 0.9%), LPS (i.v., 10mg/kg), VIPER (i.v., 0.1 mg/kg), or 4-PBA (i.p., 10 mg/kg). Two other groups were pretreated either with VIPER (TLR4 viral inhibitory peptide) LPS + VIPER (i.v., 0.1 mg/kg) or 4-Phenyl butyric acid (4-PBA) LPS + PBA (i.p., 10 mg/kg). Arterial pressure (AP) and heart rate (HR) were measured in conscious Sprague-Dawley rats. AP, HR variability, as well as baroreflex sensitivity (BrS), was determined after LPS or saline treatment for 2 hours. Immunofluorescence staining for NeuN, Ib1a, TLR4 and GRP78 in the hypothalamic paraventricular nucleus (PVN) was performed. TNF-α, TLR4 and GRP78 protein expression in the PVN were evaluated by western blot. Plasma norepinephrine levels were determined by ELISA., Key Results: Acute LPS treatment increased HR and plasma norepinephrine concentration. It also decreased HR variability and high frequency (HF) components of HR variability, as well BrS. Acute LPS treatment increased TLR4 and TNF-α protein expression in the PVN. These hemodynamic and molecular effects were partially abrogated with TLR4 blocker or ER stress inhibitor pretreatment. In addition, immunofluorescence study showed that TLR4 is co-localized with GRP78in the neurons. Further inhibition of TLR4 or ER stress was able to attenuate the LPS-induced microglia activation., Conclusions & Implications: TLR4 signaling promotes autonomic dysfunction, inflammation and microglia activation, through neuronal ER stress, in the PVN.

The gut/brain peptide, glucagon like peptide 1 (GLP-1), suppresses food intake by acting on receptors located in key energy balance regulating CNS areas, the hypothalamus or the hindbrain. Moreover, GLP-1 can reduce reward derived from food and motivation to obtain food by acting on its mesolimbic receptors. Together these data suggest a neuroanatomical segregation between homeostatic and reward effects of GLP-1. Here we aim to challenge this view and hypothesize that GLP-1 can regulate food reward behavior by acting directly on the hindbrain, the nucleus of the solitary tract (NTS), GLP-1 receptors (GLP-1R). Using two models of food reward, sucrose progressive ratio operant conditioning and conditioned place preference for food in rats, we show that intra-NTS microinjections of GLP-1 or Exendin-4, a stable analogue of GLP-1, inhibit food reward behavior. When the rats were given a choice between palatable food and chow, intra-NTS Exendin-4 treatment preferentially reduced intake of palatable food but not chow. However, chow intake and body weight were reduced by the NTS GLP-1R activation if chow was offered alone. The NTS GLP-1 activation did not alter general locomotor activity and did not induce nausea, measured by PICA. We further show that GLP-1 fibers are in close apposition to the NTS noradrenergic neurons, which were previously shown to provide a monosynaptic connection between the NTS and the mesolimbic system. Central GLP-1R activation also increased NTS expression of dopamine-β-hydroxylase, a key enzyme in noradrenaline synthesis, indicating a biological link between these two systems. Moreover, NTS GLP-1R activation altered the expression of dopamine-related genes in the ventral tegmental area. These data reveal a food reward-suppressing role of the NTS GLP-1R and indicate that the neurobiological targets underlying food reward control are not limited to the mesolimbic system, instead they are distributed throughout the CNS.

Background: ADRB-2 was implicated in rodent ovarian functions, including initial follicular growth. In contrast, ADRB-2 expression and function in nonhuman primate and human ovary were not fully known but innervation and significant levels of norepinephrine (NE), which is a ligand at the ADRB-2, were reported in the ovary., Methods: We studied expression of ADRB-2 in human and rhesus monkey ovary (RT-PCR, immunohistochemistry; laser micro dissection) and measured levels of norepinephrine (NE; ELISA) in monkey follicular fluid (FF). 3D cultures of monkey follicles (4 animals) were exposed to NE or the ADRB-2 agonist isoproterenol (ISO), and follicular development (size) was monitored. Upon termination expression of ADRB-2, FSH receptor and aromatase genes were examined., Results: Immunohistochemistry and RT-PCR of either human follicular granulosa cells (GCs) obtained by laser micro dissection or isolated monkey follicles revealed ADRB-2 in GCs of primordial, primary, secondary and tertiary follicles. Staining of GCs in primordial and primary follicles was intense. In large preantral and antral follicles the staining was heterogeneous, with positive and negative GCs present but GCs lining the antrum of large follicles were generally strongly immunopositive. Theca, interstitial, and ovarian surface epithelial cells were also positive. NE was detected in FF of preovulatory antral monkey follicles (0.37 + 0.05 ng/ml; n = 7; ELISA) but not in serum. We examined preantral follicles ranging from 152 to 366 μm in diameter in a 3D culture in media supplemented with follicle stimulating hormone (FSH). Under these conditions, neither NE, nor ISO, influenced growth rate in a period lasting up to one month. Upon termination of the cultures, all surviving follicles expressed aromatase and FSH receptors, but only about half of them also co-expressed ADRB-2. The ADRB-2 expression was not correlated with the treatment but was positively correlated with the follicular size at the beginning and at the end of the culture period. Hence, expression of ADRB-2 was found in the largest and fastest-in vitro growing follicles., Conclusions: The results imply ADRB-2-mediated actions in the development of primate follicles. Drugs interfering with ADRB-2 are used to treat medical conditions and may have unexplored effects in the human ovary.

The nicotinic acetylcholine receptor alpha 7 (α7) is a ligand-activated ion channel that contributes to a diversity of cellular processes involved in development, neurotransmission and inflammation. In this report the expression of α7 was examined in the mouse developing and adult adrenal gland that expresses a green fluorescent protein (GFP) reporter as a bi-cistronic extension of the endogenous α7 transcript (α7(G)). At embryonic day 12.5 (E12.5) α7(G) expression was associated with the suprarenal ganglion and precursor cells of the adrenal gland. The α7(G) cells are catecholaminergic chromaffin cells as reflected by their progressive increase in the co-expression of tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) that is complete by E18.5. In the adult, α7(G) expression is limited to a subset of chromaffin cells in the adrenal medulla that cluster near the border with the adrenal cortex. These chromaffin cells co-express α7(G), TH and DBH, but they lack phenylethanolamine N-methyltransferase (PNMT) consistent with only norepinephrine (NE) synthesis. These cell groups appear to be preferentially innervated by pre-ganglionic afferents identified by the neurotrophin receptor p75. No afferents identified by beta-III tubulin, neurofilament proteins or p75 co-expressed α7(G). Occasional α7(G) cells in the pre-E14.5 embryos express neuronal markers consistent with intrinsic ganglion cells and in the adult some α7(G) cells co-express glutamic acid decarboxylase. The transient expression of α7 during adrenal gland development and its prominent co-expression by a subset of NE chromaffin cells in the adult suggests that the α7 receptor contributes to multiple aspects of adrenal gland development and function that persist into adulthood.

Histone acetylation has been linked to depression, the etiology of which involves many factors such as genetics, environments, and epigenetics. The aim of the present study was to investigate whether it was associated with epigenetic histone modification and gene expression of enzymes responsible for the biosynthesis of norepinephrine and serotonin in rat depression model induced by chronic unpredictable stress (CUS). Eight-week-old male Sprague-Dawley rats were exposed to CUS over 28 days. It was shown that the CUS-induced rats displayed remarked anxiety- and depression-like behavior with weakened locomotor activity in open field test and prolonged immobility in forced swimming test. Western blot revealed that CUS led to significant decrease in acetylation of H3 at Lysine 9 (K9) and H4 at Lysine 12 (K12) with obviously increasing histone deacetylases 5 (HDAC5) expression in hippocampus of CUS-induced rats. Meanwhile, there was an obviously decreased expression of tyrosine hydroxylase (TH) and tryptophan hydroxylase (TPH) both at protein and mRNA levels. Administration of sodium valproate (VPA), a histone deacetylase 5 (HDAC5) inhibitor, not only significantly relieved the anxiety- and depression-like behaviors of CUS-induced rats but also clearly blunted decrease of H3(K9) and H4(K12) acetylation and expression of TH and TPH, and prevented increase of HDAC5 expression. The results indicate that there exists possible interrelation between TH and TPH gene expression and epigenetic histone acetylation in CUS-induced depressive rats, which at least partly contributes to the etiology of depression.

The left and right ventricles fulfill different role in heart function. Here we compare chamber specific changes in local catecholamine concentrations; gene expression and the receptor protein amount of all three β-adrenoceptors (β-AR) in rat right heart ventricles exposed to acute (1 session) and repeated (7 sessions) immobilization stress (IMMO) vs. previously observed changes in left ventricles. Density of muscarinic receptors as main cardio-inhibitive receptors was also measured. In the right ventricles, noradrenaline and adrenaline were increased. No β1-AR changes were observed, in spite of the increased sympathetic activity. On the other hand, we have found a decrease of β2-AR gene expression (reduction to 30%) after 7 IMMO and protein (to 59%) after 1 IMMO. β3-AR gene expression was increased after 7 IMMO. Muscarinic receptor density was not changed. When comparing correlation in left and right ventricles, there was strong correlation between adrenaline and β2-AR gene expression, protein and β3-AR gene expression in the left ventricles while only correlation between adrenaline and β2-AR mRNA and protein in the right ventricles was found. Our results show that maintenance of cardiac homeostasis under stress conditions are to a great extent achieved by a balance between different receptors and also by a balanced receptor changes in left vs. right ventricles. Taken together, decrease of cardio-stimulating β2-AR represents a new important mechanism by which β2-AR contributes to the heart physiology.

Sympathoadrenergic pathways are crucial to the communication between the nervous system and the immune system. The present review addresses emerging issues in the adrenergic modulation of immune cells, including: the specific pattern of adrenoceptor expression on immune cells and their role and changes upon cell differentiation and activation; the production and utilization of noradrenaline and adrenaline by immune cells themselves; the dysregulation of adrenergic immune mechanisms in disease and their potential as novel therapeutic targets. A wide array of sympathoadrenergic therapeutics is currently used for non-immune indications, and could represent an attractive source of non-conventional immunomodulating agents.

Omentin-1, a visceral fat depot-specific secretory protein, is inversely correlated with obesity and insulin resistance. We investigated, in rats, the effects of chronic omentin-1 administration (8 μg/kg, intraperitoneally, once daily for 14-days) on feeding behavior and related hypothalamic peptides and neurotransmitters. Food intake and body weight were recorded daily throughout the study. We found a significantly increased food intake compared to controls, but only in days 10-14, while body weight significantly increased since day 12 (P<0.05). Compared with vehicle, omentin-1 treatment led to a significant reduction in both cocaine and amphetamine-regulated transcript (CART) (P<0.05) and corticotrophin releasing hormone (CRH) (P<0.05) gene expression, while pro-opiomelanocortin (POMC), agouti-related peptide (AgRP), neuropeptide Y (NPY) and orexin-A gene expression were not modified with respect to vehicle-treated rats. We also found an increase in hypothalamic levodopa (l-dopa) (P<0.05) and norepinephrine (NE) (P<0.01) synthesis, without any effect on dopamine (DA) and serotonin (5-hydroxytryptamine, 5-HT) metabolism. Furthermore, in hypothalamic synaptosomes, omentin-1 (10-100 ng/ml) stimulated basal NE release (ANOVA, P<0.0001; post hoc, P<0.001 vs. vehicle), in a dose-dependent manner, leaving unaffected both basal and depolarization-induced DA and 5-HT release. Finally, when synaptosomes were co-perfused with leptin and omentin-1, we observed that leptin was able to reverse omentin-1-induced stimulation of NE. In conclusion, the orexigenic effects of omentin-1 could be related, at least in part, to decreased CART and CRH gene expression and increased NE synthesis and release in the hypothalamus., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Objectives: Stress is accompanied also by a rise in splenic catecholamines (CAs). However, indications about endogenous CA production in the spleen exist but there are no data about the cellular source of this production and possible modification by stress. Therefore, our aim was to investigate whether splenic T- and B-cells are one of main sources in the spleen expressing tyrosine hydroxylase (TH), enzyme crucial for CA biosynthesis, and phenylethanolamine N-methyltransferase (PNMT) which is necessary for epinephrine production. We also investigated whether stress is able to modify expression of both enzymes and CA levels within these cell fractions as well as tried to explain functional consequences of changes observed., Results: T-cells contain higher levels of TH mRNA than B-cells although protein levels appeared similar. On contrary, the PNMT mRNA and protein were higher in B-cells, which appeared to be the main source of PNMT in the spleen. T-cells increased TH and PNMT expression after acute stress while similar rise was observed in B-cells after repeated stress, most probably as a consequence of higher CA turnover in both cell populations. The rise in TH and PNMT was accompanied by an elevation of Bax/Bcl-2 mRNA ratio, number of apoptotic cells and also by a decline of IFN-γ mRNA in both cell types. Reduction of IL-2 and IL-4 mRNA was also observed in B-cells., Conclusion: Stress-induced stimulation of endogenous CA biosynthesis in lymphocytes is dependent on the type of lymphocyte population and duration of stressor and leads to attenuated IFN-γ expression and induction of apoptosis. These changes might contribute to dysregulation of specific immune functions involving T- and B-cells and may decrease the ability to cope with intracellular agents following stress situations., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

A body of knowledge implicates an increase in output from the locus ceruleus (LC) during stress. We questioned the innervation and function of the LC in our macaque model of Functional Hypothalamic Amenorrhea, also known as Stress-Induced Amenorrhea. Cohorts of macaques were initially characterized as highly stress resilient (HSR) or stress-sensitive (SS) based upon the presence or absence of ovulation during a protocol involving 2 menstrual cycles with psychosocial and metabolic stress. Afterwards, the animals were rested until normal menstrual cycles resumed and then euthanized on day 5 of a new menstrual cycle [a] in the absence of further stress; or [b] after 5 days of resumed psychosocial and metabolic stress. In this study, parameters of the LC were examined in HSR and SS animals in the presence and absence of stress (2×2 block design) using ICC and image analysis. Tyrosine hydroxylase (TH) is the rate-limiting enzyme for the synthesis of catecholamines; and the TH level was used to assess by inference, NE output. The pixel area of TH-positive dendrites extending outside the medial border of the LC was significantly increased by stress to a similar degree in both HSR and SS animals (p<0.0001). There is a significant CRF innervation of the LC. The positive pixel area of CRF boutons, lateral to the LC, was higher in SS than HSR animals in the absence of stress. Five days of moderate stress significantly increased the CRF-positive bouton pixel area in the HSR group (p<0.02), but not in the SS group. There is also a significant serotonin innervation of the LC. A marked increase in medial serotonin dendrite swelling and beading was observed in the SS+stress group, which may be a consequence of excitotoxicity. The dendrite beading interfered with analysis of axonal boutons. However, at one anatomical level, the serotonin-positive bouton area was obtained between the LC and the superior cerebellar peduncle. Serotonin-positive bouton pixel area was significantly higher in HSR than SS animals (p<0.04). There was no change in either group after 5 days of moderate stress. The ratio of serotonin/TH correlates with ovarian estrogen production with a sensitivity×stress interaction. Therefore, it appears that the serotonin system determines stress sensitivity and the NE system responds to stress. We hypothesize that elevated NE with low serotonin functionality ultimately leads to stress-induced infertility. In contrast, high serotonin functionality maintains ovulation in the presence of stress even with elevated NE., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Objective: Menkes disease is a lethal neurodegenerative disorder of infancy caused by mutations in a copper-transporting adenosine triphosphatase gene, ATP7A. Among its multiple cellular tasks, ATP7A transfers copper to dopamine beta hydroxylase (DBH) within the lumen of the Golgi network or secretory granules, catalyzing the conversion of dopamine to norepinephrine. In a well-established mouse model of Menkes disease, mottled-brindled (mo-br), we tested whether systemic administration of L-threo-dihydroxyphenylserine (L-DOPS), a drug used successfully to treat autosomal recessive norepinephrine deficiency, would improve brain neurochemical abnormalities and neuropathology., Methods: At 8, 10, and 12 days of age, wild-type and mo-br mice received intraperitoneal injections of 200μg/g body weight of L-DOPS, or mock solution. Five hours after the final injection, the mice were euthanized, and brains were removed. We measured catecholamine metabolites affected by DBH via high-performance liquid chromatography with electrochemical detection, and assessed brain histopathology., Results: Compared to mock-treated controls, mo-br mice that received intraperitoneal L-DOPS showed significant increases in brain norepinephrine (p < 0.001) and its deaminated metabolite, dihydroxyphenylglycol (p < 0.05). The ratio of a non-beta-hydroxylated metabolite in the catecholamine biosynthetic pathway, dihydroxyphenylacetic acid, to the beta-hydroxylated metabolite, dihydroxyphenylglycol, improved equivalently to results obtained previously with brain-directed ATP7A gene therapy (p < 0.01). However, L-DOPS treatment did not arrest global brain pathology or improve somatic growth, as gene therapy had., Interpretation: We conclude that (1) L-DOPS crosses the blood-brain barrier in mo-br mice and corrects brain neurochemical abnormalities, (2) norepinephrine deficiency is not the cause of neurodegeneration in mo-br mice, and (3) L-DOPS treatment may ameliorate noradrenergic hypofunction in Menkes disease., (Copyright © 2012 American Neurological Association.)

Unlabelled: Aging in female rats is associated with cessation of reproductive cycles, development of mammary cancer, and increased incidence of autoimmune diseases. Previously, we demonstrated an age-related decline in sympathetic noradrenergic (NA) innervation in the spleen and lymph nodes of female F344 rats accompanied by significantly reduced natural killer cell activity, interleukin (IL)-2 and interferon (IFN)-γ production, and T- and B-cell proliferation, suggesting possible links between sympathetic activity and immunosenescence., Objectives: The aim of this study is to investigate the effects of L-(-)-deprenyl, a monoamine oxidase-B inhibitor, on the sympathetic nervous system and cell-mediated immune responses in old female rats., Methods: Low doses of L-deprenyl (0.25 or 1.0 mg/kg body weight, BW) were administered intraperitoneally to 19- to 21-month-old female F344 rats for 8 weeks. To assess the stereoselectivity of the effects of deprenyl on splenic sympathetic activity and immune responses, the D-enantiomer (D-(+)-deprenyl; 1.0 mg/kg BW) was also included in the studies. Norepinephrine (NE) concentration and content, and mitogen-induced T-cell proliferation and cytokine production were assessed in the splenocytes after deprenyl treatment., Results: Treatment with L-deprenyl reversed the age-related decrease in NE concentration and content and IFN-γ production, and increased IL-2 production in the spleen while D-deprenyl did not affect the age-associated reduction in splenic NE levels or cytokine production., Conclusions: These findings demonstrate that L-deprenyl exerts neurorestorative and immunostimulatory effects on the sympathetic nervous system and cell-mediated immune responses during aging and provides evidence for a causal relationship between some aspects of immunosenescence and the age-related decline in sympathetic nerves in the spleens of female F344 rats., (Copyright © 2012 S. Karger AG, Basel.)

The purpose of this study was to elucidate the alteration of catecholamine metabolism and the contribution of catecholamines to the decline of learning and memory in the brain of the senescence-accelerated mouse prone 10 (SAMP10) with aging. Catecholamines and their metabolites in the cerebral cortex were measured by HPLC-ECD. The protein levels of tyrosine hydroxylase (TH) as well as TH phosphorylated at Ser19 or Ser40, dopamine-β-hydroxylase (DβH), and cAMP-dependent protein kinase (PKA) were determined by western blot analysis. Dopamine (DA) and norepinephrine (NE) levels in SAMP10 were significantly lower than those in control animals. However, no significant difference was observed in catecholamine metabolite levels between SAMP10 and control mice. The level of TH phosphorylation at Ser40 in SAMP10 was significantly lower than that in control mice, but no significant difference was observed in the levels of TH, TH phosphorylated at Ser19, or DβH. The amount of PKA, which regulates the phosphorylation of TH at Ser40, was significantly lower in SAMP10 than in control mice. The present study demonstrated that a decline in DA and NE concentrations was observed in the cerebral cortex of SAMP10 with aging, and this decrease of catecholamine levels was caused by impairment of their synthetic pathway. These impairments are considered to be caused by downregulation of TH phosphorylation at Ser40 as a result of PKA deficiency. The present study suggests that the decline of learning and memory abilities of SAMP10 is caused by a decrease in catecholamine synthesis in the cerebral cortex with aging., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

There is increasing interest in the bidirectional communication between the mammalian host and prokaryotic cells. Catecholamines (CA), candidate molecules for such communication, are presumed to play an important role in the gut lumen; however, available evidence is limited because of the lack of actual data about luminal CA. This study evaluated luminal CA levels in the gastrointestinal tract and elucidated the involvement of gut microbiota in the generation of luminal CA by comparing the findings among specific pathogen-free mice (SPF-M), germ-free mice (GF-M), and gnotobiotic mice. Substantial levels of free dopamine and norepinephrine were identified in the gut lumen of SPF-M. The free CA levels in the gut lumen were lower in GF-M than in SPF-M. The majority of CA was a biologically active, free form in SPF-M, whereas it was a biologically inactive, conjugated form in GF-M. The association of GF-M with either Clostridium species or SPF fecal flora, both of which have abundant β-glucuronidase activity, resulted in the drastic elevation of free CA. The inoculation of E. coli strain into GF-M induced a substantial amount of free CA, but the inoculation of its mutant strain deficient in the β-glucuronidase gene did not. The intraluminal administration of DA increased colonic water absorption in an in vivo ligated loop model of SPF-M, thus suggesting that luminal DA plays a role as a proabsorptive modulator of water transport in the colon. These results indicate that gut microbiota play a critical role in the generation of free CA in the gut lumen.

Ascorbic acid is well known to acutely stimulate norepinephrine synthesis in neurosecretory cells, but it has also been shown over several days to increase tyrosine hydroxylase mRNA and norepinephrine synthesis in cultured neurons. Since tyrosine hydroxylase is the rate-limiting step in catecholamine synthesis, an effect of ascorbate to increase tyrosine hydroxylase protein could contribute to its ability to increase or sustain catecholamine synthesis. Therefore, we evaluated whether tyrosine hydroxylase protein expression and function is increased in SH-SY5Y neuroblastoma cells by physiologically relevant intracellular ascorbate concentrations. SH-SY5Y neuroblastoma cells did not contain ascorbate and had only very low levels of norepinephrine in culture with L-tyrosine, the substrate for tyrosine hydroxylase. However, treatment of cells with ascorbate for 6 h or more markedly increased norepinephrine synthesis, such that intracellular ascorbate and norepinephrine increased in parallel with half maximal intracellular concentrations of about 1 mM ascorbate and 150 μM norepinephrine. This increase was enhanced by supplementing tetrahydrobiopterin, but was not mimicked by several antioxidants or by catalase or superoxide dismutase. Tyrosine hydroxylase protein expression increased at intracellular ascorbate concentrations above 1.5 mM. This contributed to norepinephrine generation, which was decreased 50-60% by inhibition of protein synthesis with cycloheximide at high intracellular ascorbate. These results suggest that expected physiologic neuronal ascorbate concentrations enhance norepinephrine synthesis both by maintaining tetrahydrobiopterin and increasing tyrosine hydroxylase expression., (Copyright © 2012 Elsevier Inc. All rights reserved.)

A number of preclinical and clinical studies indicate multiple types of interaction between ethanol intake and the mood-related neurotransmitter, norepinephrine (NE). For example, ethanol interacts with dopamine beta-hydroxylase (DBH), an enzyme that plays an essential role in the only well-established endogenous synthetic pathway for NE, whereby dopamine is hydroxylated to form NE. While the DBH pathway may indeed be the only endogenous mechanism for producing NE, another possibility is that multiple means have evolved for the biosynthesis of this very important neurotransmitter, where some pathways may be independent of DBH. If so, such redundancy would provide greater assurance that enough NE is available for the body to use in this neurotransmitter's various physiological roles. This paper puts forth the hypothesis ethanol is a substrate in a novel, endogenous synthetic pathway for NE, consistent with some studies showing that intake of ethanol increases the concentration of endogenous NE. Also consistent with this hypothesis, the molecular structure of ethanol is a physical subset of the structure of NE itself. If the hypothesis is correct, it may have important implications for understanding the physiological basis of alcohol use, abuse, and dependence in humans, as well as modeling these phenomena in animals. Importantly, the hypothesis is directly testable in rodents by presenting ethanol to DBH knockout mice, which are thought to lack NE, and then measuring if NE is synthesized in these animals., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The effects of testosterone on norepinephrine release were investigated in the isolated rat hearts. Sprague-Dawley male rats (n=120) were randomized to testosterone and control groups. The rats in testosterone group were perfused with modified Krebs-Henseleit buffer containing different concentrations of testosterone (0.1, 1.0, 10.0, and 100.0 nmol/L, respectively). Myocardial ischemia was induced by globally stopping the perfusion flow. Exocytotic norepinephrine release was induced by electrical field stimulation at 5 V (effective voltage) and 6 Hz (pulse width of 2 ms) for 1 min. The overflow of norepinephrine was determined by high pressure liquid chromatography and electrochemical detection (HPLC-EC). Following acute ischemia, testosterone (1.0, 10.0 and 100.0 nmol/L) significantly reduced norepinephrine release (P<0.01), and the norepinepherine overflow was similar between the control and 0.1 nmol/L testosterone group (P>0.05). Electrical stimulation of the ventricle evoked norepinepherine release, and this was diminished by the perfusion with testosterone at the concentrations of 1.0, 10.0 and 100.0 nmol/L (P<0.01). It is suggested that testosterone suppresses ischemia- and electrical stimulation-induced norepinepherine release in the isolated rat hearts.

Objectives: The antipyretic and neuroprotective potential of the nonsteroidal anti-inflammatory drug "indomethacin" was tested against lipopolysaccharide-produced hyperthermia and biosynthesis of norepinephrine and dopamine, in six brain regions of male rat., Methods: Observations were based on a single intraperitoneal injection of each of lipopolysaccharide (250 µg Kg-1 body wt) and indomethacin (20 mg Kg-1 body wt) followed by sampling and assaying of brain specimens after 2, 8, 12 and 24 hrs. lipopolysaccharide induced a general hyperthermia (8-24 hr) that was completely abolished by pretreatment with indomethacin., Results: In virtually all brain regions tested, lipopolysaccharide stimulated the biosynthesis of norepinephrine and dopamine. Yet, pretreatment with indomethacin provoked substantial mitigation predominantly after 24 hrs. A time-based manner attended by a regionally nonselective manner characterized lipopolysaccharide-induced monoamine biosynthesis; whereas, indomethacin alleviation seems to proceed in a time-dependent and regionally-selective pathway since the pons proved the fastest and/or most responsive brain region to indomethacin action. A role of prostaglandin synthesis in the development of lipopolysaccharide-induced fever and catecholamine biosynthesis was suggested, given that both responses were abolished by the cyclooxygenase-inhibitor indomethacin., Conclusion: Accordingly, our data verified the potent therapy potential of indomethacin in protecting cerebral noradrenergic and dopaminergic systems against lipopolysaccharide-induced acute phase reactions.