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Gold is considered one of the biochemical components of the human body and has an effect on the activity of some organs including the reproductive system. This study inspects the impact of gold metal on male reproductive system. A total of 12 mature males were divided into two equal groups. The first group (Control) injected subcutaneously (s/c) with physiological sterile saline solution o.5ml/kg body weight/day for 28 days. The second animal group (induction) was injected with 0.2 mg gold chloride/ ml (in sterile distilled water) /kg body weight/day for 28 days. The results showed that rats treated with gold chlorideled to both extreme significant decrease (P< 0.001) of testosterone level and a highly significant increase (P< 0.01) in GOT & GOP levels in comparison to control group. Furthermore, an extremely significant decrease (P< 0.001) of relative sperm content level to control group. While in this study, no significant differences appeared concerning Hb content and total WBCs differential count values in comparison to control group. However, histological section of testis of gold treated (induction) group showed vaculation of seminiferous tubules, a decrease in the amount of sperms in the seminiferous tubules lumen and degeneration of interstitial cell compared with control ones. In the present study, the results have shown that there was an inhibition (negative) effect of gold metal on male fertility. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the anti-inflammatory effects of different dosage of low-level laser therapy (LLLT) in an experimental model of temporomandibular joint (TMJ) arthritis. One hundred male Wistar rats were used and divided into the following groups: CG, control group; AG, animals group with left TMJ arthritis induced by intra-articular injection of Complete Freund's adjuvant - CFA; LG5, LG10 and LG20 - animals with arthritis and treated with LLLT at doses 5, 10, and 20 J/cm2, respectively. Morphological analysis was performed by TMJ histological sections stained with hematoxylin-eosin (HE), picrosirius (PSR), and toluidine blue (TB), as well as histomorphometric evaluation of cartilage, articular disc, and masticatory muscles. The amount of feed consumed within 3 weeks was evaluated, and biochemical analysis of TMJ tissues included measurement of sulfated glycosaminoglycans (GAGs), matrix metalloproteinases (MMPs) 2 and 9 zymography, and ELISA for cytokines IL-6, TNF-α, and IL-1β. Only the 20 J/cm2 dose promoted higher feed intake compared to AG. On the other hand, all LLLT doses promoted better organization of articular disc collagen fibers, greater number of proteoglycans in articular cartilage, increased area and diameter of left lateral pterygoid fibers, reduced latent and active MMP 9 and 2 activity, and lower IL-1β concentration compared to AG. Considering the study limitations, it was observed that LLLT treatments were effective in protecting and tissue cleansing joint structures, accelerating tissue repair, especially at lower doses. [ABSTRACT FROM AUTHOR]

The main purpose of this work was to construct an energy-dependent response curve of photobiomodulation on arterial pressure in hypertension animal model. To reach this objective, we have used a two-kidney one clip (2K-1C) rat model. Animals received acute laser light irradiation (660 nm) on abdominal region using different energy (0.6, 1.8, 3.6, 7.2, 13.8, 28.2, 55.8, and 111.6 J), the direct arterial pressure was measured by femoral cannulation, and systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), and time of effect were obtained. Our results indicated that 660 nm laser light presents an energy-dependent hypotensive effect, and 28.2 J energy irradiation reached the maximum hypotensive effect, inducing a decreased SAP, DAP, and HR (decrease in SAP: - 19.23 ± 1.82 mmHg, n = 11; DAP: - 9.57 ± 2.23 mmHg, n = 11; HR: - 39.15 ± 5.10 bpm, n = 11; and time of hypotensive effect: 3068.00 ± 719.00 s, n = 11). The higher energy irradiation evaluated (111.6 J) did not induce a hypotensive effect and induced an increase in HR (21.69 ± 7.89 bpm, n = 7). Taken together, our results indicate that red laser energy irradiation from 7.2 to 55.8 J is the effective therapeutic window to reduce SAP, DAP, MAP, and HR and induce a long-lasting hypotensive effect in rats, with effect loss at higher energy irradiation (111.6 J). [ABSTRACT FROM AUTHOR]

Introduction: Objective: the purpose of this study was to investigate the effects of Chrysobalanus icaco on adiposity and its mechanism of action in the gene and protein expression of acetyl-CoA carboxylase (ACC), a key enzyme in lipogenesis. Method: Wistar rats were divided into a regular or control group (CG) and a high-fat diet (HFD) group. HFD was treated with saline or aqueous extract of Chrysobalanus icaco (AECI) for four weeks. Body weight and food intake were assessed. Subcutaneous, retroperitoneal and periepididymal adipose tissue samples were collected and weighed. Adipocytes from periepididymal tissue were isolated and analyzed. The gene and protein expression of ACC in subcutaneous tissue was determined. Results: AECI showed no effect on intake or body weight. However, the weight of the fat pads and the gene and protein expression of ACC were lower, and glucose tolerance was improved. Conclusion: the aqueous extract of Chrysobalanus icaco proved beneficial for the treatment of obesity, preventing fat storage and improving glycemic homeostasis. [ABSTRACT FROM AUTHOR]

Copyright of Meandros Medical & Dental Journal is the property of Galenos Yayinevi Tic. LTD. STI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The role of fish oil, primrose oil and their mixture in ameliorating the changes in Alzheimer's like model was evaluated in rats. Primrose oil and primrose/fish oil mixture fatty acids composition was assessed by gas chromatography. The rat experiment consisted of 5 groups; the first fed on balanced diet as control normal (CN); the other four groups treated with intraperitoneal aluminum lactate and consumed dyslipidemic diet; one group served as control Alzheimer's like disease (CA) while the other three groups (test groups) received daily oral dose from primrose oil, fish oil and primrose/fish oil mixture separately for 5 weeks. Results showed primrose oil and primrose/fish oil mixture to contain gamma linolenic acid as 9.15 and 4.3% of total fatty acids, respectively. Eicosapentaenoic and docosahexaenoic were present as 10.9 and 6.5%, respectively in the oil mixture. Dyslipidemia and increased erythrocyte sedimentation rate (ESR), plasma butyrylcholinesterase (BChE), brain malondialdehyde (MDA) and NO with decrease in plasma magnesium, brain catalase, reduced glutathione, body weight gain and brain weight were demonstrated in CA compared to CN. Brain histopathology and immuno-histochemistry showed neuronal degeneration and neurofibrillary tangles with elevated myeloperoxidase and nuclear factor-kappa B in CA compared to CN. The tested oils demonstrated neuro-protection reflected in the variable significant improvement of biochemical parameters, immuno-histochemistry and brain histopathology. Primrose/fish oil mixture was superior in reducing ESR, brain MDA, plasma activity of BChE and brain histopathological changes along with elevating plasma magnesium. Primrose/fish oil mixture and fish oil were more promising in improving plasma high density lipoprotein cholesterol (HDL-C) than primrose. Fish oil was the most efficient in improving plasma total cholesterol (T-C), low density lipoprotein cholesterol and T-C/HDL-C. Primrose/fish oil mixture and primrose oil were superior in elevating brain catalase compared to fish oil. Other parameters were equally improved by the different oil treatments. Primrose oil, fish oil and their mixture reduced the progression of Alzheimer's disease in rats with superiority to primrose/fish oil mixture. [ABSTRACT FROM AUTHOR]

As 2020 is "The Year of the Rat" in the Chinese astrological calendar, it seems an appropriate time to consider whether we should bring back the laboratory rat to front-and-center in research on the basic biology of mammalian aging. Beginning in the 1970s, aging research with rats became common, peaking in 1992 but then declined dramatically by 2018 as the mouse became preeminent. The purpose of this review is to highlight some of the historical contributions as well as current advantages of the rat as a mammalian model of human aging, because we suspect at least a generation of researchers is no longer aware of this history or these advantages. Herein, we compare and contrast the mouse and rat in the context of several biological domains relevant to their use as appropriate models of aging: phylogeny/domestication, longevity interventions, pathology/physiology, and behavior/cognition. It is not the goal of this review to give a complete characterization of the differences between mice and rats, but to provide important examples of why using rats as well as mice is important to advance our understanding of the biology of aging. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to evaluate the effect of intravenous irradiation of different low-level laser wavelengths on the activity of lecithin-cholesterol acyltransferase (LCAT), paraoxonase (PON1), catalase, and ferric reducing ability of plasma (FRAP) in diabetic rats. First, diabetes was induced in rats using streptozotocin (STZ). Enzymes' activity was measured in the blood samples and compared before and after intravenous laser blood irradiation. We used four continuous-wave lasers-IR (λ = 808 nm), Red (λ = 638 nm), Green (λ = 532 nm), and Blue (λ = 450 nm)-to compare the wavelength's effect on different enzymes' activity. Laser power was fixed at 0.01 mW and laser energy was changed by 2-, 4-, 6-, and 8-min time of radiations.The enzymes' activity of blood samples was measured 2, 6, and 24 h after radiation. The results show an increase in the activity of different enzymes when compare with diabetic non-radiated samples. More importantly, with a constant laser energy, the enzymes' activity increased with decreasing laser wavelength. It is important to note that with a constant laser energy, as the wavelength decreases, the photon energy increases and the number of photons decrease, while the enzyme's activity elevation increases. As a result, we can conclude that in intravenous low-level laser therapy, photon energy is more important than the number of photons even if their product, energy, is kept constant. [ABSTRACT FROM AUTHOR]

BACKGROUND: Standardized leaf extract of Gingko biloba (EGb 761®) is a modern herbal medicinal product. It is one of the bestselling and popular botanical drug preparations in the world. OBJECTIVES: The study was carried out to evaluate the phytochemical constituents of Ginkgo biloba leaf extract (EGb 761®), to determine the effect of the extract on erythrocyte osmotic fragility under hypotonic stress, and to investigate the effect of the extract on haematological parameters and erythrocyte osmotic fragility in rats experimentally exposed to chlorpyrifos-induced oxidative stress. METHODS: A total of 35 adult albino rats, divided into 7 groups of 5 rats each, were used. Group A served as control, Groups B and C were pre-treated and post-treated with vitamin E respectively, while Groups D and E were pre-treated and post-treated with EGb 761® respectively before administration of chlorpyrifos. Groups F and G were only treated with the extract and chlorpyrifos respectively. RESULTS: The findings showed that there was no significant difference in erythrocyte osmotic fragility between pre-treatment and post-treatment with EGb 761 in chlorpyrifos induced oxidative stress (P>0.05). However, the erythrocytes of rats treated with EGb 761® were significantly more resistant to hypotonic haemolysis in comparison to vitamin E and control (P˂0.05). Pre-treatment with EGb 761 resulted in significantly higher packed cell volume, haemoglobin concentration, and red blood cell counts than pre-treatment with vitamin E and control (P˂0.05). Also, post-treatment with EGb761® significantly increased total protein in comparison to control (P˂0.05). CONCLUSIONS: It was concluded that EGb 761® administration resulted in increased erythrocyte resistance to haemolysis and increased blood cellular components. [ABSTRACT FROM AUTHOR]

Copyright of Japanese Journal of Food Chemistry & Safety is the property of Japanese Society of Food Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was conducted to investigate the possible protective role of (CoQ10) on reproductive dysfunction of male rats induced by sodium fluoride (NaF). thirty two rats were divided into four even groups and treated for 56 days as follows: the first group served as control (C) The second group (G1) received coenzyme Q10 at dose of 10 mg/Kg.B.W; while third group (G2) received 100ppmsodium fluoride in drinking water and fourth groups (G3) received NaF 100 ppm and CoQ10 10 mg/Kg.B.W for 56 days. The results showed that exposure of rats to NaF caused decrease in serum testosterone (T) and luteinizing hormones (LH) concentrations. Whereas Administration of CoQ10 caused an increase the concentrations of theses hormones in group G3 as compared with group G2. Testicular morphometric and histopathological alterations were observed in group G2 in the form of marked microvacuolation in the basal level of germinal cells, amyloid deposited within seminiferous tubules with disarrangement and depletion of germ cells. Whereas testicular histological alterations were improved in rats treated with CoQ10. In conclusion, the results of the present study showed that use of Co Q10 can alleviating the deleterious effects on male reproductive function following exposure to NaF, may be via improvement the testicular functions or other related endocrine glands. [ABSTRACT FROM AUTHOR]

Chronic alcohol exposure can affect the osteoblastic activity and the proliferation and differentiation of cells due to its toxic effect, which can affect negatively bone repair and bone microarchitecture. The aim of this study was to evaluate the effects of chronic use of 20% alcohol on rats regarding osteoblastic differentiation, extrinsic and intrinsic properties of the tibia, and hepatic and renal morphology. Wistar rats were divided into three groups (n = 9) in accordance with a 24-week diet. After euthanasia, kidneys, liver, and tibias were removed for analysis and femurs mesenchymal cells were collected. The results showed that chronic use of 20% alcohol influenced neither the alkaline phosphatase production nor total protein (p > 0.05) in rats, with similar formation of nodules in all groups (p > 0.05). However, significant changes in the liver and kidneys and adverse effects on the mechanical properties of the tibia were observed. According to the results, it can be concluded that the chronic use of alcohol for 24 weeks had no negative influence on the activity and differentiation of osteoblasts, but the mechanical properties of the tibia were impaired and the organs responsible for metabolism and excretion were also affected due to the consumption of alcohol. [ABSTRACT FROM AUTHOR]

Prolactin (PRL) and oxytocin (OT) are pituitary hormones essential for lactation, but also promote sexual behavior. OT stimulates social behaviors, such as recognition, approach, and learning, but less is known about PRL in these behaviors. Since PRL and OT have complementary functions in reproduction, we hypothesized that PRL increases social recognition, approach, and learning. Male Long-Evans rats received ovine PRL (oPRL; 0.5, 2.0 or 5.0 mg/kg), the PRL antagonist bromocriptine (0.1, 3.0 or 5.0 mg/kg) or saline 20 mins before testing for recognition of familiar vs. unfamiliar stimulus males. Saline controls preferred the unfamiliar male ( p < 0.05), while bromocriptine blocked this preference. oPRL did not increase preference. To measure social approach, we determined if PRL restores approach 2 h after defeat by an aggressive male. Defeated rats avoided the aggressive male. 2 mg/kg oPRL, before or after defeat, restored approach towards the aggressive male ( p < 0.05). In non-defeated rats, oPRL or 3 mg/kg bromocriptine had no effect. To determine if PRL increases social learning, we tested social transmission of food preference. Rats choose between two unfamiliar flavors, one of which they have previously been exposed to through interaction with a demonstrator rat. Vehicle controls preferred chow with the demonstrated flavor over the novel flavor. oPRL-treated rats were similar. Bromocriptine-treated rats failed to show a preference. When tested one week later, only oPRL-treated rats preferred the demonstrated flavor. The results suggest that PRL is required for social recognition and learning, and that increasing PRL enhances social memory and approach, similar to OT. [ABSTRACT FROM AUTHOR]

The expression of Notch2, Numb, and Cas8 genes, whose protein products are involved in regulation of neurogenesis/neuroapoptosis processes, was studied in the relevant cerebral structures of male Wistar rats trained in a spatial habit. The formation of long-term spatial memory was found to be associated with the formation of a specific pattern of transcription activity of the studied genes in different brain structures. The maximum expression of Notch2 gene was found in the hippocampus and cerebellum, the maximum expression of Numb was detected in the prefrontal cortex and cerebellum, and the maximum expression of Cas8 was revealed in the prefrontal cortex of trained animals. [ABSTRACT FROM AUTHOR]

Measuring the activity and temperature of rats is commonly required in biomedical research. Conventional approaches necessitate single housing, which affects their behavior and wellbeing. We have used a subcutaneous radiofrequency identification (RFID) transponder to measure ambulatory activity and temperature of individual rats when group-housed in conventional, rack-mounted home cages. The transponder location and temperature is detected by a matrix of antennae in a baseplate under the cage. An infrared high-definition camera acquires side-view video of the cage and also enables automated detection of vertical activity. Validation studies showed that baseplate-derived ambulatory activity correlated well with manual tracking and with side-view whole-cage video pixel movement. This technology enables individual behavioral and temperature data to be acquired continuously from group-housed rats in their familiar, home cage environment. We demonstrate its ability to reliably detect naturally occurring behavioral effects, extending beyond the capabilities of routine observational tests and conventional monitoring equipment. It has numerous potential applications including safety pharmacology, toxicology, circadian biology, disease models and drug discovery. [ABSTRACT FROM AUTHOR]

We investigated the effects of physical exercise (PE) on locomotor activity and anxiety-like behavior in Lewis (LEW) and Spontaneously Hypertensive Rats (SHR) male rats. Rats received either four weeks of forced training, 5 days/week, on a treadmill (experiment 1) or were given 21 days of free access to running wheels (experiment 2). We also tested the effects of social isolation (SI) (seven days of isolation − experiment 3) on behavior. In experiment 1, 20% of LEW rats and 63% of SHR rats completed the training protocol. PE significantly increased central and peripheral locomotion in the open field (OF) and entries into the open arms in the elevated plus-maze (EPM) in both strains. In experiment 2, the distance traveled by SHR rats on running wheels was significantly higher compared with LEW rats. PE on running wheels also increased the time spent in the center of the OF in SHR rats only. In experiment 3, SI decreased central and peripheral locomotion in the OF in both strains. In summary, forced PE on a treadmill reduced anxiety-like behavior and increased locomotion in male rats of both strains, whereas voluntary PE on running wheels decreased anxiety-like behavior in SHR rats only. SI decreased locomotion in both strains in the OF. This study suggests that spontaneous activity levels are genotype-dependent and the effects of PE depend on the type of exercise performed. [ABSTRACT FROM AUTHOR]

Atmospheric CO 2 concentrations increased significantly over the last century and continuing increases are expected to have significant effects on current ecosystems. This study evaluated the behavioural and physiological (hormone status, muscle structure) effects of prolonged CO 2 exposure in young female Wistar rats exposed at 700 ppm of CO 2 during 6 h a day for 15 days. Prolonged CO 2 exposure, though not continuous, produced significant disturbances in behaviour with an increase in drinking, grooming and resting, and a reduction in rearing, jumping-play and locomotor activity. Furthermore, CO 2 exposure was accompanied by increased plasma levels of corticosterone, suggesting that prolonged exposure to CO 2 was stressful. The muscular structure can also be modified also when respiratory working conditions change. The expression of myosin heavy chain was significantly affected in the diaphragm and oral respiratory muscles: Masseter Superficialis and Anterior Digastric . Modified behaviour and hormonal changes both appear to be at the origin of the observed muscular adaptation. [ABSTRACT FROM AUTHOR]

Purpose: To compare the blood-brain barrier permeability changes induced by synchrotron microbeam radiation therapy (MRT, which relies on spatial fractionation of the incident x-ray beam into parallel micron-wide beams) with changes induced by a spatially uniform synchrotron x-ray radiation therapy.Methods and Materials: Male rats bearing malignant intracranial F98 gliomas were randomized into 3 groups: untreated, exposed to MRT (peak and valley dose: 241 and 10.5 Gy, respectively), or exposed to broad beam irradiation (BB) delivered at comparable doses (ie, equivalent to MRT valley dose); both applied by 2 arrays, intersecting orthogonally the tumor region. Vessel permeability was monitored in vivo by magnetic resonance imaging 1 day before (T-1) and 1, 2, 7, and 14 days after treatment start. To determine whether physiologic parameters influence vascular permeability, we evaluated vessel integrity in the tumor area with different values for cerebral blood flow, blood volume, edema, and tissue oxygenation.Results: Microbeam radiation therapy does not modify the vascular permeability of normal brain tissue. Microbeam radiation therapy-induced increase of tumor vascular permeability was detectable from T2 with a maximum at T7 after exposure, whereas BB enhanced vessel permeability only at T7. At this stage MRT was more efficient at increasing tumor vessel permeability (BB vs untreated: +19.1%; P=.0467; MRT vs untreated: +44.8%; P<.0001), and its effects lasted until T14 (MRT vs BB, +22.6%; P=.0199). We also showed that MRT was more efficient at targeting highly oxygenated (high blood volume and flow) and more proliferative parts of the tumor than BB.Conclusions: Microbeam radiation therapy-induced increased tumor vascular permeability is: (1) significantly greater; (2) earlier and more prolonged than that induced by BB irradiation, especially in highly proliferative tumor areas; and (3) targets all tumor areas discriminated by physiologic characteristics, including those not damaged by homogeneous irradiation. [ABSTRACT FROM AUTHOR]

Background and Objective Doxycycline is an antibiotic agent that inhibits the activity of matrix metalloproteinases ( MMPs) present in the extracellular matrix. In this study, the rat incisor was submitted to a hypofunctional condition, and the effects of doxycycline (80 mg/kg/d) on the expression and activity of MMP-2, as well as on eruption rate, were determined in the odontogenic region and in the periodontal ligament for 14 d. Material and Methods Rats were distributed into four groups: normofunctional ( NF); doxycyline normofunctional ( DNF); hypofunctional ( HP); and doxycyline hypofunctional ( DHP). The left lower incisors of 10 rats were shortened every 2 d, using a high-rotation drill, to produce the HP and DHP groups, after starting doxycycline treatment (80 mg/kg) by gavage. Eruption was measured using a millimeter ocular, from the gingival margin to the top of the tooth in the HP and DHP groups, and also by a mark made in the tooth previously, in the NF and DNF groups. The hemimandibles were removed and the teeth were extracted to collect the periodontal and odontogenic tissues for immunohistochemical analyses and zymography. Results The eruption rates were higher in the HP and the DHP groups than in the NF and DNF groups, respectively ( p < 0.05). In the odontogenic region, neither of the treatments changed the expression and activity of MMP-2. In the HP group, the shortening treatment decreased the expression, but not the activity, of MMP-2, while doxycycline was able to inhibit the increase of expression and activity of MMP-2. Conclusion We conclude that the inhibition of MMP-2 by doxycycline, during incisor shortening, was not enough to alter the eruption rate, which suggests that MMP-2 may have an important role in the turnover of extracellular matrix of the periodontal ligament during the tooth-eruption process. [ABSTRACT FROM AUTHOR]

Rationale: The polyglutamine disease spinocerebellar ataxia type 17 (SCA17) is a neurodegenerative disease leading to severe neurological symptoms during development. Additionally, patients affected by SCA17 display psychosis earlier than their motor disorders.Objective: Here the putative psychotic phenotype and endophenotype of transgenic SCA17 rats was examined.Methods: The expression of schizophrenia-like symptoms was evaluated over a longitudinal period before and after the onset of neurological symptoms in SCA17. To this end, transgenic SCA17 rats' monoamine neurotransmission was investigated along with their locomotion at baseline and in response to amphetamine using in-vivo microdialysis in free moving conditions, their sensorimotor gating using pre-pulse inhibition of startle reaction, and their object memory using the novel object recognition test as an index of cognitive impairments.Results: Presymptomatic SCA17 rats displayed dysregulated monoamine levels at baseline and in response to amphetamine compared with control wild-type (wt) rats. At that stage, neither amphetamine-induced hyperlocomotion nor sensorimotor gating differed from that in wt rats. Symptomatic SCA17 rats developed sensorimotor gating deficits and also showed an impaired object memory, while their monoaminergic responses remained supersensitive to amphetamine.Conclusions: The data of the present study demonstrate a neurochemical endophenotype in SCA17 rats resembling that of prodromal schizophrenia. These findings suggest that a sensitization of the monoamine systems arises early in adulthood in SCA17 rats and may predispose them to express schizophrenia-like symptoms later in life. [ABSTRACT FROM AUTHOR]

The effects of early environmental enrichment (EE) and voluntary wheel running on the preference for using a landmark or pool geometry when solving a simple spatial task in adult male and female rats were assessed. After weaning, rats were housed in same-sex pairs in enriched or standard cages (EE and control groups) for two and a half months. Then the rats were trained in a triangular-shaped pool to find a hidden platform whose location was defined in terms of these two sources of information, a landmark outside the pool and a particular corner of the pool. As expected, enriched rats reached the platform faster than control animals, and males and females did not differ. Enriched rats also performed better on subsequent test trials without the platform with the cues individually presented (either pool geometry or landmark). However, on a preference test without the platform, a clear sex difference was found: Females spent more time in an area of the pool that corresponded to the landmark, whereas males spent more time in the distinctive corner of the pool. The present EE protocol did not alter females' preference for the landmark cue. The results agree with the claim that environmental enrichment is a consequence of a reduced anxiety response (measured by thigmotaxis) during cognitive testing. A possible implication of ancestral selection pressures is discussed. [ABSTRACT FROM AUTHOR]

The article presents research of structural and functional changes in the liver in the conditions of modeling of micronutrient deficiencies in the organism of experimental animals with subsequent inclusion of complex minerals into their food ration. The object of the study was the liver of rats «Wistar». The elemental composition of biological substrates has been studied using atomic emission and mass spectrometry (ICP-AES and ICP-MS) in the test laboratory ANO «Center for Biotic Medicine». It has been established that the addition of selenium to the ration increases the concentration of this element in the liver by 15,0% (p=0,05) against the background of lowering nickel by 50,0% (p=0,05) in the experimental group I relative to control. When you turn on zinc into the ration, the concentration of it increases by 14,3% (p=0,05) in the experimental group II relative to the control. Inclusion of iodine in the ration contributed to the increase of the iodine concentration by 4,52% in the experimental group III relative to the control group. Thus, the intake by the animal organism of toxic elements (lead and cadmium salts) leads to a change in the structural elements of the liver, resulting in depletion of hepatocyte in glycogen, or its complete disappearance, in offensive vacuolization and necrosis of hepatocytes and in changes in vessels diameter microvasculature, i.e. structural and functional changes in the liver are identified. Introduction into the ration of complex of essential trace elements (I, Se, Zn) involves an increase in functional activity of the liver. [ABSTRACT FROM AUTHOR]

Information on the effects of phytoestrogens on animals has increased recently; however, there were only few studies on prenatal exposure on cellular immune response. Pregnant rats were assigned to 3 groups (12 rats per group), the first was fed control diet, the second was fed low-dose (6.5 g/100 g of diet) soy isoflavones, while the third was fed high-dose (26 g/100 g of diet) soy isoflavones. The female offspring cell-mediated immune response was determined using phytohemagglutinin (PHA) injection, and intumesce index was calculated on postnatal day 50. After 24 hours of PHA injection, blood samples were collected for tumor necrosis factor α, interferon γ (IFN-γ), and interleukin (IL)-12 determination. Spleen, thymus, and PHA-injected footpads were fixed for histopathology. Intumesce index was significantly (P < 0.05) reduced in rats’ offspring born from dams fed low- and high-dietary soy isoflavones than that in control groups. Thymic relative weights in offspring of rats fed high-dietary soy isoflavones showed a significant (P < 0.05) decrease compared to that in the control group. Female offspring where low and high-dietary soy isoflavones were fed to their dams showed a significant (P < 0.05) decrease in IFN-γ and IL-12 than that in control ones. Spleen of rats born from dams fed high dose of dietary soy isoflavones showed lymphocytic depletion in white pulp. Taking together, it is clear that dietary soy isoflavones at prenatal period had immunosuppressive effect on female offspring after PHA stimulation. This effect was mediated through reduced IFN-γ that interplayed in IL-12 production pathway thus reducing its level. [ABSTRACT FROM AUTHOR]

Food and Drug Administration (FDA, USA)-approved category B antibiotics are commonly prescribed to treat infections during pregnancy. The aim of this study was to investigate antibiotic-induced changes in gut microbiota (GM) that occur during pregnancy. The 16S rRNA amplicon deep-sequencing method was used to analyze the effect of category B antibiotics (azithromycin, amoxicillin and cefaclor) on GM during pregnancy using a rat model. The GM composition was substantially modulated by pregnancy and antibiotics administration. Firmicutes, Bacteroidetes, Proteobacteria, Chlamydiae, Actinobacteria, and Cyanobacteria were the dominant phyla. Antibiotic treatment during pregnancy increased the relative abundance of Proteobacteria and reduced Firmicutes. The genera Shigella, Streptococcus, Candidatus Arthromitus, and Helicobacter were significantly (p < 0.05) more abundant during pregnancy. Antibiotics significantly (p < 0.05) reduced the relative abundance of Lactobacillus but increased that of Enterobacter. There was a significant (p < 0.05) decrease in Lactobacillus sp., Lactobacillus gallinarum and Lactobacillus crispatus during pregnancy. Antibiotic treatment reduced bacterial diversity; the lowest number of operational taxonomic units (OTUs) were detected in the cefaclor-treated groups. Antibiotics significantly (p < 0.05) promoted weight gain during pregnancy, and increased relative abundance of Shigella sonnei, Enterococcus hormaechei, and Acinetobacter sp. GM perturbations were accompanied by increases in Proteobacteria abundance and weight gain in pregnancy following antibiotic treatment. [ABSTRACT FROM AUTHOR]

The goal of this study was to quantitatively assess the changes in the cerebral neurochemical profile and to identify those factors that contribute to the alteration of endogenous biomolecules when rats are subjected to stress-induced sleep disturbance. We exposed Sprague-Dawley rats (controls: n = 9; stress-induced sleep perturbation rats: n = 11) to a psychological stressor (cage exchange method) to achieve stress-induced sleep perturbation. In vivo magnetic resonance imaging assessments were carried out using a high-resolution 9.4 T system. For in vivo neurochemical analysis, a single voxel was localized in the right dorsal hippocampal region, and in vivo spectra were quantified for 17 cerebral neurochemical signals. Rats were sacrificed upon completion of the magnetic resonance spectroscopy protocol, and whole-brain tissue was harvested from twenty subjects. The dopamine and serotonin signals were obtained by performing in vitro liquid chromatography-tandem mass spectrometry on the harvested tissue. In the right dorsal hippocampal region, the gamma-aminobutyric-acid (GABA) and glutamine (Gln) concentrations were significantly higher in the sleep-perturbed rats than in the sham controls. The ratios of Gln/Glu (glutamate), Gln/tCr (total-creatine), and GABA/Glu were also significantly higher in the sleep-perturbed group, while serotonin concentrations were significantly lower in the sleep-perturbed rats. Pearson correlation results among individual rat data indicate that concentrations of dopamine (DA) and serotonin (5-HT) were significantly higher in SSP rats. A larger correlation coefficient was also observed for the SSP rats. Analysis of the correlation between the in vivo and in vitro signals indicated that the concentrations of Gln, 5-HT, and DA exhibited a significant negative correlation in the SSP rat data but not in that of control rats. The authors propose that the altered and correlated GABA, Gln, 5-HT, and DA concentrations/ratios could be considered key markers of neurological function in animal models of stress-induced sleep perturbation. [ABSTRACT FROM AUTHOR]

Thirty six clinically healthy adult Wistar rats of either sex were used in the study and randomly divided into three groups having twelve animals in each group. Under general anesthesia, a full-thickness skin wound (20 × 20 mm 2 ) was created on the dorsum of each rat. The defect in group I was kept as open wound and was taken as control. In group II, the defect was repaired with commercially available collagen sheet (b-CS). In group III, the defect was repaired with reticulum derived extracellular matrix of bovine origin (b-REM). Healing was evaluated on the basis of wound contraction, gross, haematological, immunological and histopathological observations. On critical analysis of the observed parameters it was found that b-REM has healing potential and shown better healing response than commercially available collagen sheet to reconstruct full thickness skin wounds in rats. [ABSTRACT FROM AUTHOR]

Background: Patients with liver cirrhosis and minimal hepatic encephalopathy (MHE) show mild cognitive impairment and spatial learning dysfunction. Hyperammonemia acts synergistically with inflammation to induce cognitive impairment in MHE. Hyperammonemia-induced neuroinflammation in hippocampus could contribute to spatial learning impairment in MHE. Two main aims of this work were: (1) to assess whether chronic hyperammonemia increases inflammatory factors in the hippocampus and if this is associated with microglia and/or astrocytes activation and (2) to assess whether hyperammonemia-induced neuroinflammation in the hippocampus is associated with altered membrane expression of glutamate and GABA receptors and spatial learning impairment. There are no specific treatments for cognitive alterations in patients with MHE. A third aim was to assess whether treatment with sulforaphane enhances endogenous the anti-inflammatory system, reduces neuroinflammation in the hippocampus of hyperammonemic rats, and restores spatial learning and if normalization of receptor membrane expression is associated with learning improvement.Methods: We analyzed the following in control and hyperammonemic rats, treated or not with sulforaphane: (1) microglia and astrocytes activation by immunohistochemistry, (2) markers of pro-inflammatory (M1) (IL-1β, IL-6) and anti-inflammatory (M2) microglia (Arg1, YM-1) by Western blot, (3) membrane expression of GABA, AMPA, and NMDA receptors using the BS3 cross-linker, and (4) spatial learning using the radial maze.Results: The results reported show that hyperammonemia induces astrocytes and microglia activation in the hippocampus, increasing pro-inflammatory cytokines IL-1β and IL-6. This is associated with altered membrane expression of AMPA, NMDA, and GABA receptors which would be responsible for altered neurotransmission and impairment of spatial learning in the radial maze. Treatment with sulforaphane promotes microglia differentiation from pro-inflammatory M1 to anti-inflammatory M2 phenotype and reduces activation of astrocytes in hyperammonemic rats. This reduces neuroinflammation, normalizes membrane expression of glutamate and GABA receptors, and restores spatial learning in hyperammonemic rats.Conclusions: Hyperammonemia-induced neuroinflammation impairs glutamatergic and GABAergic neurotransmission by altering membrane expression of glutamate and GABA receptors, resulting in impaired spatial learning. Sulforaphane reverses all these effects. Treatment with sulforaphane could be useful to improve cognitive function in cirrhotic patients with minimal or clinical hepatic encephalopathy. [ABSTRACT FROM AUTHOR]

ABSTRACT.This study was designed to verify whether different lactation conditions influenced nervous system development. The authors used motor tasks to verify changes in exploratory activity and muscle strength of weaned rats from different litter sizes and evaluated the applicability of the grid-walking test for assessing motor abnormalities caused by undernutrition. Alterations in litter size during the suckling period perturbed the nutritional status of pups, which exhibited body weight differences between the groups. Large-litter (L) pups showed significant delays in achieving developmental milestones and neurological reflexes compared to the small-litter (S) and medium-litter (M) pups. The S, M, and L group pups exhibited similar exploratory responses and muscle strength. In the grid-walking and foot-fault tests, the L group pups traveled shorter distances and, consequently, had less footsteps. However, the percentages of foot faults in the L group were higher than S and M groups. These results reflect delayed maturation of structures responsible for sensorimotor responses, such as the cerebellum, because much cerebellar maturation takes place postnatally. This is the first study to report that early undernutrition in pups resulted in suboptimal performances on the grid-walking and foot-fault tests and that the former test was sensitive to alterations caused by nutritional deficiency. [ABSTRACT FROM PUBLISHER]

This study aimed to evaluate the clinicopathological and immunological profiles of two pesticides widely used in Egypt, Lampcon® and Saturn® in rats. Rats divided into three groups of 10 animals in each. The first group received no treatment and served as control, the second group received Lampcon at a dose of 168 ppm in food, and the third group received Saturn at a dose of 4230 ppm in food. Pesticides (treatments) were administrated daily via food for 60 consecutive days. Blood samples were collected for evaluating the selected hematological, biochemical and immunological parameters. The results of hematological variables implicated no significant effect on red blood cell parameters, but there was a significant leukopenia, lymphopenia and neutrophilia in both treated groups. The blood biochemical parameters showed a significant increase in serum levels of urea and enzymatic activities of ALT, AST and ALP. The findings of immunological studies clarified that Lampcon and Saturn induced oxidative stress in leukocytes and had immunosuppressive effects. The main histopathological alterations induced by Lampcon and Saturn included lymphoid depletion in lymphoid organs. Conclusion: we can conclude that the exposure of rats to Lampcon and Saturn pesticides pose many hematological, biochemical, and histopathological alterations in addition to immunotoxic effects. It is thus advisable that Lampcon and Saturn should be used with caution and at the recommended levels indicated by the producing company to ensure minimal exposure to these pesticides during domestic, veterinary, agricultural or industrial use. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effect of thymus factor X (TFX-Jelfa) treatment in hypoestrogenic female rats for the purpose of decreasing skin impairments. Ovariectomised rats were used as a model. The histopathological analysis of the skin after TFX-Jelfa treatment demonstrated that the epidermis was thicker and more desquamated, without deep wrinkles or hypersecretion in comparison to the skin of animals only castrated and not treated with TFX-Jelfa. Collagen and elastic fibres were arranged more uniformly in the dermis and there were numerous fibroblasts, hair follicles, and small vessels. Ultrastructural analysis showed keratinocytes without degenerative changes and the proliferation of lymphatic and dendritic cells in the skin. The results indicate that thymus extracts can have beneficial effects on skin aging, which is often accompanied by hormonal perturbances. [ABSTRACT FROM AUTHOR]

Background Because methamphetamine (METH) pharmacokinetics after single iv doses show significant differences between male and female rats, we hypothesized that pharmacokinetic differences in METH disposition could be a contributing factor to the patterns of METH self-administration behaviors in rats. Methods For the studies, we used a passive (non-contingent) METH dosing schedule consisting of 27 METH iv bolus injections (0.048 mg/kg) over 2 h derived from a previous active (contingent) METH self-administration behavioral study in male rats. After METH dosing of male and female Sprague-Dawley rats ( n = 5/group), METH and amphetamine serum concentrations were determined by LC–MS/MS. Pharmacokinetic analysis, including predictive mathematical simulations of the data, was then conducted. Results Male and female rats achieved relatively stable METH serum concentrations within 20 min, which remained constant from 20 to 120 min. While not statistically different, METH clearance and volume of distribution values for females were 25% and 33% lower (respectively) than males. Linear regression analysis of predicted METH concentrations from pharmacokinetic simulations versus observed concentrations showed a substantially better correlation with male data than female data ( r 2 = 0.71 vs. 0.56; slope = 0.95 vs. 0.45, respectively). At 120 min, the time of predicted peak METH serum concentrations, female values were 42% higher than expected, while male values were within 3%. Conclusions Unlike METH male pharmacokinetic data, the female data was less predictable during multiple METH administrations and produced overall higher than expected METH concentrations. These findings demonstrate that METH pharmacokinetics could contribute to differences in METH self-administration behaviors in rats. [ABSTRACT FROM AUTHOR]

Transfer from the breeding facility to a research facility is a stressful event for laboratory animals. Heat stress has been reported to constitute one of the major concerns during transport of animals. This study measured ambient and body temperature, corticosterone and glucose levels, body weight, behavior and water and food intake before, during and after transfer in Wistar rats. Decreased body weight, water and food intake were observed on the day of transfer in rats. Environmental temperature strongly affected body temperature of rats and needs to be controlled. Male rats need to habituate for at least one week, females for two weeks after transfer. [ABSTRACT FROM AUTHOR]

The adult central nervous system is capable of significant reorganization and adaptation following neurotrauma. After a thoracic contusive spinal cord injury (SCI) neuropathways that innervate the cord below the epicenter of injury are damaged, with minimal prospects for functional recovery. In contrast, pathways above the site of injury remain intact and may undergo adaptive changes in response to injury. We used cortical somatosensory evoked potentials (SSEPs) to evaluate changes in intact forelimb pathways. Rats received a midline contusion SCI, unilateral contusion SCI, or laminectomy with no contusion at the T8 level and were monitored for 28 days post-injury. In the midline injury group, SSEPs recorded from the contralateral forelimb region of the primary somatosensory cortex were 59.7% (CI 34.7%, 84.8%; c2 = 21.9; dof = 1; p = 2.9 ×10-6) greater than the laminectomy group; SSEPs from the ipsilateral somatosensory cortex were 47.6% (CI 18.3%, 77%; c2 = 10.1; dof = 1; p = 0.001) greater. Activation of the ipsilateral somatosensory cortex was further supported by BOLD-fMRI, which showed increased oxygenation at the ipsilateral hemisphere at day seven post-injury. In the unilateral injury group, ipsilesional side was compared to the contralesional side. SSEPs on day 14 (148%; CI 111%, 185%) and day 21 (137%; CI 110%, 163%) for ipsilesional forelimb stimulation were significantly increased over baseline (100%). SSEPs recorded from the hindlimb sensory cortex upon ipsilesional stimulation were 33.9% (CI 14.3%, 53.4%; c2 = 11.6; dof = 1; p = 0.0007) greater than contralesional stimulation. Therefore, these results demonstrate the ability of SSEPs to detect significant enhancements in the activation of forelimb sensory pathways following both midline and unilateral contusive SCI at T8. Reorganization of forelimb pathways may occur after thoracic SCI, which SSEPs can monitor to aid the development of future therapies. [ABSTRACT FROM AUTHOR]

In two experiments with rats, we analyzed the effect of experiencing extinction in one task on the context specificity of a new association learned within a different task. Rats were trained to run in a runway for water in Task 1, and received taste aversion conditioning in Task 2 (the tasks were reversed in Exp. 2). Half of the rats received conditioning and extinction of Task 1 in Context A, whereas the other half received no extinction. Then all animals received training in the alternate task in Context B, prior to testing in Context C. When they were tested in Context C, Task 2 performance was attenuated if Task 1 had been extinguished prior to Task 2. These results are similar to those we have reported in humans, and consistent with the idea that extinction prompts attention to contexts, regardless of whether or not the contexts were involved in extinction. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the influence of trivalent chromium ions (Cr3+) supplementation on antioxidant status and immune defense of rats. During the 30 days of the experiment, the male rats (n = 10 per group) were supplemented with CrCl3, dissolved in distilled drinking water in doses of 0, 70, or 140 µg Cr3+/dm³. Next, the contents of hydroperoxides of lipids (HPL) and thiobarbituric acid reactive substances (TBARS) in plasma were determined, as well as the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and reduced glutathione (GSH) in erythrocytes. Lysozymic and bactericidal activities of blood serum were also determined. Results of the experiment indicated that 140 µg Cr3+/dm3³ increased HPL concentration by 22.1%, while the dose of 70 µg Cr3+/dm³ decreased concentration of TBARS by 20.3% (P ≤ 0.05) in comparison with the control. Activity of SOD in rats supplied with both doses of Cr3+ significantly decreased, whereas activity of CAT, GPx, and GR significantly increased, similar to lysozymic and bactericidal activity. In general, the obtained results showed that a diet with chromium supplementation can strengthen the main mechanisms of lipid peroxidation defense by stimulation of enzyme activity of the antioxidant system and natural resistance factors. [ABSTRACT FROM AUTHOR]

Objective and design: This study is aimed at exploring the role of neurokinin-1 receptor (NK-1R) in the development of allergic rhinitis (AR) in rats. Methods: Sprague-Dawley rats were sensitized and challenged with ovalbumin to induce AR. The rats were treated intranasally with saline, control, or NK-1R-specific small interfering RNA (siRNA) before and during the challenge period. The numbers of sneezes and nose rubs and amount of nasal secretion in individual rats were measured. The levels of NK-1R expression in the nasal mucosal tissues after the last challenge were determined. The numbers of eosinophils in the collected nasal lavage fluid and the levels of serum interleukin (IL)-5 in individual rats were determined. Results: The levels of NK-1R expression in the nasal mucosal tissues of the AR rats that had been treated with saline or control siRNA were significantly higher than those in the healthy controls and the rats treated with NK-1R-specific siRNA, demonstrating NK-1R silencing. Furthermore, knockdown of NK-1R expression significantly reduced the amounts of sneezing, nose rubbing, and nasal secretions in AR rats. Knockdown of NK-1R expression also significantly eliminated eosinophil infiltration in the nasal tissues and reduced the levels of serum IL-5 in rats. Conclusions: Knockdown of NK-1R expression decreased allergic inflammation in nasal mucosal tissues and alleviated the allergic rhinitis symptoms, suggesting that NK-1R may be a critical mediator of the development of AR. [ABSTRACT FROM AUTHOR]

Abstract: Although increasing consumption of sugar drinks is recognized as a significant public health concern, little is known about (a) the cognitive effects resulting from sucrose consumption; and (b) whether the long-term effects of sucrose consumption are more pronounced for adolescents. This experiment directly compared performance on a task of spatial learning and memory (the Morris Water Maze) and sensitivity to outcome devaluation following 28days of 2-h/day access to a 10% sucrose solution in adolescent and young-adult Wistar rats. Sucrose groups developed elevated fasting blood glucose levels after the diet intervention, despite drawing <15% of calories from sucrose and gaining no more weight than controls. In subsequent behavioral testing, sucrose groups were impaired on the Morris Water Maze, with some residual deficits in spatial memory observed more than 6weeks after the end of sucrose exposure. Further, results from outcome devaluation testing indicated that in the older cohort of rats, those fed sucrose showed reduced sensitivity to devaluation of the outcome, suggestive of differences in instrumental learning following sucrose exposure. Data provide strong evidence that sucrose consumption can induce deficits in spatial cognition and reward-oriented behavior at levels that resemble patterns of sugar drink consumption in young people, and which can remain long after exposure. [Copyright &y& Elsevier]

Abstract: Conflicting results have been obtained by several groups when studying the effects of streptozotocin (STZ)–treated rats in the elevated plus-maze (EPM). Since thirst is a prominent feature in STZ-induced diabetic-like condition, we studied whether the walls of the closed arms of the EPM, by limiting the search for water in the environment, may contribute to the observed differential behavioral outcomes. The aim of this study was to ascertain whether visual barriers within the EPM have an influence on the behavior of STZ-treated rats in this test of anxiety. A striking similarity between STZ-treated (50mg/kg, i.p., in two consecutive days) and water deprived rats (72h) was found in exploratory behavior in the EPM, showing an anxiolytic-like profile. However the anxiolytic response of STZ-treated rats exposed to the EPM shifts into an anxiogenic profile when they are subsequently tested in the open-field test, which unlike the EPM is devoid of visual barriers. Likewise, water deprived rats (72h) also showed an anxiogenic profile when they were exposed to the open-field test. Our results indicate that experimental outcomes based on EPM observations can be misleading when studying physiological or pathological conditions, e.g. diabetes, in which thirst may increase exploratory behavior. [Copyright &y& Elsevier]

Background: This study aimed at determining the effects of administration of mature green fruits of Musa paradisiaca on the semen quality of adult male Wistar rats. Materials and Methods: The animals used for the study were grouped into three: the control group, given 2 ml of double distilled water, a low dose group given 500 mg/kg/day and a high dose group given 1000 mg/kg/day of the plantain fruits, which was made into f lour, and dissolved in 2 ml of double distilled water for easy oral administration. Results: Significant increment in the semen parameters was noticed in animals that received a lower dose of the plantain f lour, but those animals who received the high dose had marked and very significant reduction in sperm cell concentration and percentage of morphologically normal spermatozoa. Conclusion: Musa paradisiaca should be consumed in moderate quantities in order to derive its beneficial effects of enhancing male reproductive functions. [ABSTRACT FROM AUTHOR]

We studied the effects of NMDA receptor antagonist MK-801 on the storage and reconsolidation of spatial memory in Morris water maze in adult rats. MK-801 (50 μg/kg) administered 24 h after the completion of training was shown to improve the resistance of spatial memory to spontaneous extinction, while reminder against the background of MK-801 suppresses its ameliorating effect on memory storage. The detected behavioral effects of MK-801 persisted over 60 days after administration and can be associated with its influence on coupled neurogenesis/apoptosis processes induced during memory trace formation in adult animals. [ABSTRACT FROM AUTHOR]

Abstract: Perfluorohexanesulfonate (PFHxS) has been found in biological samples from wildlife and humans. The human geometric mean serum PFHxS elimination half-life has been estimated to be 2665days. A series of studies was undertaken to establish pharmacokinetic parameters for PFHxS in rats, mice, and monkeys after single administration with pharmacokinetic parameters determined by WinNonlin® software. Rats and mice appeared to be more effective at eliminating PFHxS than monkeys. With the exception of female rats, which had serum PFHxS elimination half-life of approximately 2 days, the serum elimination half-lives in the rodent species and monkeys approximated 1month and 4months, respectively, when followed over extended time periods (10–24weeks). Collectively, these studies provide valuable insight for human health risk assessment regarding the potential for accumulation of PFHxS in humans. [Copyright &y& Elsevier]

Sex hormone fluctuations in females are involved in some behavioral states such as mood, anxiety, aggression and stress response, due to functional changes in the central nervous system (CNS) activity induced by the cyclic sex hormone fluctuation. This review includes three sections. 1.- A description of the three major hormone fluctuations in the estrous cycle: estrogens (E2), progesterone (P4) and prolactine (PRL). E2 achieves the maximum circulation levels during P. E2 is mainly excitatory and has been considered to have an antidepressive action. The highest plasma levels of P4 and its metabolite allopregnenolone (ALLO) occur in P. Ovulation takes place in the night of P, and the resulting corpora lutea produces a secondary increase in P4 (and ALLO) on D. The P4 peak level occurring in D1 and in the evening of P was shown to exert benzodiazepine-like effects, including sedation. It has been proposed that ALLO, rather than P4 is the one acting on GABA systems. Circulating levels of ALLO parallel those of P4 across the estrous cycle and is known to have anxiolytic properties. PRL is produced mainly in the adeno hypophysis, though synthesis in other sites of the brain also occurs. Its regulation is mostly inhibitory and is exerted by dopamine (DA) released in the hypothalamus. A surge in PRL secretion occurs during P. PRL would be a modulator of the HPA-axis, and is considered as a stress hormone. 2.- Some behavioral and neural changes occur at each stage of the cycle. Lower anxiety level in P females was described. This has been correlated with increased circulating levels of endogenous ALLO in P. PRL is another hormone that may cause the lower scores of anxiety observed at P, since the peak of plasma PRL is observed at this stage. A novel peptide, the Prolactin Releasing Peptide (PrRP), which is sensitive to E2 fluctuation, has also been linked to the lower activity of the HPA axis. Stress-induced activation of PrRP neurons is significantly decreased in E compared with P and D, suggesting that E2 suppresses the activation of PrRP neurons. The late luteal phase (D) correlates with the premenstrual phase in women, commonly associated with psychological disturbances, including mood disorders and increased aggression. Consistently, increased levels of anxiety and aggression have been detected in rats during D. 3.- Findings about cyclic hormone influences on the CNS neurotransmitters and on the stress mediator, prolactine-releasing peptide (PrRP) were described. GABA is the main inhibitory system in the brain. Estrous-cycle-dependent increases in δ-GABAA receptors were reported; this subtype underlying a tonic inhibitory current, is the most sensitive target of P4 and ALLO. E2 causes a reduction in GABAergic inhibition, leading to an increase in the excitatory tone. It also acts on hippocampus causing a transient lowering of GABA synthesis in the interneuron. These findings suggest an excitatory role for E2 through inhibition of the GABA system. The serotonin system, involved in behavioral responses such as stress, anxiety and depression, also exhibits variations along the estrous cycle, in part dependant of GABA-receptor changes. Gender differences were described for DA func tion in the brain, due to E2 and P4 modulation. DA release and reuptake fluctuate with changes in circulating steroid levels. E2 enhances DA release and DA-mediated behaviors, such as general activity stimulation, food seeking behavior and sexual motivation. PrRP is produced in hypothalamic and extra hypothalamic structures. It has been propos ed as a mediator of stress responses. Though gender differences have been shown, distribution of PrRP does not change during the estrous cycle. We hope this review may contribute to understand the mechanism of female behavioral variations and their pharmacological and diagnostic implications. [ABSTRACT FROM AUTHOR]

We analyzed the morphological changes in rat aortas during nicotine administration in order to investigate the involvement of vascular smooth muscle cells (VSMCs) in the regulation of vascular wall homeostasis. We also considered the possibility of restoring VSMC changes using melatonin as an antioxidant. We studied 4 groups of animals over 56 days. Three groups of rats were used as controls (the first without treatment, the second with melatonin alone and the third with nicotine alone). The last group of rats was orally treated with nicotine for the first 28 days and with melatonin for the last 28 days. Morphological changes in vessels were evaluated by histological procedures and immunohistochemical analysis using thrombospondin-1 (TSP-1), transforming growth factor-β1 (TGF-β1), plasminogen activator inhibitor-1 (PAI-1) and CD31 antibodies. We demonstrated that TSP-1, TGF-β1 and PAI-1 increased after nicotine administration. We believe that TSP-1 is responsible for neointima formation and that it is able to influence TGF-β1 and PAI-1 expression. Histological and immunohistochemical analysis by CD31 antibody showed that only a few endothelial cells were present in the aorta after nicotine administration compared to controls and rats treated with melatonin after nicotine administration. Moreover, histological analysis showed that neointima formation was present after nicotine treatment. Furthermore, melatonin inhibited neointima formation increasing TSP-1 expression. The ability of melatonin to inhibit neointima formation suggests that it could be a useful treatment for homeostasis of vascular walls. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Abstract: This study aimed to determine the effect of dietary actinidin (provided as Hayward kiwifruit) on the gastric and small intestine digestion of six food protein sources in rats. For each protein source, two semi-synthetic test diets were formulated containing either freeze-dried Hayward kiwifruit (actinidin present) or freeze-dried Hort16A kiwifruit (actinidin absent). Actinidin activity is extremely low in Hort16A kiwifruit. Titanium dioxide was also included as an indigestible marker. Rats were fed freshly-prepared diets, euthanised and the gastric and ileal contents collected. The chyme and digesta samples were subjected to electrophoresis (SDS–PAGE), densitometry and titanium analysis and the degradability of individual proteins calculated. Dietary actinidin had no (p >0.05) effect on the gastric degradability of zein and whey protein isolate but increased gastric degradability of beef muscle protein, gelatin, soy protein isolate and gluten by 40%, 60%, 27% and 29% units, respectively. Dietary actinidin had little or no effect on ileal protein degradability. Overall, dietary actinidin enhanced the gastric digestion of some food proteins. [Copyright &y& Elsevier]

The ability of 2 combinations of oximes (HI-6 + trimedoxime and HI-6 + K203) to reactivate VX-inhibited acetylcholinesterase and reduce acute toxicity of VX was compared with the reactivating and therapeutic efficacy of antidotal treatment involving a single oxime (HI-6, trimedoxime, K203) in rats and mice. Our results showed that the reactivating efficacy of both combinations of oximes studied in rats is significantly higher than the reactivating efficacy of all individual oximes in diaphragm and roughly corresponds to the most effective individual oxime in blood and brain. Both combinations of oximes were found to be more effective in the reduction of acute lethal toxicity of VX in mice than the antidotal treatment involving the most efficacious individual oxime although the difference is not significant. Based on the obtained data, we can conclude that the antidotal treatment involving the chosen combinations of oximes brings benefit for the reactivation of VX-inhibited acetylcholinesterase in rats and for the antidotal treatment of VX-induced acute poisoning in mice. [ABSTRACT FROM PUBLISHER]

The influence of the cloned-cattle meat diets upon reproduction in mammals was rarely studied. This study was performed to analyze the effects of the diets containing cloned-cattle (Korean native beef, Hanwoo) meat on the reproductive physiology in rats. The male and female rats were fed with the diets containing 5% or 10% of normal- (N-5 or N-10) or cloned- (C-5 or C-10) cattle meat during test periods. The rats fed with commercial pellets were used as control. Lower food consumption in normaland cloned-cattle meat diet groups is detected in both male and female rats compared with that of control ( P,0.05, 0.01 and 0.001). No signs of cloned-cattle meat diets on male reproductive parameters are found in all groups, except for lower sperm deformity in C-5 group ( P,0.05) and higher testosterone concentration in C-10 group ( P,0.05), respectively. There are no significant test substance-related differences of Caesarean section and delivery in dams and external examination and physiological development test in neonate compared with control and normal meat groups. Based on these results, it can be postulated that there are no obvious negative effects on the reproductive physiology in rats fed with cloned-cattle meat diets compared to their comparators. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the protective effect of Withania somnifera, an indigenous medicinal herb used in ayurvedic traditional systems for more than 3000 years in India, on gentamicin (GEN)-induced nephrotoxicity. The root extract of three different doses of W. somnifera (viz., 250, 500, and 750 mg/kg) was administered orally to rats for 14 days before GEN treatment and thereafter concurrently with GEN (100 mg/kg) for 8 days. Nephrotoxicity was evident in GEN-treated rats by significant increase in kidney weight, urea, creatinine, urinary protein, and glucose, and significant reduction in body weights and potassium, which was histopathologically confirmed by tubular necrosis. In contrast W. somnifera (500 mg/kg) significantly reversed these changes as evidenced microscopically when compared to other two doses of W. somnifera (250 and 750 mg/kg), and there were no significant changes in the levels of sodium in the experimental animals compared to control. Thus, our results suggested the nephroprotective effect of Withania somnifera, which could be by enhancing antioxidant activity with natural antioxidants and scavenging the free radicals. [ABSTRACT FROM AUTHOR]

Human interaction and physical environmental factors are part of the stimuli presented to laboratory animals everyday, influencing their behaviour and physiology and contributing to their welfare. Certain environmental conditions and routine procedures in the animal facility might induce stress responses and when the animal is unable to maintain its homeostasis in the presence of a particular stressor, the animal's wellbeing is threatened. This review article summarizes several published studies on the impact of environmental factors such as light, noise, cage cleaning and in-house transport on welfare and stress of laboratory rats. The behaviour and physiological responses of laboratory rats to different environmental housing conditions and routine procedures are reviewed. Recommendations on the welfare of laboratory rats and refinements in experimental design are discussed and how these can influence and improve the quality of scientific data. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to determine the effects of 14 days of microgravity on specific rat fast-twitch muscles, and to compare these data with previous data from rat fast-twitch muscles exposed to microgravity for 10 days (Kraemer et al. 2000). Hindlimb muscles containing predominately fast fibers [extensor digitorum longus (EDL), superficial "white" (GSW) and deep "red" (GDR) gastrocnemius] and the diaphragm (DIA) were removed from flight and ground-based control animals and analyzed for: muscle mass, fiber type distribution, cross-sectional area, and myosin heavy chain (MHC) isoform content. Gravitational unloading for 14 days caused significant decreases in muscle mass (8-9%) and cross-sectional area of almost all fiber types (10-35%) from both EDL and gastrocnemius muscles. However, microgravity had little effect on fiber type composition in these muscles with significant changes occurring only in the EDL type IID fiber population (9.5% decrease). Similarly, relative MHC isoform content was only slightly altered by exposure to microgravity (increased content of MHCIIa in flight EDL). No changes in area, fiber type percentages, or MHC isoform content were detected in the DIA following the 14-day spaceflight. Similar to data gathered following a 10-day spaceflight (Kraemer et al. 2000), the 14-day flight did not appear to cause significant slow-to-fast (I --> IIA) or fast-to-faster (IIA --> IID --> IIB) transformations in hindlimb muscles containing predominantly fast-twitch fibers. However, the longer period of gravitational unloading did result in additional loss in muscle fiber cross-sectional area with involvement of more major fiber types. [ABSTRACT FROM AUTHOR]

Objectives: In the present study, central effects of physostigmine and atropine have investigated in the formalin-induced pain in rats. Materials and Methods: In conscious rats implanted with an intracerebroventricular (i.c.v.) cannula, the effects of i.c.v. injection of physostigmine and atropine were investigated on the formalin test in the rat. Formalin test was induced by subcutaneous (s.c.) injection of formalin (50 μl, 1%) in ventral surface of left hind paw, and durations of licking and biting of the injected paw were measured in 5-min blocks for 1 h. Results: Formalin produced a biphasic response (first phase: 0-5 and second phase: 15-40 min) in durations of licking and biting of the injected paw. Physostigmine at doses of 2.5, 5 and 10 ug significantly (P < 0.05) attenuated both first and second phases of pain response. Atropine (5 and 10 ug), used alone, produced no significant effect on pain, but pretreatment with atropine (10 ug) significantly (P < 0.05) blocked antinociception induced by physostigmine (5 ug). Conclusion: These results indicate that i.c.v. physostigmine can affect both neurogenic and inflammatory phases of formalin-induced pain through a mechanism in which the muscarinic cholinergic receptors are involved. [ABSTRACT FROM AUTHOR]