A study on the effects of vitamin D supplementation on hematological parameters and serum 25-hydroxy vitamin D in healthy dogs

BACKGROUND

Limited studies are available on vitamin D supplementation in dogs. This study evaluates the effect of a commercial vitamin D3 supplement on serum 25-hydroxy vitamin D as well as selected biochemical and hematological parameters in healthy dogs. Eight intact male adult dogs with a mean body weight of 20 kg from mixed breeds were included in the study. After adaptation period, dogs received vitamin D3 supplement at the dose of 50 IU/kg body weight per day. Blood samples were collected on days 0, 14, 28 and 42 of supplementation. Food was used for analysis of vitamin D3 content.

RESULTS

Significant increase in serum level of 25-hydroxy vitamin D3 was detected since day 14 of supplementation. Changes in serum 25-hydroxy vitamin D3 concentration during time showed an upward significance (p < 0.05). Vitamin D3 content of the food was 2900 IU/kg dry matter. Changes in serum phosphorus levels were upward significant. No dog showed calcium or phosphorus levels above the highest reference level. Liver and kidney parameters remained in the reference range during the experiment. A gradual significant increase was observed in hemoglobin and hematocrit which was started from day 14. Vitamin D3 supplementation had no significant effect on neutrophils, monocytes and lymphocytes percent during the study.

CONCLUSIONS

Vitamin D3 supplementation at 50 IU/kg BW daily, increases serum levels of 25-hydroxy vitamin D in healthy dogs fed with a diet containing proper amount of this vitamin. It also increases hemoglobin and hematocrit levels in a time dependent manner without inducing adverse effects.

The neuroprotective effects of Chalcones from Ashitaba on cuprizone-induced demyelination via modulation of brain-derived neurotrophic factor and tumor necrosis factor α

INTRODUCTION

Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system. However, the limitations of available therapeutic strategies are frustrating, both in terms of their low efficacy and multiple side effects. Previous studies showed that natural compounds such as Chalcones possess neuroprotective effects on neurodegenerative disorders. However, few studies have so far been published on the potential effects of Chalcones on treating demyelinating disease. The present study was designed to investigate the effects of Chalcones from Ashitaba (ChA) on cuprizone-induced noxious changes in the C57BL6 mice model of MS.

METHODS

The mice received normal diets (Control group: CNT), or Cuprizone-supplemented diets either without ChA (Cuprizone group: CPZ) or with low or high (300, 600 mg/kg/day) doses of ChA (ChA-treated groups: CPZ+ChA300/600). Brain-derived neurotrophic factor (BDNF) and tumor necrosis factor alpha (TNFα) levels, demyelination scores in the corpus callosum (CC), and cognitive impairment were evaluated using the enzyme-linked immunosorbent assay, histological, and Y-maze tests, respectively.

RESULTS

The findings showed that ChA Co-treatment significantly reduced the extent of demyelination in the CC and the serum and brain levels of TNFα in the ChA-treated groups compared to the CPZ group. Besides, treatment with a higher dose of ChA significantly improved the behavioral responses and BDNF levels in the serum and brain of the CPZ+ChA600 group when compared with the CPZ group.

CONCLUSION

The present study provided evidence for the neuroprotective effects of ChA on cuprizone-induced demyelination and behavioral dysfunction in C57BL/6 mice, possibly by modulating TNFα secretion and BDNF expression.

The passive avoidance task ameliorate the toxic effects of bisphenol A on dopamine D1 receptor density in hippocampus, amygdala, and cerebellum of male rats

INTRODUCTION

Dopamine D1 receptor seems to play a role in mediating plasticity. Therefore, the present study aimed to investigate the effects of passive avoidance tasks postexposed to BPA on dopamine D1 receptor density in the hippocampus, amygdala, and cerebellum of male rats.

METHODS

Thirty-five male Sprague-Dawley rats weighing 220.300 g, in standard light-dark 12 h light/12 h dark were used in the present study; water and food were ad libitum. Animals were divided into six groups. Administration of BPA 5 and 50 mg/kg/day were gavaged for 15 days. Learning and memory assessment were done by a shuttle box after 15 days of BPA administration. The density of the dopamine D1 receptor was investigated using an immunohistochemistry (IH) procedure. For determining the color difference in IH sections, Image Analyzer software was used. The data were analyzed by one-way ANOVA followed by Tukey's as a post hoc test.

RESULTS

The data showed that BPA in both doses could significantly increase the density of dopamine D1 receptors in the hippocampus, amygdala, and cerebellum of male rats; learning in rats postexposed to BPA improves dopamine D1 receptor density significantly in three brain structures.

DISCUSSION

According to the results, passive avoidance learning and memory can improve the density of dopamine D1 receptors in the hippocampus, amygdala, and cerebellum of male rats.

Effect of insulin and cinnamon extract on spatial memory and gene expression of GLUT1, 3, and 4 in streptozotocin-induced Alzheimer's model in rats

Objectives

Since diminished hippocampal insulin signaling leads to memory impairment, insulin resistance and hyperinsulinemia are probably associated with Alzheimer's disease (AD). The effect of intracerebroventricular injection of insulin (Ins) and oral cinnamon extract (Cinn) on glucose transporter (GLUT) 1, 3, and 4 gene expressions in the hippocampus and spatial memory in a streptozotocin (STZ)-induced AD rat model was investigated in the present study.

Materials and Methods

Fifty-six adult male Sprague-Dawley rats (280±20 g) were allocated into eight distinct groups (n=7) of five controls (negative, Ins, Cinn, Ins+Cinn, and STZs) and three treatments (STZ+ Ins, STZ+ Cinn, and STZ+ Ins + Cinn). Single dose STZ 4 mg/kg (icv), Cinn at a dose of 200 mg/ kg (orally for 14 days), and Ins 5 mIU/5 µl (icv for 14 days) were administered in the defined groups. To evaluate the behavioral performance the animals were subjected to the Morris Water Maze (MWM) test. The level of mRNA expression of GLUTs was evaluated by the Real time-PCR method.

Results

In the STZ+Cinn+Ins group, the performance of animals in the MWM test was improved and the over-expression of GLUTs genes in hippocampal tissue was observed. The results of Ins and Cinn synergist treatment groups revealed improvement in the behavioral tests and gene expression compared with Ins and Cinn treatment groups (P<0.001).

Conclusion

Administration of Ins and Cinn has a positive effect on the function of the AD rat model. To clarify the effect of Ins and Cinn extract on the GLUTs investigated in this study, it is essential to evaluate their influence on the protein levels.

Possible therapeutic effect of royal jelly on endometriotic lesion size, pain sensitivity, and neurotrophic factors in a rat model of endometriosis

Endometriosis is the abnormal growth of endometrial tissue. The goals of the study are: (1) Is any correlation between endometriosis pain and neurotrophins in the serum, dorsal root ganglion (DRG), and peritoneal fluid (PF) in rat models of experimental endometriosis?, (2) Possible therapeutic effects of royal jelly (RJ) on pain scores, size of endometriotic lesion, and neurotrophic factors. Forty-eight Sprague Dawley female rats weighing 205.023 ± 21.54 g were maintained in a standard condition. The rats were randomly divided into one of the six groups: Control (no intervention), Sham-1 (remove of uterine horn), RJ (administration of 200 mg/kg/day RJ for 21 days), Endometriosis (induction of endometriosis), Treatment (induction of endometriosis+administration of 200 mg/kg/day RJ for 21 days), and Sham-2 (induction of endometriosis+administration of water). Formalin test performed for pain evaluation. The levels of Brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), substance P, and calcitonin gene-related peptide (CGRP) were measured by enzyme-linked immunosorbent assay. The mean pain scores in all three phases of the formalin test were significantly increased by endometriosis induction (p < 0.05). The concentrations of BDNF, NGF, and CGRP in DRG of the endometriosis group were significantly higher than these factors in the Control, Sham-1, and RJ groups (p < 0.05). RJ could significantly (p < 0.001) decrease the mean lesion size and the mean pain score in the late phase (p < 0.05). The present results determine that endometriosis pain may be related to nervous system neurotrophic factors. Treatment with RJ could decrease the size of endometriosis lesions as well as pain scores. The findings may shed light on other complementary and alternative remedies for endometriosis.

Assessing Pain Behavioral Responses and Neurotrophic Factors in the Dorsal Root Ganglion, Serum and Peritoneal Fluid in Rat Models of Endometriosis

Objective: Pain is the most frequently reported symptom involving in endometriosis. The alterations of neurotrophic factors and certain neuropeptides in the dorsal root ganglion (DRG), as well as serum and peritoneal fluid (PF), were evaluated in rat models of endometriosis.

Materials and methods: Twenty-four Sprague Dawley female rats were selected and maintained in a standard condition with 12 hours’ dark-light cycles. All the rats were randomly assigned to 3 groups: Control (intact rats); Sham (the operation was conducted without endometriosis induction); and Endometriosis (endometriosis induction was performed). The formalin test was performed for all groups on the first and the 21^st day of the study. The assessments of Brain-Derived Neurotrophic Factor (BDNF), Nerve Growth Factor (NGF), Calcitonin Gene-Related Peptide (CGRP), and Substance P levels were carried out by enzyme-linked immunosorbent assay (Elisa). The data were analyzed by One-Way ANOVA. The Tukey’s test was used as post-hoc.

Results: Endometriosis induction significantly increased the mean pain scores in the endometriosis group in all three phases of the formalin test. The concentrations of DRG-CGRP (p=0.035), BDNF (p<0.001), and NGF (p=0.006) in the endometriosis group were significantly higher than that of the other groups while serum-BDNF (p<0.001), Substance P (p=0.009), and NGF (p=0.015) were significantly lower in endometriosis group compared to other groups. The concentrations of PF-BDNF (p=0.025) and Substance P (p=0.009) were significantly lower than those of other groups.

Conclusion: The present results delineate that endometriosis induction could lead to hyperalgesia. This may be related to the significant increases in the BDNF, NGF, and CGRP in DRG.

Effects of Pretreatment With Ginseng Extract on Dopamine D2 Receptor Analgesia

Introduction:

The ginseng extract is an herb that has been used for many purposes such as analgesic effect. Dopamine D2 receptors are involved in the regulation of pain in humans. Therefore, the present investigation aims to study how pretreatment with aqueous-alcoholic extract of ginseng can affect dopamine D2 receptors’ pain sensitivity.

Methods:

We used 45 adult male rats weighing 250±20 for this study. Animals were maintained in a standard condition at a temperature of 21°C–24°C. The experimental groups were as follows: 1. Sham 1 (intraperitoneal [IP] injection of normal saline); 2. Sham 2 (intracerebroventricular [ICV] injection of artificial cerebrospinal fluid [ACSF]); 3. Experimental 1 (IP injection of ginseng extract); 4 and 5. Experimental groups 2 and 3 (IP injection of ginseng extract + bromocriptine 10 and 30 μg/rat by ICV injection); 6 and 7) experimental groups 4 and 5 (IP injection of ginseng extract + chlorpromazine 20 and 40 μg/rat by ICV injection). Ginseng extract 100 mg/kg/d was used for 7 days. Pain sensitivity test was done in all groups with the formalin test. Lateral ventricles of the rats were cannulated unilaterally by the stereotaxic procedure.

Results:

Our data showed that ginseng (100 mg/kg/d) significantly (P<0.05) decreased pain sensitivity compared to the sham 1 group. Bromocriptine in two doses significantly decreased pain sensitivity compared to the sham 2 group. Chlorpromazine in high doses significantly increased pain sensitivity compared to the sham 2 group.

Conclusion:

The present results indicate that ginseng can modulate the D2 receptor of the dopamine system in the control of pain sensitivity in the formalin test. Because bromocriptine and ginseng have similar effects, it seems that they had synergistic effects.

Zataria multiflora could improve hippocampal tau protein and TNFα levels and cognitive behavior defects in a rat model of Alzheimer's disease

OBJECTIVE

Zataria multiflora (ZM) is a plant with ethnopharmacological value which was recently tested to reduce symptoms of Alzheimer's disease (AD). The aim of the present study was to determine the effect of ZM essential oil on spatial cognitive and noncognitive behavior, as well as hippocampal tau protein and tumor necrosis factor alpha (TNFα) concentrations in rats with AD.

MATERIALS AND METHODS

Thirty-five adult male Sprague Dawley rats (300±30 g) were randomly divided into 5 groups: control (intact rats); sham (received intracerebroventricular (ICV) microinjection of normal saline); AD control (rats with AD that did not receive any treatment); vehicle control (rats with AD that orally received tween-80, 5% (ZM essential oil vehicle) for 20 days) and experimental (rats with AD that orally received ZM essential oil 100 µl/kg/day for 20 days). AD was induced by bidirectional microinjection of β amyloid 1-42 (10 µg/2µl). Tau protein and TNFα concentrations were measured by ELISA methods. Spatial cognitive and noncognitive behavior were determined by Morris water maze (MWM) test.

RESULTS

ZM essential oil significantly improved latency time, time spent in the target quarter and cognitive behavior of rats with AD compared to control and sham groups (p<0.05). Hippocampal tau protein and TNFα concentrations were significantly higher in both AD control and vehicle groups compared to control and sham groups respectively (p<0.01 and p<0.001), administration of ZM essential oil reduced these parameters as compared to AD control and vehicle groups respectively (p<0.01 and p<0.001).

CONCLUSION

ZM essential oil improves spatial learning and memory of rats with AD as assessed by MWM test. These effects are associated with decreased concentrations of hippocampal tau protein and TNFα.

Neuroprotective Effect of Zataria Multiflora Essential Oil on Rats With Alzheimer Disease: A Mechanistic Study

INTRODUCTION

Finding herbs with promising effects to prevent or postpone Alzheimer Disease (AD) is highly demanded. The present study aimed at clarifying plausible effects and related mechanism(s) of Zataria Multiflora Essential Oil (ZMEO) against memory impairment in a rat model of the AD.

METHODS

Forty male adult rats were categorized into four groups and treated as follows: 1. The Negative Control (NC): no treatment; 2. Sham control (sham): distilled water by Intracerebroventricular (ICV) injection; 3. The AD control (AD): Aβ 1-42 by ICV injection; and 4. The ZMEO group: Aβ 1-42 by ICV injection and ZMEO at 100 μL/kg/d orally for 20 days.

RESULTS

After Congo red staining of the hippocampus, a relative decrease in amyloid deposits was observed in the ZMEO group. Moreover, rats showed better outcomes in Morris Water Maze (MWM) test, reduced hippocampal acetylcholinesterase (AchE) activity, and higher Brain-Derived Neurotrophic Factor (BDNF) content as compared with the AD group (P<0.05). However, no significant changes in antioxidant status was observed (P>0.05).

CONCLUSION

ZMEO has a protective effect against memory impairment in rats with AD at least partly via reducing hippocampal AchE activity and enhancement of BDNF levels without a change in antioxidant status. These findings can pave the way for future studies on the usefulness of this herb in AD prevention.

Effect of pharmacological doses of niacin on testicular structure and function in normal and diabetic rats

Male diabetic patients may experience adverse changes in testicular functions or structure. Niacin has antidyslipidemic properties in diabetic patients. We aimed to clarify the effect of pharmacological doses of niacin on testicular structure and function of normal and diabetic rats. Sixty adult male rats were treated as follows. Healthy control (HC); diabetic control (DC); NL and NH groups: normal rats that received niacin at 800 and 4,000 mg/kg of diet; DL and DH groups: diabetic rats that received niacin at 800 and 4,000 mg/kg diet for 50 days. In normal rats, obvious increase in serum testosterone especially in NL group associated with improved antioxidant status of testicular tissue was observed. In diabetic rats, niacin resulted in higher testicular weight/body weight and improved some histological parameters without affecting blood glucose, testosterone and sperm count. Testicular MDA content decreased. In conclusion, niacin especially at 800 mg/kg diet improves serum testosterone levels and antioxidant status of testes in normal rats. In diabetic rats, despite positive changes in histological features and antioxidant status of testes reproductive outcome including sperm count or testosterone levels were not improved. This study set the scene for further investigations on the effect of niacin on male reproductive system.

Synergistic effect of spexin and progesterone on pain sensitivity attenuation in ovariectomized rats

Spexin is a central modulator of nociception. The aim of the present study was to investigate the effect of intra-hippocampal CA3 (IHCA3) injection of spexin and spexin-progesterone co-administration on pain sensitivity in ovariectomized rat. Thirty-five adult female rats were divided into five groups. Sham: the animals received injection of 0.5 μL ACSF by IHCA3. Experiments 1 and 2: the animals received injection of 0.5 μL of spexin bilaterally (10 and 30 nmol/rat respectively). Experiments 3 and 4: the animals received injection of 0.5 μL of spexin bilaterally (10 and 30 nmol/rat respectively) + subcutaneous (s.c.) injection of progesterone (5 mg/kg). Ovariectomy was performed in all groups to eliminate the effects of cyclic changes in the female rats. The formalin test (formalin 2.5%) was performed following the administration of spexin and progesterone. Results showed that bilateral injection of spexin in IHCA3 at both concentrations a significant (P < .05) decrease in the pain sensitivity in the two phases of formalin test. Similarly, the bilateral injection of spexin in IHCA3 at both concentrations following the s.c. injection of progesterone significantly (P < .05) decreases pain sensitivity in two phases of the formalin test. This pain attenuation due to the co-administration of spexin and progesterone was more potent than spexin-induced analgesia. According to the present results, spexin has a modulatory effect on pain sensitivity, which becomes more pronounced by progesterone administration.

Boswellic Acid Improves Cognitive Function in a Rat Model Through Its Antioxidant Activity: - Neuroprotective effect of Boswellic acid

Objectives:

Boswellic acid (BA), a compound isolated from the gum-resin of Boswellia carterii, is a pentacyclic terpenoid that is active against many inflammatory diseases, including cancer, arthritis, chronic colitis, ulcerative colitis, Crohn's disease, and memory impairment, but the mechanism is poorly understood. This study investigated the effects of boswellic acid on spatial learning and memory impairment induced by trimethyltin (TMT) in Wistar rats.

Methods:

Forty male Wistar rats were randomly divided into 5 groups: Normal group, TMT-administrated rats (8.0 mg/kg, Intraperitoneally, i.p.) and TMT + BA (40, 80 and 160 mg/kg, i.p.)-administrated rats. BA was used daily for 21 days. To evaluate the cognitive improving of BA, we performed the Morris water maze test. Moreover, to investigate the neuroprotective effect of BA, we determined the acetylcholinesterase (AchE) activity, the malondialdehyde (MDA) level as a marker of lipid peroxidation, and the glutathione (GSH) content in the cerebral cortex.

Results:

Treatment with TMT impaired learning and memory, and treatment with BA at a dose of 160 mg/kg produced a significant improvement in learning and memory abilities in the water maze tasks. Consistent with behavioral data, the activity of AChE was significantly increased in the TMT-injected rats compared to the control group (P < 0.01) whereas all groups treated with BA presented a more significant inhibitory effect against AChE than the TMT-injected animals. In addition, TMT reduced the GSH content and increased the MDA level in the cerebral cortex as compared to the control group) P < 0.01). On the other hand, treatment with BA at 160 mg/kg slightly increased the GSH content and reduced the MDA level in comparison to the TMT-administered group (P < 0.01).

Conclusion:

The above results suggest that the effect of BA in improving the cognitive function may be mediated through its antioxidant activity.

Effect of Extremely Low Frequency Electromagnetic Field and GABAA Receptors on Serum Testosterone Level of Male Rats

BACKGROUND

GABA can influence the steroidogenesis in peripheral and central nervoussystems.

OBJECTIVES

The present study investigates the interactive effect of GABAA receptors and extremely low frequency electromagnetic field on serum testosterone level of male rats.

PATIENTS AND METHODS

Fifty adult male rats were randomly assigned into 10 groups. Groups 2, 4, 6, 8, and 10 were exposed to ELF-EMF for 30 days 8hrs per day; while, the remaining groups (1, 3, 5, 7, and 9) were sham exposed animals. At the end of the experiment, animals in groups 1 and 2 received normal saline; while, animals in groups 3 and 4 were treated with 1 mg/kg of bicuculline methiodide, and for animals of groups 5 and 6,3 mg/kg of bicuculline was injected. Animals of groups 7 and 8 were treated with 0.5 mg/kg of muscimol hydrobromide and rats in groups 9 and 10 received 2 mg/kg muscimol hydrobromide. About forty minutes after the injection, blood samples were collected and serum testosterone level was assayed using RIA.

RESULTS

Administration of muscimol hydrobromide at both doses to sham exposed rats significantly decreased serum testosterone level as compared to sham exposed animals which received saline. Administration of bicuculline methiodide without exposure to ELF-EMF, had no significant effect on testosterone level as compared to group 1. Serum testosterone levels of rats in different groups, exposed to ELF-EMF were statistically the same. Moreover, serum testosterone of exposed and sham exposed rats in each treatment showed no significant difference.

CONCLUSIONS

No interactivity is present in modulatory effects of GABAA receptors and ELF-EMFs on serum testosterone of male rats.

Niacin Ameliorates Lipid Disturbances due to Glucocorticoid Administration in Rats

OBJECTIVES

This study was conducted to evaluate the effects of niacin on glucocorticoid-induced dyslipidemia and fatty liver in rats.

MATERIALS AND METHODS

TWENTY FOUR ADULT MALE RATS WERE DIVIDED RANDOMLY INTO FOUR EQUAL GROUPS: 1- normal saline (control), 2- dexamathasone 0.125 mg/kg/day, i.m., 3- dexamathasone + niacin 200 mg/kg/day, oral gavages, 4- niacin. After 2 weeks, serum total cholesterol, triglycerides, HDL-c, LDL-c and VLDL-c concentrations were assayed and liver sections examined for fatty liver changes. Data were analyzed by ANOVA method and P< 0.05 was considered significant.

RESULTS

Dexamethasone increased all lipid parameters as compared to control (P< 0.05). Lipid parameters in group 3, were lower than group 2 (P< 0.05) except for HDL-c which remained statistically the same. Moderate fatty liver changes were observed in one third of rats in dexamethasone group. Rats in groups 1, 3 and 4 had no sign of fatty changes.

CONCLUSION

Niacin positively affects glucocorticoid-induced dyslipidemia and fatty liver changes in rats.

Modulation of NR1 subunit of N-methyl-D-aspartate receptor by ovariectomy and passive avoidance learning

BACKGROUND

Learning and memory are the most intensively studied subjects in neuroscience. Two sites of mammalian brain which are important in learning and memory are CA1 region of hippocampus and Purkinje cell layer of cerebellum. So, the aim of present investigation was to study of the effect of ovariectomy and passive avoidance learning on NR1 subunit of N-methyl-D-aspartate (NMDA) receptor distribution in CA1 region of hippocampus and Purkinje cell layer of cerebellum.

METHODS

Twenty four Sprague-Dawley rats were used in 4 groups: control-1 (intact without learning), control-2 (intact with learning), ovariectomy without learning, and ovariectomy with learning. Immunohistochemical procedure was used for determination of NR1 subunit of NMDA receptor. A shuttle box apparatus used for passive avoidance learning procedure. The determination of color intensity was cone by Photoshop software.

RESULTS

Immunohistological findings indicated that ovariectomy has a negative effect on density of NR1 subunit of NMDA receptors in two brain regions. Passive avoidance learning significantly increased density of NR1 subunit of NMDA receptors in two brain regions.

CONCLUSION

The results indicated that the sex hormone can modulate function and expression of the NR1 subunit of NMDA receptor in CA1 region of hippocampus and Purkinje cell layer of cerebellum.

Hippocampal GABA(A) Receptor and Pain Sensitivity during Estrous Cycle in the Rat

BACKGROUND

Estradiol and progesterone as well as hippocampal GABA(A) receptors are believed to play a role in the modulation of pain. The aim of present study was to investigate the effect of intrahippocampal injections of GABA(A) receptor agonist (muscimol) and GABA(A) receptor antagonist (picrotoxin) on pain sensitivity during estrous cycle.

METHODS

Pain sensitivity was evaluated in rats by formalin test during all stages of estrous cycle. Animals were divided into five groups including; 1- control (intact animal); 2- sham 1 receiving 0.75 µl artificial cerebrospinal fluids (ACSF); 3- sham 2 receiving 0.75 µl alcoholic ACSF; 4- experimental 1 receiving 250 or 500 µg/rat of muscimol in 0.75 µl vehicle, and 5- experimental 2 receiving 20 or 30 µg/rat picrotoxin in 0.75 µl vehicle. Data were analyzed by Kruskal-Wallis followed by Tucky's test for pairwise comparisons using a P value of ≤0.50 for statistical significance.

RESULTS

Muscimol significantly (P<0.05) decreased pain sensitivity in all stages of estrous cycle, and the analgesic effect was higher during proestrus and estrus stages of estrous cycle than that during metestrus and diestrus stages. Picrotoxin significantly (P<0.05) increased pain sensitivity in all stages of estrous cycle, and such a hyperalgesic effect was lower during proestrus and estrus stages of estrous cycle than that during metestrus and diestrus stages.

CONCLUSION

The findings of the present study indicate that the role of hippocampal GABA(A) receptor in the control of the pain sensitivity can be modulated by variation in gonadal steroids during different stages of the estrous cycle.

Concentration of four heavy metals (cadmium, lead, mercury, and arsenic) in organs of two cyprinid fish (Cyprinus carpio and Capoeta sp.) from the Kor River (Iran)

Concentration of heavy metals in aquatic animals mainly occurs due to industrial contamination. In this study, the concentrations of four heavy metals (cadmium, lead, mercury, and arsenic) in organs of two cyprinid fish and in water collected from three sections of the Kor River, Iran were determined using the inductively coupled plasma method. Pathological and hormonal changes due to metal contamination were also measured. The concentrations of heavy metals in tissue of fish from the middle sampling zone were significantly higher (p < 0.05) than those from the other two sampling zones, whereas no significant differences (p > 0.05) were detected between the two sexes and species. High levels of metals were found in the ovaries and testes; estradiol in females and progesterone and testosterone in males from the middle study site were significantly (p < 0.05) lower than values from the other two sites. Pathological changes in blood cells, liver, and kidneys of fishes were significantly higher in highly polluted areas (middle sampling zone). These results show that industrial activities have polluted the river and that the maximum concentrations of Cd, Pb, and Hg were higher than the permissible levels for human consumption.

CNS alpha 1 receptor in tonic pain during estrous cycle in rats

Estrogen and progesterone are known to affect nociception. The plasma concentrations of these hormones vary during estrous cycle in rodents. The aim of the present study was to investigate the effect of evidence of alpha1 receptor agonist and antagonist on tonic pain in all phases of estrous cycle in female rats. Phenylephrine (alpha1 agonist) and prazosin (alpha1 antagonist) were administered via intracerebroventicular (ICV) injection. Adult female rats weighting 200-220 g were maintained on 12 h light/dark cycle for 10-14 days prior to the experiment. Food and water were made available ad libitum. Formalin test was performed in all phases of estrous cycle. Results showed that phenylephrine caused significant (P<0.05) reduction in pain sensitivity. This reduction was more pronounced during proestrus phase. Prazosin significantly (P<0.05) increased pain sensitivity, particularly during metestrus phase. It is possible that fluctuation in pain sensitivity during estrous cycle is related to the level of sex hormones during estrous cycle.

Evaluation of serum steroid hormones in schizophrenic patients

BACKGROUND

Recent studies have implicated the abnormalities in the gamma-aminobutyric acid (GABA) neurotransmmiter system in the pathophysiology of schizophrenia. There are also evidences indicating that steroids of central or peripheral origin may modulate GABAergic system through direct interaction with the GABAA receptor complex. These raise the possibility that alternations in serum steroid hormones may contribute to the pathophysiological process in the schizophrenia.

AIMS

The purposes of this study were first, to determine whether alternations in steroid serum levels occur in schizophrenic patients, and secondly to determine whether such alternations normalize with clinical improvement.

METHODS AND MATERIAL

Serum concentrations of testosterone (T), estradiol (E), progesterone (P) and cortisol (C) were determined in male schizophrenic patients (N = 49) before treatment, during treatment and after recovery and in age-matched healthy male subjects (N = 17). All steroid hormones were assayed by ELISA method.

STATISTICAL ANALYSIS USED

Differences in steroids concentrations between groups were assayed by One-Way Analysis of Variance (ANOVA), followed by Tukey's post hoc test. The level of significance was considered at P < 0.05.

RESULTS AND CONCLUSION

The serum concentrations of E, P and C were significantly (P < 0.05) lower in male schizophrenic patients in all three stages of the study, compared with healthy subjects. Serum concentrations of T were significantly (P < 0.05) lower in male schizophrenic patients before and during treatment, but not after recovery, compared with healthy subjects. These findings support the occurrence of abnormal steroid concentrations in schizophrenic patients and suggest that lower T level in this disorder is related to the illness and normalizes with remission, while trait-related factors may contribute to lower serum E and C levels in schizophrenia.