The purpose of this study was to evaluate the effect of intrahippocampal injection of vitamin C and progesterone, alone or in combination, on passive avoidance learning (PAL) in multiple sclerosis.Sixty- three male wistar rats were divided into nine groups (n=7) as following: control (saline), lesion, vitamin C (0.2, 1, 5 mg/kg), progesterone (0.01, 0.1, 1 µg/µl) and combination therapy. Lesion was induced by intrahippocampal injection of ethidium bromide. In combination therapy, animals were treated with vitamin C (5 mg/kg) plus progesterone (0.01 mg/kg). Animals in experimental groups received different treatments for 7 days, and then all groups were tested for step through latency (STL).Our results showed that intrahippocampal injection of ethidium bromide destroys PAL significantly (p<0.001). Treatment with vitamin C (5mg/kg) significantly (p<0.05) improved PAL. Lower doses of progesterone did not affect latency but dose of 1 µg/µl significantly (p<0.05) increased STL. In combination therapy group STL was significantly (p<0.05) more than in the lesion group, although it was not significantly different from the vitamin C group.Based on our results, we concluded that intrahippocampal injection of vitamin C improves memory for PAL, but progesterone alone or in combination with vitamin C had no improving effects on memory.
It has been proposed that opioid tolerance is a model of neuronal plasticity similar to learning and memory. Recent evidence suggests that neurotrophins may be involved in synaptic development and plasticity. Observations indicate that neurotrophin 4 (NT4) is required for the synaptic plasticity mediating both tolerance and memory. Also there are lines of evidence to indicate that NMDA receptors are involved in the neural plasticity underlying the development of opiate tolerance. Neurotrophins affect central transmission postsynaptically by enhancing NMDA receptor responsiveness. So we used the clinically available NMDA receptor antagonist, dextromethorphan, and the neurotrophin 4 antibody, anti-NT4, concomitantly and alone to investigate their effects on morphine tolerance. Tolerance was induced by injecting morphine (7 and 10 mg/kg i.p.) once per day for 4 days. Anti-NT4 (1 microg/rat i.c.v.) was administered 15 min before morphine. Results showed that chronic concomitant treatment of anti-NT4 with morphine in both doses inhibited the development of morphine tolerance. Also acute treatment of anti-NT4 significantly reversed the tolerance that was induced by morphine 7 mg/kg but failed to reverse the tolerance of morphine 10 mg/kg. Dextromethorphan in both doses (10 or 30 mg/kg) has an additive effect on the inhibitory effect of anti-NT4 on the reversal of morphine tolerance (7 mg/kg). These findings provide additional support for the hypothesis that NMDA receptor and NT4 may be involved in neural plasticity underlying opiate tolerance.
Background and Objectives: Several studies have described the effects of brain-derived neurotrophic factor (BDNF) during tissue injury or inflammation. BDNF expression levels in the nervous system are altered in a number of pain models including peripheral inflammation, injury and neuropathic pain paradigms. Immune cell are considered as the source of circulating BDNF. Opioid receptors participate in the function of immune cells. The aim of this study was to investigate the alteration of BDNF during carrageenan-induced inflammation and morphine anti-inflammatory effects. Materials and Methods: Inflammation was induced by 0.05 ml of 3% W/V solution of lambda carrageenan in saline injected into the plantar surface of the right hind paw. Edema of the injected paw was measured during the 6 h period after the carrageenan injection. Moreover, to assess the anti-inflammatory effect of morphine, morphine hydrochloride (7mg/kg) was injected 30 minutes prior to the carrageenan. BDNF levels in serum were determined by ELISA. Results: Four hours after the injection of carrageenan, the volume of the paw was significantly higher than the non-inflamed paw. Pretreatment with morphine, produced a significant decrease in the carrageenan-induced swelling. Naloxone evoked development of the carrageenan inflammation at 2 hours. Administration of carrageenan elicited a significant increase in BDNF serum levels. Conclusion: It seems that the inflammatory effects of the carrageenan are mediated in part by BDNF. Such association is not attributable to the anti-inflammatory effects of morphine.
Background and Objectives: The aim of this study was to evaluate the effects of ethanolic extract of saffron on oxidative stress markers in the hippocampus of experimental models of MS. Materials and Methods: Induction of Multiple Sclerosis (MS) was carried out by direct single injection of 0.01 % ethidium bromide (EB) into the Cornu ammonis (CA1) of hippocampal formation. One week after MS induction, animals received intrahippocampal (5 μg/rat and 10 μg/rat) injection of the saffron. At the end, the bilateral hippocampi were dissected to measure oxidative stress parameters. one-way ANOVA followed by Tukey test were used for Statistical analyses activity. Results: Hippocampal injection of EB had no effect on catalase (CAT) activity, but it induced significant increment of antioxidant enzymes GPx and SOD (P<0.05). Short-term local injection of saffron extract significantly reduced the activity of GPx and SOD enzymes (P<0.05). But the activity of CAT was significantly increased following microinjection of saffron extract (P<0.05). Conclusion: The results of the present study show that the local injection of EB may cause increased production of free radicals. Antioxidant capacity and activity are increased. Saffron extract as a potent antioxidant modulates oxidative stress markers, probably through scavenging of ROS and clearing of cells milieu from free radicals.
It has widely been reported that the brain in Alzheimer's disease (AD) is affected by increased oxidative stress, and this may have a role in the pathogenesis of this disorder. Quercetin, a polyphenol extensively found in nature, has recently been considered. Also, physical activities have a paradoxical effect on brain function in older adults. Therefore, this study aimed at investigating the synergic effects of quercetin (as chemical treatment) and exercise (as physical treatment) on AD-induced learning and memory impairment. Fifty-six adult male Wistar rats were randomly assigned into one of the following eight groups (n=7): The Control, Sham (saline), AD (intracerebroventricular administration of streptozotocin (STZ)), AD+80 mg/kg Quercetin (STZ+Q80), Quercetin vehicle (1 % Ethanol)+STZ, Exercise pretreatment (EX)+STZ, Off the treadmill+STZ, and EX+Q80+STZ. Quercetin administration was done intraperitoneally for 21 days after STZ injection. The rats ran on the treadmill for one hour a day for 60 days at a speed of 20-22 m/min. After the treatment, the spatial memory and levels of oxidative stress parameters were evaluated. The results showed that STZ caused spatial memory impairment and increased oxidative stress in the hippocampus. Exercise pretreatment or Quercetin injection improved the spatial memory impairment and oxidative stress caused by STZ injection. However, the combination of quercetin and exercise pretreatment was more effective. It can be concluded that the combined exercise pretreatment and Quercetin injection affected the antioxidant defense system and improved STZ-induced memory impairment.
Abstract Objective. Reproductive disorders are one of the complications of diabetes mellitus. Since conflicting results have been obtained from different studies, which examined serum levels of cytokines in patients with diabetes, and considering the fact that the origin of cytokines cannot be accurately determined from their serum changes, attempts were made in the present study to study histological changes and testicular tissue levels of TNF-α and IL-1 in rats treated with exercise. Considering the effects of exercise in reducing blood sugar level and its complications, two types of short-term and long-term regular exercises were also considered to evaluate their effects on male reproductive tissues. Methods. In this study, 60 male rats with the weight range of 250±50 g were used and were randomly divided into six groups (10 rats each). Healthy groups included sedentary control group, and groups treated with two and eight weeks of exercise. Rats with type 1 diabetes (induced by streptozotocin) included sedentary control group, groups treated with two and eight weeks of exercise (six groups). All groups were evaluated in terms of testicular tissue levels of TNF-α and IL-1 using ELISA and the histometry of spermatogonia, primary spermatocytes, Sertoli cells, epithelial thickness, diameter of veins, and thickness of the seminiferous tubule. Results. Histological changes resulting from diabetes, particularly in the diameter of testicular veins and a number of cells, including Sertoli, highlights the important fact that tissue perfusion in patients with diabetes is especially crucial, in a way that exercise proved useful for tissue structures by offsetting this complication. Measurement of the cytokines IL-1 and TNF-α in the current study showed that perfusion problems are more important in diabetic complications than inflammatory factors. Conclusions. The main result of this research is recommendation of investigating the tissue of interest for diagnosis of diabetes complications, measuring inflammatory mediators of tissue rather than evaluating their serum concentrations, and focusing on vascular complications as a major complication of diabetes. Furthermore, regular exercise could help improve the function of reproductive organs in healthy groups and prevent diabetes infertility complications to an acceptable degree in diabetic groups.
Background: Psychostimulant amphetamine (Ecstasy and Crystal meth or n-methyl-1- phenyl-propan-2- amine) abuse has been prevalent among the youth of Iran in recant years. These substances have many adverse and destructive effects on several organs. Therefore, this study was done to determine the effect of crystal meth on pituitary-gonadal axis in adult male rats.
Material and Methods: 28 male adult rats were divided into four groups; normal control group, and 5, 10 and 15 mg/kg bw Crystal meth-treatment groups. Animals in the Crystal meth-treated groups received 5, 10 and 15 mg/kg bw of Crystal meth intraperitoneally for seven days. After 7 days, blood sample was taken from the left ventricle of the animal's heart and LH, FSH and testosterone concentration were measured using ELISA kit. The SPSS-16 statistical software was used to analyze data. All data were analyzed by one-way analysis of variance (ANOVA) and the differences were considered significant at the p<0.05 level.
Results: Testosterone hormone concentration significantly increased in experimental groups (10 and 15 mg/kg bw) in comparison with control group (P<0.05). Concentrations of FSH and LH in the experimental groups (5, 10 and 15 mg/kg bw) significantly reduced in comparison with control group (P<0.05).
Conclusion: According to the hormonal examinations, we concluded that the use of Crystal meth causes destructive effects on the male pituitary-gonadal axis.
Keywords: Crystal meth, Testosterone, FSH and LH, Pituitary- gonad axis.
'%3e%3cg id='e'%3e%3cg id='c' fill='none' stroke='%23fff' stroke-width='2'%3e%3cpath id='b' d='M0 1h26M1 10V5h8v4h8V5h-5M4 9h2m20 0h-5V5h8m0-5v9h8V0m-4 0v9' transform='scale(1.4)'/%3e%3cpath id='a' d='M0 7h9m1 0h9' transform='scale(2.8)'/%3e%3cuse xlink:href='%23a' y='120'/%3e%3cuse xlink:href='%23b' y='145.2'/%3e%3c/g%3e%3cg id='d'%3e%3cuse xlink:href='%23c' x='56'/%3e%3cuse xlink:href='%23c' x='112'/%3e%3cuse xlink:href='%23c' x='168'/%3e%3c/g%3e%3c/g%3e%3cuse xlink:href='%23d' x='168'/%3e%3cuse xlink:href='%23e' x='392'/%3e%3c/g%3e%3cg fill='%23da0000' transform='matrix(45 0 0 45 315 180)'%3e%3cg id='f'%3e%3cpath d='M-.548.836A.912.912 0 0 0 .329-.722 1 1 0 0 1-.548.836'/%3e%3cpath d='M.618.661A.764.764 0 0 0 .422-.74 1 1 0 0 1 .618.661M0 1l-.05-1L0-.787a.31.31 0 0 0 .118.099V-.1l-.04.993zM-.02-.85 0-.831a.144.144 0 0 0 .252-.137A.136.136 0 0 1 0-.925'/%3e%3c/g%3e%3cuse xlink:href='%23f' transform='scale(-1 1)'/%3e%3c/g%3e%3c/svg%3e)
