فهرست مطالب samin abbaszadeh

Stroke is one of the major causes of mortality worldwide. Memantine, an NMDA receptor antagonist, has protective effects on neuronal cells and is important candidate as a neuroprotective agent in cerebral ischemia. On the other hand, thyroid hormones are one of the important factors in the development of the central nervous system (CNS) and its activity and the long-term adverse effects of transient thyroid function abnormalities at birth on intellectual development has been proven. Therefore, the aim of the present study was to evaluate the effects of memantine on cerebral ischemia/reperfusion (I/R) induced injuries in transient congenital hypothyroidism (TCH). The adult male Wistar TCH rats (240±20 g) were underwent forebrain ischemia by bilateral common carotid artery occlusion for 17 min. Memantine (20 mg/kg) alone or in combination with vitamin C (200 mg/kg) were administered intraperitoneally (ip) for 7 days after cerebral ischemia. Then, histopathology, cerebral infarct size and malondialdehyde level were evaluated. Histopathological analysis showed that memantine significantly decreased leukocyte infiltration in comparison to I/R group (p<0.01). Memantine also reduced infarct size and malondialdehyde level compared with I/R group (p<0.01). Memantine and vitamin C combination group had no significant effects on leukocyte infiltration, infarct size and malondialdehyde level. Our results showed that memantine through reduction in leukocyte infiltration, lipid peroxidation and infarct size could reduce cerebral ischemia/reperfusion induced injuries in transient congenital hypothyroidism. Hence, memantine might be considered as a neuroprotective agent in hypothyroidism.

Hypertensive crisis is a severe elevation in blood pressure (BP) that requires urgent reduction in BP to prevent or reduce target organ damage. The antihypertensive effects of nitroglycerin have been proven, but there are limited reports on the effects of various factors on the effectiveness of nitroglycerin in the treatment of hypertensive crisis. The purpose of this study was to evaluate the effects of diabetes, history of hypertension and age as well as gender differences in the effectiveness of nitroglycerin in patients with hypertensive crisis. This study included 76 patients with hypertensive crisis. For management, nitroglycerin initially started at 5 μg/min by intravenous infusion and, if needed, every 3 to 5 min, 5 μg/min was added to the above dose to a maximum of 20 μg/min as long as the blood pressure level reaches to the desired level. The results showed that the mean time of reduction of BP to the desired level in patients with history of hypertension and diabetes alone or both diseases, increased significantly in comparison to patients without these underlying diseases (P<0.01, P<0.01 and P<0.05 respectively). The results also demonstrated that there is a significant difference between patients younger than 45 and over 65 years with patients aged 45-65 (P<0.05). There is no difference between two genders in each group (P>0.05). In conclusion, patients with diabetes and/or history of hypertension are more resistant to pressure lowering effect of nitroglycerin in hypertensive crisis. Patients under 45 years of age as well as the elderly are also resistant. Therefore, it is advisable for physicians to choose the appropriate treatment for the desired outcome, considering the patient's condition.

Neuropathic pain results from trauma or diseases affecting the central nervous system (CNS) and triggers a cascade of events in different CNS parts that eventually lead to oxidative injury. This study was aimed to investigate the protective effects of some selected analgesics in neuropathic pain-induced oxidative damage in the isolated glial cells of the rat brain. In this experiment, rats were randomly divided into 5 main groups. Rats in group 1 received no medication, whereas rats in groups 2 to 5 received ASA (aspirin), celecoxib, morphine, and etanercept daily, respectively. Each main group divides into 3 subgroups: normal, sham, and neuropathic pain model rats. The glial cells of the rat brain were isolated at different time points. Our results demonstrate that neuropathic pain induces ROS generation as the major cause of mitochondrial membrane potential collapse (%∆Ψm) and lysosomal membrane rupture, which result in oxidative damage of the glial cells. In addition, ASA and celecoxib had protective effects on the neuropathic pain-induced oxidative stress markers, including ROS production, mitochondrial membrane potential collapse, and lysosomal membrane leakiness at different time points.Furthermore, the oxidative damage markers were significantly decreased by morphine and etanercept in all investigated days. Since arachidonic acid metabolites and TNF-α are produced during neuropathic pain and inflammation, it can be concluded that the inhibition of the substances production or inhibition of the ligands binding with their receptors would help to decrease the destructive effects of neuropathic pain in the glial cells of rat brain.

Cynodon dactylon is a herbal medicine of interest in Iranian traditional medicine, which is used in cardiovascular diseases such as atherosclerosis and heart failure. The purpose of this study was to evaluate the effects of total extract of C. dactylon rhizomes on myocardial infarction and on post myocardial infarction (MI) heart tissue injuries.

Isoproterenol (100 mg/kg) was injected subcutaneously for two consecutive days for induction of MI in rats and C. dactylon extract was administered orally twice daily started before isoproterenol injection for 4 consecutive days.

Histopathological analysis showed a marked increase in myocardial necrosis in rats with MI (p<0.001). Treatment with C. dactylon (200 mg/kg) significantly (P<0.05) decreased myocardial necrosis. Hemodynamic variables were significantly suppressed in MI group and treatment with C. dactylon improved the hemodynamic parameters (P<0.05). Our electrocardiogram analysis demonstrated that C. dactylon with all doses increased R-Amplitude and R-R Interval (p<0.05, p<0.01) which were suppressed in MI group. Furthermore in treated groups with 100 and 200 mg/kg, P-R interval was also significantly increased in compared to MI group.

This study demonstrated that C. dactylon can improve hemodynamic and electrocardiogram parameters in isoproterenol-induced myocardial infarction and thereby suggest that it can be used as a cardioprotective agent in myocardial infarction.

Metformin is one of the most popular drugs tested against nonalcoholic fatty liver disease (NAFLD). The present study aimed to investigate whether calcium-vitamin D3 cosupplementation will intensify the effect of metformin on the prevention of high-fat, high-fructose (HFFr) diet-induced hepatic steatosis.
Male wistar rats (210±16 g) were assigned into the following seven groups: a Control group to receive a standard chow and six HFFr-fed groups to receive diets containing either normal (0.5% calcium and 1000 IU/kg vitamin D3) or high amount of calcium and vitamin D3 (2.4% calcium and 10000 IU/kg vitamin D3) (CaD), in combination with gastric gavage administration of either saline or 25 or 200 mg/kg body weight/day metformin. After 60 days, rats were assessed with respect to their anthropometric, metabolic and hepatic parameters, as well as their hepatic AMP-activated protein kinase (AMPK) phosphorylation.
Metformin and CaD, either alone or in combination, caused a significant reduction in HFFr diet-induced high serum aspartate aminotransferase (AST), hepatic steatosis and lipid accumulation without effect on insulin resistance and AMPK phosphorylation. In addition, slightly (and non-significantly) better effects of the combination in ameliorating steatosis and hepatic cholesterol content were observed.
Taken together, our results suggest that metformin and CaD could protect against the onset of HFFr diet-induced NAFLD in an insulin and AMPK-independent manner, without any marked additional benefits of their combination.