مجله فیزیولوژی و فارماکولوژی ایران
پیاپی 4 (زمستان 1396)

Myocardial infarction is the worst consequence of coronary disease. The present study aimed at evaluating the effect of resveratrol (RES) supplementation and aerobic training (EXE) on cardiac tissue alteration in rats with acute myocardial infarction due to isoproterenol (ISO) application.

Fifty male Wistar rats (age; 8-10 weeks, weight; 180-200 g) were randomly divided into five groups (n = 10): control, ISO, ISO + RES, ISO + EXE and ISO + RES + EXE groups. The EXE groups ran for 8 weeks and 5 times per week on treadmill at speed of 22m/min for 30 minutes. Rats in the RES groups received daily 25 mg/kg of resveratrol orally for 8 weeks. At the end of the experiment all animals received subcutaneous injection of isoproterenol (150 mg/kg/day) on two consecutive days. Twenty-four h after the second injection of isoproterenol all animals were anesthetized and EEG patterns were recorded. Then myeloperoxidase activity, superoxide dismutase and apoptosis were measured in the isolated cardiac tissue.

The results showed that rats in control group had a normal ECG patterns without deviation. Isoproterenol caused disturbances in the ECG pattern. In ISO group, rate of infarction size, MPO and apoptosis were significantly increased, and level of SOD was decreased (p < 0.001). Pretreatment with resveratrol and exercise training led to significantly decreased in infarction size, MPO and apoptosis and significantly increased in SOD. These changes in the ISO + Ex + Res group was significant than other groups (p < 0.01).

The combination of resveratrol and aerobic exercise by reducing the production of superoxide, lipid peroxides and activation of antioxidant defense helps to protect the heart against oxidative stress and development of apoptosis after ischemia.

Role of NMDA receptors in persistence of pathological pain is not clear. In addition, long-term potentiation (LTP) has a crucial role in development and maintenance of neuropathic pain. The aim of this study was to investigate the role of glutamate NMDA receptor and electrophysiological changes in spinal dorsal horn following L5 spinal nerve ligation.

The model of spinal nerve  ligation (SNL) was used in this study. In behavioral experiments to evaluate mechanical allodynia, Von frey filaments were used from a day before induction of neuropathy up to 7 days after neuropathy. Memantin 10 mg/Kg, i.p.,  as NMDA antagonist, was injected one hour before SNL up to 7 days afer SNL. LTP induction  and dorsal horn WDR neurons recording was performed by spinal single unit set up on day 7 after high frequeny stimulus (HFS) induction.

SNL induced mechanical allodynia . Daily injection of memantin increased thershold of pain significantly (p < 0.01) at the period of maximum pain (days 5, 6 and 7). Electrophsiological recording showed a significant decrease in the thershold of activation of C and Aδ fibers or LTP induction (p < 0.001) 7 days after SNL, compared to sham group. Daily administration of memantin prevented  induction of LTP.

It seems that NMDA receptors are involved in development of plasticity during neuropathic pain. Control of neuropathic pain by memantin might open a new insight  in treatment of neuropathic pain.

Non-communicable diseases account 29.2% of deaths. Hypertension is one of the most debilitating factors among these illnesses. The prevalence of hypertension and its relationship with other cardiovascular disease risk factors in Kerman was the purpose of this study.

This is a cross sectional study performed on 5900 Kerman adults 15- 75 years old. Information on blood pressure, blood glucose and lipids, anthropometry, opium addiction, smoking, physical activity and mental health (anxiety and depression) were collected by interview and clinical examination and paraclinical laboratory findings. For statistical analysis STATA11 was used.  Qualitative variables and the quantitative variables were compared using the chi-square and t-test respectively.  Poisson regression was used to examine the relationship between hypertension and other cardiovascular risk factors.

The mean age of participants was 33.5 years, and 45.1% were male. The prevalence of hypertension was 18.4% in total (20.2% in males vs.16.75% in females), and it was significantly higher in subjects with low physical activity, addicted to opium, diabetics, overweight and obese. The highest prevalence was seen in age group above 65 years (66.5%). Illiterates had higher prevalence of hypertension (36 % more risk compared to educated people). In multivariate analysis, risk of hypertension in dependent and fancy consumers of opium was 36% and 42% higher than non-consumers, respectively. High levels of blood glucose, cholesterol and triglyceride increased risk of hypertension by 76%, 21% and 14%, respectively (most significance for   blood glucose, p < 0.001). Male gender had significant effect on the risk of hypertension. Low physical activity, significantly increased prevalence of hypertension (19.8% vs. 13.9%, p = 0.009).

The prevalence of hypertension in Kerman was about 18.5 percent and was positively associated with opium addiction, age, lower education, low physical activity, high serum glucose, overweight and obesity.

Remote ischemic preconditioning (RIPC) is an episode of intermittent sub lethal and brief ischemia in one organ, which causes protection against severe ischemia in another remote organ. The main purpose of this study was to assess the relevance of nitric oxide (NO) in renal ischemic preconditioning during brain ischemia-reperfusion in hippocampal tissue.

60 male BALB/C mice weighting 30-35g randomly were divided into six groups. Sham-operated group, IPC group (transient renal ischemia), IR group (global brain ischemia), RIPC (IPC+IR) group, L-NAME + IPC + IR group (L-NAME was injected 30 min before RIPC), L-NAME + sham + IR group. Three days after brain ischemia, the cell density in hippocampal CA1 subregion and the level of nitric oxide (NO) in hippocampus tissue were measured in different groups.

RIPC prevented the reduction in cell density in hippocampal CA1 area following ischemia (p ≤ 0.05). The level of nitric oxide was significantly increased in the hippocampus in comparison with the IR group (p ≤ 0.05). L-NAME reversed the protective effects of RIPC on ischemic hippocampal damage by inhibition of nitric oxide (p ≤ 0.01).

Increased nitric oxide during RIPC can protect the hippocampus against damage caused by ischemia-reperfusion.

The normal activity of thyroid depends on the presence of some trace elements required for the synthesis and metabolism of thyroid hormones. Manganese (Mn) and Vanadium (Vn) are two important elements for maintaining thyroid health. The aim of this study was to investigate serum levels of Mn, V, triiodothyronine (T3) and thyroxine (T4) after hypothyroidism induced by propylthiouracil (PTU).

Twenty-one male adult rats divided into three groups. The control group received tap water. Low-dose treatment group received 1 mg PTU in 100 ml tap water and high-dose treatment group received 10 mg PTU per 100 ml of tap water for 45 days. Under deep anesthesia, blood samples were obtained. Serum levels of thyroid hormones and the trace elements ) Mn and Vn) were measured by radioimmunoassay and flameless atomic absorption, respectively.

PTU decreased serum levels of T3 and T4 in a significant dose-dependent manner in two treatment groups (p < 0.001) .The Mn level increased by the both doses (p < 0.05 and p < 0.001) but Vn serum level did not change significantly.

PTU-induced hypothyroidism decreases thyroid hormones and increases serum level of Mn but not Vn. Administration of PTU changes manganese homeostasis. Further studies are required to ensure this consequence during treatment of hyperthyroidism by PTU.

Strenuous and prolonged exercise cause muscle fatigue. The purpose of the present study was to investigate the effect of naringin supplementation on muscle fatigue and some biochemical parameters related to fatigue in female rats.

Tenty female Wistar rats were randomly divided into 2 groups including control and 80 mg/kg naringin treatment. Naringin was administered by oral gavage once daily for 30 days. On the 30th day, the rats performed an exhaustive swimming exercise, and serum glucose level and lactate dehydrogenase activity were measured.

The time to exhaustion was significantly prolonged in naringin supplementation group compared to the control group. Naringin increased serum glucose level (p < 0.01) and reduced lactate dehydrogenase activity (p < 0.001).

Naringin can significantly delay exercise-induced muscle fatigue.

Diabetic neuropathy is a chronic disease characterized by allodynia and hyperalgesia. Many different studies show that nitric oxide, prostaglandin E2, preinflammatory cytokines and adipocytokines such as leptin increase in diabetic neuropathy. The purpose of this study was to investigate the effect of Cyclooxygenase-2 enzyme and nitrergic system on serum level of leptin in diabetic neuropathy.

Diabetes was induced in rats by streptozotocin (60 mg/kg, i.p). Separate groups of rats were treated with celecoxib (5 mg/kg), L-arginine (50 mg/kg), L-NAME (50 mg/kg), combination of celecoxib and L-arginine, and combination of celecoxib and L-NAME. Serum level of leptin was measured 14 days after streptozotocin injection.

The leptin level significant decreased in all experimental groups (p < 0.01) except for L-arginine group which showed an increase in the leptin level.

Inhibition of cyclooxygenase 2 can reduce the serum level of leptin in diabetic neuropathy. Nitrergic system is partly responsible for this effect.

The blood-testis barrier (BTB) is a unique ultrastructure in adult mammals’ testis, which creates a unique microenvironment for normal spermatogenesis. Knowing the BTB mechanisms of actions can be used to reveals new targets for male contraceptive development. Meanwhile, understanding the molecular mechanisms of some BTB disruptors  such as cadmium and bisphenol-A not only provide approaches to manage toxicant-induced reproductive dysfunctions but it also illustrates new candidates molecules for contraceptive developments. The BTB is constituted by coexisting tight junctions (TJ), basal ectoplasmic specializations (basal ES), desmosomes and gap junctions between adjacent Sertoli cells. Some of the junctional proteins function as structural proteins of BTB and some other have regulatory roles. Studies have shown that male fertility can be impaired by various toxicants. Exposure of men to several environmental toxicants is reported to be associated with reduced sperm counts, poor semen quality, and infertility in addition to their effects to induce cancer and other pathological conditions. Some of them (cadmium, bisphenol A, phthalates, perfluorooctanoic acid) are known to exert their effects by targeting junctions in the blood -testis barrier. In this review, we will summarize the findings on the BTB structure and function as well as environmental pollutant-induced testicular injuries in men, such as BTB disruption.