Protective Role of Melatonin in L-Name Induced Hypertension in Male Albino Rats

The objective for the present study is to investigate the effects of melatonin (MEL) on systolic blood pressure (SBP), some biochemical parameters; serum (malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), nitric oxide (NO)) in NG-nitro-L-arginine methyl ester hydrochloride (L-NAME) treated rats. The male albino rats divided into five groups treated for 4 weeks: Group 1: Control rats. Group 2: L-NAME (35 mg/100 ml drinking water). Group 3: L-NAME (35 mg/100 ml drinking water) + melatonin (30 mg/Kg diet). Group 4: L-NAME (35 mg/100 ml drinking water) + melatonin (60 mg/Kg diet). Group 5: L-NAME (35 mg/100 ml drinking water) + melatonin (120 mg/Kg diet). A significant elevation in SBP and serum MDA were detected in L-NAME treated rats. Co-administration of melatonin with L-NAME prevented increasing in SBP and serum level of MDA in a dose dependent manner. On the other hand serum levels of SOD and GSH were decreased in response to L-NAME treatment, while, co-treatment with melatonin increased SOD and GSH in a dose dependent manner. The decrease serum NO level in response to L-NAME was significantly increased by melatonin but its level was decreased by increasing melatonin doses. In conclusion: L-NAME induced hypertension model was associated with decreased NO level, interestingly; melatonin increased serum NO in L-NAME treatments, but with increasing dose of MEL, NO level was decreased. Furthermore; MEL through its antioxidant properties reduced oxidative stress and prevented lipid peroxidation