Metabolic effects of melatonin supplementation in stressed immobilized rats

ABSTRACT

Therapeutic interventions aimed at reducing metabolic perturbances are recommended in chronic immobilization stress via administration of melatonin. This study was conducted to evaluate the effects of melatonin supplementation on carbohydrate and lipoproteins metabolism in chronic stressed immobilized rats. A total of 32 male albino rats [150-250 grams, each] were divided into 4 equal groups; control group, stressed immobilized group, melatonin-supplemented group and melatonin supplemented + stressed immobilized group. Fasting blood glucose level and rate of glucose uptake by skeletal muscle [diaphragm] were investigated. Also plasma levels of triglyceride [TG], total cholesterol [TC], low density lipoprotein-cholesterol [LDL-C], high density lipoprotein-cholesterol [HDL-C] and malondialdehyde [MDA] were measured. Stressed immobilized group showed significant hyperglycemia associated with decreased glucose uptake by diaphragm. In addition, plasma levels of TG, TC, LDL-C and MDA were significantly increased. But the level of HDL-C in plasma was decreased significantly. Melatonin supplementation for stressed immobilized rats resulted in significant increase of glucose uptake by diaphragm, as well as HDL-C. On the other hand blood, glucose level, TG, TC, LDL-C and MDA were significantly decreased. In addition melatonin supplementation for normally fed rats produced significant increase of glucose uptake by diaphragm with significant reduction of plasma levels of TG, TC and LDL-C. Melatonin supplementation could ameliorate the metabolic disturbances in carbohydrate and lipoproteins metabolism in chronic immobilization stress in rats