PROTECTIVE EFFECT OF MELATONIN ON KIDNEY IN DIABETIC RATS / 解放军医学杂志

ABSTRACT

To investigate the protective effect of melatonin on the kidneys of STZ-induced diabetic rats, experimental diabetes was induced by intraperitoneal injection of streptozotocin 50 mg/kg in male Sprague-Dawley rats (150～200g). Three days after streptozotocin injection, the diabetic rats were assigned to one of the following groups: (1) DM, untreated; (2) DM+Mel 1, melatonin supplement at 0.2mg?kg -1?d -1, by gavage; (3) DM+Mel 2, melatonin supplement at 5mg?kg -1?d -1, by gavage. The treatment continued for 8 weeks. Periodically, body weight, blood glucose, plasma triglyceride and cholesterol levels were measured as clinical and biochemical parameters; plasma creatinine, creatinine clearance( Ccr), urinary protein excretion were detected as renal function indexes; kidney weight, glomerular area, PAS positive area, and cell counts were evaluated as histological damage indexes. Melatonin treatment had no significant effects on blood glucose and plasma cholesteral, but lowered plasma triglyceride level in diabetic rats. Melatonin treatment reduced urinary protein excretion. Until the end of the experiment, there were no significant changes in plasma creatinine level, Ccr in diabetic rats. Melatonin treatment decreased kidney weight/body weight ratio, reduced PAS positive area, glomerular cellular number and glomerular area which were increased in DM rats. The protective effects of melatonin were more obviose in high dosage groups. Melatonin treatment can aggravate glomerular hypertrophy and mesangial cell proliferation, delay the progression of glomerulosclerosis, and improve renal function of diabetic rats.