Effect of valsartan on nitric oxide and endothelin level of plasma,urine and renal tissues in streptozotocin induced diabetic rats

Objective: To evaluate the protective effect of the angiotensin II type 1 (AT1) receptor antagonist, valsartan, on the kidneys of diabetic rats and study their mechanisms. Methods: Fourty male Wistar rats were randomized into A, B and C groups. Diabetes were induced by injection of streptozotocin (STZ). Group A was the normal control, group B consisted of untreated STZ-diabetics rats, group C consisted of diabetic rats treated with valsartan 24mg/kg per day for 84 days. Kidney/body weight, glomerular size, serum creatinine (Cr) urinary albumin, β2-m excretion, creatinine clearance (Ccr), nitric oxied (NO), endothelin (ET) level of plasma,urine and renal tissues were measured after 84 days. The results were compared in three groups. Results: Valsartan could correctly elevate urinary albumin, β2-m excretion, Ccr and mean glomerular volume. Urinary and renal tissues NO and ET concentratisons decreased after diabetic rats had received valsartan. Kidney/ body weight, glomerular size, serum creatinine, urinary albumin, β2-m excretion, creatinine clearance, NO and ET level of plasma, urine and renal tissues of valsartan treated group were significantly lower than those of diabetic untreated group, but still higher than those of the normal control rats. There was a significant increase in those of diabetic untreated group than those of the normal control. Conclusion: Valsartan has renal protective effect on diabetic rats, partly through down-regulating NO and ET concentrations in renal tissues expression.