Effects of Tangshenling Mixture and benazepril on rats with diabetic nephropathy and its mechanism

OBJECTIVE: To investigate the effects of Tangshenling Mixture (TSLM) and benazepril on rats with diabetic nephropathy (DN) and its mechanism. METHODS: Diabetic nephropathy was induced in rats by intraperitoneal injection of streptozotocin. Fifty-eight rats with DN were randomly divided into four groups: untreated group, TSLM-treated group, TSLM plus benazepril-treated group and benazepril-treated group. Another seven normal rats were included in normal control group. Then, rats in each group were accordingly given normal saline, TSLM, TSLM plus benazepril and benazepril orally for six weeks respectively. Blood and urine biochemical indexes, plasma atrial natriuretic factor (ANF), pathomorphology of renal tissue, transforming growth factor beta1 (TGF-beta1) and glucose transporter 1 (GLUT1) mRNAs in renal tissue were observed. RESULTS: Both TSLM and benazepril could decrease urinary albumin excretion rates, creatinine clearance and ratio of kidney weight to body weight of the rats with DN as well as reduce the pathological damages of the renal tissues. TSLM could reduce the level of plasma ANF and the expression of GLUT1 mRNA, but had no significant effect on the expression of TGF-beta1 mRNA. Benazepril could reduce the expression of TGF-beta1 mRNA, but had no significant effect on plasma ANF and the expression of GLUT1 mRNA. CONCLUSION: TSLM can reduce the pathological damages of renal tissues in rats with early-stage DN, and its mechanism may relate to decreasing the level of plasma ANF and the expression of GLUT1 mRNA which is different from that of benazepril. It seems that TSLM has synergetic effect with benazepril.