The Kidney-protect Effect Of The XSW Granule On The Diabetic Rats And It's Correlation With The Intrarenal RAS Gene Expression

Objective: To observe the effect of Xiao-Si-Wu Granule (XSW) on renal function of streptozotocin (STZ)-induced diabetic rats, at the same time, evaluate the intrarenal RAS components gene expression, trying to find the therapeutic mechanism of the XSW to the diabetic nephropathy.Methods: 1. Diabetic Rats were induced by intraperitoneal injection of STZ. Rats were allocated to normal control group, model group, enalapril group, XSW group. All rats were treated with corresponding drugs for 12 weeks. During and after the treatment, the general state, blood and urine glucose levels, excretion rate of the 24h urine protein and albumin, serum creatinine, blood urea nitrogen contents, kidney weigh and relative kidney weigh were measured. Kidney pathological features were observed under microscope and electron microscope.2. The kidneys of the rats were used for the study of intrarenal RAS components gene expression. The intrarenal angitensin II concentration was assayed by radioimmunology, renal cortex ACE activity was assayed using ultraviolet spectrophotometer. Renal cortex ATi mRNA levels was assayed by semi-quantitativ RT-PCR.Results: 1. Diabetic mellitus and renal lesions occurred in the three diabetic groups. Enalapril and XSW had no effect on the blood and urine glucose levels, while they could improve the general state and renal function, decrease the excretion rate of the 24h urine protein and albumin and relievethe renal lesion.2. The study on the intrareal RAS components gene expression shows: the intrareal angiotensin II concentration and the renal cortex ACE activity of diabetic rats were significantly upregulated, the ATi mRNA content was significantly downregulated. The enalapril and XSW could downregulate the intrarenal angiotensin II and ACE expression, but had no effect on the renalcortex AT1 mRNAlevel.Conclusion: XSW has no effect in decreasing the blood sugar level but has a certain effect in preventing nephropathy process. Enalapril and XSW could modulate the intrarenal RAS gene expression and that could be the reason for their renal-protecting effect.