| Objective:to research the protective effect and mechanism of Cortex Mori combined with captopril to kidney of diabetic nephropathy rats.Methods:42 healthy male SD rats were randomly divided into two groups: 30 rats in model group were intraperitoneal injected with STZ60mg/kg,12 rats in normal control group were given equivalent dosage of citrate buffer solution. After 72 hours, the blood sugar leval of rats in model group increased steadily. All of the rats in model group presented polydipsia, polyuria, polyphagia. After 8 weeks,6 rats in each group were sacrificed and blood samples, urine samples, kidneys were obtained for examination. The results suggested that the model of diabetic nephropathy rats had been copied successfully. Other rats of the model group were divided into 4 groups: diabetic nephropathy control group(DN); Captopril group(DN+A); Cortex Mori group(DN+B); Cortex Mori and Captopril group(DN+A+B), there were 6 rats in every group. Rats of DN+A group were given Captopril 50mg/kg/d. Rats of DN+B group were given Cortex Mori 5g/kg/d. Rats of DN+A+B group were given Captopril 50mg/kg/d and Cortex Mori 5g/kg/d. Normal control group and the DN control group were given the same dosage of saline. After 4 weeks, the analytical indexes (fasting blood glucose, blood urea nitrogen, serum creatinine, serum malondialdehyde, NO in renal tissue, NO in serum, serum superoxide dismutase) in all groups were detected by biochemical method. The a-smooth muscle actin and endothelial nitric oxide synthase in renal tissue were detected by immunohistochemistry. The microalbuminuria were detected by radioimmunoassay. Theα-SMAmRNA in renal cortex were detected by RT-PCR. The changes of renal histology were observed by microscope. Results:1. Compared with the normal control group, the levels of FBG, BUN, Scr, serum MDA and 24hmALb,the expressions of a-SMAmRNA in cortex renis and a-SMA in nephridial tissue in model group were increased significantly (P<0.05); SOD, NO and eNOS in model group were decreased significantly (P<0.05). The changes of renal histology in model group rats revealed expansion of extracellular matrix in the mesangial area and basement membrane thickening. The model of diabetic nephropathy rats had been copied successfully.2. Compared with DN control group, the levels of FBG, BUN, Scr, serum MDA and 24hmALb, the expressions of a-SMAmRNA in cortex renis and a-SMA in nephridial tissue in DN+A+B group were decreased obviously(P<0.05); serum SOD, NO in renal tissue, NO in serum and the expressions of eNOS in renal tissue were increased significantly (P<0.05). The levels of BUN, Scr,24hmAlb and serum MDA, the expressions ofα-SMAmRNA in cortex renis and a-SMA in nephridial tissue were decreased obviously in group DN+A (P<0.05); The levels of serum SOD increased obviously(P<0.05), but the content of NO in renal tissue and in serum, the expressions of eNOS in renal tissue and the levels of FBG had no obvious change (P>0.05). FBQ BUN, Scr, and serum MDA in DN+B group were decreased obviously(P<0.05), serum SOD, NO in renal tissue and in serum, the expressions of eNOS in renal tissue were increased significantly (P<0.05); the level of 24hmALb, the expressions of a-SMAmRNA in cortex renis andα-SMA in nephridial tissue in DN+B group had no obvious change (P>0.05). Compared with DN+A group, FBG, 24hmALb, BUN, Scr, serum MDA in DN+A+B group were decreased obviously(P<0.05), serum SOD, NO in renal tissue and in serum, the expressions of eNOS in renal tissue were increased significantly (P<0.05), the expressions of a-SMAmRNA in cortex renis and a-SMA in nephridial tissue decreased obviously(P<0.05), The levels of serum SOD increased obviously(P<0.05). Compared with DN+B group,24hmALb, BUN, Scr, the expressions of a-SMAmRNA in cortex renis and a-SMA in nephridial tissue in DN+A+S group decreased obviously (P<0.05). Conclusions:1. Renal function and kidney pathology can be improved through the application of Cortex Mori combined with captopril.2. Cortex Mori combined with captopril had significant protective effect on kidney of diabetic nephropathy rats, and the combination was better than cortex mori or captopril alone.3.The results indicated that the protective mechanisms may be related to hypoglycemic effect, antioxidation, regulation of nitric oxide and inhibition of renin-angiotensin system and so on. |
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