Abstract: Objective To investigate the regulatory mechanism of enalapril to BMP-7 in diabetic nephropathy.Methods SD rats were divided in to control group and model group.The diabetes model was established by injecting STZ through vena caudalis,and the rats in the model group were divided randomly into diabetic group(DG)and diabetic enalapriltreated group(DEG).After 12 weeks,blood glucose,creatinine and 24 hours urineprote in were analyzed with biochemi calmethods.Kidney index was calculated.Immunohisto chemistry was employed to detect expressions of BMP-7,PKCα,ANGⅡ,CTGF and FN prote in in renal tubules of all groups.The mRNA levels of BMP-7 and PKCα in renal cortex were examined by RTPCR.Results Compared to control guoup,the expressions of PKC prote in and mRNA,ANGⅡ,CTGF and FN protein inrenal tubular cells were increased remarkably to 94.3%,62.2%,86.2%,93.6%,and 90.8% in DG group.On the other hand,the prote in and mRNA of BMP 7 decrea sed remarkably to 21% and 59.7% in DG.In DEG group,the expression of PKCα protein,PKCα mRNA,ANGⅡ,and FN protein was down regutated to 31.6%,41.3%,40.2%,54.7%,and 24%,respectively compared with that of DG;but the prote in and mRNA of BMP-7 were up regulated no tably to 21.1% and 15.3%.The expression of BMP 7 protein was negatively correlated with PKCα,ANGⅡ,CTGF and FN in DEG(r=-0.838,-0.885,-0.829,and-0.931,P<0.05 or P<0.01).Conclusion Enalapril can dmiinish renal ANGⅡ level and up regulatie PKCα and CTGF expression,then inhibit the expression of BMP-7 and therefore improve the damage in diabetic nephropathy.