Objective To investigate the effect of losartan,a blocker of angiotensin Ⅱ type-1 receptor,on the expressions of matrix metalloproteinase-2(MMP2),matrix metalloproteinase-9(MMP9) and tissue inhibitor of metalloproteinase1((TIMP1)) in kidney tissues of rats with diabetes mellitus.Methods 35 SD male adult rats of SPF level 35 were divided into such 3 groups randomly as normal control group(C group,n=12),diabetes mellitus group(DM group,n=11) and losartan on diabetes mellitus rat group(DL group,n=12).After diabetes was induced by administrating streptozotocin(STZ),losartan was perfused into stomach of rats in DL group distilled water into stomach of other rats.After treatment of 8 weeks,35 rats were put to death once,their kidneys were removed for the study of the expressions of MMP2,MMP9,TIMP1 using StreptAvidin-Biotin Complex(SABC) immunohistochemistry method.The sections were scanned and analyzed by Motic Med 6.0 CMIAS medical colour picture analysis system.The blood glucose,glycosylated hemoglobin,serum creatinine,serum uria nitrogen,creatinine clearance rate and urinary albumin excretion rate were measured.Results Compared with C group,the expressions of MMP2 and MMP9 were decreased in DM group(P<0.01).The expressions of MMP2 and MMP9 in DL group werehigher than those in DM group(P<0.01),but they were still lower than those in C group((P<)0.01).Compared with C group,the expression of TIMP1 was increased in DM group(P<0.01).The expression of TIMP1 in DL group is lower than that in DM group(P<0.01),but it was still higher than that in C group((P<)0.01).Conclusion The changes of the expressions of MMP2,MMP9 and TIMP1 decrease the degradation extracellular matrix,which promote the occurrence and progress of diabetic nephropathy.Losartan may attenuate the occurrence and progress of diabetic nephropathy through intervening this change. |