Objective:To explore the effects and mechanism of Yanshen Capsule on the remnant kidney.Methods:Thirty healthy Wistar rats
were randomly divided into 3 groups: control group rats were sham-operated and gavaged with saline daily,
operation group rats were 5/6 nephrectomized and gavaged with saline daily,treatment group rats were 5/6 nephrectomized and gavaged with Yanshen Capsule daily.The body weight(BW),blood urea nitrogen(BUN) and creatinine(Scr) levels,renal morphological changes,the
expression of collagen Ⅳ(Col Ⅳ) and cathepsin B(CB) were observed using biochemistry,morphometry and immunohistochemistry at 60 days after operation.Results:The BUN and Scr of Yanshen Capsule-treated group also slightly higher than that of control group,but were significantly lower than that of operation group(P<0.01).In Yanshen Capsule-treated group,lower ratio of sclerosis glomeruli,higher expression of CB and lower expression of Col Ⅳ were observed compared to that of operation group.Conclusion:Yanshen Capsule retards the development of renal fibrosis through increasing CB and suppressing Col Ⅳ expression.