Department of Nephrology, Xiangya Hospital, Central South University, Changsha 410008, China

Objective To investigate the effects of enalapril on the early stage of renal interstitial fibrosis in rats and the underlying mechanism.MethodsSixty male Sprague -Dawley rats were randomly divided into 3 groups: a sham-operated group, a unilateral ureteral obstruction (UUO) model group and a enalapril treated group (n=20 in each group).For the enalapril group, rats received enalapril by gastric gavage  from Day 4 after UUO. All rats from each group were killed on Day 14 after surgery. Renal tissue were observed by HE and Masson staining,  the mRNA expression of collagen I, collagen III, platelet derived growth factor (PDGF)-B, transforming growth factor (TGF)-β1,connective tissue growth factor (CTGF) were detected by Real-time PCR, and the protein expressions of collagen I and III or PDGF-B was examined by immunohistochemical assay or Western blot. ResultsThe renal tubulointerstitial injury score, interstitial collagen deposition, and the expression of collagen I, collagen III, PDGF-B, TGF-β1, CTGF were reduced in enalapril group compared with UUO group (P<0.05).Conclusion Enalapril is able to attenuate the tubulointerstitial fibrosis in UUO rats by decreasing the expression of cytokines including PDGF-B, TGF-β1 and CTGF.