[Effect of enalapril on the expression of TGF-beta1, p-Smad2/3 and Smad7 in renal interstitial fibrosis in rats].

OBJECTIVE: To explore the mechanism of enalapril for renal interstitial fibrosis by observing the effect of enalapril on the expression of transforming growth factor-beta1(TGF-beta1), p-Smad2/3 and Smad7 in renal tissuess of unilateral urethral obstruction (UUO) rat model. METHODS: Thirty female Sprague-Dawley(SD) rats were randomly subdivided into a sham-operated group, a model group and an enalapril treated group. UUO model was induced by ligating the left ureter of rats. All rats were sacrificed 14 days after UUO. Pathological changes of the renal tissue were observed by HE and Masson staining, the protein expressions of Collagen I (ColI), TGF-beta1, p-Smad2/3 and Smad7 were detected by immunohistochemical staining,and the mRNA expressions of TGF-beta1 and Smad7 were detected by RT-PCR. RESULTS: The renal interstitial damage index, the relative Collagen area and the expression of ColI in the model group significantly increased(P<0.01). Enalapril reduced these indexes. The protein and mRNA expressions of TGF-beta1 and the protein expressions of p-Smad2/3 were low in the sham-operated group, but were strongly positive in the model group, and enalapril could decrease the expressions of TGF-beta1 and p-Smad2/3(P<0.01). The protein and mRNA expressions of Smad7 in the model group were less than that in the sham-operated group(P<0.01),and enalapril could improve the expressions of Smad7(P<0.01). CONCLUSION: Enalapril could inhibit the renal interstitial fibrosis by affecting TGF-beta1, p-Smad2/3 and Smad7 of TGF-beta/smads pathway in the renal tissues of UUO rats.