AIM: To investigate the inhibitory effect of tea polyphenols (TP)on the transforming growth factor-β1 (TGF-β1)expression in rat model of cyclosporine A (CsA)-induced chronic nephrotoxicity. METHODS: The rat model of CsA-induced chronic nephrotoxicity was used, 4 groups of rats were respectively treated with vehicle (0.1 mL·kg^-1.d^-1sc), TP (80 mg.kg^-1.d^-1 ig), CsA (15 mg.kg^-1.d^-1sc) and TP plus CsA (CsA 15 mg.kg^-1.d^-1 sc+TP 80 mg.kg^-1.d^-1ig).At the end of day 28 of treatment, serum and urine are analyzed for creatinine clearance, kidney tissue for pathologic analysis. The TGF-β1 mRNA and its protein expression were detected by RT-PCR, immunohistochemistry,and Western blot. RESULTS: CsA-treated rats had increased renal expression of TGF-β1 mRNA and its protein,compared with the vehicle- or TP- treated controls. The renal function and interstitial fibrosis were ameliorated and renal expression of TGF-β1 mRNA and its protein was decreased in animals treated with CsA plus TP, compared with aminals treated with CsA alone (P<0.05). CONCLUSION: TP significantly inhibits renal expression of TGF-β1 in rat model of cyclosporine-induced chronic nephrotoxicity, suggesting that the decreased renal expression of TGF-β1 exerted by TP is one of mechanisms to protect renal function and tissue structure.

完成机构：[1]DepartmentofHepatobiliarySurgery,theFirstAffiliatedHospital,MedicalCollege,ZhejiangUniversity [2]DepartmentofHepatobiliarySurgery,theFirstAffiliatedHospital,MedicalCollege,ZhejiangUniversity [3]DepartmentofPathology,MedicalCollege,ZhejiangUniversity [4]InstituteofSurgery,ZhejiangUniversity,Hangzhou310003,China

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