Abstract: Objective To observe the expression of VEGF,bFGF and TGF-β₁ in nephropathy induced by aristolochic acid I in rats.Methods 20 female Wistar rats were in the experiment group and their stomachs were perfused with 50 mg·kg^-1·d^-1(AAⅠ) one time per day for 7 d continuously,and 6 rats were in the control group whose stomachs were perfused with pure water per day for 7 d,too.In the test group,every week 5 rats were killed from the first to the fourth week respectively,and in the control group,3 rats were killed in the second and fourth week respectively.The expression and regulation of VEGF,bFGF and TGF-β₁ in kidney in all groups were examined with 2-step immunohistochemistry.Results Since the second week,the transparent renal tubular epithelial defect were found in each test group;in the initial stage,the lesion mainly situated in the proximal convoluted tubule,in the fourth week,the lesion involved all of the renal tubules. From the first to the fourth week,the positive expression of VEGF,bFGF and TGF-β₁ in the test groups showed a tendency to expand gradually,and which were wide spreadly distributing over every segment of the renal tubular epithelial cells in the cortex and medulla.The quantity and degree of positive cells increased strikingly,and there was significant difference between the control and the test groups in the mean expression quantity(P<0.01).Conclusion AAⅠ can injure the renal tubular epithelial cell directly and induce the expression of VEGF,bFGF and TGF-β₁.The early and super expression of VEGF,bFGF and TGF-β₁ in the renal tubular epithelial cells may be the important cause of renal tubular interstitial lesion and interstitial fibrosis.

Key words: aristolochic acid nephropathy, VEGF, bFGF, TGF-β₁, renal tubular interstitial lesion, renal interstitial fibrosis