Abstract Objective To assess the potential effects of Metformin on the development of tubulointerstitial fibrosis after acute renal ischemia-reperfusion. Methods Twenty-four male Sprague Dawley rats were randomly assigned to three groups: Sham group, I/R group and Metformin group (n = 8). Twelve weeks after reperfusion, levels of serum urea nitrogen (BUN) and creatinine (Cr) were assessed; Hematoxylin-eosin (H&E) and Masson′s trichrome staining were used to assess renal fibrosis; the expression spot and protein levels of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were analyzed by immunohistochemistry (IHC) and Western blot. Results There was no statistically significant difference in levels of Cr and BUN among Sham group, I/R group and Metformin group (P > 0.05). Compared with the Sham group, tubulointerstitial fibrosis was more obvious in the I/R group and the Metformin group; however, the level of tubulointerstitial fibrosis in the Metformin group was less than that of the I/R group. Compared with the Sham group, the levels of α-SMA and TGF-β1 were significantly increased in the I/R group and the Metformin group, the expression of α-SMA and TGF-β1 in the Metformin group were significantly decreased compared with those in the I/R group; the differences were statistically significant (P < 0.01). Conclusion Administration of metformin significantly attenuated tubuleinterstitial fibrosis following I/R in rats, potentially via down-regulating expressions of α-SMA and TGF-β1.
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