Abstract: 【Abstract】Objective To examine the effect and to explore the mechanism of EPO on renal interstitial fibrosis in the rat model of unilateral ureteral obstruction. Methods Sixty male Wistar rats were divided into sham-operation group (n=20), unilateral ureteral obstruction (UUO) group (n=20), and EPO group (n=20) in which UUO rats were treated with EPO 100IU/kg three times a week. Rats were sacrificed at day 3, 7, 14 or 21 after the treatment. The extent of renal interstitial fibrosis was evaluated by Masson staining of the renal tissue. Immunohistological method and western blot were used to estimate the expression of transforming growth factor-β1 (TGF-β1), and monocyte chemoattractant protein-1 (MCP-1). Results The extent of interstitial fibrosis was significantly lower in EPO group at day 3 and 7 after the operation, compared with that in UUO group (p<0.05). The expression of MCP-1 and TGF-β1 in renal tissue was significantly lower in EPO group than that in UUO group at day 3, 7 and 14, respectively (p<0.05). Conclusions EPO may reduce the extent of renal fibrosis in the rat UUO model. This effect may relate to the down-regulation of TGF-β1 and MCP-1 expression, but the exact mechanism needs to be further studied.

Key words: Erythropoietin, Transforming growth factor-β1, Monocyte chemoattractant protein-1