RESUMEN
OBJECTIVE To investigate the effect and mechanism of Astragalus polysaccharide （APS） on peritoneal fibrosis and angiogenesis in rats with peritoneal dialysis （PD）. METHODS Rats were randomly divided into normal control group （Control group）， model group （PD group）， 70 mg/kg APS group （APS-L group）， 140 mg/kg APS group （APS-H group）， and 140 mg/kg APS+40 mg/kg hypoxia-inducible factor-1α （HIF-1α） agonist DMOG group （APS-H+DMOG group）， with 12 rats in each group. PD rat models were constructed in the last four groups of rats. Administration groups were given APS intragastrically and DMOG intraperitoneally. Control group and PD group were given constant volume of normal saline intragastrically， once a day， for 4 consecutive weeks. After the last medication， the peritoneal ultrafiltration （UF）， mass transfer of glucose （MTG）， the levels of serum creatinine （Scr） and blood urea nitrogen （BUN） were detected in rats； peritoneal histomorphology and peritoneal fibrosis （peritoneal thickness and proportion of collagen fiber deposition） were observed； the microvascular density and the expression levels of α-smooth muscle actin （α-SMA）， laminin （LN）， HIF-1α and vascular endothelial growth factor （VEGF） proteins were detected in peritoneal tissue of rats. RESULTS Compared with Control group， the mesothelium of rats in the PD group was loosely arranged and shed， inflammatory cells infiltrated， the peritoneal thickness and proportion of collagen fiber deposition were increased significantly （P＜0.05）. The levels of MTG， Scr and BUN in serum， microvascular density and the expressions of α-SMA， LN， HIF-1α and VEGF proteins were significantly increased， while the level of UF was significantly decreased （P＜ 0.05）； compared with PD group， the levels of above indexes were significantly reversed in APS-L and APS-H groups （P＜0.05）， and the improvement of APS-H group was better than APS-L group （P＜0.05）. Compared with APS-H group， the levels of above indexes in APS-H+DMOG group were all reversed （P＜0.05）. CONCLUSIONS APS inhibits peritoneal fibrosis and angioge-nesis in PD rats by inhibiting HIF-1α/VEGF signaling pathway.