OBJECTIVETo study the effects of puerarin on pulmonary Vascular remodeling in rats with pulmonary hypertension induced by chronic hypoxia and hypercapnia.

METHODForty male rats (180-220) g of grade two were randomly divided into five groups: normal control group (NC), hypoxia-hypercapnia 1, 2, 3 week groups (LH1, LH2, LH3) and hypoxia-hypercapnia 3-week + puerarin group (LHP3 group, puerarin intraperitoneal injection, 20 mg x kg(-1) x d(-1)). Collagen I, III and their mRNA were observed in pulmonary arterioles by the technique of immunohistochemistry and in situ hybridization.

RESULTLight microscopy showed media thickness of pulmonary arterioles was much higher in LH3 group than that of NC group, and, vessel cavity turned more straiter in LH3 group than that of NC group. Howerer, the damage of pulmonary arterioles in LHP3 group was much slighter than that of LH3 group. The levels of plasma ET-1 and lung homogenates Hyr and MDA were much higher in rats of LH3 group than those of NC group (P < 0.01), and lower in LHP3 group than LH3 groups (P < 0.01). The activities of SOD in lung homogenates were significantly lowered in hypoxic and hypercapnic groups compared with control group (P < 0.01), but higher in LHP3 group than that of LH3 group. Plasma NO content of group LH was lower than that of group NC (P < 0.01), it was highter in group LHP3 than that of group LH3 (P < 0.01). Expression of collagen I and collagen I mRNA in pulmonary arterioles were significantly higher in rats of LH groups than those of NC group (P < 0.01), and they were lower in rats of LHP3 group than those of LH3 group (P < 0. 01). Expression of collagen III and collagen III mRNA were not significant difference among three groups.

CONCLUSIONPuerarin could improve pulmonary vascular remodeling in rats with pulmonary hypertension by inhibiting the deposition of collagen.