目的　探讨N -去硫酸肝素对肝和肾缺血 再灌流损伤的防治作用。方法　分别建立大鼠肝及肾缺血 再灌流损伤模型 ,观察和比较经N 去硫酸肝素处理前后大鼠肝、肾组织P 选择素表达 ,组织病理学改变及肝、肾功能变化 ,以及对凝血指标 (PT和KPTT)的影响。结果　肝、肾缺血再灌流后 ,大鼠肝、肾组织内P -选择素广泛表达 ,出现明显的组织病理学改变及肝、肾功能损伤。经给予N -去硫酸肝素处理后 ,肝、肾组织P -选择素表达受到抑制 ,组织病理学改变减轻 ,肝、肾功能得到改善。进一步发现N -去硫酸肝素对PT和KTPP无明显影响。结论　N -去硫酸肝素可能通过间接抑制P -选择素作用 ,而对肝和肾缺血 -再灌流损伤起到防治效果 ,且对凝血指标无明显影响 Objective To investigate the preventive and therapeutic effects of N - desulfated heparin on liver and renal ischemia - reperfusion injury. Methods The models of liver and renal ischemia-reperfusion injury in rats were established respectively. The expression of P-selectin, histopathological changes, liver and kidney function in liver and kidney of rats before and after treatment with N-desulfated heparin were observed and compared. Indicators (PT and KPTT) effects. Results After liver and kidney ischemia and reperfusion, the expression of P - selectin in liver and kidney tissues of rats was extensively expressed, with obvious histopathological changes and liver and renal dysfunction. After administration of N - desulfated heparin, the expression of P - selectin in the liver and kidney tissues was inhibited, the histopathological changes were alleviated and the liver and kidney functions were improved. It was further found that N - desulfated heparin had no significant effect on PT and KTPP. Conclusions N - desulfated heparin may prevent and treat hepatic and renal ischemia - reperfusion injury by indirectly inhibiting the effect of P - selectin, and has no obvious effect on the coagulation index