麦角新碱预处理对减轻大鼠移植肝缺血再灌注损伤的作用

目的 探讨使用外源性药物麦角新碱预处理对减轻大鼠移植肝缺血再灌注损伤的作用.方法 在大鼠的门静脉-左肾静脉搭桥、肝后下腔静脉内置管分流法自体原位肝移植模型中,于肝门阻断前10 min经大鼠尾静脉注射麦角新碱;观察移植肝缺血前和再灌注后5 min、30 min、2 h时血清一氧化氮(NO)和血浆内皮素1(ET1)水平以及NO/ET1的比值变化;测定血清丙氨酸转氨酶(ALT)酶学差异和肝组织内三磷酸腺苷(ATP)和丙二醛(MDA)含量变化;再灌注2 h取肝组织检测肝细胞、肝小叶超微结构.结果 应用麦角新碱预处理的大鼠移植肝缺血前门脉血浆中ET1升高(P＜0.01),但再灌注后5 min、30 min时,血浆中ET1水平降低(P＜0.05);而缺血前NO/ET1比值降低(P＜0.01),再灌注后5 min时,NO/ET1比值升高(P＜0.01);再灌注后ALT的升高有逐渐降低趋势;再灌注后2 h肝细胞内超微结构的损害程度减轻.结论 使用麦角新碱预处理能减轻大鼠移植肝缺血再灌注损伤.移植肝缺血再灌注损伤的靶细胞是肝血窦内皮细胞,NO/ET1比值平衡可能是影响移植肝微循环血流量变化的调节因素.

Protective effect of ergonovine pretreatment on ischemia-reperfusion injury of the hepatic grafts in rats

Objective To investigate the effect of ergonovine pretreatment on ischemia-reperfusion injury of the hepatic grafts in rats. Methods In the auto-orthotopic liver transplantation model of rats,ergonovine was injected via the tail vein of rats 10 min before hepatic portal occlusion. Before is chemia and 5 min,30 min and 2 h after perfusion in the hepatic grafts, changes in serum NO and plasma ET1 levelS and the ratio of NO/ET1 were observed. Serum ALT and contents of ATP and MDA in liver tissues were determined. At 2nd h post-reperfusion,the changes in ultrastructures of hepatocytes and hepatic lobules were examined. Results In the rats pretreated with ergonovine,plasma ET1 levels in portal vein of transplanted liver before ischemia was elevated(P＜0.01),but 5 and min after reperfusion,serum ET1 levels were reduced(P＜0.05). Before ischemia,the ratio of NO/ET1 was decreased(P＜0.01),but that was increased 5 min after reperfusion(P＜0.05).After reperfusion,ALT levels had a trend of gradual decrease. Moreover, ergonovine could improve the microculation of transplanted liver with ischemia-reperfusion injury, and alleviate the damage to the hepatic ultrastructures. Conclusions Pretreatment with ergonovine could alleviate the transplanted liver ischemia-reperfusion injury. The ratio of NO/ET1 may be the regulatory factor involved in the blood flow of the transplanted liver microcirculation.