缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用

目的探讨在体条件下缺血后处理对大鼠移植肝缺血再灌注损伤的保护作用及其可能机制。方法采用SD大鼠原位肝移植模型,供肝冷保存时间100min,无肝期控制于18min以内,60只雄性健康SD大鼠随机分为3组,对照组12只,缺血再灌注损伤组和后处理组各24只。对照组开腹后仅游离肝周韧带;缺血再灌注损伤组受体大鼠供肝切除前仅以肝素化生理盐水经门静脉灌注;后处理组供肝植入后完全再灌注前,给予多次短暂复灌复停作为缺血后处理。缺血再灌注损伤组、后处理组受体一半（6只）于再灌注后2h留取血液及肝组织,另一半（6只）于再灌注后6h留取肝组织。对照组于关腹后相应时间留取血液及肝组织。各组分别检测肝功能,采用酶联免疫吸附法测定血清肿瘤坏死因子Or．和中性粒细胞弹性蛋白酶。根据酶促反应原理,利用分光光度仪测定肝脏谷胱甘肽过氧化物酶、丙二醛、髓过氧化物酶、超氧化物歧化酶。肝组织HE染色后光镜下观察组织学变化。结果缺血再灌注损伤组和后处理组血清肝功能指标、炎性细胞因子水平及肝组织过氧化物含量均高于对照组（P〈0．05）,而后处理组较缺血再灌注损伤组则明显低（P〈0．05）;缺血再灌注损伤组和后处理组肝组织抗氧化酶活力显著低于对照组（P〈0．05）,而后处理组较缺血再灌注损伤组则明显高（P〈0．05）。结论缺血后处理对大鼠移植肝的缺血再灌注损伤有明显的保护作用。提高组织的抗氧化能力和降低炎性细胞因子水平可能是缺血后处理保护作用的机制之一。

Protective effect of ischemic postconditioning on ischemic reperfusion injury of rat liver graft

Objective To observe the protective effect of ischemic postconditioning on ischemic reperfusion injury of rat liver graft and to investigate the possible mechanism.Methods Male Sprague Dawley rats were used as donors and recipients of orthotopic liver transplantation,and the period of cold preservation and anhepatic phase were 100 min and 18 min,respectively.Sixty rats were randomly divided into three groups,twelve rats in control group,twenty-four rats in ischemical reperfusion injury group and ischemic postconditioning group respectively.Control group is sham operation group,only the ligaments around liver were cut off;donor livers in ischemical reperfusion injury group were infused through portal vein with heparinized saline before harvested;ischemic postconditioning group: at very onset of reperfusion after donor liver was implanted,several brief reperfusion-ischemia were given before persistent reperfusion of portal vein.Half recipients of ischemical reperfusion injury group and ischemic postconditioning group were taken blood samples and hepatic tissue samples after 2 hours of reperfusion of liver graft.Rest recipients were taken samples of hepatic tissue after 6 hours of reperfusion.Recipients of control group were taken blood and hepatic tissue samples at corresponding time after abdomen was sutured.Results Compared with ischemical reperfusion injury group,liver functional parameters,cytokines and peroxidized products contents were lower in ischemic postconditioning group(P<0.05);meanwhile,the antioxidases contents of hepatic tissue were higher in ischemic postconditioning group than those in ischemical reperfusion injury group(P<0.05).Conclusions Ischemic postconditioning could relieve the ischemic reperfusion injury of rat liver(graft.) Through improving antioxidation capability and cutting down cytokines(contents,) ischemic postconditioning could apply its protective effect.