冷保存再灌注期间离体肝组织内氧自由基及[Ca2+]i对p38MAPK激活的影响

目的:了解离体肝脏缺血再灌注期间氧自由基及钙离子超载是否是激活p38MAPK的因素之一,为进一步揭示肝脏缺血再灌注损伤的信号转导机制打下基础.方法:通过自行建立的兔离体肝脏缺血再灌注模型,根据冷保存液中别嘌呤醇浓度的不同分为A、B、C、D 4组;根据冷保存液中维拉帕米浓度的不同又分为E、F、G、H4组;分别于离体前、冷保存末及再灌注5 min、10 min、60 min、120 min获取离体肝组织,分别应用免疫映迹杂交(western-blot)和免疫沉淀法测定磷酸化p38MAPK的表达及活性水平;并进行肝组织内氧自由基(oxygenfree radicals,OFR)含量的测定(A、B、C、D组);用Fura-2/AM负载法进行肝细胞内钙离子浓度测定(A、E、F、G组).结果:于再灌注5 min各组离体肝组织的氧自由基水平升高至峰值,但各组两两之间存在显著性差异(A、B、C、D组:2.32±0.22,1.82±0.15,1.63±0.11,1.29±0.10,P＜0.05,t=2.57);于再灌注10 min供肝组织p38MAPK磷酸化水平及活性均升高至峰值,但各组两两之间存在显著性差异(A、B、C、D组p38MAPK磷酸化水平:76.2±7.0,61.4±5.9,47.3±2.5,37.7±3.0,P＜0.05,t=.61;A、B、C、D组p38MAPK活性水平:82.7±6.8,69.7±5.2,54.5±5.5,41.2±3.1,P＜0.05,t=2.61;A、E、F、G组p38MAPK磷酸化水平:80.3±8.7,63.3±4.2,50.4±5.6,39.2±5.7,P＜0.05,t=2.61;A、E、F、G组p38MAPK活性水平:80.8±8.9,66.7±4.2,53.7±4.1,39.4±5.5,P＜0.05,t=2.61);再灌注5 min时氧自由基及[Ca2+]j越高的离体肝,则再灌注10 min时离体肝组织p38活性峰值越高,二者之间呈显著性相关关系.(P<0.05,ROFR=0.976,RCa=0.970)结论:别嘌呤醇能显著性抑制离体肝缺血再灌注期间肝组织内OFR水平,而维拉帕米能显著性抑制离体肝缺血再灌注期间肝细胞内钙离子浓度超载;而且OFR水平及钙离子与离体肝组织p38MAPK的激活密切相关.

INTRODUCTION Although liver transplantation for irreversible liver diseases is increasingly prevalent worldwide, patient die while waiting for donors because of organ shortages. One important problem commonly encountered is that fatty livers often affect the outcome of liver transplantation. It is reported that the incidence of abnormal fatty livers in autopsies after accidental death ranged from 15% to 24%.Since fatty livers may result in a primary nonfunction (PNF) liver graft, which contributes to an increased risk of mortality[1], they are usually out of consideration in liver transplantation.However, some fatty livers can be successfully transplanted. Therefore, how to choose fatty livers as donor organs correctly is the crux of success in liver transplantation.