缺血预处理对缺血再灌注的大鼠肝脏中肿瘤坏死因子—α、细胞间黏附分子—1 mRNA表达的影响

目的 通过观察缺血预处理对缺血再灌注大鼠肝脏中的一些生化指标的变化，以及肿瘤坏死因子－α和细胞间粘附分子－1 mRNA表达的变化，研究缺血预处理对缺血再灌注损伤的干预方式及干预程度。方法 利用大鼠肝脏缺血再灌注损伤模型，比较缺血预处理组与缺血再灌注组以及各预处理组间在血清天冬氨酸转氨酶、丙氨酸转氨酶、乳酸脱氢酶，肝组织中丙二醛、过氧化物歧化酶等生化指标的含量变化，并观察了组织中中性粒细胞（PMNs)浸润量，研究了TNF－α及ICAM－1 mRNA表达的变化。结果 各预处理组酶的漏出和脂质过氧化物的形成减少，抗氧自由基能力增强，组织中PMNs浸润量降低。TNF－α和ICAM－1mRNA表达减少。结论 缺血预处理对肝脏缺血再灌注损伤有显著的保护作用。一次缺血10min再灌注10min的预处理保护效果最佳。缺血预处理的干预机制可能是通过下调TNF－α和ICAM－1 mRNA表达，减轻PMNs在病变部位聚集及其所产生的病理损伤作用而实现的。

Effect of ischemic preconditioning on the expression of tumor necrosis factor and intercellular adhesion molecule-1 mRNA in rat hepatic ischemia reperfusion

Objective To study the molecular mechanism of preconditioning on liver ischemia reperfusion(I/R) injury by examining the expression of tumor necrosis factor alpha(TNF-a) and intercellular adhesion molecular-l(ICAM-1) mRNA. Methods Hepatic ischemia reperfusion rat model was used to evaluate the levels of plasma、alanine transferase(ALT), lactate dehydrogenase(LDH), superoxide dismutase(SOD), the numbers of polymorphonuclear cells(PMNs), the expression of TNF-a and ICAM-1 mRNA. Results ;;;In preconditioning groups, leakage of enzymes and production of lipid peroxidation decreased, while the ability of anti-free radicals increased. Infiltration of PMNs in the liver increased. The levels of TNF-a and ICAM-1 mRNA both declined. Conclusion Preconditioning significantly protects liver from ischemia-reperfusion injury. Ten min ischemia followed by 10 min reperfusion produces better protection on liver I/R injury. The mechanism of preconditioning is to down-regulate the expression of TNF-a and ICAM-1 mRNA, so as to reduce infiltration of PMNs in reperfused liver.