缺血预处理通过抑制白三烯C4生成减轻大鼠肝缺血再灌注损伤

Ischemic preconditioning protects against hepatic ischemia-reperfusion injury by attenuating leukotriene C4 production

目的:研究缺血预处理(IP)减轻大鼠肝脏缺血再灌注(I/R)损伤是否涉及前炎症因子白三烯C4(LTC4)。方法:健康成年雄性SD大鼠随机分为3组(每组6只)。I/R组:采用大鼠部分(70%左右)肝脏缺血60min再灌注5 h模型,缺血前15 min开始至复灌5 h经颈外静脉输注生理盐水(3 mL.kg-1.min-1);假手术组:只麻醉开腹,不阻断肝脏血流;IP组:在I/R前先阻断肝左、中叶血流10 min,然后开放血流10 min,余步骤同I/R模型组。应用反相高效液相色谱法(RP-HPLC)检查肝组织LTC4含量,同时生化检测血清丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)活性和肝组织谷胱甘肽(GSH)含量,以及HE染色法检查肝组织学损伤。结果:肝脏IP处理完全逆转了再灌注5 h所致肝组织LTC4含量增加(P<0.05);同时增加肝组织GSH含量,明显降低血清ALT和AST活性(P<0.05),并减轻肝脏组织结构损伤。结论:IP处理减少肝脏I/R期间LTC4堆积,同时伴随血清肝酶释放减少和肝组织结构损伤降低,以及保护肝组织氧化还原状态,表明IP的有利影响可能涉及其在肝脏I/R损伤期间抑制LTC4生成。

AIM： To investigate the effect of ischemic preconditioning （IP） on leukotriene C4 （LTC4） gener- ation during hepatic ischemia-reperfusion（I/R） injury. METHODS： Adult male Sprague-Dawley rats were randomly di- vided into sham （control） group, I/R group and 1P ＋ I/R group. The rat liver was subject to 60 rain of partial hepatic is- chemia followed by 5 h of reperfusion. LTC4 content was measured by reversed-phase high-performance liquid chromatogra- phy （RP-HPLC）. The activity of serum alanine aminotransferase （ALT） and aspartate aminotransferase （AST） was deter- mined, and the changes of histological structures were observed to assess the tissue injury. The reduced glutathione （GSH） level in the liver tissues was also examined by biochemical methods. RESULTS： IP markedly decreased LTCA content in rat livers compared with I/R group. The activity of serum ALT and AST in I/R group and IP ＋ I/R group was higher than that in control group. Compared with I/R group, the levels of serum ALT and AST were markedly decreased, and the level of GSH in hepatic tissues was elevated in IP ＋ I/R group. In addition, the structural damage of the rat liver tissues in IP ＋ I/R group displayed slighter than that in I/R group. CONCLUSION： IP treatment reduces LTCA production accompanied with improving the liver function and histological structure during I/R injury, suggesting that the beneficial effects of IP may be involved in its repressing LTC4 generation during hepatic I/R injury.