脑死亡时猪肝脏功能及组织学改变的研究

目的 观察脑死亡对猪肝脏功能、形态的影响并探讨核因子κB(nuclear factor κB,NF-κB)在脑死亡发生机制中的作用.方法 健康长白猪12头,随机分为2组:对照组6头,仅行麻醉维持24 h;脑死亡组6头,建立猪脑死亡模型并维持脑死亡状态24 h.脑死亡后(对照组持续麻醉后)6、12、24 h取血标本及开腹取同一部位肝组织,检测血清中丙氨酸氨基转移酶(alanine aminotransferase,ALT)、天冬氨酸氨基转移酶(espartate aminotransferase,AST)水平;ELISA法检测血清白细胞介素1β(intedeukin-1β,IL-1β)水平;实时荧光定量PCR(real-time fluorescence quantitative polymerase chain reaction,real-time PCR)法检测肝组织NF-κB mRNA变化;免疫组织化学法观察肝组织NF-κB p65蛋白表达情况.结果 脑死亡组长白猪各时间点血清ALT、AST、IL-1β水平、肝组织NF-κB mRNA转录水平及肝组织NF-κB p65蛋白表达水平均较对照组高,两者相比差异有统计学意义(P<0.05).脑死亡组脑死亡后12 h肝细胞轻度浊肿;24 h细胞水肿,肝细胞疏松化.结论 脑死亡导致猪肝脏出现功能与形态学的损伤性变化.其机制可能是脑死亡引起肝细胞NF-κB mRNA 转录和蛋白翻译水平升高,进而导致机体炎症介质合成与释放.

Alterations of hepatic function and histology in brain death pigs

Objective To observe how brain death affects the hepatic morphology and function of pigs and explore the roles of NF-κB. Methods Under general anaesthesia twelve healthy pigs were allocated randomly to two groups:control group(6 pigs),with non-inflacted Foley balloon catheter placed in the cerebral ventricle for 24 h,and brain death group,6 pigs,with estabhshment of brain death for 24 h.The serum and hepatic tissues in the same locus were taken at 6 h,12 h,and 24 h after the initial conformation of brain death.AST and ALT were determined by automatic biochemistry analyzer.IL-1βwas determined by ELISA.The NF-κB mRNA was determined by Real-time PCR and the NF-κB p65 by immunohistochemistry. Results The AST,ALT,IL-1β in serum,the NF-κB mRNA and the NF-κB p65 in hepatic tissues in brain death group were higher than those in control group and they all increased with the time(P<0.05).In brain death group,hepatocytes were edematous lightly after 12 hours,and the swelling progressively deteriorated after 24 hours,but there were no necrosis. Conclusion The activated NF-κB by brain death promoted the synthesis and release of inflammatory mediators,resulting in the hepatic dysfunction.