脓毒症小鼠肝脏功能的改变及Leptin保护作用的研究

Changes of hepatic function in sepsis mice and protective effects of Leptin on it

目的:研究脓毒症对肝功能及相关酶活性的影响,探讨Leptin在急性炎症反应中的作用。方法:建立小鼠盲肠结扎致脓毒症模型,设立假手术组、脓毒症组、Leptin保护组(腹腔内注射0.1 mg/kg Leptin)和消炎痛(吲哚美辛)保护组(腹腔内注射2 mg/kg消炎痛)。于脓毒症后6 h和12 h,采用放射免疫法测量肝组织匀浆液中Leptin水平,采用96孔分光光度法检测血清丙氨酸氨基转移酶(ALT)及髓过氧化物酶(MPO)、谷胱甘肽-S转移酶(GST)、黄嘌呤氧化酶(XOD)、超氧化物歧化酶(SOD)等4种与自由基合成、解毒和嘌呤生成代谢相关的酶的水平,同时以H-E染色法观察肝组织病理学改变。结果:与假手术组相比,脓毒症组伤后12 h血清ALT明显上升(P<0.05),6 h时无显著改变。Leptin保护组在12 h时可见ALT显著低于脓毒症组水平(P<0.05),消炎痛保护组在6 h和12 h时有ALT下降,但无显著差异。Leptin保护组和消炎痛保护组肝组织内MPO活性没有显著变化,但GST和SOD活性明显降低(P<0.01,P<0.05),同时XOD活性明显增加(P<0.05)。另外,脓毒症组肝内Leptin有下降趋势,Leptin保护组肝内Leptin水平有所恢复,而消炎痛保护组肝内Leptin水平也有所恢复,但在12 h时与脓毒症组有显著差异(P<0.05)。结论:Leptin对脓毒症造成的肝功能损害有明显保护效应,其保护作用可能涉及肝细胞代谢过程中氧化-还原反应、氧自由基形成和解毒功能的调节。

Objective：To study the influence of sepsis on hepatic function and corresponding enzymes in mice and to explore the role of Leptin in acute inflammation. Methods： Mice sepsis models were established through cecum ligation and perforation. Mice were divided into sham-operation, sepsis, leptin-protection （peritoneal injection of 0. lmg/kg Leptin） and indomethacin- protection （peritoneal injection of 2 mg/mg indomethacin） groups. Six and twelve hours after sepsis, leptin levels in liver homogenate were detected by radioimmunoassay; serum alanine aminotransferase （ALT） and 4 enzymes in liver homogenate, myeloperoxidase （MPO）, glutathin-S-transferase （GST）, xanthine oxidase （XOD） and superoxide dismutase （SOD）, all related with synthesis of free radicals, detoxication and purine metabolism, were detected by 96 well spectrophotometry. H-E staining was used to examine the histopathologic changes of liver. Results： Compared with the sham group, sepsis group had an in- creased serum ALT level （P〈0.05） at 12 h after sepsis, but not at 6 h. Serum ALT was significantly lower in Leptin-protection group than in sepsis group 12 h after sepsis （P〈0.05）. Indomethacin injection had no obvious effect on serum ALT at either 6 h or 12 h after sepsis. Both leptin and indomethacin had no significant effect on hepatic MPO activity, but decreased GST （P〈0.01） and SOD （P〈0.05） activities and increased XOD （P〈0.05） activity. Leptin decreased in sepsis mice but recovered after leptin injection. Indomethacin injection also recovered Leptin level and the level was significantly higher than that of sepsis group at 12 h （P〈0.05）. Conclusion： Leptin has obviously protective effect on sepsis-induced hepatic injury, the mechanism of which may be related to oxidoreductive reaction, synthesis of oxygen free radicals and detoxication in the metabolic process of hepatic cells.