高海拔地区大鼠严重烧伤延迟复苏后肝脏HSP70的表达及其意义

HSP70 expression in liver tissue of severe scald rats treated with delayed fluid resuscitation at high altitude

目的:探讨高海拔地区大鼠严重烧伤延迟复苏后肝脏HSP70表达的意义及与肝损伤的关系。方法:雄性Wistar大鼠240只,分别在海拔1 517 m和3 848 m分为即时复苏组(IFR,n=60)、延迟复苏组(DFR,n=50)和假伤组(SG,n=10),建立30%体表面积Ⅲ度烫伤模型,分别于伤后1、6、12、24、72和168 h取材。采用组织病理学、组织芯片技术、原位末端标记(TUNEL)法、免疫组织化学染色与图像分析技术,观察肝组织病理学改变与细胞凋亡及HSP70蛋白的表达。结果:两个海拔高度HSP70表达强度,实验组均高于假伤组,高海拔组表达强度均高于低海拔组的强度,各海拔高度DFR组高于IFR组(P<0.05);肝细胞凋亡率DFR组高于IFR组,且高海拔组高于低海拔组(P<0.05)。结论:HSP70可能参与肝缺血缺氧等应激损伤过程,HSP70在一定程度上反映机体应激水平和损伤程度,其表达可能与肝细胞自我保护机制启动有关。

Objective：To study the HSP70 expression in liver tissue of severe scald rats treated with delayed resuscitation at high altitude.Methods：A total of 240 Wistar rats were employed as the experimental models（30%TBSA,Ⅲ degree）,and they were randomly divided into 3 groups at different altitudes（1 517 m and 3 848 m）：immediate fluid resuscitation group（IFR,n=60）,delayed fluid resuscitation group（DFR,n=50）,and sham group（SG,n=10）.The liver tissues of rats were harvested at 1,6,12,24,72 and 168 h after severe scald respectively.The pathological changes,HSP70 expression and apoptosis rate in liver tissue were detected by tissue microarray,TUNEL,immunohistochemistry,image analysis and pathological technique.Results：The expression level of HSP70 in DFR and IFR was significantly higher than those in SG,higher at 3 848 m altitude than those at 1 517 m altitude,and higher in DFR than those in IFR（P0.05）.The apoptosis percentage in liver tissue in DFR was significantly higher than those in IFR,and higher at 3 848 m altitude than those at 1 517m altitude（P0.05）.Conclusion：HSP70 may participate in liver injury caused by severe scald at high altitude.The HSP70 expression may be related to the initiation of self-protection mechanism of liver cell,which reflects the stress reaction of organism and the injury degree to a certain extent.