热适应与热应激对大鼠肝细胞HSP70表达的影响

Expression of HSP70 in liver cells of rats undergoing heat acclimation and heat stress

目的 :研究不同时段的热适应及再经受热应激时大鼠肝细胞HSP70的表达变化及临床意义。方法 :采用人工热气候室 ,建立热适应 (34℃± 1℃、相对湿度 6 0 % )和热应激 (4 1℃± 1℃、相对湿度 80 % )动物模型。SD大鼠 16 0只 ,分为对照组、热适应组、热适应后热应激组、单纯热应激组 ,每组又分为 2、7、14、2 8d四个时段。取肝组织作免疫组化SP法染色 ,应用图像分析系统分析组织HSP70含量的变化。结果 :在热适应的四个时段 ,肝细胞的HSP70表达强度呈如下趋势 :热适应后热应激组 >热适应组 >对照组 ;单纯热应激组 >对照组 (P <0 .0 1或 0 .0 5 ) ;适应时段对HSP70表达强度变化无明显影响 ;2d时热适应组和热适应后热应激组的HSP70阳性枯否氏细胞数显著高于对照组 (P <0 .0 5 ) ,单纯热应激组与对照组无差别。结论 :热应激与热适应都可作为独立因素使肝细胞中HSP70表达增强 ,热适应加热应激则使HSP70表达更进一步加强 ;

Objective:To investigate the changes of HSP70 expression in different heat acclimation stages and heat stress and its significance.Methods:The heat acclimation(34℃±1℃,rh60%) and heat stress(41℃±1℃,rh80%)models were established in experimental rats.160 SD rats were distributed randomly into control group(C) and heat acclimation group(A),heat acclimation add stress group(AS),heat stress group(S),and into subgroups including 2 d,7 d,14 d,28 d stages from each group.The immunocyto-chemistry was used in detecting HSP70 expression in the liver of rats and photography analytic software was used in analyzing HSP70 expression.Results:The expression intensity of HSP70 in liver cells in various groups were as follows:AS>A>C,S>C(P<0.01 or P<0.05)during all stages of heat acclimation.Kuffer's cells of liver expressed evidently HSP70 in both A and AS groups in 2 d stage,but not in S group.Conclusion:Both heat acclimation and heat stress can increase the expression of HSP70 and heat stress after on heat acclimation increases the expression intensity of HSP70 much more.An increasing expression of HSP70 in Kuffer's cell of liver in the 2 d stage is resulted from heat adaptation.