Changes of HSP70 mRNA and Protein Expression by Different Levels of + Gz Exposure in Rat Liver

Zhu Huaicheng; Zhang Hongyi; Liu Chengli; Zhao Gang; Kong Yalin

Abstract：Objective To observe changes of expression level of HSP70 mRNA and protein in rat liver under + Gz exposure,and to explore the physiological and pathological mechanisms of these changes.Methods There were 100 rats divided into four groups randomly.One of the groups was blank control,and the other three groups proceeded in exposure conditions of + 2 Gz,+ 6 Gz and + 10 Gz.The peak working time was 3 min,and the growth rate of acceleration speed is 1 G/s.Post + Gz exposure 6 h,12 h,24 h,48 h and 96 h,liver tissues of rats were taken out after anaesthetized and sacrificed immerdiately.The expression levels of HSP70 mRNA and HSP70 in rat livers were tested with RT-PCR and Western blot.Results Compared with the control group,the expression levels of HSP70 mRNA and HSP70 of three + Gz groups were significantly rised at 6 h,12 h,24 h,48 h after exposure of + Gz (P ＜ 0.05),but at 96 h after exposure,the expression levels of HSP70 mRNA and HSP70 had no significant increase (P ＞ 0.05).The expression levels of HSP70mRNA and HSP70 began to rise from post-exposure 6 h,until 12 h it reached the peak.At the same post-exposure time,the expression levels of HSP70 mRNA and HSP70 under three different + Gz conditions were compared,the +6 Gz group was the highest,the +2 Gz group was the second,the + 10 Gz group was the lowest(P ＜ 0.05).Post-exposure 12 h,the expression level of HSP70 mRNA and HSP70 of group +2 Gz,+6 Gz,+ 10 Gz had the same trend.Conclusion The expression of HSP70 mRNA and HSP70 in rat liver is increased in post-exposure of + Gz conditions,which can enhance the protection of the liver by a compensatory mechanism to increase the expression level of HSP70.