不同+Gz暴露后大鼠脑皮层HSP70 Mrna表达水平的变化

目的：观察不同大小的＋Gz暴露对大鼠脑皮层HSP70 mRNA表达水平的影响，探讨＋Gz暴露致脑损伤的机制。方法：80只SD大鼠随机分为对照组、＋2Gz暴露组、＋6G2暴露组和＋10Gz暴露组。各组在G暴露后的5h、10h、1d、2d和4d分批处死，采用原位分子杂交方法观察大鼠脑皮层HSP70 mRNA表达情况，并对实验结果进行统计分析。结果：3个＋G2暴露组，HSP70 mRNA表达水平表现出相同的变化趋势：即在＋Gz暴露后5h,HSP70 mRNA表达水平开始增加，10h达峰值，4d时基本恢复正常，而对照组没有这一变化趋势。不同G值之间的比较表明，＋6Gz组HSP70 mRNA总体表达水平最高，且分布较广泛，＋10Gz组最低，且分布较局限，主要位于靠近颅底部的皮层中。结论：＋Gz暴露对大鼠脑皮层HSP70 mRNA表达水平有着显著的影响。

Changes of expression level of HSP70 mRNA in rat cortex after exposure to +Gz of different magnitudes

Objective To observe changes of expression level of HSP70 mRNA in rat cortex after exposure to +G z of different magnitudes and investigate the mechanism of brain injury induced by +G z exposure.Methods Eighty rats were divided into 4 groups: control group, +2 G z group, +6 G z group, +10 G z group. The experimental rats underwent +2 G z, +6 G z, +10 G z exposure for 3 min . respectively. The rats were killed 5 h,10 h,1 d,2 d,4 d after exposure and brain specimens were got for sliding. The changes of HSP70 mRNA expression level were observed using in situ hybridization technology. Results The HSP70 mRNA expression level in 3 experimented groups were significantly higher than that of control group. It began to rise at 5 h after exposure, reached to peak at 10 h , and resumed to normal 4 d after exposure. The expression level was highest in +6 G z group and lowest in +10 G z group. The scope of expression was most extensive in +6 G z group, while in +10 G z group the expression was limited to bottom of the cortex. Conclusion The +G z exposure can induce obvious changes of HSP70 mRNA expression level and the most prominent changes were found in +6 G z group.