Studies On Correlativity Of+Gz Exposure And HSP70 Gene Expression Of Brain

Modem high-performance aircrafi has very good flexibility. The positive acceleration that it produced can reach almost +9Gz and last for 45s. It's beyond the endurance limit of pilots. With the serve of the high-performance aircraft, the probabilities of +Gz-induced loss of consciousness (G-LOC) have obviously increased, which have become the main factor that affect flying safety. In order to improve the endurance ability of +Gz, the pilots were subjected to high G simulated training with the human centrifuge, and some scientists think experience of G-LOC should be used as one of training item. However, whether repeated high G exposure can injure the brain of pilots and produce cumulative effect? Whether repeated low G exposure can protect pilots from later high G exposure injury? What is the reason of this protection, if it indeed have the protect effect? There is very important meaning to clarify these problems for guiding +Gz training of pilots and ensure flying safety. It's one of main research problems of aviation medicine field that influence pilots?brain. Heat shock protein 70(HSP7O) is the most important and conservative protein in heal shock protein (HSP) family. Most scientists think that HSP7O can protect brain from injury induced by brain ischemia and anoxia. The purpose of this study is to open out the law of expression of gene under difference +Gz exposure level, and validate the pertinence of +Gz exposure level and gene expression by observing the expression of HSP7O gene in rats?brain after +Gz exposure. Thereby, we can get the molecule mechanism of brain injury induced by +Gz exposure and provide theory for high G protection. In this study, we used SD rats exposed under the condition of +Gz with animal centrifuge (the rats offered by animal experiment center of the fourth military medical university), then the rats were anaesthetized and the rats brain were got after heart perfusion at the time of lh, ld, 2d, 4d, 6d after +Gz exposure. The in situ hybridization technology were used to study the changes of expression level of HSP7OmRNA in rats brain under the condition of +Gz exposure, the immunohistochemistiy and Western blot method were used to observe the influence of HSP7O protein expression level after +Gz exposure, the electron microscope and pathology slice technology were used to study the changes of pathology injury of rats brain after +Gz exposure. Changes of expression level of HSP7OmRNA in rats?brain after +Gz exposure The results of in situ hybridization technology showed: The expression level of HSP7OmRNA increased obviously in rats?brain under the condition of +Gz exposure; by comparison of different time groups, we could get that expression level of HSP7OmRNA in rats brain began to rise at 5h after +Gz exposure, reached the peak at lob after +Gz exposure, then the expression level of HSP7OniRNA began to decline, almost resumed to normal level at 4d after z exposure; by comparison of different +Gz exposure level groups ,we could get that the expression range of HSP7OniRNA in rats?brain was more extensive when rats were exposed lower +Gz level(+2Gz),but the presslon level was lower； when exposed moderate＋Gz level(+6Gz),the qresslon level of HSP70mRNA was the IUghest and the range was the most extensive；under the higher +Gz exposure level,the pression level of HSP...