低+Gz重复暴露后对高+Gz致大鼠脑损伤的影响  

Influences of Repeated Lower +Gz Exposures on High +Gz Exposure Induced Brain Injury in Rats.

作　　者：李金声[1] 孙喜庆[1] 吴兴裕 饶志仁[2] 刘惠玲[2] 谢小萍[1] 

机构地区：[1]第四军医大学航空航天生物动力学教研室,陕西西安710032 [2]第四军医大学神经生物研究所,陕西西安710032

出　　处：《航天医学与医学工程》2002年第5期339-342,共4页Space Medicine & Medical Engineering

基　　金：国家自然科学基金资助项目 (3 980 0 15 8)

摘　　要：目的探讨低 +Gz重复暴露后对高 +Gz致脑损伤的影响。方法SD大鼠 40只 ,随机分为正常对照组 ( 5只 ) ,+ 1 0Gz/5min单次暴露组 ( 5只 )和 + 4Gz/3min暴露 1次、3次和 5次组 (每组 1 0只 ,每天暴露1次 ) ,分别于暴露后 1d和 6d再暴露于 + 1 0Gz/5min ,于 + 1 0Gz暴露后 3d处死取脑 ,观察脑组织病理损伤情况。结果 + 4Gz/3min锻炼 1～ 5次 ,每天 1次 ,大鼠脑组织未见病理性损伤。而 + 1 0Gz/5min单次暴露后 ,在皮层、海马、丘脑等部位均可见到变性的神经元 ,个别脑区出现神经细胞凝固性坏死。经过+ 4Gz/3min锻炼 3次和 5次后再暴露于 + 1 0Gz ,变性神经元的数目在顶叶皮层、梨状皮层、海马和丘脑下部等部位明显减少。结论 + 4Gz/3min反复锻炼 3次和 5次 ,再暴露于损伤强度的 + 1 0Gz/5min ,其神经元损伤程度明显轻于 + 1 0Gz/5min单次暴露。Objective To explore the influence of repeated lower +Gz exposures on high +Gz exposure induced brain injury in rats. Method Forty SD male rats were randomly divided into control group(5 rats),+10 Gz/5 min group (5 rats) +4 Gz exposure one time , three times and five times group(10 rats each group). After 1 d or 6 d of +4 Gz exposure each group were exposed to +10 Gz again. Three days after +10 Gz exposure the neuron damage was observed by light microscope in HE stained section. Result There was no brain damage after repeated +4 Gz/3 min exposure 5 times so it was reasonable to use this exposure intensity as ischemia stimulation. +10 Gz/5 min exposure could result in irreversible neuron damage such as neuron degeneration and coagulation necrosis. The experiment results suggested that after +10 Gz/5 min exposure there were degenerated neurons in cortex, hippocampus and thalamus. The number of degenerated neurons were obviously decreased in cortex, hippocampus and thalamus when exposed to +10 Gz/5 min again after repeated +4 Gz/3 min 3～5 times. Conclusion The degree of neuron damage was obviously slight at the time of exposure to +10 Gz/5 min again after repeated +4 Gz/3 min 3～5 times. The ischemia tolerance at the time of exposure to +Gz was simivar to other brain ischemia.

关 键 词：+GZ 脑损伤 缺血 神经元 热休克蛋白70 加速度 

分 类 号：R852.21[医药卫生—航空、航天与航海医学]