高濕熱環(huán)境下谷氨酸及其受體在大鼠下丘腦的表達(dá)變化

摘要： 目的探討高濕熱環(huán)境下大鼠的耐熱極限時(shí)間和下丘腦內(nèi)谷氨酸(Glu)和N-甲基-D-天門(mén)冬氨酸(NMDA)受體2(NMDAR2)的表達(dá)及其意義。方法將大鼠置于仿真氣候艙[干球溫度(40.0±0.5)℃,相對(duì)濕度(60±5)%]內(nèi),觀察動(dòng)物的行為反應(yīng),動(dòng)物出現(xiàn)昏迷或抽搐則立即取出動(dòng)物,常規(guī)固定、取腦制片,用免疫組織化學(xué)方法顯示Glu、NMDAR2和加壓素(VP)在下丘腦的室旁核(PVN)和視上核(SON)的表達(dá)。結(jié)果動(dòng)物在高濕熱環(huán)境下表現(xiàn)躁動(dòng)不安、呼吸加快、前爪抓撓面部,持續(xù)120 min左右時(shí)部分動(dòng)物死亡。切片觀察濕熱刺激組的下丘腦PVN和SON中Glu、NMDAR2以及VP表達(dá)比對(duì)照組明顯上調(diào)(P<0.01)。結(jié)論高濕熱環(huán)境下大鼠的耐熱極限時(shí)間約是120 min。下丘腦內(nèi)的谷氨酸代謝參與機(jī)體對(duì)高濕熱刺激的反應(yīng)及其調(diào)節(jié)過(guò)程。
Objective To study the effect of high humid and warm environment on the central nervous system and the changes of expression of glutamate(Glu) and N-methyl-D-asparate receptors 2(NMDAR-2) in rat hypothalamus. Methods The experimental rats were put into a simulated climate cabin(with the dry ball temperature of(40.0±0.5)℃ and relative humidity of (60±5)%.Behavioral responses of the rats were observed on the time.The rats that displayed a twitch or coma were taken out of the cabin.By using immunohistochemical ABC methods,we observed the expression of Glu,NMDAR-2 and Vasopressin(VP) in the paraventricular nucleus(PVN) and supraoptic nucleus(SON). Results The animals showed restlessness and agitation;their breath frequency increased;they scratched the face with the forelimbs and some animals died in 120 minutes.The expression of Glu,NMDAR-2 and VP in PVN and SON were significantly increased in the high humid heat stimulation group as compared with control group(P<0.01).Conclusion The ultimate endurance of rats to survive in a high humid and warm enviroment lasts about 120 minutes.The glutamate in hypothalamus might be involved in the body's response and its regulation to the stimulation from the high humid and warm environment.