高湿热环境下谷氨酸及其受体在大鼠下丘脑的表达变化

目的 探讨高湿热环境下大鼠的耐热极限时间和下丘脑内谷氨酸(Glu)和N-甲基-D-天门冬氨酸(NMDA)受体2(NMDAR2)的表达及其意义.方法 将大鼠置于仿真气候舱干球温度(40.0±0.5)℃,相对湿度(60±5)%]内,观察动物的行为反应,动物出现昏迷或抽搐则立即取出动物,常规固定、取脑制片,用免疫组织化学方法显示Glu、NMDAR2和加压素(VP)在下丘脑的室旁核(PVN)和视上核(SON)的表达.结果 动物在高湿热环境下表现躁动不安、呼吸加快、前爪抓挠面部,持续120min左右时部分动物死亡.切片观察湿热刺激组的下丘脑PVN和SON中Glu、NMDAR2以及VP表达比对照组明显上调(P＜0.01).结论 高湿热环境下大鼠的耐热极限时间约是120 min.下丘脑内的谷氨酸代谢参与机体对高湿热刺激的反应及其调节过程.

CHANGES OF THE EXPRESSION OF GLUTAMATE AND NMDAR2 IN RAT HYPOTHALAMUS IN HIGH HUMID AND WARM ENVIRONMENT

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 (NMDAR2) 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, NMDAR2 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, NMDAR2 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 migh