过热对大鼠下丘脑肾上腺素α_2受体的影响  

Effects of hyperthermia on α_2-adrenergic receptor in hypothalamus of rat

作　　者：谭淼[1] 邱仞之[1] 

机构地区：[1]第一军医大学高温医学研究室

出　　处：《中国病理生理杂志》1996年第1期69-71,共3页Chinese Journal of Pathophysiology

摘　　要：本文用ＳＤ大鼠，清醒状态于热环境中引起过热（至直肠温度３９．５±０．５℃和４２．０±０．５℃，并维持３０ｍｉｎ），用放射配基结合分析方法（￣３Ｈ－ｄｏｎｉｄｉｎｅ）发现急性热暴露后，其４２℃组α＿２受体最大结合容量（Ｂｍａｘ）为４５．０±１７．７ｍｏｌ／ｍｇ蛋白，低于对照组（７５．５±２３．９ｆｍｏｌ／ｍｇ蛋白）和３９．５℃组（８１．１±２１，７ｆｍｏｌ／ｍｇ），而亲和力（Ｋｄ）无显著差别．结果表明，在过热状态下，α＿２受体数量明显下降，但其亲和力并不下降。由于α＿２受体密度的下降，可能使儿茶酚胺对体温调节中枢的作用下降。The changes of α_2-adrenergic rasptor in rat hypothalamus exposed to hightemperature environment was detected with radioligand(_3H-clonidine)binding assay.The resultsshowed that the maximal binding capacity(Bmax)and Kd value of α_2-adrenergic raseptor inhypothalamus of the hyperthermia Ⅰ group rats(rectal temperature 39.5℃ for 3omin)was not changedafter exposed to heat environment. But the Bmax of the heat stressⅡ group rats(rectal temperature 42℃ for 30min)decreased markedly(P<0.05)as compared with both control group and hyperthermia I group and the Kd value deereaSed insignmcantly.It indicated the contents of α_2-adrenergicreceptor in hypothalamus decreased markedly ouly during heat strock or heat shock. The affinity ofthe receptor was, not changed in the experiment. The changes described above demonstrated that thereduction of α_2-adrenergic rasptor was related with heat strock. Thus it was suggested that the in-creased activity of α_2-adrenergic receptor in hypothalamus during hyperthermia was a very impor-tant protective faactor.

关 键 词：受体 肾上腺素能Α 下丘脑 过热 

分 类 号：R363.123[医药卫生—病理学]