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.
出处
《中国病理生理杂志》
CAS
CSCD
北大核心
1996年第1期69-71,共3页
Chinese Journal of Pathophysiology
关键词
受体
肾上腺素能Α
下丘脑
过热
Raceptors, adrenergic alpha·Hypothalamus· Rats
