高血压病人中枢α_(2)受体功能紊乱以及β受体阻断剂对它们的影响

THE DYSFUNCTION OF CENTRAL ALPHA-2 ADRENOCEPTORS IN HYPERTENSIVE PATIENTS AND THE INFLUENCES OF β-BLOCKING AGENTS ON THEM

观察10例健康人与12例高血压病人可乐定(clonidino)诱导生长激素释放的区别以及在β受体阻断剂普洛茶尔(propranolol)作用1周后10例高血压病人可乐定/生长激素(C/GH)试验的变化。研究证明中枢神经α_2受体激动剂可乐定(150ug)静注后30、60 min,正常人血清生长激素分别增加7.8和6.4倍,高血压病人分别增加2.3和1.7倍(P<0.01),提示高血压病人有中枢神经α_2受体功能紊乱。10例病人接受普洛萘尔治疗1周后,在已经出现明显心率减慢,可乐定降压作用被拮抗的同时,病人可乐定/生长激素试验反应低下的状态未能纠正,提示高血压病人视丘下部的α_2受体有选择性损害。

Clonidine,the central alpha 2 adrenoceptor agonist,induced release of growth hormone was investigated in 10 nornal suojects and12hypertensive patients.The changes of growth hormone release by clonidine before and after B-adrenoceptor blocking agent (propranolol)were studied as well.Growth hormone increaseb by 7.8 and 6.4 times, respectively after 30 and 60 min of intravenous clonidine(150 μg)in normal subjects, compared to 2.3 and 1.7 times in hypertensive patients(p<0.01).The attennated release of growth hormone by clonidine in hypertensive patients couldnot be reversed by propranolol(20 mg tid 1 W)when tne antagonistic effect between propranolol and clonidine occurred.It is thus suggested that there is a selective impairment of the alpha2-adrenergic mechanism controlling growth hormone release in hypertensive patients.