Effect of ramipril on alpha-adrenoceptor-mediated oscillatory contractions in tail artery of hypertensive rats.
Effect of ramipril on alpha-adrenoceptor-mediated oscillatory contractions in tail artery of hypertensive rats.
复制标题
雷米普利对高血压大鼠尾动脉α-肾上腺素受体介导的振荡收缩的影响。
DOI：
10.1016/0014-2999(93)90248-g
复制
发表时间：
1993
影响因子：
5
通讯作者：
Webb,RC
中科院分区：
文献类型：
--
作者：
Watts,SW;Traub,O;Lamb,FS;Myers,JH;Webb,RC
Recent studies indicate that norepinephrine-induced contractile oscillations in the tail artery from stroke-prone spontaneously hypertensive rats (SHRSP) may be a vascular phenomenon independent of blood pressure level. The objectives of this study were: (1) to characterize pharmacologically the α-adrenoceptor mediating norepinephrine-induced oscillations in tail artery; and (2) to investigate the relationship between blood pressure level, altered by treatments with hydralazine/hydrochlorothiazide or the angiotensin converting enzyme inhibitor ramipril, and the observation of norepinephrine-induced oscillations in tail artery. Theα2-adrenoceptor agonists clonidine and guanabenz potently stimulated oscillatory contractions in the tail artery while theα1-adrenoceptor agonists phenylephrine and methoxamine were considerably less potent. Yohimbine, anα2-adrenoceptor antagonist, but not theα1-adrenoceptor antagonist prazosin demonstrated high affinity for the receptor mediating norepinephrine-induced oscillatory contractions. These results support the hypothesis that norepinephrine-induced oscillatory contractions in the tail artery from SHRSP occur primarily through stimulation ofα2-adrenoceptors. Ramipril lowered blood pressure in SHRSP after 4 weeks of treatment during 6–10 weeks of life but did not alter the ability of theα2-adrenoceptor agonist clonidine (10−5M) to induce contractile oscillations in tail arteries from SHRSP, indicating these oscillations are not a secondary effect of high blood pressure. These studies suggest that norepinephrine-induced oscillations in tail artery from SHRSP may be a vascular trait separate and distinct from blood pressure level and angiotensin II expression early in life.
