Jie K, van Brummelen P, Vermey P, Timmermans P B, van Zwieten P A
J Cardiovasc Pharmacol. 1986 Jan-Feb;8(1):190-6. doi: 10.1097/00005344-198601000-00028.
alpha 1- And alpha 2-adrenoceptor mediated vasoconstriction were studied in 13 patients with essential hypertension and 13 age-matched normotensive controls. This was done by comparing the changes in forearm blood flow induced by intra-arterial infusion of the selective alpha 1- and alpha 2-adrenoceptor agonists methoxamine and B-HT 933, the catecholamines adrenaline and noradrenaline, and the selective alpha 2-adrenoceptor antagonist yohimbine in both study groups. The catecholamines were infused in the presence of propranolol in order to prevent beta-adrenergic effects. Forearm blood flow was measured by plethysmography. All agonists produced a dose-dependent vasoconstriction which was more pronounced in the hypertensive patients, although the difference was significant only for the infusion of the catecholamines and for the combined effects of methoxamine and B-HT 933. No preference was found for either the alpha 1- or alpha 2-adrenoceptor mediated vasoconstriction in the greater response of the hypertensive patients. These results could well be explained by structural vascular changes, secondary to the elevated blood pressure. No evidence was found for increased alpha 2-adrenoceptor mediated basal vascular tone in patients with essential hypertension, since yohimbine tended to induce a greater vasodilatation in the normotensive subjects.
对13例原发性高血压患者和13例年龄匹配的血压正常对照者进行了α1和α2肾上腺素能受体介导的血管收缩研究。通过比较在两个研究组中动脉内输注选择性α1和α2肾上腺素能受体激动剂甲氧明和B-HT 933、儿茶酚胺肾上腺素和去甲肾上腺素以及选择性α2肾上腺素能受体拮抗剂育亨宾所诱导的前臂血流量变化来进行此项研究。在普萘洛尔存在的情况下输注儿茶酚胺，以防止β肾上腺素能效应。通过体积描记法测量前臂血流量。所有激动剂均产生剂量依赖性血管收缩，在高血压患者中更为明显，尽管差异仅在输注儿茶酚胺以及甲氧明和B-HT 933的联合效应时具有显著性。在高血压患者的更大反应中，未发现对α1或α2肾上腺素能受体介导的血管收缩有偏好。这些结果很可能由血压升高继发的结构性血管变化来解释。未发现原发性高血压患者中α2肾上腺素能受体介导的基础血管张力增加的证据，因为育亨宾在血压正常的受试者中倾向于诱导更大的血管舒张。
