在清醒犬中，关于突触后α1和α2肾上腺素能受体介导儿茶酚胺诱导的心室负性变时反应的证据。
Evidence for postsynaptic alpha 1- and alpha 2-adrenoceptors mediating catecholamine-induced negative chronotropic ventricular responses in the conscious dog.
作者信息
Boucher M, Duchene-Marullaz P
机构信息
U.195 INSERM, Faculty of Medicine, Clermont-Ferrand, France.
出版信息
Gen Pharmacol. 1990;21(5):791-8. doi: 10.1016/0306-3623(90)91035-p.
PMID:1980475
Abstract
- Adrenaline (0.25-1 microgram/kg), noradrenaline (0.125-0.5 microgram/kg) and dopamine (25-100 micrograms/kg) given in the conscious dog with chronic atrio-ventricular block after beta-adrenoceptor blockade, increased ventricular cycle length (VCL) and mean blood pressure (MBP). 2. Atropine (muscarinic receptor blocker) reduced the catecholamine-induced effects on VCL without modifying their hypertensive effects. 3. Phenoxybenzamine or phentolamine (alpha-adrenoceptor blockers) only decreased the effects of adrenaline on VCL but suppressed those of noradrenaline and dopamine. They only reduced the effects of adrenaline and noradrenaline on MBP, but reversed that of dopamine. 4. Yohimbine (alpha-adrenoceptor blocker) suppressed the catecholamine-induced effects on VCL, and reduced strongly the hypertensive effects of adrenaline and noradrenaline and reversed that of dopamine. 5. Thus, these results show the existence of negative chronotropic postsynaptic alpha-adrenoceptors in the ventricles.
摘要
- 在β-肾上腺素受体阻断后，给患有慢性房室传导阻滞的清醒犬静脉注射肾上腺素（0.25 - 1微克/千克）、去甲肾上腺素（0.125 - 0.5微克/千克）和多巴胺（25 - 100微克/千克），可增加心室周期长度（VCL）和平均血压（MBP）。2. 阿托品（毒蕈碱受体阻断剂）可减弱儿茶酚胺对VCL的影响，但不改变其升压作用。3. 酚苄明或酚妥拉明（α-肾上腺素受体阻断剂）仅减弱肾上腺素对VCL的作用，但抑制去甲肾上腺素和多巴胺对VCL的作用。它们仅降低肾上腺素和去甲肾上腺素对MBP的作用，但使多巴胺的作用逆转。4. 育亨宾（α-肾上腺素受体阻断剂）抑制儿茶酚胺对VCL的作用，并强烈降低肾上腺素和去甲肾上腺素的升压作用，使多巴胺的作用逆转。5. 因此，这些结果表明心室中存在负性变时性突触后α-肾上腺素受体。
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