【摘要】 本实验观察了在存在M受体阻断剂阿托品（2μM）的情况下,胆碱能N₁受体激动剂洛贝林（lobeline）对儿茶酚胺耗竭的豚鼠心室乳头肌电活动及收缩力的影响。洛贝林（0.5—8μM）使动作电位时程（APD）显著延长,动作电位0期最大除极速率(V_max)和动作电位幅值（APA）下降,心肌收缩力（FC）减弱,以及收缩峰值出现时间（time-to-Peak force,TTP）提前。N₁ 受体阻断剂六甲双铵（hexamethonium,10μM）使洛贝林对APD的剂量-反应曲线平行右移。这些实验结果提示:在豚鼠心室肌可能存在胆碱能N受体。更多还原

【Abstract】 Electrophysiological and mechanical effects of N₁-receptor agonist lobelinewere observed in catecholamine-depleted guinea pig papillary muscle in the presenceof a M-Cholinergic receptor antagonist atropine （2μM）. Lobeline （0.5-8μM）significantly prolonged the action potential duration （APD）, decreased the maximumupstroke velocity of phase 0 depolarization (V_max), the action potential amplitude（APA）, force of contraction （FC） and the time-to-peak force （TTP）. The cumula-tive log dose-response curve of lobeline on the APD was shifted parallelly to theright by N₁-cholinergic receptor blocker hexamethonium （10μM）. These resultssuggest that cholinergic N receptors may be present in guinea pig ventricular myo-cardium.更多还原