摘要
用常规细胞内微电极记录绵羊心室浦肯野纤维及肌小梁、和豚鼠心室乳头肌的跨膜动作电位。α-受体激动剂新福林使这三种心肌的动作电位时程(APD)延长。α_2-受体阻断剂育亨宾不能阻断这效应;α_1-受体阻断剂哌唑嗪可阻断这效应。实验中,β-受体阻断剂心得安浓度为1.0×10^(-6)mol/L。实验结果表明,α_1-受体激动可使这三种心肌ADP延长。秩和法统计检验表明。α_1-受体激动对浦肯野纤维APD的延长作用大于对心室肌APD的延长作用;对两种心室肌APD延长作用无显著差异。这提示,特殊传导系统心肌与工作心肌对心肌α_1-受体激动的反应机制有所不同。
The transmembrane action potentials of shecp ventricular Purkinje fiber, sheep ventricular trabecular muscle and guinea-pig ventricular papillary muscle were recorded by standard intracellular micro-electrode. α-adrenoceptor agonist phenylephrine prolonged the action potential duration (APD) of the three myocardial tissues. The effects could not be blocked by α_2-adrenceptor blocker yohimbine, but could be blocked by the α_1-adrenoceptor blocker prazosin. β-adrenoceptor blocker propranolol (1.0×10^(-6) mol/L) was used throughout the experiment. The results showed that the effect of α_1-adrenoceptor stimulation prolonged the APD of the three myocardial tissues. Rank sum test showed that this effect was significantly stronger on sheep ventricular Purkinje fiber than on sheep ventricular trabecular muscle and guinea-pig ventricular papillary muscle. However, there was no significant difference between the effects on the ventricular muscle of the two species. It is suggested that the mechanism by which the myocardial fiber of the special conduction system responds to α_1-adrenoceptor stimulation might be different from that by which the working myocardial muscle does.
出处
《上海第二医科大学学报》
CSCD
1989年第3期213-220,共8页
Acta Universitatis Medicinalis Secondae Shanghai
关键词
肾上腺素受体
心肌动作电位
新福林
α_1-adrenoceptor transmembrane action potential phenylephrine prazosin yohimbine
