【摘要】 用常规微电极技术探讨了5—羟色胺（5—HT）对豚鼠右室乳头状肌动作电位（AP）的影响,5—HT1—30μM表现剂量相关地延长动作电位时程(APD₂₀,APD₅₀,APD₉₀)和有效不应期（ERP）, 但对ERP/APD₉₀值, 静息膜电位（RP）、动作电位幅度（APA）和O相上升速率（Vmax）均无明显影响。赛庚啶8μM明显缩短APD和ERP,并拮抗5—HT对APD的影响。在含赛庚啶的灌流液中,5—HT只有在30—100μM时显示延长APD的作用。以上结果说明5—HT对乳头状肌AP的影响可能是通过与5—HT受体作用所致。更多还原

【Abstract】 The effect of 5-hydroxytryptamine（5-HT） on the action potential（AP）of guinea pig papillary muscles were studied by means of intracellular microelectrodes.Concentrations of 5-HT from 1 to 30 μM had the effect of prolonging the action potential duration(APD₂₀ APD₅₀,APD₉₀)and the effective refractory period（ERP）,in a concentration-dependent manner. However,ratio of ERP to APD₉₀ (ERP/APD₉₀),resting potential （RP）,action potential amplitude （APA）and maximum rate of rise of action potential（Vmax）were not obviouly affected by5 —HT. Cyproheptadine 8μM shortened APD and ERP and antagonized the effect of prolonging APD of 5 —HT.When preparation bathed in perfusion fluid contained 8μM cyproheptadine,the effect of prolonging APD of 5-HT was showed for only 30 and 100μM.The result indicate that the effect of 5-HT on papillary muscles may be induced by its effect on 5-HT receptor.更多还原