【摘要】 甲基莲心碱（Nef）0.1mM使豚鼠右心室乳头状肌的收缩力降低68. 3％,使动作电位APA和Vmax分别从112±5mV,240±37V/s降低到97±9 mV和86±25V/s;APD₅₀,APD₉₀和ERP分别从173±23ms,205±17ms和201±16ms延长到201±26ms,239±28ms和249±23ms。Nef 1-200μM浓度依赖性地延长APD₅₀,APD₉₀和ERP,降低Vmax和收缩力。30μM Nef能明显对抗10μM乙酰胆碱缩短豚鼠左心房APD的作用。结果提示,Nef对心肌Na⁺,K⁺,Ca²⁺的跨膜转运均有抑制作用。更多还原

【Abstract】 Neferine, an alkaloid extracted from the green seed bud of Nelumbo nucifera Gaertn, was reported to possess antiarrhythmic action. Its effects on the electrical and mechanical activity were investigated in guinea pig papillary muscles and atria.Neferine 0.1 mM which reduced the force of contraction by 68.3 % in guinea pig papillary muscles decreased the amplitude and Vmax of action potential from 112±5ms and 240±37V/s to 97±9ms and 86±25V/s, prolonged the action potential duration at 50 % repolarization and at 90 % repolariza-tion and the effective refractory period from 173±23ms, 205±17ms and 201± 16ms to 201±26ms, 239±28 ms and 249±23 ms, respectively.Neferine 1 -200 μM increased the duration of action potential and effective refractory period and reduced the amplitude and Vmax of action potential, and the force of contraction in a concentration dependent manner.The effect of acetylcholine 10 μM which shortened the action potential duration of the left atria was partly antagonized by neferine 30 μM. The results of neferine can be explained by a non-specific inhibition of the current of Na+, Ca2+ and K+. Its antagonistic efficiency to arrhythmias may be related to these effects.更多还原