Dihydropyridine derivatives prolong the open state of Ca channels in cultured cardiac cells.
Dihydropyridine derivatives prolong the open state of Ca channels in cultured cardiac cells.
复制标题
二氢吡啶衍生物可延长培养的心肌细胞中 Ca2+ 通道的开放状态。
DOI：
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发表时间：
1984
影响因子：
11.1
通讯作者：
H. Reuter
中科院分区：
文献类型：
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作者：
S. Kokubun;H. Reuter
二氢吡啶衍生物CGP 28392和BAY K 8644在哺乳动物心肌中发挥强烈的正性肌力作用，可能是通过增加动作电位期间的Ca内流。用膜片钳法分析单钙通道水平的药物效应，揭示了通道门控动力学的复杂变化。主要的影响是延长钙通道的平均打开时间。此外，通道打开之间的间隔可以稍微延长。单通道迹线的整体平均显示药物对平均电流振幅的浓度依赖性增加。与β -肾上腺素能受体激动剂相比，二氢吡啶衍生物引起的Ca电流的增加与细胞内环AMP水平的增加无关。
The dihydropyridine derivatives CGP 28392 and BAY K 8644 exert a strong positive inotropic effect in mammalian cardiac muscle, presumably by increasing Ca influx during the action potential. Analysis of the drug effects at the level of single Ca channels by means of the patch-clamp method revealed complicated changes in the kinetics of channel gating. The prevailing effect is a prolongation of the mean open time of Ca channels. In addition, the intervals between channel openings can be slightly prolonged. Ensemble averages of single-channel traces showed a concentration-dependent increase in the mean current amplitude by the drugs. In contrast to beta-adrenoceptor agonists, the increase in Ca current by the dihydropyridine derivatives is not associated with an increase in the intracellular cyclic AMP level.