骆驼蓬碱对大鼠心房肌的双重变力效应。

Dual inotropic effect of harmaline on the rat heart atrial muscle.

作者信息

Carpentier R, Diaz G

出版信息

Eur J Pharmacol. 1977 Mar 21;42(2):131-8. doi: 10.1016/0014-2999(77)90352-1.

Abstract

The effect of harmaline (HME) was analyzed in rat atrial strips superfused in vitro. A dual inotropic action was found: the positive component was due to a transient catechol-mediated enhancement of the velocity of development of tension (dT/dt) and to a prolongation of the duration of the rising phase of the contraction (TPT). The negative component was due to a depression of dT/dt, which overcame the persistent TPT-prolonging effect of HME, and it was abolished by rising the [K]0. It is concluded that: (1) the positive inotropic effect of HME depends on its actions on the dT/dt and TPT; (2) the enhancement of dT/dt is due to an adrenergic mechanism, which stimulates the Ca2+-dependent slowly activated current (Is); (3) a negative inotropic effect becomes evident whenever the dT/dt is depressed by the drug, regardless of the persistence of the TPT-prolonging effect; (4) the depression of the dT/dt is not due to an inhibition of Is.

摘要

对体外灌流的大鼠心房肌条进行了 harmaline（HME）效应分析。发现其具有双重变力作用：正向成分是由于儿茶酚介导的张力发展速度（dT/dt）短暂增强以及收缩上升期持续时间（TPT）延长。负向成分是由于 dT/dt 降低，这克服了 HME 对 TPT 的持续延长作用，并且通过提高[K]0 可消除该负向成分。得出以下结论：（1）HME 的正向变力作用取决于其对 dT/dt 和 TPT 的作用；（2）dT/dt 的增强是由于一种肾上腺素能机制，该机制刺激钙依赖性慢激活电流（Is）；（3）无论 TPT 延长作用是否持续，只要药物使 dT/dt 降低，负向变力作用就会明显；（4）dT/dt 的降低并非由于对 Is 的抑制。