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摘要

Effects of vagal stimulation on transmembrane potentials of in situ rabbit's cardiac ventricular

Abstract

Transmembrane potentials of rabbit's cardiac ventricular fibers were recorded
with floating microelectrode technique in situ. Vagal stimulation caused an in.crease in resting potential (RP), action potential amplitude (APA) and maximum upstroke velocity of phase 0 (dv/dt)_(max) and shortening of action potential duration (APD).These effects were unrelated to heart rate. However, the shortening effect of vagal stimulation on APD was masked by slowing of heart rate. Intracoronary arterial injection of K channel blocker tetraethylammonium chloride greatly retared the rate repolarization of action potential, abolished the effect of vagal stimulation to increase RP and APA, APD can no longer be shorted, while (dv/dt)_(max) a, was ,decreased. These results suggested that the influence of vagal stimulation on membrane potential of cardiac ventricular fiber might be due to an increase of outward potassium current.

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引用本文：

. [J]. 生理学报 1987; 39 (2): .

. Effects of vagal stimulation on transmembrane potentials of in situ rabbit's cardiac ventricular. Acta Physiol Sin 1987; 39 (2): (in Chinese with English abstract).