[Role of protein biosynthesis activation in the mechanism of the negative chronotropic action of the vagus nerve and acetylcholine on the heart].

In rats, the following data were obtained: a) acetylcholine activates the rate of protein biosynthesis in auricles in vitro; b) protein biosynthesis inhibitors (actinomycine D, sarcolysine, neutral rot, tolluidine blue) weaken the negative chronotropic effect of acetylcholine and vagus on the heart; c) anabolic hormones increase the cholinergic effect on heart; d) acetylcholine induces hyperpolarization of the myocardial fibers which is prevented by actinomycine D. The activation of protein biosynthesis followed by hyperpolarization of the pacemaker cells seems to play an important role in the mechanism of negative chronotropic effect of acetylcholine and vagus on the heart.