[Effect of cordarone on blood circulation under general anesthesia and in free behavior].

Experimental data on the effect of cordarone (10 mg/kg) upon blood circulation in animals under general anesthesia and in free behavior are presented. It was established that under general anesthesia cordarone induced in animals hypotension (16 +/- 2%), bradycardia (19 +/- 1.82%), heart contractility inhibition (29 +/- 6.10%). In animals under conditions of free behavior cordarone causes hypertension (9 +/- 3.1%), tachycardia (11 +/- 1.3%) and potentiates cardiac contractility. Practolole, a selective beta1-adrenoblocking agent, potentiates the effect of cordarone on the myocardium and also obliterates the difference between the effects of the drug in animals under general anesthesia and in free behavior. These data point to the drug exerting a direct inhibitory effect on the myocardium. It is suggested that the difference in the effects of cordarone in animals under general anesthesia and in conditions of free behavior is due to a lesser degree of activation produced by the drug in anesthetized animals.