A comparison of the cardiovascular effects of proscillaridin and ouabain in anaesthetised dogs.

Summary: The activities of ouabain and proscillaridin (20, erg/kg) were compared in the dog. The two glycosides produced equal positive inotropic effects, a peak increase of myocardial contractility of approximately 20% being recorded at 20 to 30 minutes after their administration and for a further 30 minutes thereafter. Both drugs produced small immediate increases in systemic arterial blood pressure which fell below control levels 30 minutes after ouabain, and at a slower rate after proscillaridin. The bradycardia produced by ouabain was approximately twice that following proscillaridin. Both glycosides produced insignificant in-creases in the PR interval and no difference on AV conduction could be detected between the two drugs during atrial pacing.