RT Journal Article SR Electronic T1 THE INFLUENCE OF DIGOXIN ON THE POTASSIUM CONTENT OF HEART MUSCLE JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 268 OP 274 VO 65 IS 3 A1 ALFRED M. WEDD YR 1939 UL http://jpet.aspetjournals.org/content/65/3/268.abstract AB The influence of digoxin on the potassium content of ventricular muscle has been studied in the cat and the turtle heart. In two experiments with intact cats the amount of potassium in the ventricles two hours after adequate doses of digoxin was approximately the same as that found in two control animals. Strips of the same turtle ventricle were kept in baths for periods of two or 24 hours; one bath contained digoxin while the other served as a control. The beat was recorded at intervals, and at the end of the experiment the potassium content of each muscle strip was determined and compared with that of the fresh ventricle of the same heart. It was found that digoxin may exert a profound effect on the muscle strip without causing significant change in its potassium content. High concentrations of digoxin at times did result in marked potassium loss, but with that went great impairment of beat or even complete loss of excitability. These experiments lend no support to the view that the therapeutic action of digitalis may be accomplished by lowering the potassium content of heart muscle cells, but rather they indicate that when digitalis does cause potassium loss it represents a late toxic or injury effect of the drug.