Effect of digitoxin and quinidine on intracellular electrolytes of the rabbit heart.

Abstract

1. 32 rabbits were injected intramuscularly in the gluteal region with 0.12 g of quinidine gluconate twice daily and 21 rabbits were similarly injected daily with 0.3 mg digitaline nativelle for 5 days and 10 days respectively. 2. A gain in intracellular cardiac potassium as expressed in liters of intracellular water was observed in the quinidine treated animals (from 108 to 124 mEq). A loss in intracellular cardiac sodium from 13.6 to 6.8 was also observed. 3. The mechanism of digitoxin toxicity and its reversal by quinidine is discussed. It is suggested that one of the actions of quinidine may be to reverse the ionic flow of sodium and potassium (and perhaps other ions) in cardiac muscle which occurs in digitoxin toxicity.