THE WASH-OUT OF CARDIAC GLUCOSIDES FROM THE FROG'S VENTRICLE

¹ From the Department of Pharmacology, University of Edinburgh

1. The author has investigated the reversibility of the action on the isolated and artificially stimulated frog's ventricle of the following drugs: (a) infusion of digitalis, (b) g-strophanthin, (c) ouabain, (d) digoxin, (e) scillaren, (f) k-strophanthin, (g) digitoxin.

2. In the case of all these drugs washing out produced recovery even after systolic arrest had been induced. The recovery was complete because a second intoxication followed exactly the same course as the first.

3. The action was equally reversible when Ringer's solution or blood plasma was used, or when the drug was given to the intact frog and the arrested heart was excised and perfused.

4. The ease with which the action could be reversed varied greatly with the different drugs.

5. The process of intoxication can be maintained by concentrations of glucoside far smaller than those needed to initiate intoxication.

6. The combination between glucosides and heart muscle resembles an adsorption process, but it is necessary to assume that hysteresis occurs.