Inhibition of incorporation of leucine into myocardial proteins of the rat by antiarrhythmic agents.

Incorporation of tritiated leucine into myocardial proteins was inhibited at low concentration by quinidine, procaine amide, and diphenylhydantoin, but not by lidocaine or propranolol. This inhibition could be demonstrated in vitro and when the animals were treated with these agents. The relationship between this finding and myocardial depression produced by these antiarrhythmic agents is not known but may reside in general depression of cellular metabolism and protein synthesis or in inhibition of synthesis of a specific membrane carrier protein. ADDITIONAL