Phosphocreatine Content of Mammalian Cardiac Muscle.

Abstract

1. “Resting” values for the phosphocreatine content of the ventricles of several mammalian species are reported and an explanation is offered for some of the low values recorded in the literature. The necessary precautions are noted if maximal values are to be obtained. 2. The isolated dog heart (heart-lung preparation) does not contain more phosphocreatine or adenosine triphosphate than the intact heart provided that heart failure has not set in. If, on the other hand, failure is induced by barbiturates the level of phosphocreatine increases without a change in the labile “nucleotide” phosphorus. This constitutes further evidence that this kind of heart failure is not due to the lack of production of high-energy phosphate bonds.