Abnormalities of glycogen metabolism in cardiomyopathy of phosphorous depletion.

In severely phosphorous depleted rats, no change of glycogen content or activities of enzymes catalysing glycogen synthesis or breakdown was observed. In contrast in heart muscle, a decrease of myocardial glycogen content was observed which was accompanied by increased activity of phosphorylase and decreased activity of synthetase. It is assumed that these changes result from increased catecholamine action secondary to an activation of the sympathetic nerve system resulting from impaired contractile state of the myocardium. The changes observed are analogous to those found in heart failure.