GSBS Student Publications


Use of adult rat cardiomyocytes to study cardiac glycogen metabolism

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Biochemistry and Molecular Pharmacology



Document Type


Medical Subject Headings

Alloxan; Animals; Cell Survival; Diabetes Mellitus, Experimental; Enzyme Activation; Epinephrine; Glycogen; Glycogen Synthase; Male; Myocardial Contraction; Myocardium; Phosphorylase a; Phosphorylases; Rats; Rats, Inbred Strains


Life Sciences | Medicine and Health Sciences


The use of adult rat cardiomyocytes to model cardiac glycogen metabolism was investigated by monitoring the response of glycogen phosphorylase and glycogen synthase to epinephrine and insulin treatment. Cardiomyocytes derived from normal rats respond to epinephrine in the range of 1 X 10(-7) to 5.5 X 10(-6) M epinephrine with an increase in the percent of phosphorylase in the AMP-independent form from 11.5 to 24.8%. In the same cells, insulin in the range of 10(-9) to 10(-7) M increased the glucose 6-phosphate independent form of glycogen synthase from 30.5 to 40.5%. Cells derived from alloxan-diabetic hearts exhibit a hypersensitive phosphorylase activation and a refractile synthase inactivation in response to epinephrine treatment. This pattern is similar to that recorded using perfused heart preparations. The data presented suggests that adult rat cardiomyocytes represent a valid model of glycogen metabolism in both the normal and alloxan-diabetic rat.

Rights and Permissions

Citation: Am J Physiol. 1987 May;252(5 Pt 1):E673-8.

Related Resources

Link to Article in PubMed

Journal Title

The American journal of physiology

PubMed ID