Structural and functional characteristics of cardiac myocytes.

Canine and rat cardiac myocytes, prepared by proteolytic disaggregation, retain morphological and topographical features of intact tissue. Cells are rod-shaped and are cleanly separated at their sarcolemmal and intercalated disc borders. Cells demonstrate glucose and fatty acid uptake and metabolic features comparable to intact organ, and are responsive to insulin and epinephrine, but nor carnitine. Although rat cardiac cells contain immunodetectable lipoprotein lipase, they are incapable of metabolizing extracellular lipoprotein triglyceride, nor the glycerol or monoglyceride moieties of the triglyceride. These and other metabolic characteristics suggest that cardiac cells can provide a useful cellular model for studies on cardiac pathophysiology.