The effects of insulin and anoxia on the metabolism of isolated mature rat cardiac myocytes

Cardiac myocytes from adult rat ventricles were isolated by perfusion and incubation with buffer containing collagenase and hyaluronidase. This method gave a high yield of viable cells with normal morphology and metabolic properties. The isolated cells can tolerate 2.5 m m extracellular calcium and have physiologic levels of ATP (20 μmol/g protein). The cells metabolized glucose at a linear rate up to 4 h. Glucose utilization was stimulated by insulin and anoxia. Protein synthesis was maintained at a steady rate for 3 h and was significantly stimulated by insulin. A reasonably constant rate of protein degradation was observed for 3 h. Insulin significantly inhibited the rate of protein degradation.