Creatine Metabolism in Skeletal Muscle V. An Intracellular Abnormality of Creatine Trapping in Dystrophic Muscle 1

Abstract

Summary

Radioactive creatine was given parenterally to normal and to dystrophic mice of Bar Harbor Strain 129 either 1 hr (short-term ¹⁴C-creatine) or 1 week (long-term ¹⁴C-creatine) before their extensor digitorum longus muscles were removed for study in vitro. After short-term ¹⁴C-creatine and under aerobic conditions, part of the radioactivity was lost more rapidly from dystrophic muscles than from normal muscles; but, under anaerobic conditions, the losses of radioactivity from normal and dystrophic muscles were similar because the rate of loss from normal muscles accelerated. After long-term ¹⁴C-creatine and under aerobic conditions, losses of radioactivity from both groups of muscles were small; but, under anaerobic conditions, part of the radioactivity was lost more slowly from dystrophic muscles than from normal muscles. These findings are evidence of an intracellular abnormality in the metabolism of creatine in dystrophic muscle.

We are indebted to Mrs. Judy M. Dacus for technical assistance.