Protein synthesis in muscle cultures from patients with myotonic dystrophy. Influence of A23187 ionophore and calcium: preliminary investigation.

Muscle samples for cultures were obtained from the tibialis anterior by open biopsy under local anesthesia in 12 patients with myotonic dystrophy and 15 controls. Total protein synthesis in muscle cultures from patients with myotonic dystrophy showed a nonsignificant increase in (3H)-leucine incorporation. Addition of A23187 ionophore significantly stimulated the protein synthesis in muscle cultures from patients with myotonic dystrophy, but had an inhibitory effect in the cultures from controls. Myosin heavy chain synthesis was measured and found normal in all patients with myotonic dystrophy.