Excitability in experimental myopathy

Abstract

Needle electrodes in paravertebral muscles were used for stimulation and recording. Action potentials were studied oscillographically and recovery of excitability was measured in terms of relative response to a second stimulus. Controls showed a time constant of the refractory period of 1.6 mseconds. Quinidine prolonged the time constant significantly. Animals with metabolic myopathy following cortisone administration showed mainly severe muscle degeneration and some signs of regeneration. No changes in refractory period were found.