Recovery of the membrane potential of the sectioned striated muscle fibers of the guinea-pig cremaster.

Publisher Website
Google Scholar
Abstract
Changes in membrane potential after small transections (2-4 mm) of the striated muscle of the guinea pig cremaster and the rate of penetration of procion yellow (1-5 mg/ml) into the injured fibers were investigated. Transverse severance of the striated muscle fibers was followed by a marked drop of the membrane potential near the site of injury, such a fall being undetectable .apprx. 2 mm from the lesion. The depolarization reached a peak value (40 mV at 0.5 mm from the lesion) 3-5 min after injury and was followed by a gradual repolarization which was complete in .apprx. 60 min. A 2nd lesion evoked the same changes, but under conditions of a low Ca solution, there was no recovery in the potential. The rate of indicator penetration reached a peak value (20 .mu.m/min) when depolarization was near maximal, declined as the membrane repolarized and became negligible in .apprx. 50 min. The transected striated muscle fibers of the guinea pig diaphragm remained depolarized for > 1 h after injury. The healing-over process is a property of the striated muscle fibers of the guinea pig cremaster and may tentatively be ascribed to the development of a Ca-dependent diffusion barrier (of unknown nature) in the area of the injury.