Healing-over in skeletal muscles of the guinea pig following induced injury.

Electrical membrane properties of cremaster muscle fibers of the guinea pig were determined before and after sectioning, using the microelectrode method. After sectioning, the membrane was depolarized to a maximum level within 5 minutes and the original level was reverted to within 60 minutes. Following restoration of the membrane potential, the spatial distribution of electrotonic potential indicated an electrical sealing at the cut end, and an action potential could be evoked. Therefore, it would appear that the cremaster muscle possesses the healing-over phenomenon. This process was dependent on temperature and [Ca2+]o and was not affected by pretreatment of actinomycin D, a protein synthesis inhibitor. This healing-over process also occurs in the extensor digitorum longus (EDL) muscle of the guinea pig but not in the diaphragm. These results indicate that some mammalian skeletal muscle fibers possess the healing-over phenomenon, as is observed in cardiac muscle fibers.