DISSOCIATION OF ELECTRICAL AND MECHANICAL EVENTS IN DENERVATED FROG SKELETAL MUSCLE

Abstract

The mechanical responses to direct electrical stimulations were gradually decreased with the lapse of time after denervation of frog sartorius muscles. Even at the end of 30 days after denervation the resting and the action potentials of denervated muscle fibers were normal. The developed tension due to 2 m[image] ATP in glycerol-extracted muscle fibers prepared from the 7 weeks-denervated muscles was not different from that in contralateral innervated muscle fibers. Both the shape and the size of caffeine-induced contracture in denervated muscles were the same as those in the contralateral innervated ones. The duration of plateau of the active state in denervated muscles was ranged from 22.6 to 29.2 msec. at about 18[degree]C. These results were not different from those of the contralateral innervated ones. Based on the above-mentioned results it is concluded that the E-C coupling process of frog sartorius muscle is depressed due to denervation.