Failure of Potentiation in Successive, Posttetanic, and Summated Twitches in Cooled Skeletal Muscle of the Rat

Publisher Website
Google Scholar
Abstract
The in situ triceps surae of the rat at normal body temp (37[degree]C) shows an increase of twitch tension as a result of stimulation through the cut nerve. Increase of twitch tension is regarded as due to potentiation of contractile strength of the component muscle fibers because the action potential usually decreases in height and seldom increases as twitch tension increases. Three types of potentiation are observed: (a) potentiation in successive single responses, (b) posttetanic potentiation, and (c) potentiation resulting from 2 stimuli. Cooling the muscle to 29 to 20[degree]C abolishes the 3 types of potentiation observed in normal muscle. There is some evidence that failure of potentiation in cooled muscle is not due to fatigue. The question is raised whether similar mechanisms are involved in bringing about the 3 types of potentiation observed in normal muscle.
Keywords