Effect of Potassium-induced Depolarization on Caffeine Contracture in Frog Twitch Muscle Fibers

DOI IR Web Site

Bibliographic Information

Other Title
  • カエルの Twitch Muscle Fiber のCaffeine拘縮に対するカリウム脱分極の影響
  • カエル ノ Twitch Muscle Fiber ノ Caffeine コウ

Search this article

Description

The effect of potassium-induced depolarization on caffeine contracture was examined using single twitch fibers and thin bundles consisting of 2 or 3 twitch fibers which were isolated from frog semitendinosus muscle. The following results were obtained.1） The magnitude and the rate of rise of caffeine contracture tension increased, whereas the rate of spontaneous relaxation of the contracture decreased markedly in the depolarized muscle fibers. 2） The extent of increase in the magnitude of the contracture tension was hardly affected by that of depolarization. 3） In the depolarized muscle fibers, the extent of increase in the magnitude of the contracture tension induced by 5 mM caffeine was more pronounced than that by 7.5 mM caffeine. On the basis of these results, the mechanisms of the increase of caffeine contracture and of the decrease of its spontaneous relaxation in the depolarized muscle fibers were discussed.

Journal

Details 詳細情報について

Report a problem

Back to top