Similar inhibitory effects of dantrolene sodium on twitch tension and on silver ion-induced contracture in skeletal muscle

Abstract

To determine the mechanism by which Ag + induces a transient contracture in skeletal muscle, the effect of dantrolene sodium on the Ag + contracture was examined and the findings compared with those for the twitch, tetanus and caffeine contrature. The inhibition of twitch by dantrolene was equivalent to that of the Ag + contracture at concentrations of 1, 2 or 5 μM of dantrolene. The tetanus tension was slightly inhibited by dantrolene, but not the caffeine contracture. These observations suggest that the Ag + contracture may be governed by the same mechanism as that involved in the development of twitch tension.