Abstract
A smooth muscle relaxant (suloctidil) relaxed a contractile response of taenia coli to acetylcholine and noncompetitively depressed a dose response curve of CaCl2. Ca-uptake by the microsomal fraction was inhibited by suloctidil. Its noncompetitive antiacetylcholine activity and inhibitory action on Ca-uptake were not influenced by an increase of external Caconcentration. Ca-release from the Ca-incorporated microsomal fraction was not significantly influenced by suloctidil. These results suggest that suloctidil inhibit Ca-influx noncompetitively, thus inducing smooth muscle relaxation.
