Biochemical basis for the spasmolytic effect of isoquinoline and phenothiazine derivatives

Experiments with isolated ring-like strips of pig heart veins and arteries and those with rat small intestinal strips made in the presence of hyperpotassium contracture have demonstrated that spasmolytic activity of papaverine, nospa, nonachlazine, and ethmozine is a consequence of the reduced respiratory intensity and phosphorylation in smooth muscle mitochondria. No changes in the anaerobic glycolysis rate have been found after drug administrations.