Calcium antagonists affect calmodulin-dependent contractility of a skinned smooth muscle.
The calcium antagonist prenylamine which had previously been found to inhibit fully the calmodulin myosin light chain kinase systems in concentrations of 200 mumol/l has now been found to inhibit the calmodulin-dependent contraction of skinned smooth muscle (guinea pig taenia coli). The inhibition by prenylamine is itself calcium-dependent. At maximum activation with Ca2+ and calmodulin, little inhibition is observed. Verapamil as well as prenylamine in small concentrations (less than 10 mumol/l) have been found to increase the rate of calcium-induced isometric tension development.
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors*; D002147:Calmodulin / Q000037:antagonists & inhibitors*; D003106:Colon / Q000187:drug effects; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009126:Muscle Relaxation / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D011299:Prenylamine / Q000494:pharmacology
D002121:Calcium Channel Blockers; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D011299:Prenylamine