Activation of gastro-intestinal smooth muscle induced by the calcium ionophore A23187.
Tension development was recorded in isolated smooth muscle preparations from the guinea-pig, namely circular strips from the fundus and antrum region of the stomach, and taenia coli. The calcium ionophore A23187 (2-10(-6)-2-10(-5) mol/1) induced maximum activity in fundus and taenia coli, and in antrum an activity slightly smaller than that obtained with acetylcholine (ACh) (5-10(-6) mol/1). The ionophore-induced activity could be suppressed by so-called calcium antagonists: D600 (3-10(-6) mol/1) suppressed the ionophore-induced activity of taenia coli completely; phasic and tonic components in the stomach preparations were selectively suppressed by D600 and sodium nitroprusside (10(-6) mol/1), respectively.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005260:Female; D005711:Gallopamil / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D009599:Nitroprusside / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D009599:Nitroprusside; D000001:Calcimycin; D005711:Gallopamil; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium