[Mechanism of activation of contraction of smooth muscle cells of coronary arteries induced by acetylcholine].
Acetylcholine (ACh) caused a slight depolarization, decrease of the membrane resistance and tonic contraction of the circular muscle strips from bovine coronary arteries. On removal of Ca2+ ions by adding EGTA and Mg2+ ions, a drop in basal tone was observed, as well as the decrease of the membrane resistance and a considerable reduction of the SMC contractile reaction (by 90% from normal value) in response to ACh. In presence of verapamil, ACh also caused contraction which, however, was half of that in normal conditions. In the course of potassium depolarization, ACh produced contraction of the strip, the maximal decrease of contraction being observed at 80 mM potassium depolarization. The ACh-induced contraction of coronary arteries seems to be activated mainly by extracellular calcium ions.
Taranenko
V M
VM
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000502:physiology; D002417:Cattle; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*
D000109:Acetylcholine; D002118:Calcium
Mekhanizm aktivatsii sokrashcheniia gladkomyshechnykh kletok koronarnykh arteriĭ pod vliianiem atsetilkholina.