Vasorelaxation in prostacyclin-hyperpolarized arterial smooth musculature.
In arterial smooth muscle with normal tone or predepolarized and precontracted by noradrenaline, prostacyclin (10(-9) to 10(-6) M) effects a dose-dependent hyperpolarization and relaxation. The hyperpolarization is due to K+ channel opening. In this hyperpolarized portion of the stationary, sigmoid activation curve, vasodilation can be explained by means of Ca2+ channels that are closed between -40 mV and -80 mV in a voltage-dependent manner.
Siegel
G
G
Institute of Physiology, Free University of Berlin, Germany.
Schnalke
F
F
Stock
G
G
D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology; D002339:Carotid Arteries / Q000187:drug effects / Q000502:physiology; D004285:Dogs; D011464:Epoprostenol / Q000494:pharmacology*; D016285:Iloprost; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects; D015222:Sodium Channels / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*
D002317:Cardiovascular Agents; D015221:Potassium Channels; D015222:Sodium Channels; D011464:Epoprostenol; D016285:Iloprost