title: Prostacyclin and cerebral vessel relaxation.
abstract: The authors have studied the ability of prostacyclin to reverse contractions of human basilar arteries in vitro that were induced by a wide range of substances implicated in the etiology of cerebral arterial spasm. Prostacyclin (10(-10) to 10(-6)M) caused a dose-related reversal of contractions induced by 5-hydroxytryptamine, noradrenaline, angiotensin II, prostaglandin (PG)F2 alpha, and U-46619 (a thromboxane-A2 mimetic). These agents were tested at concentrations or volumes that produced almost maximum or maximum responses and those that produced approximately 50% of the maximum response. Contractions induced by maximum concentrations of angiotensin II and U-46619 were least affected by prostacyclin. In addition, contractions induced by thromboxane-A2 generated from guinea-pig lung were reversed in a dose-dependent fashion by prostacyclin. This ability of prostacyclin to physiologically antagonize contractions of the human basilar artery in vitro induced by high concentrations of various spasmogenic agents suggests that such a potent vasodilator agent or more stable analogue may be of value in the treatment of such disorders as cerebral arterial spasm following subarachnoid hemorrhage.
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000502:physiology; D002555:Cerebrospinal Fluid; D004305:Dose-Response Relationship, Drug; D011464:Epoprostenol / Q000378:metabolism / Q000494:pharmacology / Q000627:therapeutic use*; D006168:Guinea Pigs; D002546:Ischemic Attack, Transient / Q000188:drug therapy*; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011450:Prostaglandin Endoperoxides, Synthetic / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011453:Prostaglandins / Q000627:therapeutic use*; D011460:Prostaglandins F / Q000494:pharmacology; D012701:Serotonin / Q000494:pharmacology; D012702:Serotonin Antagonists; D013928:Thromboxane A2 / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D011450:Prostaglandin Endoperoxides, Synthetic; D011453:Prostaglandins; D011460:Prostaglandins F; D012702:Serotonin Antagonists; D000804:Angiotensin II; D012701:Serotonin; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D011464:Epoprostenol; D009638:Norepinephrine