title: Effect of leukotrienes, 12-HETE, histamine, bradykinin, and 5-hydroxytryptamine on in vivo rabbit cerebral arteriolar diameter.
abstract: To determine the possible role that leukotrienes (LTs) may play in the regulation of cerebral blood flow, the responses of cerebral arterioles to LTs and 12-hydroxyeicosatetraenoic acid (12-HETE) were studied in vivo in rabbits equipped with a cranial window for direct observation of the microcirculation. Topical application of LTC4, LTD4, or 12-HETE (1.6 X 10(-9)-3.1 X 10(-6) M) neither constricted nor dilated the pial arteries. LTB4 produced only a 5% vasoconstriction at 3.0 X 10(-6) M. However, bradykinin induced dose-dependent arteriolar vasodilation and histamine and 5-hydroxytryptamine induced dose-dependent arteriolar vasoconstriction. Although some LTs have potent vasoconstrictor activity in peripheral tissues and 5-lipoxygenase products have been hypothesized to be mediators of vasospasm after subarachnoid hemorrhage, LTB4, LTC4, LTD4, and 12-HETE apparently are unable to induce significant constriction of the cerebral arterioles in the anesthetized rabbit.
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D001158:Arteries / Q000187:drug effects; D001920:Bradykinin / Q000494:pharmacology*; D002536:Cerebral Arteries / Q000033:anatomy & histology / Q000187:drug effects*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology*; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D010841:Pia Mater / Q000098:blood supply; D011817:Rabbits; D013189:SRS-A / Q000494:pharmacology*; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D006893:Hydroxyeicosatetraenoic Acids; D013189:SRS-A; D012701:Serotonin; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D006632:Histamine; D001920:Bradykinin