title: Influence of sympathetic tone on the reactivity to indorenate in the external carotid vascular bed of the dog.
abstract: The present study was designed to analyze the effects of drugs that interfere with sympathetic transmission on the external carotid vasodilator response induced by the 5-HT1A receptor agonist, indorenate, in pentobarbital-anesthetized dogs. Intracarotid (i.c.) infusions of indorenate (1000 micrograms/l min) produced an increase in external carotid blood flow (external C.B.F.) without modifying mean arterial blood pressure or heart rate. This effect of indorenate was dose-dependently antagonized by intravenous (i.v.) administration of the alpha 1-adrenoceptor antagonist, prazosin (1, 3.1, 10, 31 and 100 micrograms/kg), the ganglionic blocking agent, mecamylamine (0.031, 0.1, 0.31, 1, 3.1 and 10 mg/kg) or the 5-HT2 receptor and alpha 1-adrenoceptor antagonist, ketanserin (10, 31 and 100 micrograms/kg). It is concluded that indorenate-induced increase in canine external C.B.F. is dependent on the vascular neurogenic tone.
authors.affiliation: Departamento de Farmacología y Toxicología, Centro de Investigación de Estudios Avanzados del Instituto Politécnico Nacional, México, D.F.
authors.forename: C M
authors.initials: CM
authors.lastname: Villalón
authors.forename: E
authors.initials: E
authors.lastname: Hong
authors.forename: J A
authors.initials: JA
authors.lastname: Terrón
mesh_terms: D008735:5-Methoxytryptamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002342:Carotid Artery, External / Q000187:drug effects* / Q000294:innervation; D004285:Dogs; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D011985:Receptors, Serotonin / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D011985:Receptors, Serotonin; D008735:5-Methoxytryptamine; C033600:indorenate