title: Comparison of the effect of naloxone on cerebral versus mesenteric arterial smooth muscle in feline and primate species.
abstract: This study was conducted in order to investigate naloxone's in vitro action on both epinephrine-induced constriction of mesenteric artery and norephinephrine-induced constriction of cerebral arteries in different species (cat and monkey). Naloxone (3 X 10(-5)M) augmented the epinephrine-induced constriction of both feline and monkey mesenteric artery at epinephrine concentrations of 10(-7) to 10(-5) M. Naloxone (3 X 10(-5)M) suppressed the constriction of feline basilar artery induced by high concentrations (10(-4), 10(-3) and 3 X 10(-3)M) of norepinephrine, while it failed to alter the constriction induced by lower concentrations (10(-7) to 10(-5)M) of norepinephrine. The constrictor response of monkey basilar artery to norepinephrine (10(-8) to 10(-5) M) was not altered by treatment with naloxone (3 X 10(-6) and 3 X 10(-5)M). Such varying effects of naloxone in different tissues and species may have to be taken into account when evaluating the cerebral blood flow changes following naloxone administration.
mesh_terms: D000818:Animals; D001488:Basilar Artery / Q000187:drug effects; D002415:Cats; D002536:Cerebral Arteries / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D008252:Macaca fascicularis; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D009270:Naloxone; D009638:Norepinephrine; D004837:Epinephrine