Comparison of the effect of naloxone on cerebral versus mesenteric arterial smooth muscle in feline and primate species.
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.
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*
D009270:Naloxone; D009638:Norepinephrine; D004837:Epinephrine