Vasoconstrictor mechanism of 5-hydroxytryptamine in isolated and perfused canine basilar arteries.
The stainless steel cannula inserting method was applied to investigate the vasoconstrictor mechanism of 5-hydroxytryptamine (5-HT) in isolated and perfused canine basilar arteries. An intraluminal administration of 5-HT induced vasoconstriction in a dose-dependent manner. Pretreatment with ketanserin, a specific 5-HT2 inhibitor, and with methysergide, a mixed 5-HT inhibitor blocked the vasoconstriction induced by 5-HT. Pretreatment with diltiazem, a potent calcium antagonist, also definitely depressed the vasoconstriction by 5-HT, as well as that by potassium chloride (KCl). The endothelial removal by intraluminal saponin treatment little influenced vasoconstriction by 5-HT. It is concluded that 5-HT-induced vasoconstriction of canine basilar arteries may be in part due to the stimulation of 5-HT2 receptors, which activate an intracellular calcium movement, rather than the influx from the extracellular space.
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects*; D004110:Diltiazem / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D011189:Potassium Chloride / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000187:drug effects; D012503:Saponins / Q000494:pharmacology; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*; D014661:Vasoconstriction / Q000187:drug effects*
D011985:Receptors, Serotonin; D012503:Saponins; D012701:Serotonin; D011189:Potassium Chloride; D007650:Ketanserin; D004110:Diltiazem; D008784:Methysergide