title: The mode of ATP-induced vasoconstriction in the canine internal carotid artery.
abstract: The mode of the ATP-induced vasoconstriction in the internal carotid artery was studied from the physiological and pharmacological points of view. ATP caused dose-dependent vasoconstrictions in the canine internal carotid artery. The ATP-induced vasoconstriction was not affected by pretreatment with phenoxybenzamine, propranolol, atropine, cyproheptadine, or tetrodotoxin. Verapamil suppressed the contractile response. ATP produced no vasoconstriction in a calcium-free Krebs solution containing 1 mM EGTA nor augmentation of Ca2+-induced contraction in potassium-depolarized tissues. These results suggest that an increase of potential-dependent Ca2+ influx into the arterial smooth muscle may play a major role in the ATP-induced vasoconstriction.
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002343:Carotid Artery, Internal / Q000187:drug effects*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D007473:Ion Channels; D018377:Neurotransmitter Agents / Q000037:antagonists & inhibitors; D012701:Serotonin / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D007473:Ion Channels; D018377:Neurotransmitter Agents; D012701:Serotonin; D000255:Adenosine Triphosphate; D014700:Verapamil; D002118:Calcium