Effects of 5-hydroxytryptamine and ergotamine on human superficial temporal artery.
Isometric tension was recorded in ring preparations of human superficial temporal arteries contracted by noradrenaline (NA), 5-hydroxytryptamine (5-HT), and ergotamine. In contrast to NA and 5-HT, ergotamine induced long-lasting contractions refractive to additional stimulations and resistant to repeated wash-out. When tested against 5-HT, ergotamine acted as a non-competitive antagonist. When repeating the 5-HT stimulations (4.7 x 10(-5) M) the contractile response decreased indicating tachyphylaxis to this agent. As ergotamine revealed both a vasoconstrictive and a 5-HT-blocking activity, the beneficial effect in migraine may be by an interference during both the vasoconstrictory and vasodilatory phases.
D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D004878:Ergotamine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D008881:Migraine Disorders / Q000188:drug therapy; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D012701:Serotonin / Q000008:administration & dosage / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013618:Tachyphylaxis; D013699:Temporal Arteries / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects
D012702:Serotonin Antagonists; D012701:Serotonin; D004878:Ergotamine; D009638:Norepinephrine