5-HT1B receptors mediate potent contractile responses to 5-HT in rat caudal artery.
5-Hydroxytryptamine (5-HT) evoked potent contractile responses in phenoxybenzamine-treated ring segments of rat caudal artery, partially contracted with U46619. Responses were mimicked by 5-HT1-selective agonists with the potency order: RU24969 > 5-carboxamidotryptamine > 5-HT = CP-93,129 >> sumatriptan. 8-Hydroxy-N,N-dipropylaminotetralin was virtually inactive. Responses were unaffected by spiperone (0.1 microM) and mesulergine (1.0 microM), but were antagonized competitively by (+/-)-cyanopindolol affording agonist-independent pKB estimates of 8.4 to 8.9. The pharmacological profile of this receptor is consistent with that of the 5-HT1B subtype. Since the 5-HT1B receptor is the rodent homologue of the 5-HT1D beta subtype, it might be anticipated that 5-HT1D beta receptors will be found to mediate vasoconstrictor responses in non-rodent species.
Craig
D A
DA
Analytical Pharmacology Group, Wellcome Research Laboratories, Beckenham, Kent.
Martin
G R
GR
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D000818:Animals; D001158:Arteries / Q000187:drug effects; D004873:Ergolines / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D010869:Pindolol / Q000031:analogs & derivatives / Q000494:pharmacology; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists / Q000037:antagonists & inhibitors / Q000494:pharmacology; D013134:Spiperone / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D004873:Ergolines; D011450:Prostaglandin Endoperoxides, Synthetic; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D014662:Vasoconstrictor Agents; D012701:Serotonin; C047975:cyanopindolol; D013134:Spiperone; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D010869:Pindolol; C031649:mesulergine