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Updated: Aug 11, 2026

Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography
Published on: September 22, 2011
5-HT1B receptors mediate potent contractile responses to 5-HT in rat caudal artery
1Analytical Pharmacology Group, Wellcome Research Laboratories, Beckenham, Kent.
Abstract:
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.
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