title: A comparison of 5-hydroxytryptamine receptors mediating contraction in rabbit aorta and dog saphenous vein: evidence for different receptor types obtained by use of selective agonists and antagonists.
abstract: Using recently available selective agonists and antagonists we have examined further our postulate (Apperley et al., 1980) that 5-hydroxytryptamine (5-HT) mediates contraction of dog saphenous vein via a different 5-HT receptor type from that in the rabbit aorta. In the rabbit isolated aorta, ketanserin and spiperone were potent, specific, competitively-acting antagonists of the contractile effects of 5-HT. In contrast, in the dog isolated saphenous vein neither ketanserin nor spiperone caused any rightward displacement of concentration-response curves to 5-HT although the maximum response was reduced by about 10%. In the rabbit aorta 5-carboxamidotryptamine (5-CONH2-T) was a weak agonist whilst the 5-N,N-dimethyl and 5-N-ethyl derivatives were even weaker or inactive. The contractile effect of 5-CONH2-T in the rabbit aorta was potently and competitively antagonized by ketanserin. In contrast, in the dog saphenous vein 5-CONH2-T and its 5-N,N-dimethyl and 5-N-ethyl derivatives were all potent agonists. The contractile effect of 5-CONH2-T was not markedly affected by ketanserin. The profile of action of ketanserin and spiperone in the rabbit aorta is consistent with the view that 5-HT2 receptors mediate contraction in this preparation. However, the 5-HT receptor mediating contraction in the dog saphenous vein appears to be '5-HT1-like', sharing a number of characteristics with the 5-HT1 recognition site identified from [3H]-5-HT ligand binding studies in brain tissue.
authors.forename: W
authors.initials: W
authors.lastname: Feniuk
authors.forename: P P
authors.initials: PP
authors.lastname: Humphrey
authors.forename: M J
authors.initials: MJ
authors.lastname: Perren
authors.forename: A D
authors.initials: AD
authors.lastname: Watts
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects; D004285:Dogs; D066298:In Vitro Techniques; D007650:Ketanserin; D008729:Methoxamine / Q000037:antagonists & inhibitors; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D010880:Piperidines / Q000494:pharmacology; D011817:Rabbits; D011985:Receptors, Serotonin / Q000187:drug effects*; D012501:Saphenous Vein / Q000187:drug effects; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D012702:Serotonin Antagonists / Q000494:pharmacology; D013134:Spiperone / Q000494:pharmacology
chemical_list: D010880:Piperidines; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D012701:Serotonin; D013134:Spiperone; C047087:5-carboxamidotryptamine; D007650:Ketanserin; D008729:Methoxamine