title: Endothelial relaxing 5-hydroxytryptamine receptors in the rat jugular vein: similarity with the 5-hydroxytryptamine1C receptor.
abstract: Serotonin (5-HT) at low concentrations induces an endothelium-dependent relaxation in the rat jugular vein mediated via a 5-HT1-like receptor. The receptor mediating this relaxation was characterized in vitro using agonists and antagonists in segments precontracted with prostaglandin F2 alpha in the presence of the 5-HT2 receptor antagonist ketanserin. The following substances acted as agonists, with the order of potency: 5-HT > dl-alpha-methyl-5-hydroxytryptamine = 5-carboxamidotryptamine > quipazine > 8-hydroxy-2-(dl-n-propylamino) tetralin. dl-Propranolol, mesulergine and mianserin acted as competitive, methysergide, 6-methyl-1-(1-methylethyl)-ergoline-8 beta-carboxylic acid 2-hydroxy-1-methylpropyl ester and sumatriptan as non-competitive, and ritanserin acted as both a competitive and non-competitive antagonist of the 5-HT-induced relaxation. Neither the 5-HT2 antagonists ketanserin and spiperone nor the 5-HT3 antagonist 1 alpha-H,3 alpha,5 alpha-H-tropan-3-yl,3,5-dichlorbenzoate affected the 5-HT-induced relaxation. The pEC50 values of the agonists and the pA2 and pAh values of the antagonists correlated strongly with pKD values at the 5-HT1C binding site. These results are consistent with a peripheral vascular 5-HT1C receptor in the rat jugular vein.
authors.affiliation: Department of Anesthesiology, University of Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Bodelsson
authors.forename: K
authors.initials: K
authors.lastname: Törnebrandt
authors.forename: B
authors.initials: B
authors.lastname: Arneklo-Nobin
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D007601:Jugular Veins / Q000187:drug effects / Q000502:physiology; D007650:Ketanserin / Q000494:pharmacology; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology*
chemical_list: D011985:Receptors, Serotonin; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C047087:5-carboxamidotryptamine; D007650:Ketanserin