PT  - JOURNAL ARTICLE
AU  - M Bodelsson
AU  - K Törnebrandt
AU  - B Arneklo-Nobin
TI  - Endothelial relaxing 5-hydroxytryptamine receptors in the rat jugular vein: similarity with the 5-hydroxytryptamine1C receptor.
DP  - 1993 Feb 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 709--716
VI  - 264
IP  - 2
4099  - http://jpet.aspetjournals.org/content/264/2/709.short
4100  - http://jpet.aspetjournals.org/content/264/2/709.full
SO  - J Pharmacol Exp Ther1993 Feb 01; 264
AB  - 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.