Characterization of 5-HT receptors on human pulmonary artery and vein: functional and binding studies

1. This study aimed to investigate the 5-hydroxytryptamine (5-HT) receptors mediating contraction of ring preparations isolated from human pulmonary arteries and veins. In functional studies, the responses to 5-HT, sumatriptan, ergotamine, serotonin-O-carboxymethyl-glycyl-tyrosinamide (SCMGT), alpha-methyl 5-HT (alpha-Me) and 2-methyl 5-HT (2-Me) were studied with WAY100635, GR127935, ritanserin, zacopride and SB204070 as antagonists. 2. All agonists produced concentration-dependent contractions of human pulmonary artery and vein preparations. The order of potency (-log ECS0 values) was ergotamine (6.88) > 5-HT (6.41) > or = SCMGT (6.20) = sumatriptan (6.19) > or = alpha-Me (6.04) in the ar…