title: 5-Hydroxytryptamine stimulates 45Ca2+ uptake by human umbilical vein endothelial cells in culture: mediation by 5-HT2 receptor subtypes.
abstract: In cultured human umbilical vein endothelial cells, 5-HT and alpha-methyl 5-HT stimulated [45Ca2+] uptake in concentration-dependent manner, whereas the 5-HT1 agonists, m-CPP (1-(3-chlorophenyl)piperazine and 2-MPP (1-(2-methoxyphenyl)piperazine), were without effect. In turn, 5-HT-stimulated [45Ca2+] uptake was inhibited in concentration-dependent manners by the 5-HT receptor antagonists ketanserin (5-HT2), LY 53,857 (5-HT2) and methiothepine (5-HT1/2) and to a lesser degeree by MDL 72222 (5-HT3) and BRL 43694 (5-HT3) whereas (+/-)-propranolol (5-HT1) was without effect. These data indicate that 5-HT stimulates Ca2+ uptake by endothelial cells via activation of a 5-HT2 receptor subtype. 5-HT was without effect on de novo prostacyclin (PGI2) synthesis over the concentration of 5-HT that elicited [45Ca2+] uptake. Since 5-HT did not stimulate PGI2, an event associated with an increase in levels of intracellular Ca2+, it is postulated that the uptake of 45Ca2+ reflects changes of Ca2+ at the level of the plasma membrane rather than on intracellular changes. 5-HT-stimulated Ca2+ uptake may be of relevance to endothelium-dependent relaxation, vascular permeability and endothelial repair and proliferation.
authors.affiliation: Department of Chemical Pathology and Human Metabolism, Royal Free Hospital, London, U.K.
authors.forename: J K
authors.initials: JK
authors.lastname: Gill
authors.forename: G
authors.initials: G
authors.lastname: Stansby
authors.forename: N
authors.initials: N
authors.lastname: Shukla
authors.forename: G
authors.initials: G
authors.lastname: Hamilton
authors.forename: M A
authors.initials: MA
authors.lastname: Barradas
authors.forename: J Y
authors.initials: JY
authors.lastname: Jeremy
mesh_terms: D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D011464:Epoprostenol / Q000096:biosynthesis; D006801:Humans; D007650:Ketanserin / Q000494:pharmacology; D007700:Kinetics; D011985:Receptors, Serotonin / Q000145:classification / Q000187:drug effects / Q000378:metabolism; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology*
chemical_list: D011985:Receptors, Serotonin; C042390:alpha-methylserotonin; D012701:Serotonin; D007650:Ketanserin; D011464:Epoprostenol; D002118:Calcium