title: Effect of serotonin on intracellular free calcium of rat cerebrovascular smooth muscle cells in culture.
abstract: Smooth muscle cells were dissociated from conducting cerebral arteries of adult rats and maintained in culture for 2-4 days. The calcium-sensitive fluorescent probe, fura-2, was used to study the effect of the vasoconstrictor serotonin (5-HT) on the level of free intracellular Ca2+ in these cells. The baseline level of free intracellular calcium was 39 +/- 3.6 nM. In 74 out of 110 cells, 5-HT application transiently increased the free Ca2+ content. This effect was dose-dependent and was suppressed by nanomolar concentrations of the 5-HT2 receptor antagonist, ketanserin. The 5-HT induced rise in free intracellular calcium was not prevented by the presence of Co2+, La3+, or nifedipine, blockers of voltage-sensitive calcium channels. These results indicate that 5-HT mobilizes intracellular Ca2+ in cultured smooth muscle cells derived from the rat cerebrovasculature. The mobilization of intracellular Ca2+ appears to be triggered by a 5-HT2 type receptor, although further pharmacological experiments are required to verify this hypothesis.
authors.affiliation: Department of Physiology, University of British Columbia, Vancouver, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: K G
authors.initials: KG
authors.lastname: Baimbridge
authors.forename: D A
authors.initials: DA
authors.lastname: Mathers
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D002536:Cerebral Arteries / Q000187:drug effects / Q000378:metabolism; D003035:Cobalt / Q000494:pharmacology; D016257:Fura-2; D007650:Ketanserin / Q000494:pharmacology; D007811:Lanthanum / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D009543:Nifedipine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects; D012701:Serotonin / Q000494:pharmacology*
chemical_list: D011985:Receptors, Serotonin; D012701:Serotonin; D003035:Cobalt; D007811:Lanthanum; D007650:Ketanserin; D009543:Nifedipine; D011188:Potassium; D002118:Calcium; D016257:Fura-2