title: Effect of serotonin and tricyclic antidepressants on intracellular calcium concentrations in Spisula oocytes.
abstract: Microspectrofluorometry and video imaging techniques were used to study and to compare the changes in intracellular calcium concentrations ([Ca2+]i) of individual Fura-2 loaded Spisula oocytes treated with serotonin (5-hydroxytryptamine, 5-HT) or tricyclic antidepressants. In the present study, we showed that 5-HT increased [Ca2+]i in freshly isolated Spisula oocytes suspended in artificial sea water. In the absence of extracellular Ca2+, 5-HT did not influence [Ca2+]i. Stimulation of [Ca2+]i by 5-HT was blocked by calcium channel blocker, e.g. verapamil, and by tricyclic antidepressants. These observations combined with our previous results on the effects of 5-HT, tricyclic antidepressants and verapamil on calcium uptake suggest that the increase in [Ca2+]i induced by 5-HT results from an influx of extracellular calcium through calcium channels, which can be blocked by tricyclic antidepressants. The use of the Fura-2 imaging technique allowed single-cell measurements and defined changes induced by 5-HT in [Ca2+]i which is the net result of calcium uptake and release of intracellular calcium from storage sites in individual Spisula oocytes.
authors.affiliation: Center for Biomedical Research, Population Council, New York.
authors.forename: R
authors.initials: R
authors.lastname: Juneja
authors.forename: E
authors.initials: E
authors.lastname: Ito
authors.forename: S S
authors.initials: SS
authors.lastname: Koide
mesh_terms: D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D049872:Bivalvia / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D005260:Female; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D014741:Video Recording
chemical_list: D000929:Antidepressive Agents, Tricyclic; D012701:Serotonin; D002118:Calcium