title: Action of serotonin antagonists on cytoplasmic calcium levels in early embryos of sea urchin Lytechinus pictus.
abstract: Possible interaction of the serotonergic system with intracellular calcium mechanisms was investigated using techniques of ratio imaging measurement of intracellular Ca2+ and confocal microscopy in cleaving embryos of sea urchin Lytechinus pictus. Some serotonin antagonists specifically increase free intracellular Ca2+ and evoke transient regression of the first cleavage furrow, suggesting possible linkage of serotonergic and calcium mechanisms in the regulation of cellular events during cleavage divisions. These effects were more pronounced in the experiments with hydrophilic 5-HT-antagonists, quarternary ammonium salts that do not penetrate the cell membrane. Thus, it appears that 5-HT-receptors which mediate these effects are localised on the cell membrane, whereas previously studied receptors mediating the cytostatic action of lipophilic 5-HT-antagonists are localised intracellularly.
authors.affiliation: N.K.Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow. ybshm@ibrran.msk.su
authors.forename: Y B
authors.initials: YB
authors.lastname: Shmukler
authors.forename: G A
authors.initials: GA
authors.lastname: Buznikov
authors.forename: M J
authors.initials: MJ
authors.lastname: Whitaker
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002455:Cell Division; D003593:Cytoplasm / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018613:Microscopy, Confocal; D012617:Sea Urchins / Q000196:embryology*; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013997:Time Factors
chemical_list: D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D002118:Calcium