title: ATP-induced increase in intracellular Ca2+ concentration in the cultured marginal cell of the stria vascularis of guinea-pigs.
abstract: The primary culture of marginal cells from the explant of the stria vascularis of guinea-pigs was established and confirmed by morphological, immunohistochemical and physiological characters of the cultivated cells. The positive stain of cytokeratin 18 without vimentin and desmin expressions indicated the epithelial origin of the cultured polygonal cells. Electron microscopical findings of cultured cells resembled the morphological characteristics of marginal cells. The addition of 100 microM ouabain to the cultured cells significantly increased the intracellular Na+ concentration, providing the evidence for the presence of Na+ pump. Using the cultured marginal cells identified by the above-mentioned findings, the effects of neurotransmitters and hormones in regulating intracellular Ca2+ concentration ([Ca2+]i) were investigated. The addition of 10(-4) M ATP caused an increase in [Ca2+]i, which was independent of the presence of extracellular Ca2+. The rank order of agonist potency was ATP > alpha, beta-methylene ATP > ADP. Adenosine, however, evoked no response. Cultured marginal cells may possess P2-purinergic receptors which mobilize Ca2+ from the intracellular Ca2+ pool.
authors.affiliation: Department of Otolaryngology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.forename: H
authors.initials: H
authors.lastname: Sunose
authors.forename: K
authors.initials: K
authors.lastname: Hozawa
authors.forename: C
authors.initials: C
authors.lastname: Kusakari
authors.forename: Y
authors.initials: Y
authors.lastname: Katori
authors.forename: T
authors.initials: T
authors.lastname: Takasaka
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D048429:Cell Size; D002478:Cells, Cultured; D003893:Desmin / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005470:Fluorometry; D016257:Fura-2 / Q000737:chemistry; D006168:Guinea Pigs; D007150:Immunohistochemistry; D007633:Keratins / Q000378:metabolism; D008854:Microscopy, Electron; D010042:Ouabain / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013316:Stria Vascularis / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D014746:Vimentin / Q000378:metabolism
chemical_list: D003893:Desmin; D004791:Enzyme Inhibitors; D014746:Vimentin; D010042:Ouabain; D000244:Adenosine Diphosphate; D007633:Keratins; D000255:Adenosine Triphosphate; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D000241:Adenosine; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; D002118:Calcium; D016257:Fura-2