title: Flow cytometric analysis of the H2O2-induced increase in intracellular Ca2+ concentration of rat thymocytes.
abstract: The effect of hydrogen peroxide (H2O2) on the intracellular Ca2+ concentration ([Ca2+]i) of rat thymocytes was examined by a flow cytometer and two fluorescent dyes, fluo-3-AM and ethidium bromide, a dye impermeant to intact membranes, to characterize the H2O2-induced increase in [Ca2+]i. H2O2 at concentrations greater than 30 microM dose-dependently increased the [Ca2+]i of thymocytes which were not stained with ethidium. Removal of external Ca2+ greatly reduced the degree of H2O2-induced increase in [Ca2+]i. However, H2O2 still increased the [Ca2+]i under the external Ca(2+)-free condition. Diethylmaleate, which is known to produce a chemical depletion of cellular nonprotein thiol, significantly increased the [Ca2+]i. Dithiothreitol, which is used to protect cellular nonprotein thiol, slightly decreased the [Ca2+]i, but greatly reduced the H2O2-induced increase in [Ca2+]i. Therefore, it is considered that H2O2 may increase the [Ca2+]i through a mechanism related to the effects of H2O2 on the cellular nonprotein thiol.
authors.affiliation: Laboratory of Cell Signaling (Pharmacology), Faculty of Integrated Arts and Sciences, University of Tokushima, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Okazaki
authors.forename: L
authors.initials: L
authors.lastname: Chikahisa
authors.forename: K
authors.initials: K
authors.lastname: Kanemaru
authors.forename: Y
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects; D004996:Ethidium / Q000494:pharmacology; D005434:Flow Cytometry / Q000379:methods*; D005456:Fluorescent Dyes; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013950:Thymus Gland / Q000187:drug effects / Q000378:metabolism*; D014966:Xanthenes / Q000494:pharmacology
chemical_list: D000814:Aniline Compounds; D005456:Fluorescent Dyes; D016877:Oxidants; D014966:Xanthenes; C059715:Fluo-3; D006861:Hydrogen Peroxide; D004996:Ethidium; D002118:Calcium