title: Putative role of intracellular Zn(2+) release during oxidative stress: a trigger to restore cellular thiol content that is decreased by oxidative stress.
abstract: Although the ability of zinc to retard the oxidative process has been recognized for many years, zinc itself has been reported to induce oxidative stress. In order to give some insights into elucidating the role of intracellular Zn(2+) in cells suffering from oxidative stress, the effects of N-ethylmaleimide (NEM) and ZnCl(2) on cellular thiol content and intracellular Zn(2+) concentration were studied by use of 5-chloromethylfluorescein diacetate (5-CMF-DA) and FluoZin-3 pentaacetoxymethyl ester (FluoZin-3-AM) in rat thymocytes. The treatment of cells with NEM attenuated 5-CMF fluorescence and augmented FluoZin-3 fluorescence in a dose-dependent manner. These NEM-induced phenomena were observed under external Zn(2+)-free conditions. Results suggest that NEM decreases cellular thiol content and induces intracellular Zn(2+) release. Micromolar ZnCl(2) dose-dependently augmented both FluoZin-3 and 5-CMF fluorescences, suggesting that the elevation of intracellular Zn(2+) concentration increases cellular thiol content. Taken together, it is hypothesized that intracellular Zn(2+) release during oxidative stress is a trigger to restore cellular thiol content that is decreased by oxidative stress.
authors: Graduate School of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan.
authors: Akio
authors: A
authors: Kinazaki
authors: Hongqin
authors: H
authors: Chen
authors: Kazuki
authors: K
authors: Koizumi
authors: Takuya
authors: T
authors: Kawanai
authors: Tomohiro M
authors: TM
authors: Oyama
authors: Masaya
authors: M
authors: Satoh
authors: Shiro
authors: S
authors: Ishida
authors: Yoshiro
authors: Y
authors: Okano
authors: Yasuo
authors: Y
authors: Oyama
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005033:Ethylmaleimide / Q000494:pharmacology; D005452:Fluoresceins / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000494:pharmacology; D018384:Oxidative Stress / Q000502:physiology*; D011083:Polycyclic Compounds / Q000494:pharmacology; D051381:Rats; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D060168:Thymocytes / Q000187:drug effects / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: C451182:FluoZin-3; D005452:Fluoresceins; D005456:Fluorescent Dyes; D011083:Polycyclic Compounds; D013438:Sulfhydryl Compounds; D013439:Sulfhydryl Reagents; C069306:5-chloromethylfluorescein; D015032:Zinc; D005033:Ethylmaleimide