title: Nanomolar concentrations of zinc pyrithione increase cell susceptibility to oxidative stress induced by hydrogen peroxide in rat thymocytes.
abstract: Zinc pyrithione is used as an antifouling agent. However, the environmental impacts of zinc pyrithione have recently been of concern. Zinc induces diverse actions during oxidative stress; therefore, we examined the effect of zinc pyrithione on rat thymocytes suffering from oxidative stress using appropriate fluorescent probes. The cytotoxicity of zinc pyrithione was not observed when the cells were incubated with 3 μM zinc pyrithione for 3 h. However, zinc pyrithione at nanomolar concentrations (10 nM or more) significantly increased the lethality of cells suffering from oxidative stress induced by 3 mM H(2)O(2). The application of zinc pyrithione alone at nanomolar concentrations increased intracellular Zn(2+) level and the cellular content of superoxide anions, and decreased the cellular content of nonprotein thiols. The simultaneous application of nanomolar zinc pyrithione and micromolar H(2)O(2) synergistically increased the intracellular Zn(2+) level. Therefore, zinc pyrithione at nanomolar concentrations may exert severe cytotoxic action on cells simultaneously exposed to chemicals that induce oxidative stress. If so, zinc pyrithione leaked from antifouling materials into surrounding environments would be a risk factor for aquatic ecosystems. Alternatively, zinc pyrithione under conditions of oxidative stress may become more potent antifouling ingredient.
authors.affiliation: Division of Environmental Symbiosis Studies, Graduate School of Integrated Arts and Sciences, The University of Tokushima, Tokushima 770-8502, Japan.
authors.forename: Tomohiro M
authors.initials: TM
authors.lastname: Oyama
authors.forename: Minoru
authors.initials: M
authors.lastname: Saito
authors.forename: Takayasu
authors.initials: T
authors.lastname: Yonezawa
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okano
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oyama
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004357:Drug Synergism; D004785:Environmental Pollutants / Q000633:toxicity*; D006861:Hydrogen Peroxide / Q000633:toxicity*; D009942:Organometallic Compounds / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D011725:Pyridines / Q000633:toxicity*; D051381:Rats; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D060168:Thymocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D009942:Organometallic Compounds; D011725:Pyridines; D013438:Sulfhydryl Compounds; D013481:Superoxides; D006861:Hydrogen Peroxide; C010423:pyrithione zinc