title: Zinc increases vulnerability of rat thymic lymphocytes to arachidonic acid under in vitro conditions.
abstract: Previous studies on the cytotoxicity of arachidonic acid (ARA) elucidated the involvement of oxidative stress and Ca(2+). In the present study, the Zn(2+)-related cytotoxicity of ARA was studied by a flow cytometric technique with appropriate fluorescent probes in rat thymocytes. Addition of 10 μM ZnCl2 enhanced the increase in cell lethality induced by 10 μM ARA. The removal of Zn(2+) by Zn(2+) chelators attenuated the ARA-induced increase in cell lethality. Thus, Zn(2+) is suggested to be involved in ARA cytotoxicity. ARA at 3-10 μM elevated intracellular Zn(2+) level. The Zn(2+) chelators attenuated the ARA-induced increase in intracellular Zn(2+) level while ARA significantly increased intracellular Zn(2+) level in the presence of 3 μM ZnCl2, suggesting the involvement of external Zn(2+). Zn(2+) reportedly exerts cytotoxic action under oxidative stress induced by hydrogen peroxide, via an excessive increase in intracellular Zn(2+) levels. Since ARA induces oxidative stress, the simultaneous administration of zinc and ARA may be harmful.
authors: Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima, 770-8502, Japan.
authors: Eiko
authors: E
authors: Niwa
authors: Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima, 770-8502, Japan.
authors: Tsuyoshi
authors: T
authors: Mitani
authors: Faculty of Integrated Arts and Sciences, Tokushima University, Tokushima, 770-8502, Japan.
authors: Shohei
authors: S
authors: Saitoh
authors: Faculty of Bioscience and Bio-industry, Tokushima University, Tokushima, 770-8513, Japan.
authors: Kaori
authors: K
authors: Kanemaru
authors: Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, 770-8514, Japan.
authors: Shiro
authors: S
authors: Ishida
authors: Faculty of Bioscience and Bio-industry, Tokushima University, Tokushima, 770-8513, Japan.
authors: Kumio
authors: K
authors: Yokoigawa
authors: Faculty of Bioscience and Bio-industry, Tokushima University, Tokushima, 770-8513, Japan. Electronic address: oyamay@tokushima-u.ac.jp.
authors: Yasuo
authors: Y
authors: Oyama
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D004357:Drug Synergism; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000187:drug effects / Q000473:pathology*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D060168:Thymocytes / Q000187:drug effects / Q000473:pathology*; D015032:Zinc / Q000633:toxicity*
chemical_list: D005456:Fluorescent Dyes; D016718:Arachidonic Acid; D015032:Zinc
keywords: Arachidonic acid; Cytotoxicity; Lymphocyte; Oxidative stress; Zinc