Abstract

OBJECTIVES
To evaluate the protective effects of glutathione (GSH) on the cytotoxicity of mercurial compounds(CH3HgCl, HgCl2) or cadmium chloride(CdCl2) in EMT-6 cells. METHODS: The compounds investigated were CH3HgCl, HgCl2, CdCl2, GSH, buthionine sulfoximine(BSO), L-2-oxothiazolidine-4-carboxylic acid(OTC). Cytotoxicity analysis consist of nitric oxide(NO) production, ATP production and cell viability. RESULTS: Mercurial compounds and cadmium chloride significantly decreased cell viability and the synthesis of NO and cellular ATP in EMT-6 cells. GSH was not toxic at concentrations of 0 - 1.6 mM. In the presence of GSH, mercurial compounds and cadmium did not decrease the production of ATP and nitrite in EMT-6 cells. The protective effects of GSH against the cytotoxicity of mercurial compounds and cadmium depended on the concentration of added GSH to the culture medium for EMT-6 cells. We evaluated the effects of intracellular GSH level on mercury- or cadmium-induced cytotoxicity by the pretreatment experiments. Pretreatment of GSH was not changed NO2- and ATP production, and pretreatment of BSO was decreased in dose- and time-dependent manner. Pretreatment of OTC was increased NO2- and ATP production in dose- and time-dependent manner. Because intracellular GSH level was increased by OTC pretreatment, the protective effect on mercury- and cadmium-induced cytotoxicity was increased. CONCLUSIONS: These results indicated that sulfhydryl compounds had the protective effects against mercury-induced cytotoxicity by the intracellular GSH levels.

• Keywords: Glutathione;Mercury;Cadmium;EMT-6;Nitric Oxide