Changes in cellular glutathione levels: possible relation to selenium-mediated anticarcinogenesis

Mechanisms of Se-mediated anticarcinogenesis were investigated. Excess Se as Na2SeO3 reversibly decreased mammalian cell proliferation in vitro. This inhibitory effect was exerted primarily in G1 of the cell cycle; however, S and G2 were also affected. Cellular glutathione concentrations both in vitro and in vivo were altered by excess Se administration. These results are discussed in terms of altered cellular glutathione metabolism and its possible implications for cell proliferation.