Glutathione depletion and cytotoxicity of buthionine sulphoximine and SR2508 in rodent and human cells.

Abstract

SR2508 (1 mM) increases the rate of glutathione (GSH) depletion by L-buthionine-S-R-sulphoximine (BSO) in hypoxic V79 rodent and A549 human cells. Specifically, the GSH content for V79 and A549 cells, after incubating for about 6 hr with 50 and 100 microM BSO, respectively, was lower by at least 10-fold when 1 mM SR2508 was present. In addition, 1 mM SR2508 is extremely toxic to hypoxic cells with lower GSH content. Survival probabilities of GSH-depleted V79 and A549 cells are about 10(-3) after 10 hr incubation with 1 mM SR2508. By itself, 1 mM SR2508 or 50-100 microM BSO decreased cellular viability by about 50% with a 10 hr treatment period. Both the phenomena described above are preferential towards hypoxic cells with minimal effect on aerobic cells.