Thiol-modulating agents increase manganese superoxide dismutase activity in human lung fibroblasts

The effect of three thiol-modulating agents, buthionine sulfoximine (BSO), N-ethylmaleimide (NEM), and diazenedicarboxylic acid bis(N,N'-dimethylamide) (diamide), on cellular glutathione (GSH) level and manganese superoxide dismutase (MnSOD) activity was studied in a human lung fibroblast cell line, WI38. The results showed that treatment with BSO, NEM, or diamide can increase MnSOD activity in the human fibroblast cells. These findings are compatible with the view that alteration of intracellular GSH level may create a pro-oxidant environment in the cells and the MnSOD activity may increase as a cellular response to the oxidative stress.