Figure 3.

Hypoxia attenuates the reduction in cell viability induced by hydrogen peroxide. (A) Viability of MS-1 cells after hydrogen peroxide exposure. Cells were exposed to hydrogen peroxide either with or without hypoxic preconditioning. The results are expressed as the percentage of absorbance (MTT) relative to the control. Each value represents the mean ± SEM for three separate experiments. Statistical analyses was conducted in comparison to control values; P < 0.001. (B) Effect of hypoxia on hydrogen peroxide-mediated apoptosis-related protein expression. Before hydrogen peroxide treatment, MS-1 cells were exposed to hypoxia for indicated times. Anti-bax and bcl expression were then examined after hydrogen peroxide treatment, and protein expression was examined by blotting with bax and bcl antibodies. The lower panel demonstrates equivalent loading of total actin in the whole cell lysates.