FIGURE 1.

Carbon monoxide confers protection against apoptosis. Primary cultures of astrocytes cultured in 24-well plates were pretreated with 50 μm of CO for 3 h, following apoptosis induction by 20 h of exposure to the pro-oxidant, t-BHP (from 0 to 240 μm). The apoptotic hallmarks were assessed by flow cytometry. In A, the percentage of cells presenting high mitochondrial potential (detected by DiOC₆(3)) and containing intact plasma membrane (assessed with propidium iodide) is presented. All values are mean ± S.D. (n = 4). *, p < 0.05 compared with control and CO-treated cells for each concentration of t-BHP. B, representative picture of immunodetection of caspase-3 activation by its cleavage into the 17-kDa fraction. The first line corresponds to astrocytes treated with t-BHP at 160 μm (20 h); the second line astrocytes pretreated with 50 μm of CO (3 h) followed by t-BHP induction of apoptosis.