Apoptosis and expression of the pro-apoptotic p53 in human, mouse, and hamster RPTECs under anoxia or reoxygenation. Apoptosis was assessed by the level of cleaved caspase-3. Both cleaved caspase-3 and the pro-apoptotic p53 were measured by Western blotting and the results of three, representative of the nine performed experiments, are depicted in panel (A). Compared to the control group, in human RPTECs, both anoxia and reoxygenation increased the level of cleaved caspase-3. In mouse RPTECs, cleaved caspase-3 increased only under anoxia, whereas, in hamster RPTECs, apoptosis was not observed either under anoxia or reoxygenation (B). The alterations in cleaved caspase-3 fitted to the alterations of the pro-apoptotic protein tumor suppressor p53 (C). Hu: human; Mo: mouse; and Hm: hamster. Asterisk indicates a p < 0.05 compared to the control cultured under normoxia cells, and error bars correspond to SD.