Effect of PAO on caspase 3 and PARP cleavage. OCIM2 cells were incubated without PAO (lane C) and with it at a concentration of 0.08 μmol/L (lane 2) or 0.1 μmol/L (lane 1) for 8 hours. Cleavage of caspase 3 was already detected after 4 hours. Increments in the levels of cleaved caspase 3 (A) and cleaved PARP (B) are depicted.