Figure 6

CO-dependent cytoprotection requires ERK1/2 pathway. MLEC cultures were pretreated with room air (RA) or CO (250 ppm) for 2 h prior to the addition of antibody Jo2 (200 ng/ml). Additionally, PD 98059 (25 μM) or vehicle (DMSO) was added to the cultures for 30 min prior to Jo2 addition. Cells were then incubated an additional 24 hours in the absence or presence of CO. 200 μl of supernatant medium was removed for LDH assays as described in Methods (A). The data represent triplicate (n = 3) determinations. Comparisons between the treatment groups were performed using Student's T-test (*P< 0.05). The total lysates were subjected to Western blot to detect caspase-3. β-actin served as the standard (B).