Figure 10.

The CAP-induced processes are dependent on the action of singlet oxygen (¹O₂). MKN-45 cells in medium were treated for 1 min with CAP in the absence of inhibitors or in the presence of the indicated inhibitors. All assays were further incubated after CAP treatment for 25 min, before they were subjected to three cycles of washing. Further incubation was performed in fresh medium without any inhibitors and the percentages of apoptotic cells were monitored kinetically. The results show three kinetically different processes which all were completely blocked when the ¹O₂ scavenger histidine (HIS) was present during CAP treatment and the 25 min incubation step following CAP treatment. Assays containing L-NAME showed no apoptosis induction, as L-NAME is an irreversible inhibitor of NOS. The inhibitors were applied at the following concentrations: HIS (2 mM); AEBSF (100 µM), FeTPPS (25 µM), L-NAME (2.4 mM).