Figure 5.

Ion channel inhibitors block caspase activation by different mechanisms. Activities of caspase-9 (n=15), -3 (n=18) and -8 (n=7) induced by STS were assessed in the presence of different ion channel inhibitors. Neither caspase-9 nor caspase-8 were affected by either the combination of TEA⁺ and 4AP (T+4) or FA. However, caspase-3 was significantly inhibited by both types of ion channel inhibitors separately or in combination. This combination had an additive effect suggesting that TEA⁺ and 4AP had a different mechanism to inhibit caspase-3 than FA. Interestingly, only this combination of ion channel inhibitors reduced significantly the activation of caspase-9 and -8. ^*P<0.05