Effect of the caspase inhibitors z-VAD.fmk or Ac-DEVD-CHO on cell death induced by calcium ionophore A23187 or calcium channel inhibitor SKF 96365. Control and Scott B lymphoblasts were treated with z-VAD.fmk (50 μM) or Ac-DEVD-CHO (50 μM) for 48 or 72 h in the presence of calcium ionophore A23187 (200 nM) (a), or in the presence of the calcium channel inhibitor SKF 96365 (10 μM) (b). The degree of apoptosis was determined by measurement of hypodiploid DNA using propidium iodide (0.1 mg/ml). Values are mean ± SEM of at least 8 independent determinations. *P < 0.05 versus the corresponding value in the absence of caspase inhibitor.