Effect of calcium ionophore A23187 and/or calcium channel inhibitor SKF 96365 on cell death. Control and Scott B lymphoblasts were treated with A23187 (100–200 nM) for 48 (a) or 72 (b) h, or with SKF 96365 (10 μM) for 48 or 72 h in the absence (c) or in the presence of calcium ionophore A23187 (200 nM) (d). 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 < 0.01 versus control cells. †P < 0.05 versus the corresponding values at 48 h of treatment.