Fig. 4.

CM572-induced calcium response in SK-N-SH neuroblastoma. The effect of CM572 on calcium release was examined in fura-2–loaded SK-N-SH neuroblastoma cells. Cells were loaded with fura-2 and assays carried out as described in Materials and Methods. A 3 μM dose of CM572 did not elicit a calcium response, 10 μM CM572 elicited a very small calcium response, and concentrations at and above 30 μM induced calcium increases in a dose-dependent manner. Arrow indicates injection of CM572. The basal (preinjection) calcium concentration was determined for each trace, and that value was normalized to zero. Basal calcium concentrations ranged from 0.06–0.08 μM. Data are presented as change in calcium level above basal. Representative traces are shown from eight replicate experiments for 3 and 10 µM doses and three replicates for 30 and 100 µM doses. Experiments were performed using four wells per condition.