SIN-1, contrary to SNAP, induces human thymocyte apoptosis.

(A) The total number of cells was significantly reduced by 0.5 nM SIN-1 (■) but not by SNAP (♦) or DEA-NO (○). The results are expressed as the mean numbers of viable cells in 4 different experiments. (B) SIN-1 (0.5 mM) induced apoptosis (TUNEL reaction and annexin V staining) of a large population after as little as 4 hours. Most cells were apoptotic after 18 hours of treatment with 0.5 mM SIN-1. SNAP had no effect after 18 hours of culture. The analysis was performed on the whole population. The data are representative of 4 individual experiments. The percentages in each panel indicate the percentage of TUNEL-positive cells in the upper panel, and percentage of Annexin V–positive cells in the lower panel.