Table 1.

Effects of NGF and SPP on Apoptosis Induced by Serum Withdrawal

TreatmentApoptotic cells (%)
None73.5  ± 0.9
SPP53.9  ± 1.3
NGF9.5  ± 1.6
DMS83.4  ± 0.2
DMS + NGF18.5  ± 1.9
DMS + SPP52.6  ± 0.9
DMS + NGF + SPP10.5  ± 1.0
  • PC12 cells were incubated for 24 hr in serum-free medium in the absence or presence of NGF (100 ng/ml), SPP (5 μm),N,N-dimethylsphingosine (DMS, 10 μm), or the indicated combinations. Changes of nuclear morphology characteristic of apoptosis were quantified after staining with the DNA-specific fluorochrome bisbenzimide. Cells with chromatin condensation or segmentation of nuclei into three or more fragmentations were considered apoptotic. At a minimum, 500 cells in each field were scored. The data represent two independent determinations from three separate experiments.