Figure 1.

Effect of PE on [³H]thymidine incorporation in rat-1 cells. Cells were grown in 24-well plates in DMEM containing 10% FBS at a density of 150,000 cells/well until they reached 80–90% confluency, and then serum-deprived for 48 h in DMEM. A, Cells were treated with different concentrations of PE (2, 5, and 10 μM) for 18 h prior to the addition of [³H]thymidine (0.50 μCi/ml) for the last 4 h. B, Cells were treated with PE for different incubation periods prior to the addition of [³H]thymidine (0.50 μCi/ml). Cells were incubated with [³H]thymidine for the last 4 h and thymidine incorporation was determined as described in Methods. Data are expressed as dpm of [³H]thymidine incorporated in DNA per well. Values are the mean ± S.E. of six independent experiments performed in quadruplicates on different batches of cells. * Values significantly different from vehicle, p < .05.