Effect of forskolin on DNA-damaged induced cell death. Vehicle or 50 μM forskolin was added to cell cultures 30 min prior to exposure of Reh cells and MOPC315 cells to 10Gy and 2Gy, respectively. (A) 24 h after irradiation, cell death was assessed by PI staining. The results represent the mean values +/- SEM of 3 (Reh cells) or 6 (MOPC315 cells) experiments respectively. *P < 0.05 relative to cells treated with vehicle. (B) 4 h after irradiation, cells were harvested and examined for p53 and GAPDH expression by Western blot analysis.