Figure 4
Effect of different agonists on DNA synthesis and phosphorylation of ERK and Akt in pancreatic stellate cells. A. Effect of PDGF (10 ng/ml), EGF (10 nM), and TGFβ (10 ng/ml) on DNA synthesis. Cells in serum-free medium were stimulated for 24 hours, with [3H] thymidine added at 18 hours. DNA synthesis was assessed as described in Methods. Results are presented as mean +/−SEM of six experiments. B. Effect of pretreatment with indomethacin (10 μM) for one hour before stimulation of cells with PDGF for 24 hours. Results are presented as mean +/−SEM of three experiments. C. Effect of PDGF (10 ng/ml), EGF (10 nM), and TGFβ (10 ng/ml) on phosphorylation of Akt and ERK. Cells in serum-free medium were stimulated for 5 minutes before harvesting and analysis of cell lysates on Western blots. Blots are from one typical of four experiments. Histograms represent mean +/−SEM of four experiments. D. Effect of thrombin (1 U/ml), PGE2 (10 μM), fluprostenol (10 μM), and forskolin (10 μM) on ERK phosphorylation. Cells were stimulated for 5 minutes before harvesting. Blots from one typical of four experiments are shown. Histograms represent mean +/−SEM of four experiments. * Sign. different from control.