Figure 5

Effect of EP3 receptor selective agonists and antagonists on HT-29 cell proliferation. A HT-29 cells were deprived of serum overnight and challenged with 10 nM PGE2, 10 μM butaprost, 10 μM sulprostone or 10 μM 11-deoxy-PGE1. DNA synthesis was assessed 5 days later. Data are mean ± S.E.M. of cells/well of 3 experiments with triplicate measurements.B Serum-starved HT-29 cells were stimulated for 20 min with the same agonists as in A and cAMP levels were determined as before. C Serum-starved HT-29 cells were challenged with 10 nM PGE2 alone or in the presence of 250 nM each of L-818638 (EP1 antagonist), L-826266 (EP3 antagonist) or MF-191 (EP4 antagonist). Proliferation was measured 4 days later by [³H]-thymidine incorporation. Two-sample comparisons (all vs. control) were performed with Student's t test. P values ***P < 0,001, **P < 0,01, *P < 0,05.