Figure 1.

Effects of PGE₂ on cytokine generation from macrophages. Macrophages were pre‐incubated without (A) or with (B) indomethacin (1 μM) for 30 min and then with or without PGE₂ for 30 min before challenge with LPS (1 ng·mL⁻¹) for 22 h after which supernatants were harvested and assayed for TNF‐α generation. The data in (A) and (B) were reworked as % inhibition of the control unblocked release of TNF‐α, and this is shown in (C). In further experiments, macrophages were pre‐incubated (30 min) with indomethacin (1 μM) and then with or without PGE₂ for 30 min before challenge with LPS (1 ng·mL⁻¹) for 22 h and both IL‐6 and TNF‐α measured in the supernatants (D). Values are expressed as the % inhibition of control cytokine releases, which were 2422 ± 510 pg·mL⁻¹ of TNF‐α and 4992 ± 1980 pg·mL⁻¹ of IL‐6. Data shown are means ± SEM, for nine (A, B and C) or six (D) experiments. * P < 0.05; significantly different from unblocked control levels.