Modulation of lipopolysaccharide (LPS)- and tumor necrosis factor (TNF)-stimulated PGE2 release. Macrophages (5 × 105 cells/ml) from subcultured J774 mouse cell line were incubated with (a) LPS (2 μg/ml) or (b) TNF (10 ng/ml) in the absence or the presence of various concentrations (0–40 μM) of P-NT.II, LY315920, or scrambled P-NT.II for 20 hours. Supernatants were collected, and PGE2 release in the medium was determined by enzyme-linked immunosorbent assay. Results are shown as the mean ± SEM of five experiments performed in duplicate. **P < 0.01 between inhibitor-treated and untreated cultures.