Figure 4.

Effects of rolipram, IBMX and 8-Br-cAMP on TNF expression in J774 mouse macrophages. (A) J774 cells were incubated with rolipram alone (2 μM) or in the presence of increasing concentrations of rolipram for 1 h and stimulated then with LPS (10 ng·mL⁻¹) for 24 h, and TNF accumulated into the culture medium was measured by elisa. (B, C) J774 cells were pre-incubated by rolipram (2 μM), IBMX (100 μM), milrinone (10 μM), BIRB 796 (100 nM) and stimulated with LPS (10 ng·mL⁻¹) or with the combination of LPS and 8-Br-cAMP (100 μM) for 24 h (TNF protein) or 3 h (TNF mRNA). TNF accumulated into the culture medium was measured by elisa. TNF mRNA levels were measured by quantitative RT-PCR and normalized against GAPDH mRNA levels. The results are expressed as mean ± SEM, number of repeats = 6 for TNF protein and number of repeats = 3 for TNF mRNA. One-way anova with Dunnett's post-test (A) or Bonferroni's post-test (B, C) was performed and statistical significance is indicated as ***P < 0.001.