PT - JOURNAL ARTICLE AU - M Spatafora AU - G Chiappara AU - AM Merendino AU - D D'Amico AU - V Bellia AU - G Bonsignore TI - Theophylline suppresses the release of tumour necrosis factor-alpha by blood monocytes and alveolar macrophages AID - 10.1183/09031936.94.07020223 DP - 1994 Feb 01 TA - European Respiratory Journal PG - 223--228 VI - 7 IP - 2 4099 - http://erj.ersjournals.com/content/7/2/223.short 4100 - http://erj.ersjournals.com/content/7/2/223.full SO - Eur Respir J1994 Feb 01; 7 AB - The purpose of this study was to evaluate the effect of theophylline on tumour necrosis factor-alpha (TNF-alpha) release by human blood monocytes (BMo), and rat BMo and alveolar macrophages (AM). BMo and AM were incubated in the absence or presence of theophylline, and the cell-free supernatants were harvested and tested for TNF-alpha activity by bioassay. Theophylline dose-dependently reduced TNF-alpha release by human BMo: significant inhibition was observed at 100 microns (41 +/- 5.9% of controls) and at 50 microns (59 +/- 4.8% of controls), while the inhibitory activity of theophylline at 10 microns (71 +/- 8.9% of controls) was not statistically significant. This activity was maximal at 2 h and declined at 4 h (59 +/- 5.2% of controls) and 24 h (89 +/- 3.1% of controls). Northern analysis performed on ribonucleic acid (RNA) extracted from human BMo demonstrated that theophylline was able to reduce TNF-alpha gene expression. Comparable levels of inhibition of TNF-alpha release were observed on rat BMo and AM (rat BMo 42 +/- 4.9% of controls; rat AM 38 +/- 1.7% of controls), suggesting that BMo and AM are equally susceptible to suppression of TNF-alpha release induced by theophylline. These results indicate that theophylline suppresses TNF-alpha release by mononuclear phagocytes. Since TNF-alpha is involved in the pathogenesis of bronchial hyperresponsiveness and asthma, our results suggest that the therapeutic activity of theophylline might be partly related to its effect on TNF-alpha release.