The effect of indomethacin on colony-stimulating-factor production by the lung

In this study, indomethacin was used to investigate the production of colony-stimulating-factor by the lung tissue. Addition of various concentrations of indomethacin (10(-5)-1 mg/ml) to the lung culture showed that it enhances CSF production in a dose dependent manner. The number of colonies reached a maximum at 1 microgram/ml and gradually diminished at higher concentrations. Addition of exogenous E-series prostaglandins alone had no effect on the CSF activity of normal lung. However, in the presence of indomethacin, E-series prostaglandins reversed the enhancing effect produced by indomethacin. On the other hand, cAMP or its dibutyryl derivative also increased CSF production. Removal of alveolar macrophages from the lung by lavaging had no effect on the CSF production by the lung but reduced the enhancing effect of indomethacin by 50%. The results suggest that indomethacin stimulates CSF production and that this process is partially regulated by prostaglandins and cAMP.