Stimulation of macrophage DNA synthesis in culture by different types of acute non immunological inflammatory exudates

Acute non immunological inflammatory pleural exudates provoked by four different irritants and collected 4 hours later have been shown to be capable of stimulating DNA synthesis, in rat peritoneal macrophages in culture. It is postulated that a mitogenic factor, "Inflammatory Mitogenic Factor for Macrophages" IMF (M), could be responsible for this phenomenon. There may be a correlation between the protein concentration of the exudates and its mitogenic activity.