Effect of a lymphocyte-derived pro-inflammatory factor on carrageenan pleurisy in the rat.

An intravenous injection of a lymphocyte pro-inflammatory factor (LpIF), obtained from rat spleen, restored diminished fluid and cellular responses in carrageenan pleurisy in leucopenic animals. A similar filtrate of bone marrow cells had no restorative properties. Previous results from elsewhere indicated a single pro-inflammatory activity on the fluid component of inflammation. We propose that LpIF has a more significant effect by influencing both components of inflammation and suggest that the discrepancy may be due to the different models used.