Presence and production of migration inhibitory activity in the peritoneal cavity

The presence of migration inhibitory (MI) activity was investigated in the delayed hypersensitivity (DH) reaction induced by i.p. injection of PPD into FCA-sensitized guinea-pigs. Peritoneal exudates were studied at several times before and after the induction of the DH reaction and a non-immune control inflammation. Lymphokine (LK) fractions were prepared from individual exudates and tested in a conventional macrophage migration inhibition assay at concentrations determined to occur in vivo. The results suggest a continuous local production of MI activity and an augmented production during development of a DH reaction.