A delayed-type inflammatory response was evoked in mice using
concanavalin A (Con A) as a stimulus, and the effect of various
anti-inflammatory agents on the
inflammation was examined. The
intraperitoneal injection of Con A in the mouse resulted in the marked accumulation of leukocytes, especially macrophages, in the peritoneal cavity between 16 and 48 hr after the injection. Prior to the accumulation of macrophages, the chemotactic activity for macrophages appeared in the peritoneal fluid, and was associated with
protein(s) in the molecular weight range from 10,000 to 100,000 daltons. When the effect of various agents on Con A-induced
peritonitis was examined, neither anticomplementary agents (
FUT-175 and
K-76 COONa),
bromophenacyl bromide,
nordihydroguaiaretic acid nor
indomethacin affected the generation of chemotactic activity and the accumulation of macrophages, suggesting that C5a,
prostaglandins and
leukotriene B4 are hardly involved in the Con A-induced macrophage accumulation. On the other hand,
dexamethasone suppressed both the generation of chemotactic activity and the accumulation of macrophages. Taking into consideration the observation that the synthesis of
macrophage chemotactic factors by
mitogen-stimulated lymphocytes is inhibited by
glucocorticoids, these results suggest that the macrophage chemotactic
lymphokines might be involved in the accumulation of macrophages in Con A-induced
peritonitis.