Interleukin 1 stimulates production of LTC4 and other eicosanoids by macrophages.

Human recombinant IL-1 alpha stimulates in a dose-dependent fashion the production of 5-lipoxygenase-derived LTC4 and, to a lesser extent, of cyclooxygenase-derived eicosanoids (PGE2, 6-keto PGF1 alpha, TXB2) by murine resident peritoneal macrophages. Enhancement of eicosanoid production was evident on unstimulated macrophages, but only marginal on macrophages phagocytosing zymosan. The effect of IL-1 was similarly achieved at physiological (37 degrees C) as well as at higher (39 degrees C) temperatures. Human recombinant IL-1 beta, human natural IL-1, and partially purified murine IL-1-rich supernatant also stimulated eicosanoid production by macrophages, although IL-1 alpha appeared to be the most effective.