Leukotriene formation by mouse connective tissue mast cells

Stimulation of peritoneal cells from BALB/c, CBA/J or WBB6F₁-+/+ mice with IgE/antigen caused the release of mast cell granules and leukotriene C₄. No leukotriene formation was observed with peritoneal cells from mast cell-deficient WBB6F₁-W/W(v) mice. Mast cells (>98% purity), separated on metrizamide gradients, did not synthesize detectable amounts of leukotriene C₄ when challenged immediately after purification. Co-culture of the mast cells with 3T3 fibroblasts restored the capability of the mast cells to produce leukotrienes. Addition of IL-3 during culture enhanced the synthesis of this eicosanoid. The 5-lipoxygenase inhibitor A-63162 blocked the leukotriene formation. Western blot analysis confirmed the presence of 5-lipoxygenase in connective tissue mast cells. These experiments demonstrate that mouse peritoneal (connective tissue) mast cells can produce significant amounts of leukotrienes.