MAST-CELLS DO NOT CONTRIBUTE TO THE RAPID APPEARANCE OF TNF IN THE SERUM OF LPS-TREATED MICE - A STUDY WITH MAST CELL-DEFICIENT MICE

Mast cells have been proposed to be an important source of tumor necrosis factor (TNF). The purpose of this work was to investigate their relevance in the rapid appearance of TNF in the serum of mice after injection of an endotoxin (lipopolysaccharide, LPS). We have therefore measured TNF levels in serum and spleen homogenates of mast cell-deficient mice (WBB6F1-W/W(v)) or their normal littermate controls. The results indicated that mast cell-deficient mice are not defective in their LPS-induced TNF production. They also tend to produce more interleukin 6 (IL-6) than normal mice. To test other conditions where mast cells might be stimulated to produce TNF, we measured TNF in mice injected with the mast cell degranulator, compound 48/80 or during anaphylactic shock. Anaphylactic shock induced very low levels of TNF in the serum, while compound 48/80 (4.2 mg/kg) was ineffective. These data suggest that mast cells do not contribute significantly to systemic TNF production in these experimental models.