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 necro sis factor (TNF). The purpose of this work was to investigate their re levance in the rapid appearance of TNF in the serum of mice after inje ction of an endotoxin (lipopolysaccharide, LPS). We have therefore mea sured TNF levels in serum and spleen homogenates of mast cell-deficien t mice (WBB6F1-W/W(v)) or their normal littermate controls. The result s indicated that mast cell-deficient mice are not defective in their L PS-induced TNF production. They also tend to produce more interleukin 6 (IL-6) than normal mice. To test other conditions where mast cells m ight be stimulated to produce TNF, we measured TNF in mice injected wi th the mast cell degranulator, compound 48/80 or during anaphylactic s hock. Anaphylactic shock induced very low levels of TNF in the serum, while compound 48/80 (4.2 mg/kg) was ineffective. These data suggest t hat mast cells do not contribute significantly to systemic TNF product ion in these experimental models.