Rr. Harris et al., EFFECT OF MAST-CELL DEFICIENCY AND LEUKOTRIENE INHIBITION ON THE INFLUX OF EOSINOPHILS INDUCED BY EOTAXIN, Journal of leukocyte biology, 62(5), 1997, pp. 688-691
Eosinophils are believed to be important cells in the pathogenesis of
asthma and allergic disease, Mast cells and leukotrienes may play a ro
le in eosinophil recruitment, Eotaxin was recently described as a spec
ific chemoattractant for eosinophils, Therefore we examined the effect
s of eotaxin on eosinophil flux in the mast cell-deficient WBB6F1/J-Ki
t(W)/Kit(W-v) (W/W-v) mice and in mice treated with zileuton or ABT-76
1, specific 5-lipoxygenase inhibitors, Mice were injected intraperiton
eally with eotaxin and at various times later the peritoneal cavities
were lavaged and cell populations determined, Murine recombinant eotax
in induced a dose-dependent increase in eosinophils, which reached a m
aximum at 1-2 h and subsided at 4 h in both BALB/c and W/W-v littermat
e control mice (no other cell population was altered), However, in eot
axin-injected W/W-v mice, the peak of eosinophil influx: was delayed,
peaking at 2 h, and a lower number of eosinophils was seen, The specif
ic lipoxygenase inhibitors zileuton and ABT-761 given 30 min before eo
taxin caused a 63-79% reduction in the level of eosinophils seen in th
e lavage fluid, These data suggest that eotaxin may either be activati
ng eosinophils to release leukotrienes or making them more responsive
to leukotrienes. In addition, mast cells may be playing a role in the
amplification of the eotaxin effect.