Figure 2.
Activation of mast cells in Mac-1 KO mice. WT and Mac-1 KO mice (n = 6) were injected intradermally with pathogenic IgG (R530). At 2 hours after injection when MC degranulation peaked, skin sections were stained with toluidine blue and MCs in the dermis were counted and classified as degranulated (> 10% of the granules exhibiting fusion or discharge) or normal as previously described.21 (A) Toluidine blue staining showed similar degrees of MC degranulation (arrows) in pathogenic IgG-injected WT and Mac-1 KO mice (panels Ai vs Aiii). (B) Quantitation of degranulated MCs revealed no significant difference in MC degranulation between these 2 groups of mice (expressed as percentage of MC degranulation, mean ± SE).
