Mast Cell Granule Induced Late Phase Responses (LPR) in Rat Skin: Effect of Corticosteroids (CCS). Partial Purification of Infiltration Inducing Factors

Abstract

Mast cell degranulation in response to 48/80 or anti-IgE or the administration of purified mast cell granules (MCG) causes PMN infiltrates in rat skin by 2–8 h followed by mononuclear infiltrates at 24–48 h. MCG, purified either with perigranular membranes or free of both membranes and elutable mediators, generate a late phase reaction (LPR) in a dose related fashion; 1 μg (measured as protein) produces discernable LPR while 5 μg attract ≧ 150 cells/HPF (3 +) in rat skin after 8 or 24 h. A 3 + -infiltrate is also induced by 5 µg of two partially purified factors obtained from MCG by ultrafiltration. Fraction A (Fr A) has a MW 500–10 000; Fr B contains molecules exceeding 10 000 daltons.