Page 970 - Veterinary Immunology, 10th Edition

mediators involved. The speed of these responses also differs
VetBooks.ir among mast cells. For example, degranulation occurs within

seconds after antigen binds to IgE (Fig. 29.10). However, the
inflammatory responses induced on mucosal surfaces are much

slower than allergic responses in the skin or airways. Mast cell
proteins need time to be synthesized, although granule amines are
pre-stored and thus available immediately.

FIG. 29.10 Scanning electron micrographs. A, A normal rat mast
cell. B, A sensitized mast cell fixed 5 seconds after exposure to
antigen. C, A sensitized mast cell fixed 60 seconds after exposure
to antigen. Original magnification ×3000. (From Tizard IR, Holmes WL:
Degranulation of sensitised rat peritoneal mast cells in response to antigen,
compound 48-80 and polymyxin B. A scanning electron microscope study, Int Arch
Allergy Appl Immunol 46:867-879, 1974.)

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