Sequence of mast-cell changes in ocular anaphylaxis.

Ocular anaphylaxis was produced in rats by the injection of egg albumin into ocular adnexal tissues of immunized animals. Mast cells in the tip of the eyelid from normal, antigen-injected control and antigen-injected immunized rats were examined at 1/2, 1, 6 and 24 hr. The number of cells and their morphology was determined. All three groups had the same number of mast cells at all time intervals. Extensive mast-cell degranulation was observed at 1/2 and 1 hr in lid tips of immunized, antigen-challenged rats. By 24 hr, the mast cells appeared to have 'healed' and regranulated, although it was possible to distinguish these cells from mast cells of normal animals. We conclude that under certain conditions, mast cells participating in ocular anaphylaxis are not destroyed but survive and regenerate granules within the first 24 hr.