Macrophages in Ocular Tissues of Rats

Abstract
• The number of macrophages in rat ocular tissues was determined, with the tip of the eyelid containing about 3,000 macrophages per cubic millimeter, which is similar to the number of mast cells at this site. Fewer macrophages were present in orbital tissues and conjunctiva. Macrophages accumulated in ocular tissues of immunized rats injected locally with antigen, but the number did not exceed that observed in antigen-injected controls. Injection of various fluids into ocular tissues, but not the trauma of needle punctures alone, stimulated a marked accumulation of macrophages. Thus, the response to nonspecific stimuli masked the macrophage response to antigen-induced, ocular anaphylaxis.