The phagocytic capability of the various zones of the guinea pig conjunctival epithelium: an electron microscopic study.

The phagocytic capacity of the different zones of the guinea pig conjunctival epithelium from the corneal limbus to the lid margin was investigated using latex microspheres as tracers. After 24 h exposure to a suspension of microspheres, the phagocytic capability of the epithelium could be estimated, zonal differences compared, and the kinetics of the internalized particles followed. The epithelial cells of the perilimbal zone contained the highest number of intracellular microspheres, followed by the cells of the supranodular zone. The phagocytic capability of the other zones was low. In the perilimbal zone a significant number of microspheres seemed to be transferred to the epithelial cells in the deeper layers, but not to the basal cells. In the supranodular zone the phagocytized and apparently transcellularly transported microspheres were secondarily taken up, mainly by polymorphonuclear leukocytes that infiltrated the epithelium.