Rod-shaped bodies and crystalloid inclusions in ocular vascular endothelia of adult and developing Macaca mulatta

In addition to the usual organelles, endothelial cells of ocular blood vessels and Scheemm's canal in adult and fetal Macaca mulatta, contain two types of inclusions: rod-shaped bodies and crystalloids. The rod-shaped bodies are similar to those first described in arterial endothelia of the rat. They are between 0.2 to 0.35 μm in diameter, up to 2.5 μm in length, and are membrane bounded. The crystalloid inclusions are up to 1.2 μm in diameter and are associated with the granular endoplasmic reticulum. Their crystalline lattice consists of subunits, 28 nm in diameter, which are either arranged in rows separated by amorphous matrix or tightly packed in a honeycomb-like lattice. The rod-shaped bodies are much more numerous than the crystalloids; however, both kinds of inclusions are consistently found in both adult and fetal vessels. They represent normal components of ocular vascular endothelia which appear very early in the development of the eye.