Specialized cell types and their regional distribution in the conjunctival epithelium of the cynomolgus monkey.

In the superficial layer of the conjunctival epithelium of cynomolgus monkeys, five different cell types were found. The cell types were distinguished by ultrastructural criteria (e.g., cell organelles and cytoplasma) and are defined as follows: type I are the goblet cells; type II is characterized by the content of small electron-dense granules type III is particularly rich in Golgi material, type IV contains a specifically large amount of ER; type V shows an exceptionally large number of mitochondria. The quantitative evaluation of these cell types in 15 areas of the conjunctiva of 3 animals revealed a characteristic pattern of regional distribution, which may reflect the otherwise unknown functional significance of most of these cell types.