RETURNYonago Acta medica 1991;34:237-248
Age-related Morphological Changes in the Rat Lens Epithelium
Masaaki Okuma, Atsushi Yamasaki, Masao Nagata and Akihiko Tamai
Department of Ophthalmology, Faculty of Medicine, Tottori University, Yonago 683, Japan
To study morphological changes in the rat lens epithelium with aging, 90 male Wistar rats were observed from the age of 7 to 26 months. The mean cell density and the mean cell area of the lens epithelium were determined every 2 or 3 months. The mean cell density decreased but the mean cell area increased with aging in both the central and germinative zones of the lens epithelium. Electron microscopy revealed that changes of epithelial cells were observed more frequently in older animals. The changes were that mitochondria and ribosomes were reduced in number, and that mitochondria and rough endoplasmic reticulum degenerated. These age-related morphological changes in the lens epithelium are considered to reduce the metabolic functions of the lens and to serve as an important etiologic factor in cataract.
Key words: aging; electron microscopy; mean cell area; mean cell density; rat lens epithelium