Proliferative changes of lens epithelial cells in rat and mouse galactose cataracts--examination using whole-mount preparations.

The proliferative activity of the lens epithelium in the early stages of cataract crisis was investigated in rats and mice using the 3H-thymidine autoradiographic method with the whole-mount preparations of total lens epithelial cells. Three-week-old Sprague-Dawley (SD) rats were given a diet which included galactose in three different concentrations (15%, 25%, 50%) to produce sugar cataracts of three different degrees. Seven-week-old ICR mice were given a 50% galactose-diet. In the lenses of control rats and mice, 3H-thymidine labeled cells were observed mainly in the germinative zone at the lens equator; a few labeled cells were detected in the anterior subcapsular central zone. In the lenses of the SD rats on the 4th day of the diet, labeled cells increased remarkably in the central zone. However, labeled cells decreased as the cataract progressed. The peak in the number of labeled cells was observed on the 4th day of the diet regardless of the galactose concentrations, and was not proportional to the degree of the cataracts. In the galactose-fed ICR mice, the blood galactose level was high, but there was no increase in the number of labeled cells or the development of galactose cataract. The marked increase of labeled cells in the central zone in the SD rat lenses had probably occurred because of the accumulation of galactitol.