The functional activities of the pigment epithelium in aging

The phagocytic ability of the pigment cells of the retinae of mice of different ages was studied in 2-, 5-, 7-, and 9-month-old animals. A decrease in activity was evident as the animals aged. There was also a difference in the response pattern of enzymes (as demonstrated in the case of alkaline phosphatase) in the first 35 h after latex bead injection.