REGIONAL VARIATION AND AGE-RELATED-CHANGES OF LYSOSOMAL-ENZYMES IN THE HUMAN RETINAL-PIGMENT EPITHELIUM

In this study the activities of two lysosomal enzymes in retinal pigme nt epithelial (RPE) cells isolated from three regions of the human fun dus were examined: the macula, the nasal midzone, and the periphery. T he results obtained showed that the activities of acid phosphatase and cathepsin D were significantly higher in the RPE cells derived from t he macular region when compared with those in the periphery. The value s for the midzone appeared to be intermediate between the other two re gions. Furthermore, the overall activity of both enzymes increased as a function of age.