Arylsulfatase-cytochemical localization in lenses of normal and galactose-fed rats

Our laboratory is involved in studying the mechanism of repair in the ocular lens. As lysosomal enzymes have been shown to play an important role in tissue repair, we have been investigating the status of lysosomal enzymes, such as acid phosphatase and arylsulfatases, in the normal and injured lens. In the present investigation, we have examined the presence, distribution, and possible role of arylsulfatases (E.C. 3.1.6.1) in lenses of normal and galactose-fed rats. Arylsulfatases were localized in lenses using the cytochemical procedure described by Hopsu-Havu and Helminen (1974) using p-nitrocatechol sulfate as a substrate and then examined at the ultrastructural level. The reaction product resulting from arylsulfatase activity was mainly localized in the epithelial cells with very little activity in the cortical fibers. The intracellular activity was confined to lysosomes. Some extracellular activity was visible in the intercellular regions in both the epithelium and superficial cortex. With the progression of galactose-induced lesion in the epithelium the number of lysosomes exhibiting enzyme reaction product was found to have increased, and the lysosomes closely abutted the capsule. The biochemical assay indicated a considerable increase in the activity of arylsulfatases with the continuation of a galactose diet. The possible role of arylsulfatases in the normal and cataractous lens is discussed.