Printed in U.S.A. COMPARATIVE HISTOCHEMICAL LOCALIZATION OF LYSOSO \ IAL ENZYMES IN RAT TISSUES’

Localization of acid phosphatase, $-glucuronidase and N-acetyl-fl-glucosamin idase has beets studied in various tissues of the rat with comparable simultaneous cotpling azo dye techniques employing napht hoA AS-B I compounds as substrates and hexazonium pararosanilin as a capture reagent. These three lysosomal hydrolases were widely distributed in tissues and were generally demonst rated as discrete granules in certain portions of the cytoplasm. Granules staitted for each enzyme were localized at identical sites in most, but not all, tissues in which they were present. however, the intensity or number of granules stained for each of the enzymes was found to differ its varying degree among tissues. Acid phosphatase appeared to be more wide-spread in tissues than the two glycosidases. l)istribution of the glycosidases was also found to differ considerably. Cells of the macrophage system, for example, displayed high fl-glticitroni-dase activity, while N-acetyl-fl-glucosaminidase was mitch less active in these cells. The latter enzyme was more active its the epithelitun of the mucous membrane. Furthermore, in several tissues, the three enzymes exhibited qualitatively different localization. In these sites, one or tWo of the enzymes were not or were only faintly demonstrable while the other showed an ito-tense reaction. These findings suggest that a functional differentiation among lysosomes i