CELLULAR LOCALIZATION OF β-GLUCURONIDASE IN RAT TISSUES

1. A detailed study has been made of the use of the substrate, 8-hydroxyquinoline glucosiduronic acid as a means of localizing the enzyme, β-glucuronidase in cells and tissues of the rat. 2. Conditions for preparing the substrate solution have been developed which yield a stable mixture capable of giving satisfactory service for a period of months. 3. The introduction of chloral hydrate into the formalin fixative solution contributes greatly to the preservation of the enzyme and the successful demonstration of its cellular sites. 4. Certain refinements in technique, e.g., removal of precipitate artifact, prerefrigeration in substrate solution have greatly improved the convenience, reproducibility and uniformity of the cytochemical result. 5. Success in dealing with friable tissues in these histochemical studies has been achieved by employing a gelatin-embedding technique, sections being cut from the frozen block. 6. A systematic study of over 30 tissues and organs of the adult rat reveals striking localizations in specialized cells and tissues, e.g., Purkinje cells, pancreatic islet cells, uterine endometrium, as well as more uniform intense staining in organs such as liver and renal cortex. In most instances, the results agree with the findings of Seligman who employed a different technique. 7. The finished preparations do not deteriorate and are suitable for the observation of fine histological detail.