Histochemical Studies on D-Glucuronolactone Dehydrogenase in the Skin

Abstract

Histochemical studies were reported on D-glucuronolactone dehydrogenase, the enzyme of the metabolic pathway from D-glucuronic acid to D-glucaric acid, dealing with the normal and diseased skin. The following results were obtained. 1) It was found that the optimum incubation medium for the assay was as follows; glucuronolactone 100mg, DPN 8mg, 1/15M phosphate buffer (pH 7.8) 9ml and distilled water 1ml. 2) The existence of activities of D-glucuronolactone dehydrogenase was found to be distributed in cytoplasm of cells of the granular layer, the Malpighii layer, the inner and the outer hair sheaths, the sebaceous gland, the eccrine sweat gland and duct and fibroblasts of the normal human skin. The similar findings were also observed in mouse skin. 3) Comparative observations between activities of D-glucuronolactone dehydrogenase and beta-glucuronidase in the skin with pathological changes, were done. It was resulted that localization of both enzymes was found to be almost identical, while activities was shown to be parallel or adverse each other. These findings may presume that D-glucuronolactone dehydrogenase plays a role as a feed back control enzyme of beta-glucuronidase.