DISTRIBUTION OF β-GLUCURONIDASE ACTIVITY IN RAT TISSUES EMPLOYING THE NAPHTHOL AS-BI GLUCURONIDE HEXAZONIUM PARAROSANILIN METHOD

Abstract

The histochemical distribution of β-glucuronidase activity in rat tissues as demonstrated by the naphthol AS-BI glucuronide and hexazonium pararosanilin method has been described. The present method has demonstrated a close correlation between the amount of stain derived from the β-glucuronidase reaction and the reported enzyme activity by homogenate assay in every tissue examined. Tissues known to be enzyme-rich by homogenate assay showed a rapid and intense staining in a great number of cells. These tissues were the preputial gland, spleen, liver, epididymis, ovary, lymph node, thymus, kidney and thyroid. In enzyme-poor tissues, the staining was negative or limited to a small number of specific cells. These tissues were the brain, spinal cord, eye, testis, and muscle. Cells responsible for the intense staining in all tissues examined were those of the macrophage system, parenchymal cells of liver and kidney and several types of mucous membrane cells. In each cell the major staining appeared as discrete and, most often, spherical granules in the cytoplasm, and no staining was observed in the nucleus, Size, number and location of the granules was quite variable depending on the type of cells. Large granules were especially abundant in macrophages. The possible significance of this enzyme distribution is discussed briefly.