Abstract
1) A histochemical method for the demonstration and localization of disaccharidase activity using various disaccharides as the substrate is described. Frozen sections are incubated in a solution containing substrate plus a coupled oxidation-reduction system of glucose oxidase, phenazine methosulfate and a tetrazolium salt. Where disccharidase activity is present, the substrate is hydrolyzed with the liberation of glucose, and a deep blue insoluble formazan is formed.
2) This method has been used for the demonstration of invertase and trehalase in rat tissue sections. The small intestine, colon, stomach and kidney were investigated.
3) All the epithelial cells of the small intestinal mucosa, in the villi, crypts and glands of Brunner, contain invertase and trehalase. These enzymes appear to be localized to small rounded granules which are scattered throughout the cytoplasm of the cells. The activity is especially high in the perinuclear part of the epithelial cells, but no concentration of the granules is to be seen in "brush border" region.
4) The stomach and the kidney also contain weak invertase activity which is present in granules localized to small distinct cell groups. No trehalase activity could be demonstrated in these organs. The colon contains essentially no invertase or trehalase.