[Histochemical studies of human stomach biopsies with special reference to hydrolases]

Peptidases, phosphatases, glycosidases, non-specific esterases, succinate dehydrogenase, cholinesterases, and carbohydrate components were studied in bioptic material of the normal and diseased human stomach using well established older, modified older, and new qualitative histochemical methods. For the first time, an enzyme pattern is reported for all regions of the human mucosa. Local and regional enzyme histochemical differences existed between the cardiac, fundic, body, and pyloric mucosa. Differences were absent, however, in the same region, and no differences were found between the anterior and posterior wall and the large and small curvature of the stomach. In cases of histologically less severe gastritis as a rule, enzyme histochemical changes were not found. They were numerous, however, in biopsies of patients with severe gastritis; only amino-peptidases A and M were unchanged. Dipeptidyl peptidase IV was absent; gamma-glutamyl transpeptidase exhibited individual differences. Alkaline phosphatase occurred in the pericapillary stroma and adenosine phosphates were not hydrolysed in atrophic glandular epithelia. Activity increases of lysosomal dipeptidyl peptidase I and beta-D-glucuronidase were typical for inflammatory infiltration processes of the gastric mucosa. Severe atrophy was accompanied by an activity decrease of glandular non-specific esterases, dipeptidyl peptidase II, and beta-N-acetyl-D-glucosaminidase and an activity decrease of the stromal peptidases and glycosidases. Enzyme activity was absent in the gastric glands proper in cases of total atrophy. An increase in macrophage number was primarily linked with an increase in acid phosphatase activity. Alkaline phosphatase, aminopeptidase M and gamma-glutamyl transpeptidase activities were enhanced in malignant neoplasms. High activities of all peptidases and alkaline phosphatase were found in the brush border of surface epithelial cells in cases of intestinal metaplasia. Except for dipeptidyl peptidase I and II, the enzyme pattern corresponds to that of small intestinal enterocytes. Compared with histological routine procedures for gastric diagnosis and assessment of the course enzyme histochemical methods deliver additional information; practically, however, the enzyme histochemical analysis of gastric biopsies are only useful in special cases.