Histochemical studies of hydrolytic and oxidative enzymes in the human intestinal tumors

The distribution and activities of five hydrolytic and eight oxidative enzymes were histochemically studied in 60 different tumors of the human intestines. Benign polyp showed similar activities of most enzymes as those in normal crypt cells of large intestine with exception of higher activity of succinic dehydrogenase in benign polyp than in crypt cells. Malignant polyp had higher activities of most oxidative enzymes. Reticulo-sarcoma had weak activities of all enzymes. Carcinoid had strong activities of glucose-6-phosphate dehydrogenase and isocitric dehydrogenase while very weak of succinic dehydrogenase. Carcinoma showed varying degrees of the activity of all enzymes. Alkaline phosphatase and aminopeptidase were almost negative in all cells but in the stromal elements their weak activities were sporadically observed. Most enzymes were decreased in the central area of the carcinoma cell nestle, while in the infiltrating area or in the margin of cell nestle they were not decreased and sometimes increased.