[ATPase and 5-nucleotidase in human breast and stomach tumors].

It has been concluded from the studies on the activity and location of ATPase and 5-nucleotidase in mammary and gastric tumours that some neoplasms of the mammary gland and stomach showing a high ATPase activity are histochemically related, in the former case, to the lobular myoepithelium and in the latter case, to non-differentiated cells of gastric glands which acquired a capacity for intestinal metaplasia and preserved it in the course of malignant transformation. No essential changes have been recorded in the activity of 5-nucleotidase, depending on the tumour histologic structure and degree of its maturity.