Antigens with glycoprotein structure in the gastric juice. I. Immunological and chemical determinations.

To demonstrate the presence of specific antigens in the normal and malignant gastric juice the immunological and chemical features of certain antigens with glycoprotein structure from malignant gastric jucice and gastric tumors were studied comparatively with those of antigens obtained from normal gastric juice and gastric tissue. The investigation was carried out in tumor tissue extracts from 7 patients with malignant gastric tumors and in gastric juice from 45 patients with other non-cancerous diseases. From the five fractions obtained, which gave immunoelectrophoretic precipitin lines in the beta and alpha-globulin regions with the antiserum against total normal gastric juice, a single specific was separated by means of successive chromatographies on sephadex G--100 and DEAE-Sephadex -a--50 (eluted in NaCl concentration gradient). This fraction represented 11.1 per cent of the total proteins. None of the five fractions could be identified with carcinoembryonic antigen (value in gastric juice and gastric malignant tumors = 2 to 10 ng per mg lyophilized products).