Dehydrogenasein Malignant,NormalAdult,and Fetal ColonTissues

Carcinoembryonic antigen and activities of glucosephosphate isomerase (EC 5.3.1.9), y-glutamyltransferase (EC 2.3.2.2), and lactate dehydrogenase (EC 1.1.1.27) were measured in aqueous extracts of fetal, normal adult, and malignant human colon tissues. Fetal colon, as well as primary and metastatic colon tumor tissue, showed higher activities of these analytes than did normal adult human colon. Liver metastases of colon cancer gave the highest values, normal adult human colon the lpwest. Statistically, these differences were more striking in the case of carcinoembryonic antigen and glucosephosphate isomerase than for y-glutamyltransferase or lactate dehydrogenase. In contrast to the other markers, ‘)‘-glutamyltransferase activity was lower in fetal organs than in normal adult colon and colon tumors. These results are consistent with earlier observations that activities of these markers are significantly increased in the blood of patients with metastatic colon cancer.