title: Enzymatic characteristics of tubular adenomas and carcinomas of the large intestine.
abstract: Enzymes activities in homogenates of the large intestine were measured in biopsies from 11 tubular adenomas and six carcinomas and from the corresponding normal mucosa of each individual. A similar and significant increase was found in the total activities of glucose-6-phosphate dehydrogenase (G 6 PD), pyruvate kinase, and lactate dehydrogenase in adenomas and carcinomas as compared with the levels of normal mucosa. The lactate dehydrogenase isoenzyme patterns showed also a marked and similar change in the adenomas and carcinomas with a significant increase of lactate dehydrogenase M-monomers. Most of the adenomas showed slight to moderate dysplasia. The results indicate that the measurement of total G 6 PD, pyruvate kinase and lactate dehydrogenase activities for screening purposes has no predictive value in separating non-premalignant from premalignant adenomas. Moreover, it seems that the enzymatic characteristics of malignancy are present even in tubular adenomas. This is in agreement with the theory of a polyp-cancer sequence.
mesh_terms: D000236:Adenoma / Q000201:enzymology*; D002277:Carcinoma / Q000201:enzymology*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006801:Humans; D007414:Intestinal Neoplasms / Q000201:enzymology*; D007417:Intestinal Polyps / Q000201:enzymology; D007420:Intestine, Large; D007527:Isoenzymes / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D011770:Pyruvate Kinase / Q000378:metabolism
chemical_list: D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D011770:Pyruvate Kinase