CHEMICAL CARCINOGENESIS IN METHYL-DEFICIENT RATS

In summary, dietary deficiency of lipotropic nutrients or labile methyl supply enhances "spontaneous" and chemical carcinogenesis in the liver of rats. The deficiency also enhances DMH carcinogenesis in the rat colon and PCZ carcinogenesis in the rat mammary gland. In the PCZ model, parallel studies using MTX to induce biochemical changes analogous in some characteristics to the lipotrope-deficient model also showed evidence suggestive of enhancement of carcinogenesis, although the results were not statistically significant. PCZ interfered with hepatic choline metabolism, particularly in lipotrope-deficient and MTX-treated rats. This effect may be related to the enhanced carcinogenicity of PCZ in the mammary gland. © 1993.