Previous studies have shown that a diet high in fat and marginally deficient in lipotropes enhances aflatoxin B] hepatocarcinogenesis and depresses hepatic drug metabolism in rats. In this study we have compared induction of tumors by jV-nitrosodimethylamine, ./V-nitrosodiethylamine, or jV-nitrosodibutylamine in normal or marginally lipotrope-deficient rats fed a high-fat diet. The deficiency s...