Defective dietary control of fatty acid metabolism in four transplantable rat hepatomas: numbers 5123C, 7793, 7795, and 7800.

Fat-free and high-fat (15% corn oil) diets were offered for 2-3 days, with and without prior fasting, to normal rats (Buffalo strain) and to rats bearing the minimal deviation hepatomas: 5123C, 7793, 7795, and 7800. Liver and tumor slices were then assayed for their ability to synthesize longchain fatty acids from acetate-l-14C and to oxidize palmitate1-14C. In addition, homogenates prepared from these same tis sues were examined for their activities of various glycolytic and Krebs-cycle enzymes. The different dietary regimes greatly altered metabolic and enzymic activities in normal and host liver, but not in the hepatomas (with the possible exception of palmi tate oxidation by hepatoma 7795). This pattern of insensitivity of the metabolic activity of the hepatomas to the nutritional state of the animal is essentially similar to that already found in the mouse hepatoma BW7756, and may reflect a functional aberration that is fundamental to the neoplastic process.