Lack of Adaptation in Lipogenesis by Hepa-

SUMMARY-The present study was designed to determine if three minimal deviation hepatomas of different growth rates had lost their ability to increase their Fatty-acid synthetase activity aFter a Fasting-reFeeding regimen. The "minimal deviation " hepatomas 9098, 7794A,and 9618A bio-synthesized Fatty acids but at different rates. The slow-growing tumor 9618A biosynthesized Fatty acids at a rate comparable to that of host liver. How-ever, Fasting and reFeeding a Fat-deficient diet did not cause the adaptive response of increased Fatty-acid biosynthesis in any tumor. Fasting the rats and reFeeding them a Fat-deAcient diet did not alter the oxidation of acetate-1_14C From control in either control liver, host liver, or tumors. However, the rate of oxidation of acetate by host livers was higher than control livers. The fastest-growing tumor (9098) oxidized acetate at a rate three times greater than control liver. The Fatty-acid profiles of the total lipids of the livers and tumors were analyzed and compared.-J Nat Cancer Inst 44: 79-83, 1970