FATTY-ACID OXIDATION TO H2O BY EHRLICH ASCITES-CARCINOMA IN MICE

  • 1 January 1979
    • journal article
    • research article
    • Vol. 39  (3) , 973-980
Abstract
Oxidation of free fatty acids (FFA) by Ehrlich ascites tumor in mice was studied in vivo by the direct measurement of 3H2O formed from [9,10-3H]palmitate. The FFA tracer complexed to serum albumin was injected i.p. into unanesthetized mice, and blood plasma 3H2O was measured at different time points for 30 min. The contribution of 3H2O by desaturation of labeled palmitate to monounsaturated fatty acids in the tumor was estimated by the use of [1-14C]palmitate and was negligible during the course of the experiments. In order to estimate the rates of tumor FFA oxidation, the kinetics of the tumor-host water distribution system was studied by injecting tracer 3H2O i.p. and following the disappearance of 3H2O from the tumor and the appearance of 3H2O in the blood plasma at different time points for 30 min. Tumor FFA oxidation rate was computed by multicompartmental analyses and SAAM [simulation, analysis and modeling program code]. Despite the nearly anaerobic state of the ascites tumor fluid in vivo, cancer cells suspended in this fluid oxidized FFA at least as fast as they do in vitro under aerobic conditions. The need of the tumor for FFA as a metabolic fuel appears to be much greater than its net lipid needs for growth.