CONVERSION OF GLUCOSE AND FRUCTOSE TO FATTY ACIDS IN HUMAN LIVER

The capacity of the human liver for the glycolysis of fructose is greater than that for glucose as indicated by the greater activity of fructose glycolytic enzymes. In human liver slices [14C6] fructose was metabolized to fatty acids, CO2, and glyceride-glycerol at a greater rate than [14C6] glucose. The conversion of [14C6] glucose to fatty acids was dependent on the medium glucose concentration. These results, in the human liver, are similar to those in the rat. The rate of fatty acid synthesis in human liver is related directly to the rate of glycolysis. This dependence of fatty acid synthesis on the glycolytic rate seems to result from the fact that hepatic fatty acid synthesis is limited by the availability of substrate. The increased lipogenic potential associated with fructose as compared to glucose or with very high glucose concentrations could explain, in part, the differential effects of different carbohydrates on the plasma triglyceride concentration in man. © 1969.