Effects of glucose on the metabolization of fructose and glycerol by isolated adipocytes from rat.

Isolated white fat cells were incubated in medium containing (14C)-fructose (UL), supplemented with either 1 or 5 mM fructose, in the presence or absence of 5 mM glucose. The utilization of fructose for the formation of CO2, fatty acids or glyceride glycerol was very much dependent on its concentration in the medium. It was significantly inhibited by glucose only at fructose concentration of 5 mM. When the cells were incubated in the presence of (1(-14)C) glycerol, fructose produced a significant increase in the conversion of the tracer to CO2, fatty acids and glyceride glycerol, while glucose produced an increase in the formation of both CO2 and fatty acids, but a significant decrease of glyceride glycerol from the same labelled precursor. Glucose causes the effects of fructose, enhancing the uptake of labelled glycerol by the cells, to disappear.