The effect of high sugar intake on the esterification of dihydroxyacetone phosphate by rat liver microsomes

Abstract

Rat liver microsomes were used as an enzyme source to study dietary-induced changes in the rate of dihydroxyacetone phosphate esterification. Rats were fed (1) 75% glucose or fructose diets for various time intervals, or (2) fed a fructose diet for six days and then a chow diet. Both the glucose and fructose diets produced a 2–3-fold increase in total and neutral glycerolipid formation from dihydroxyacetone phosphate measured in the presence of ATP, palmitate, CoA, and NADH. The increased rate of dihydroxyacetone phosphate esterification and a simultaneous rise in serum triglyceride level in rats fed fructose was rapidly reversed when chow was substituted for the fructose. The results indicate that an increased rate of dihydroxyacetone phosphate esterification may contribute to the acceleration of endogenous glycerolipid biosynthesis noted under these dietary conditions.

Keywords

• carbohydrate diets
• enzyme regulation