The effect of fructose loading on fatty acid uptake in mice

Objectives Increased fructose intake by the modern diet of additives like corn syrup sweeteners is causing changes in liver metabolism of glucose and affecting lipoprotein and fat accumulation in liver. The goal of this study was to evaluate the effect of acute one day and chronic 30 day loading of fructose feeding on fatty acid uptake by administration of CardioPET (trans-9-[18F]fluoro-3,4-methylenehepta-decanoic acid), a PET tracer for assessing fatty acid metabolism.

Methods Mice (CD-1, 28g) were fed 1 g of fructose in 1 ml by gavage, twice a day, at 8 am and 5 pm before biodistribution was performed. One set of fructose treated mice were evaluated after one day and another set after 30 days. A control group with no fructose in water was evaluated for fatty acid uptake for comparison. CardioPET (100uCi per animal) was injected and the mice were sacrificed at 60 min post injection (4-8 mice per time point). The animals were euthanized by a lethal dose of CO2 and subjected to complete necroscopy. Tissues were weighed and counted using a Wizard gamma-counter and results were expressed as %dose/gram (%DPG) tissue mean +/- SD.

Results CardioPET liver uptake following acute fructose loading for one day was 1.9% DPG as compared to 4.3% DPG of control, thus a 56% reduction. Most other organs, except for heart and spinal cord, were also reduced as compared to control. No change was observed in brown fat, whereas white fat and gonadal fat showed a 40% decrease. For 30 days, CardioPET liver uptake was also reduced by 50% compared to control.

Conclusions These results are in agreement with other studies indicating that high fructose uptake impairs fatty acid metabolism and causes chronic liver lipogensis, a condition that enhances diabetes.