The development of
obesity is becoming an international problem and the role of
fructose is unclear. Studies using liver tissue and hepatocytes have contributed to the understanding of
fructose metabolism. Excess
fructose consumption also affects extra hepatic tissues including adipose tissue. The effects of
fructose on human adipocytes are not yet fully characterized, although in vivo studies have noted increased adiposity and
weight gain in response to
fructose sweetened-beverages. In order to understand and predict the metabolic responses of adipocytes to
fructose, this study examined differentiating and differentiated human adipocytes in culture, exposed to a range of
fructose concentrations equivalent to that reported in blood after consuming
fructose. A stable
isotope based dynamic profiling method using [U-13C6]-d-
fructose tracer was used to examine the metabolism and fate of
fructose. A targeted stable
isotope tracer fate association method was used to analyze metabolic fluxes and flux surrogates with exposure to escalating
fructose concentration. This study demonstrated that
fructose stimulates anabolic processes in adipocytes robustly, including
glutamate and de novo
fatty acid synthesis. Furthermore,
fructose also augments the release of free
palmitate from fully differentiated adipocytes. These results imply that in the presence of
fructose, the metabolic response of adipocytes in culture is altered in a dose dependent manner, particularly favoring increased
glutamate and
fatty acid synthesis and release, warranting further in vivo studies.