Transient increase in plasma urate induced by a single oral dose of fructose in rats

Abstract

Hyperuricemia, an elevated urate concentration in blood, is the precursor state of gout and is associated with metabolic syndrome and chronic kidney disease. The increasing prevalence of hyperuricemia in recent years is thought to be due to environmental factors, particularly diet. Here, we investigated whether and how fructose induces an increase in plasma urate concentration using a rat model. Oral administration of fructose increased plasma urate concentration within 15–30 min, without an increase in urate excretion into urine or gastrointestinal tract, and this action was evident at a dose of 7.5 g/kg b.w. On the other hand, the same dose of glucose did not elicit a hyperuricemic effect at all, and thus the effect is thought to be a specific property of fructose. The absence of an increase in urinary or gastrointestinal excretion suggested that the increase did not result from an increase in urate production. Instead, a decrease in urate clearance could have a potential to explain the increase in plasma urate concentration. In conclusion, the present study characterized the time course and dose response of a fructose-induced increase in plasma urate concentration using a rat model.