Vanadyl sulfate ameliorates insulin resistance and restores plasma dehydroepiandrosterone-sulfate levels in fructose-fed, insulin-resistant rats

Objectives: To elucidate whether vanadyl sulfate ameliorates the decreased dehydroepiandrosterone sulfate (DHEAS) in hyperinsulinemic rats, we evaluated plasma DHEAS, insulin and triglyceride (TG) levels in fructose-induced, insulin-resistant rats. Design and methods: Animals were divided into three groups: control (C), fructose fed (F-F), and vanadyl-treated fructose fed (F-T). Control animals were fed with standard chow; F-F and F-T groups fed with 66% fructose diet. F-F and C groups received tap water; F-T group received water supplemented with 0.2 mg/ml vanadyl sulfate. Results: Fasting plasma glucose levels of three groups were comparable. Vanadyl treatment prevented the increase in plasma insulin and TG in the F-T group (P< 0.001) compared with the F-F group. Fructose feeding led to a decrease in plasma DHEAS in the F-F group (P< 0.001) compared with the C group. Vanadyl treatment prevented the decrease in plasma DHEAS in the F-T group (P< 0.001) compared with the F-F group. Conclusions: Our results indicated that the hyperinsulinemia in fructose-fed, insulin-resistant rats is associated with low levels of DHEAS. Vanadyl sulfate probably restores plasma DHEAS, due to the improved insulin action.