Oxidative stress and metabolic parameters are differently affected by fructose when rats were kept sedentary or underwent swimming exercise.

Abstract

The current study evaluated whether fructose supplementation affects oxidative stress and metabolic parameters in the liver and gastrocnemius muscle of rats subjected to swimming exercise. Male adult Wistar rats received a fructose solution (10%) or water during 1 h before exercise and during the rest interval by the intragastric route. The swimming protocol consisted of 6 days: each day, rats underwent 3 sessions of 17 min each, with a load of 5% of body mass, and rest intervals of 3 min. Fructose supplementation changed metabolic and oxidative parameters in the liver and gastrocnemius muscle of sedentary rats. Swimming exercise counteracted the increase of triglyceride levels in plasma and liver induced by fructose supplementation. It also reduced thiobarbituric acid reactive species levels in the liver, and catalase and superoxide dismutase activities in the gastrocnemius muscle of supplemented rats. However, fructose supplementation worsened metabolic (hepatic triglyceride levels) and oxidative parameters (thiobarbituric acid reactive species levels) in the liver and gastrocnemius of exercised rats. This study demonstrates that oxidative stress and metabolic parameters were differently affected by fructose supplementation when rats were kept sedentary or underwent swimming exercise. The present results indicate the need of a new insight of the role of fructose supplementation during physical exercise.