Behavior of antioxidant defense system and heme oxygenase-1protein expression in fructose-hypertensive rats

Abstract

1. Addition of fructose to a rat diet for various time periods leads to hypertension, hyperinsulinemia and dyslipidemia and provides a model for testing oxidative stress parameters in the animals. 2. The oxidative stress generation, the soluble and enzymatic defense system and the heme oxygenase-1 protein expression were studied in heart, liver and kidney of fructose-fed rats during one or eight months. 3. In comparison with the control group, fructose-hypertensive rats showed only in heart increased in lipid peroxidation after both periods of fructose treatment. The behavior of soluble and enzymatic defense system and heme oxygenase-1 protein expression changed differently depending on the organ. Increased or unaltered activities of antioxidant enzymes were found in liver and kidney, respectively. The heme oxygenase-1 induction prevented the oxidative stress generation in liver, where the activity of antioxidant defense enzymes was not reduced. Increased heme oxygenase protein expression was not able to avoid the oxidative stress generation in heart where fructose treatment diminished the activity of antioxidant enzymes. 4. The results obtained demonstrated that up-regulation of HO-1 may prevent oxidative stress generation only when the antioxidant defense system remains still operative.