Résumé : In the present study, the plasma concentration, and liver, heart, kidney, soleus muscle and visceral adipose tissue content of thiobarbituric acid reactive substrates (TBARS), carbonyl radicals, hydroperoxides and nitric oxide were measured in control rats exposed for 8 weeks to a diet containing 64% (w/w) starch and 5% sunflower oil and in animals fed a diet containing 64% D-fructose and 5% sunflower oil or 3.4% sunflower oil mixed with 1.6% safflower or salmon oil. Coherent measurements of the plasma concentrations or tissue contents of these metabolites revealed increases in TBARS, carbonyl radical and hydroperoxide levels and a decrease in nitric oxide levels in the 5% sunflower oil-fed rats. In the fructose-fed rats, the partial substitution of sunflower oil by either safflower or salmon oil minimized the changes. These findings provide further evidence in support of the favorable effects of the dietary supply of long-chain polyunsaturated ω6 and ω3 fatty acids upon the metabolic disturbances prevailing in the fructose-induced metabolic syndrome.