Positive correlations were observed between NOx and CAT (p < 0.05 in SM and eAT), TAC (p < 0.05 in eAT) and GSH (p < 0.05 in liver, SM and eAT); furthermore, a marginally significant negative correlation was observed between NOx and MDA (p = 0.082 in liver and SM, p = 0.088 in eAT).<h4>Conclusion</h4>Long-term nitrate administration at low doses has a protective effect against oxidative stress in the liver, SM and eAT of rats with T2D. This evidence concerns the gene CAT and type 2 diabetes mellitus.