Fructose-enriched diet induces inflammation and reduces antioxidative defense in visceral adipose tissue of young female rats.
PURPOSE
The consumption of refined, fructose-enriched food continuously increases and has been linked to development of obesity, especially in young population. Low-grade inflammation and increased oxidative stress have been implicated in the pathogenesis of obesity-related disorders including type 2 diabetes. In this study, we examined alterations in inflammation and antioxidative defense system in the visceral adipose tissue (VAT) of fructose-fed young female rats, and related them to changes in adiposity and insulin sensitivity.


METHODS
We examined the effects of 9-week fructose-enriched diet applied immediately after weaning on nuclear factor κB (NF-κB) intracellular distribution, and on the expression of pro-inflammatory cytokines (IL-1β and TNFα) and key antioxidative enzymes in the VAT of female rats. Insulin signaling in the VAT was evaluated at the level of insulin receptor substrate-1 (IRS-1) protein and its inhibitory phosphorylation on Ser307.


RESULTS
Fructose-fed rats had increased VAT mass along with increased NF-κB nuclear accumulation and elevated IL-1β, but not TNFα expression. The protein levels of antioxidative defense enzymes, mitochondrial manganese superoxide dismutase 2, and glutathione peroxidase, were reduced, while the protein content of IRS-1 and its inhibitory phosphorylation were not altered by fructose diet.


CONCLUSIONS
The results suggest that fructose overconsumption-related alterations in pro-inflammatory markers and antioxidative capacity in the VAT of young female rats can be implicated in the development of adiposity, but do not affect inhibitory phosphorylation of IRS-1.
['Kovačević|Sanja|S|', 'Nestorov|Jelena|J|', 'Matić|Gordana|G|', 'Elaković|Ivana|I|']
D050154:Adiposity D000818:Animals D000975:Antioxidants D003924:Diabetes Mellitus, Type 2 D004032:Diet D005260:Female D005632:Fructose D005979:Glutathione Peroxidase D007249:Inflammation D055504:Insulin Receptor Substrate Proteins D007333:Insulin Resistance D053583:Interleukin-1beta D050152:Intra-Abdominal Fat D008928:Mitochondria D016328:NF-kappa B D009765:Obesity D018384:Oxidative Stress D010766:Phosphorylation D051381:Rats D017208:Rats, Wistar D013482:Superoxide Dismutase D014409:Tumor Necrosis Factor-alpha
Inflammation Visceral adipose tissue Female rats Oxidative stress NF-κB Fructose diet