The aim of the study was to determine the effects of exercise training on improving the thoracic perivascularadipose tissue (tPVAT) phenotype (inflammation, oxidative stress, and proteasome function) in metabolic syn-drome and its subsequent actions on aortic function.Methods:Lean and obese (model of metabolic syndrome) Zucker rats (n=8/group) underwent 8-weeks ofcontrol conditions or treadmill exercise (70% of max speed, 1 h/day, 5 days/week). At the end of the inter-vention, the tPVAT was removed and conditioned media was made. The cleaned aorta was attached to a forcetransducer to assess endothelium-dependent and independent dilation in the presence or absence of tPVAT-conditioned media. tPVAT gene expression, inflammatory /oxidative phenotype, and proteasome function wereassessed.Results:The mainfindings were that Ex induced: (1) a beige-like, anti-inflammatory tPVAT phenotype; (2) agreater abundance of•NO in tPVAT; (3) a reduction in tPVAT oxidant production; and (4) an improved tPVATproteasome function. Regarding aortic function, endothelium-dependent dilation was greater in exercised leanand obese groups vs. controls (p \u3c 0.05). Lean control tPVAT improved aortic relaxation, whereas obese controltPVAT decreased aortic relaxation. In contrast, the obese Ex-tPVAT increased aortic dilation, whereas the leanEx-tPVAT did not affect aortic dilation.Conclusion:Overall, exercise had the most dramatic impact on the obese tPVAT reflecting a change towards anenvironment with less oxidant load, less inflammation and improved proteasome function. Such beneficialchanges to the tPVAT micro-environment with exercise likely played a significant role in mediating the im-provement in aortic function in metabolic syndrome following 8 weeks of exercise
