Acute exercise modulates the inflammatory response in adipose tissue of lean and obese mice.

Abstract

Acute physical exercise act as a metabolic stressor, promoting activation of the immune system, and this response could be relevant in the adipose tissue remodelling process. In addition, some cytokines have important functions in lipolysis. Since chronic exercise improves obesity-related metabolic and inflammatory dysfunction, herein, we investigated the effect of acute exercise on the inflammatory responses in the adipose tissues of lean and

obese mice. Lean mice were fed a standard chow diet, whereas obese mice were fed a high- refined carbohydrate (HC) diet for 8 weeks. Both groups were subjected to 60 min of

moderately-intensity exercise. In the epididymal adipose tissue (EAT) of lean mice, exercise enhanced IL-6 and TNF-α levels, which correlated positively with increased serum free fatty acid concentrations. In vivo confocal imaging of EAT vessels revealed higher recruitment of neutrophils following exercise. Also, the number of leucocytes expressing CD11b+F480– was elevated 6 h after exercise. Similarly, the CXCL-1 level increased at 6 h and remained high until 24 h after exercise. Myeloperoxidase activity were increased at 6, 12, and 24 h after exercise. Surprisingly, however, no changes were observed in EAT from obese mice considering pro-inflammatory cytokines (IL-6 and TNF-). On the other hand, IL-13, IL-4, and IL-10 levels were higher in obese mice after exercise. These data suggest that acute exercise promotes an inflammatory response in the adipose tissue of lean mice that is observed as part of its role in adipose tissue remodelling. In contrast, acute exercise promotes an anti-inflammatory response in adipose tissue from obese mice, likely as an important tool for restoring homeostatic.