E-29 Free Communication/Poster - Exercise Immunology III: JUNE 3, 2011 7:30 AM - 12:30 PM: ROOM: Hall B
We have previously demonstrated that exercise training reduces the inflammatory profile in visceral adipose, yet this was observed in a state of existing obesity. It is important to understand the effects of exercise on adipose biology during developing obesity, in particular during initial exposure to a high fat (HF) diet, and how this impacts inflammation.
PURPOSE: To examine the effects of a 2 wk HF diet and exercise on inflammation in visceral adipose tissue in mice.
METHODS: C57BL/6 male mice (6 wks) were divided into 4 groups (n=8/grp): High fat/sedentary (HF/SED), HF/exercise (HF/EX), low fat /SED (LF/SED), and LF/EX. The HF and LF diets were 60 and 10% fat, respectively. Treadmill exercise was performed 12 m/min and 5% grade for 40 min/d for a total of 8 sessions. The diet and exercise interventions occurred concomitantly. Epididymal fat pads were excised and weighed at sacrifice. Glucose metabolism was assessed by intra-peritoneal glucose tolerance test (IPGTT). Plasma glucose and insulin levels were used for homeostatic model assessment of insulin resistance (HOMA-IR). Quantitative real-time PCR was performed to assess markers of macrophage content and inflammation in adipose. LF/EX group served as reference for relative mRNA calculations.
RESULTS: A diet effect was found for body weight (HF/SED: 23.5±0.6; HF/EX: 22. 2±0.6; LF/SED: 20.2±0.6; LF/EX: 20.0±0.5 g, p<0.05). IPGTT area under the curve was higher in the HF groups (p<0.05). No differences were found in HOMA-IR. Macrophage gene expression, F4/80 and CD11c, was not different between groups. Adipose inflammatory markers, monocyte chemoattractant protein-1 and tumor necrosis factor-α, were upregulated in the HF groups (3 fold and 2 fold change from LF, p<0.05, respectively). Anti-inflammatory marker, interleukin (IL)-10 was upregulated in the HF groups as well (1.7 fold change from LF, p<0.05). No exercise main effects or interactions effects were observed for any of these markers
CONCLUSIONS: While markers of macrophage infiltration were not evident, 2 wks of HF feeding induced upregulation of pro- and anti-inflammatory markers. Our low to moderate exercise stimulus does not appear to mitigate adipose inflammation early in the development of obesity.
Supported by University of Illinois Research Board seed grant.