A-31 Free Communication/Poster - Vascular Function: JUNE 2, 2010 7:30 AM - 12:30 PM: ROOM: Hall C
Obesity is associated with elevated white adipose tissue hypoxia. Hypoxia inducible factor-1 a (HIF-1a) can upregulate vascular endothelial growth factor (VEGF) to prevent cell death during hypoxia. However, the effects of exercise on markers of angiogenesis and hypoxia within visceral adipose tissue are unknown.
PURPOSE: To determine if high- fat (HF) diet and/or exercise training (EX) will increase gene expression of angiogenic and hypoxia markers in juvenile mice.
METHODS: C57BL/6 male mice (5 wks old) were randomized into 4 groups (n=10/group): normal chow (NC)/sedentary (SED), NC/EX, HF/SED, and HF/EX. The HF diet was 45% fat, 35% carbohydrate, and 20% protein. The mice were placed on the 6 wk diet and exercise intervention concomitantly. Treadmill exercise was performed 5d/wk at 12 m/min and12% grade for 40 min/d. HIF-1a and VEGF gene expression were assessed using quantitative real- time PCR. NC/SED group was the referent group.
RESULTS: Body weights of the HF groups were greater than the NC groups (p<0.001). The epididymal fat pad weights were greater in the HF groups (p<0.001), with the HF/SED having the greatest fat pad weight (p<0.001); this effect remained after adjusting for body weight. No differences were observed between groups for gene expression of HIF-1a. However, VEGF mRNA was greatest in the HF/EX group vs. the NC groups (p<0.05). No differences in VEGF were observed between the HF groups, nor between HF/SED and the NC groups.
CONCLUSION: Mice exposed to a HF diet while exercising exhibited an increase in gene expression of a known marker of angiogenesis, VEGF, without changes in HIF-1a mRNA. This suggests that other mechanisms may be involved in driving exercise-induced adipose tissue adaptations in obesity.