Effects of exercise training on indicators of adipose tissue angiogenesis and hypoxia in obese rats.

OBJECTIVE

To investigate the effects of obesity and exercise training on regional adipose tissue angiogenesis and hypoxia markers in rats.

METHODS

Lean (Fa/Fa) and obese (fa/fa) male Zucker rats at 2 months of age were randomly assigned to a sedentary or an exercise training group (lean sedentary: n=7, lean exercise: n=8, obese sedentary: n=7, obese exercise: n=8). The exercise group walked on a rat treadmill 5 times per week for 8 weeks. Inguinal and epididymal adipose tissue vascular endothelial growth factor A (VEGF-A) and lactate levels were determined.

RESULTS

There were significant effects of obesity in increasing inguinal (P<0.001) and epididymal (P<0.05) adipose tissue VEGF-A, and a significant effect of exercise training in increasing epididymal adipose tissue VEGF-A (P<0.05). There was a significant effect of obesity in increasing inguinal adipose tissue lactate levels (P<0.001). Compared to lean sedentary animals, obese sedentary animals had significantly higher epididymal adipose tissue lactate levels (P<0.001); compared to obese sedentary animals, obese exercise rats had significantly lower epididymal adipose tissue lactate levels (P<0.05).

CONCLUSIONS

Exercise training increased adipose tissue VEGF-A, an important factor of tissue angiogenesis, and lowered adipose tissue lactate, an indicator of adipose tissue hypoxia in obese rats. However, these effects are depot-specific and only observed in intra-abdominal adipose tissue.