Send to

Choose Destination
See comment in PubMed Commons below
Am J Physiol Regul Integr Comp Physiol. 2011 Jan;300(1):R175-82. doi: 10.1152/ajpregu.00338.2010. Epub 2010 Nov 3.

Exercise training reverses impaired skeletal muscle metabolism induced by artificial selection for low aerobic capacity.

Author information

  • 1Royal Melbourne Institute of Technology, Bundoora, Victoria, Australia.


We have used a novel model of genetically imparted endurance exercise capacity and metabolic health to study the genetic and environmental contributions to skeletal muscle glucose and lipid metabolism. We hypothesized that metabolic abnormalities associated with low intrinsic running capacity would be ameliorated by exercise training. Selective breeding for 22 generations resulted in rat models with a fivefold difference in intrinsic aerobic capacity. Low (LCR)- and high (HCR)-capacity runners remained sedentary (SED) or underwent 6 wk of exercise training (EXT). Insulin-stimulated glucose transport, insulin signal transduction, and rates of palmitate oxidation were lower in LCR SED vs. HCR SED (P < 0.05). Decreases in glucose and lipid metabolism were associated with decreased β₂-adrenergic receptor (β₂-AR), and reduced expression of Nur77 target proteins that are critical regulators of muscle glucose and lipid metabolism [uncoupling protein-3 (UCP3), fatty acid transporter (FAT)/CD36; P < 0.01 and P < 0.05, respectively]. EXT reversed the impairments to glucose and lipid metabolism observed in the skeletal muscle of LCR, while increasing the expression of β₂-AR, Nur77, GLUT4, UCP3, and FAT/CD36 (P < 0.05) in this tissue. However, no metabolic improvements were observed following exercise training in HCR. Our results demonstrate that metabolic impairments resulting from genetic factors (low intrinsic aerobic capacity) can be overcome by an environmental intervention (exercise training). Furthermore, we identify Nur77 as a potential mechanism for improved skeletal muscle metabolism in response to EXT.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk