Vascularity of myocardium and gastrocnemius muscle in rats selectively bred for endurance running capacity Article (Web of Science)


  • We tested the hypothesis that changes in the arteriolar branching architecture contributed to increased running capacity of rats subjected to two-way artificial selection for intrinsic aerobic endurance treadmill running capacity resulting in strains of low-capacity and high-capacity endurance rats. Hearts and gastrocnemius muscles were harvested from each strain, and the microvasculature's branching geometry measured from micro-CT images. The vascular branching geometry of the hearts and skeletal muscle from the high capacity was indistinguishable from low-capacity rats. Our hypothesis was not supported. Neither remodeling nor an increase in arteriolar microvasculature branching appears to play a role in the enhanced performance of the high capacity rats. We are led to speculate that endothelial tolerance for shear stress and/or increased coupling of myocardial muscle fiber metabolic-to-contractile function is increased in the high-capacity runner strain to the effect of allowing either higher flow rate per unit volume of muscle or more efficient use of oxygen and nutrients in the high-capacity endurance rats.


  • Beighley, Patricia E.
  • Zamir, Mair
  • Wentz, Robert J.
  • Koch, Lauren Gerard
  • Britton, Steven L.
  • Ritman, Erik L.

publication date

  • 2013

published in

number of pages

  • 6

start page

  • 119

end page

  • 125


  • 45


  • 3