Changes in muscle T2 and tissue damage after downhill running in mdx mice

Muscle Nerve. 2011 Jun;43(6):878-86. doi: 10.1002/mus.21986. Epub 2011 Apr 12.


Introduction: In this study we compared the effects of downhill or horizontal treadmill running on the magnetic resonance imaging (MRI) transverse relaxation time constant (T(2)) in mdx mice.

Methods: Mice underwent either downhill (n = 11 mdx, n = 6 controls) or horizontal running (n = 9, mdx only) on a treadmill. MRI was conducted prior to exercise, immediately afterward (∽20 minutes), and then 24 and 48 hours after exercise.

Results: A higher percentage of pixels with elevated T(2) in the lower hindlimb muscles was observed in the mdx mice compared with controls both pre-exercise (P < 0.001) and at each time-point after downhill running (P < 0.05), but not with horizontal running. The medial compartment muscles appeared to be the most susceptible to increased T(2).

Conclusions: Downhill running provides a stimulus for inducing acute changes in muscle T(2) in mdx mice. MRI is a non-invasive approach for examining acute muscle damage and recovery in multiple muscle groups simultaneously.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Disease Models, Animal
  • Exercise Test / methods
  • Leg Injuries / diagnosis*
  • Leg Injuries / pathology
  • Leg Injuries / physiopathology
  • Magnetic Resonance Imaging / methods
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred mdx
  • Muscle, Skeletal / injuries*
  • Muscle, Skeletal / pathology
  • Muscle, Skeletal / physiopathology
  • Muscular Dystrophy, Animal / diagnosis
  • Muscular Dystrophy, Animal / pathology
  • Muscular Dystrophy, Animal / physiopathology
  • Physical Conditioning, Animal / adverse effects
  • Physical Conditioning, Animal / methods
  • Running / injuries*