The effect of age and temperature on mdx muscle fatigue.
We have studied the in vitro contractile and fatigue characteristics of extensor digitorum longus (EDL) muscles from 8- and 62-week-old dystrophin-deficient (mdx) and control mice at 20 degrees C and 35 degrees C. There were no differences in fatigability at 20 degrees C, but at 35 degrees C the dystrophin-deficient muscles demonstrated increased fatigability compared to controls, with the older mice exhibiting the greatest fatigue. These results suggest a temperature-related mechanism of myofibrillar fatigue in dystrophin-deficient EDL muscles.
Wineinger
M A
MA
Department of Physical Medicine and Rehabilitation, University of California School of Medicine, Davis 95616, USA.
Walsh
S A
SA
Abresch
R T
RT
D000375:Aging / Q000502:physiology*; D000818:Animals; D001831:Body Temperature / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology; D018763:Muscle Fatigue / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*