Lower active force generation and improved fatigue resistance in skeletal muscle from desmin deficient mice

J Muscle Res Cell Motil. 2003;24(7):453-9. doi: 10.1023/a:1027353930229.

Abstract

The mechanical effects of the intermediate filament protein desmin was examined in desmin deficient mice (Des-/-) and their wild type control (Des+/+). Active force generation was determined in intact soleus muscles and in skinned single fibres from soleus and psoas. A decreased force generation of skinned muscle fibres from Des-/- mice and a tendency towards decreased active force in intact soleus muscle were detected. Concentrations of the contractile protein actin and myosin were not altered in Des-/- muscles. Ca(2+)-sensitivity of skinned single fibres in Des-/- muscles was unchanged compared to Des+/+. Using a protocol with repeated short tetani an increased fatigue resistance was found in the intact soleus muscles from Des-/- mice. In conclusion, desmin intermediate filaments are required for optimal generation or transmission of active force in skeletal muscle. Although other studies have shown that the desmin intermediate filaments appear to influence Ca(2+)-handling, the Ca(2+)-sensitivity of the contractile filaments is not altered in skeletal muscle of Des-/- mice. Previous studies have reported a switch towards slower myosin isoforms in slow skeletal muscle of Des-/- mice. The increased fatigue resistance show that this change is reflected in the physiological function of the muscle.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Calcium / metabolism
  • Desmin / deficiency
  • Desmin / genetics*
  • Electric Stimulation
  • Female
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Muscle Contraction / physiology*
  • Muscle Fatigue / physiology*
  • Muscle Fibers, Skeletal / metabolism
  • Muscle Fibers, Skeletal / physiology
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / physiology*
  • Myosins / metabolism
  • Psoas Muscles / innervation
  • Psoas Muscles / metabolism
  • Psoas Muscles / physiology*

Substances

  • Actins
  • Desmin
  • Myosins
  • Calcium