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Pflügers Archiv

, Volume 440, Issue 1, pp 34–41 | Cite as

Muscle and motor-skill dysfunction in a K+ channel-deficient mouse are not due to altered muscle excitability or fiber type but depend on the genetic background

  • Jorge A. Sánchez
  • Chi Shun Ho
  • Donna M. Vaughan
  • Maria C. Garcia
  • Robert W. Grange
  • Rolf H. Joho
Original Article

Abstract.

The voltage-gated K+ channel Kv3.1 is expressed in skeletal muscle and in GABAergic interneurons in the central nervous system. Hence, the absence of Kv3.1 K+ channels may lead to a phenotype of myogenic or neurogenic origin, or both. Kv3.1-deficient (Kv3.1–/–) 129/Sv mice display altered contractile properties of their skeletal muscles and show poor performance on a rotating rod. In contrast, Kv3.1–/– mice on the (129/Sv×C57BL/6)F1 background display normal muscle properties and perform like wild-type mice. The correlation of poor performance on the rotating rod with altered muscle properties supports the notion that the skeletal muscle dysfunction in Kv3.1–/– 129/Sv mice may be responsible for the impaired motor skills on the rotating rod. Surprisingly, we did not find major differences between wild-type and Kv3.1–/– 129/Sv skeletal muscles in either the resting or action potential, the delayed-rectifier potassium conductance (g K) or the distribution of fast and slow muscle fibers. These findings suggest that the Kv3.1 K+ channel may not play a major role in the intrinsic excitability of skeletal muscle fibers although its absence leads to slower contraction and relaxation and to smaller forces in muscles of 129/Sv Kv3.1–/– mice.

Excitation–contraction coupling Ion-channel mutation Knockout mouse Muscle properties 

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Copyright information

© Springer-Verlag 2000

Authors and Affiliations

  • Jorge A. Sánchez
    • 1
  • Chi Shun Ho
    • 2
  • Donna M. Vaughan
    • 2
  • Maria C. Garcia
    • 1
  • Robert W. Grange
    • 3
  • Rolf H. Joho
    • 2
  1. 1.Department of Pharmacology, Cinvestav, A.P. 14–740, Mexico DF, 07300, Mexico
  2. 2.Center for Basic Neuroscience, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390–9111, USA
  3. 3.Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390–9040, USA

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