Force-velocity properties and myosin light chain isoform composition of an identified type of skinned fibres from rat skeletal muscle

R. Bottinelli, C. Reggiani

Research output: Contribution to journalArticle


Force-velocity relations, myosin heavy chain (MHC) and myosin light chain (MLC) isoform composition of single skinned fibres from rat plantaris muscle were determined. In fibres containing the same (2X) isoform of myosin heavy chain, several parameters derived from the force-velocity relation and isometric force (Po) were tested for relation with the fibre content in alkali myosin light chain (MLC) isoforms. Whereas maximum shortening velocity was found to be proportional to the relative content in the 3f isoform of alkali MLC, velocity of shortening at 5% relative load, maximum power output, and Po were not. These results strengthen the idea that, in mammalian skeletal fibres, alkali MLC isoforms modulate shortening velocity at zero load, but suggest that they do not control the contractile behaviour at loads higher than zero.

Original languageEnglish
Pages (from-to)592-594
Number of pages3
JournalPflugers Archiv European Journal of Physiology
Issue number4
Publication statusPublished - Feb 1995



  • force-velocity
  • maximum power out-put
  • myosin light chains
  • skinned fibres

ASJC Scopus subject areas

  • Physiology

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