Fibre size and type adaptations to spinal isolation and cyclical passive stretch in cat hindlimb

R. R. Roy, David J Pierotti, V. Flores, W. Rudolph, V. R. Edgerton

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Impulse activity is known to have a strong influence in determining the characteristics that distinguish skeletal muscle fibres into types. The control of muscle proteins by the neural systems that innervate the muscles, however, is not complete (Edgerton et al. 1985, 1990). The purpose of the present study, therefore, was to determine the effects of inactivity for 6 months on the size and fibre type composition of selected cat hindlimb muscles. Inactivity was produced by isolating the lumbar region of the spinal cord, i.e. transecting the cord at T12-T13 and again at L7-S1 and then performing a bilateral dorsal rhizotomy between the transection sites (SI). In each SI cat, one hindlimb was passively manipulated for 30 min per day through a range of motion at the ankle mimicking a step cycle. SI resulted in an atrophic response in most muscles, with predominantly slow extensors showing the largest effect. In general, the predominant fibre type, which also had the largest mean size, in each muscle atrophied the most. The mean fibre size of all fibre types were similar after SI, suggesting that there may be a minimal size for inactive intact fibres. In comparison with control animals, all muscles in the SI cats had a higher proportion of fast fibres. Further, the relative contribution of the slow fibres to the total cross-sectional area of the muscle was decreased following SI. Some slow fibres in each muscle, however, were resistant to change. These data demonstrate the extent to which size and myosin type of mammalian muscle fibres are independent of activation characteristics.

Original languageEnglish (US)
Pages (from-to)491-499
Number of pages9
JournalJournal of Anatomy
Volume180
Issue number3
StatePublished - 1992
Externally publishedYes

Fingerprint

Hindlimb
muscle
Cats
cats
Muscles
muscles
muscle fibers
muscle protein
Rhizotomy
myosin
Lumbosacral Region
spinal cord
hindlimbs
fibre
Muscle Proteins
Skeletal Muscle Fibers
Myosins
Articular Range of Motion
Ankle
Spinal Cord

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Anatomy

Cite this

Fibre size and type adaptations to spinal isolation and cyclical passive stretch in cat hindlimb. / Roy, R. R.; Pierotti, David J; Flores, V.; Rudolph, W.; Edgerton, V. R.

In: Journal of Anatomy, Vol. 180, No. 3, 1992, p. 491-499.

Research output: Contribution to journalArticle

Roy, RR, Pierotti, DJ, Flores, V, Rudolph, W & Edgerton, VR 1992, 'Fibre size and type adaptations to spinal isolation and cyclical passive stretch in cat hindlimb', Journal of Anatomy, vol. 180, no. 3, pp. 491-499.
Roy, R. R. ; Pierotti, David J ; Flores, V. ; Rudolph, W. ; Edgerton, V. R. / Fibre size and type adaptations to spinal isolation and cyclical passive stretch in cat hindlimb. In: Journal of Anatomy. 1992 ; Vol. 180, No. 3. pp. 491-499.
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