Adaptations in myosin heavy chain profile in chronically unloaded muscles.

R. J. Talmadge, R. R. Roy, S. C. Bodine-Fowler, David J Pierotti, V. R. Edgerton

Research output: Contribution to journalArticle

42 Citations (Scopus)

Abstract

In this review, myosin heavy chain (MHC) adaptations in response to several models of decreased neuromuscular activity (i.e. electrical activation and loading of a muscle) are evaluated. In each of these "reduced-activity" models it is important to: a) quantify the changes in electrical activation of the muscle as a result of the intervention; b) quantify the forces generated by the muscle; and c) determine whether the neuromuscular junction remains normal. Most of the models, including spaceflight, hindlimb suspension, spinal cord isolation, spinal cord transection, denervation, and limb immobilization in a shortened position, result in increases in the percentage of fast MHCs (or fast MHC mRNA) in normally slow rat muscles. It also can be inferred from histochemical data that increases in fast MHCs occur with TTX application and bed rest. The only "reduced-activity" model to consistently increase slow muscle myosin mRNA, and slow fibers is limb immobilization in a stretched position; however, this model results in at least a temporary increase in tension. It appears that the most common feature of these models that might induce MHC adaptations is the modification in loading rather than a change in the neuromuscular activity.

Original languageEnglish (US)
Pages (from-to)117-137
Number of pages21
JournalBasic and applied myology : BAM
Volume5
Issue number2
StatePublished - 1995
Externally publishedYes

Fingerprint

Myosin Heavy Chains
Muscles
Immobilization
Extremities
Hindlimb Suspension
Space Flight
Messenger RNA
Bed Rest
Neuromuscular Junction
Denervation
Myosins
Spinal Cord Injuries
Spinal Cord

Cite this

Talmadge, R. J., Roy, R. R., Bodine-Fowler, S. C., Pierotti, D. J., & Edgerton, V. R. (1995). Adaptations in myosin heavy chain profile in chronically unloaded muscles. Basic and applied myology : BAM, 5(2), 117-137.

Adaptations in myosin heavy chain profile in chronically unloaded muscles. / Talmadge, R. J.; Roy, R. R.; Bodine-Fowler, S. C.; Pierotti, David J; Edgerton, V. R.

In: Basic and applied myology : BAM, Vol. 5, No. 2, 1995, p. 117-137.

Research output: Contribution to journalArticle

Talmadge, RJ, Roy, RR, Bodine-Fowler, SC, Pierotti, DJ & Edgerton, VR 1995, 'Adaptations in myosin heavy chain profile in chronically unloaded muscles.', Basic and applied myology : BAM, vol. 5, no. 2, pp. 117-137.
Talmadge, R. J. ; Roy, R. R. ; Bodine-Fowler, S. C. ; Pierotti, David J ; Edgerton, V. R. / Adaptations in myosin heavy chain profile in chronically unloaded muscles. In: Basic and applied myology : BAM. 1995 ; Vol. 5, No. 2. pp. 117-137.
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