We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Single muscle fiber properties in aging and disuse.
- Authors
Canepari, M.; Pellegrino, M. A.; D'Antona, G.; Bottinelli, R.
- Abstract
Since the middle of the 1980s, it was understood that myosin, the motor of contraction, can be expressed in several isoforms. The isoforms of the myosin heavy-chain (MHC) portion of the molecule were found to be mostly responsible for the diversity in the contractile and energetic properties of muscle fibers. In humans, three MHC isoforms are expressed in limb muscles (MHC-1, MHC-2A and MHC-2X) and they generate three pure fiber types (types 1, 2A and 2X) and two hybrid types (types 1-2A and -2AX). Type 1, 2A and 2X fibers widely differ with respect to most of their contractile and energetic properties, and a change in their relative distribution within muscles is known to modulate their functional properties in vivo through a “qualitative” mechanism. On the basis of the MHC regulation of muscle fibers properties, it is expected that a given fiber type develops the same force and shortens at the same speed regardless of the physiologic and pathologic conditions under which the muscle works. Surprisingly, several evidences have been accumulating to show that in aging and disuse, the properties of a muscle fiber type can change with no change in its myosin isoform content. This short review considers the latter phenomenon and the possible underlying mechanisms.
- Subjects
MUSCLE cells; MUSCLE contraction; REGULATION of muscle contraction; MUSCLE proteins; MUSCLES; MYOSIN; GLOBULINS
- Publication
Scandinavian Journal of Medicine & Science in Sports, 2010, Vol 20, Issue 1, p10
- ISSN
0905-7188
- Publication type
Article
- DOI
10.1111/j.1600-0838.2009.00965.x