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.
| Original language | English |
|---|---|
| Pages (from-to) | 10-19 |
| Number of pages | 10 |
| Journal | Scandinavian Journal of Medicine and Science in Sports |
| Volume | 20 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Feb 2010 |
Fingerprint
Keywords
- Aging
- Disuse
- Muscle fibers
- Myosin isoforms
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation
Cite this
Single muscle fiber properties in aging and disuse. / Canepari, M.; Pellegrino, M. A.; D'Antona, G.; Bottinelli, R.
In: Scandinavian Journal of Medicine and Science in Sports, Vol. 20, No. 1, 02.2010, p. 10-19.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Single muscle fiber properties in aging and disuse
AU - Canepari, M.
AU - Pellegrino, M. A.
AU - D'Antona, G.
AU - Bottinelli, R.
PY - 2010/2
Y1 - 2010/2
N2 - 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.
AB - 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.
KW - Aging
KW - Disuse
KW - Muscle fibers
KW - Myosin isoforms
UR - http://www.scopus.com/inward/record.url?scp=75649122204&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=75649122204&partnerID=8YFLogxK
U2 - 10.1111/j.1600-0838.2009.00965.x
DO - 10.1111/j.1600-0838.2009.00965.x
M3 - Article
C2 - 19843264
AN - SCOPUS:75649122204
VL - 20
SP - 10
EP - 19
JO - Scandinavian Journal of Medicine and Science in Sports
JF - Scandinavian Journal of Medicine and Science in Sports
SN - 0905-7188
IS - 1
ER -