J Physiol Wellcome Trust-funded researchers
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Physiol Vol 478, Issue Pt 3 pp 513-521
Copyright © 1994 by The Physiological Society
This Article
Right arrow Full Text (PDF)
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Galler, S
Right arrow Articles by Pette, D
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Galler, S
Right arrow Articles by Pette, D

Stretch activation, unloaded shortening velocity, and myosin heavy chain isoforms of rat skeletal muscle fibres.

 S Galler, T L Schmitt and D Pette

Department of Physiology, University of Salzburg, Austria.

1. Contractile properties were investigated on single skinned-fibre preparations from rat leg muscles. Following the mechanical measurements, the myosin heavy chain (HC) composition of the same fibre was analysed by gradient gel electrophoresis. 2. Fibres were typed according to their myosin HC isoform composition (HCI, type I; HCIIA, type IIA; HCIID, type IID; HCIIB, type IIB). Many fibres showed the co-existence of two myosin HC isoforms (hybrid fibres). 3. A strong correlation was found between fibre type and time characteristics of stretch-induced delayed force increase (stretch activation) of fully Ca(2+)-activated fibres. 4. The maximal unloaded shortening velocity (Vmax), as measured with the slack test, was lowest in type I fibres. Within the type II group, a continuum of Vmax values was found, with large overlaps of the different fibre types. 5. The results suggest that the kinetics of stretch activation is determined by the myosin HCs whereas unloaded fibre shortening seems to be determined by other myofibrillar proteins in addition to the myosin HCs. Assuming that stretch activation represents certain steps of the cross-bridge turnover under isometric conditions and Vmax reflects cross-bridge detachment under unloaded conditions it can be deduced that different myofibrillar proteins are responsible for different steps within the cross-bridge turnover.




This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
M. Suwa, H. Nakano, and S. Kumagai
Effects of chronic AICAR treatment on fiber composition, enzyme activity, UCP3, and PGC-1 in rat muscles
J Appl Physiol, September 1, 2003; 95(3): 960 - 968.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
C. Goodman, M. Patterson, and G. Stephenson
MHC-based fiber type and E-C coupling characteristics in mechanically skinned muscle fibers of the rat
Am J Physiol Cell Physiol, June 1, 2003; 284(6): C1448 - C1459.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. Suwa, H. Nakano, Y. Higaki, T. Nakamura, S. Katsuta, and S. Kumagai
Increased wheel-running activity in the genetically skeletal muscle fast-twitch fiber-dominant rats
J Appl Physiol, January 1, 2003; 94(1): 185 - 192.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1994 The Physiological Society.