|
|
||||||||
1 Laboratoire de Plasticité Neuromusculaire, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d' Ascq, France; and 2 Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
This study focuses on the effects of mechanical unloading of rat soleus muscle on the isoform patterns of the three troponin (Tn) subunits: troponin T (TnT), troponin I (TnI), and troponin C (TnC). Mechanical unloading was achieved by hindlimb unloading (HU) for time periods of 7, 15, and 28 days. Relative concentrations of slow and fast TnT, TnI, and TnC isoforms were assessed by electrophoretic and immunoblot analyses. HU induced profound slow-to-fast isoform transitions of all Tn subunits, although to different extents and with different time courses. The effectiveness of the isoform transitions was higher for TnT than for TnI and TnC. Indeed, TnI and TnC encompassed minor partial exchanges of slow isoforms with their fast counterparts, whereas the expression pattern of fast TnT isoforms (TnTf) was largely increased after HU. Moreover, slow and fast isoforms of the different Tn were not affected in the same manner by HU. This suggests that the slow and fast counterparts of the Tn subunit isoforms are regulated independently in response to HU. The changes in TnTf composition occurred in parallel with previously demonstrated transitions within the pattern of the fast myosin heavy chains in the same muscles.
hindlimb suspension; isoform transition; troponin T, I, and C.
This article has been cited by other articles:
![]() |
Y. Mounier, V. Tiffreau, V. Montel, B. Bastide, and L. Stevens Phenotypical transitions and Ca2+ activation properties in human muscle fibers: effects of a 60-day bed rest and countermeasures J Appl Physiol, April 1, 2009; 106(4): 1086 - 1099. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Hirose, K. Nakazato, H. Song, and N. Ishii TGF- 1 and TNF-{alpha} are involved in the transcription of type I collagen {alpha}2 gene in soleus muscle atrophied by mechanical unloading J Appl Physiol, January 1, 2008; 104(1): 170 - 177. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. B. Yu, F. Gao, H. Z. Feng, and J.-P. Jin Differential regulation of myofilament protein isoforms underlying the contractility changes in skeletal muscle unloading Am J Physiol Cell Physiol, March 1, 2007; 292(3): C1192 - C1203. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Kischel, B. Bastide, M. Muller, F. Dubail, F. Offredi, J. P. Jin, Y. Mounier, and J. Martial Expression and functional properties of four slow skeletal troponin T isoforms in rat muscles Am J Physiol Cell Physiol, August 1, 2005; 289(2): C437 - C443. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Picquet, V. Bouet, L. Cochon, M. Lacour, and M. Falempin Changes in rat soleus muscle phenotype consecutive to a growth in hypergravity followed by normogravity Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2005; 289(1): R217 - R224. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Stevens, C. Bozzo, T. Nemirovskaya, V. Montel, M. Falempin, and Y. Mounier Contractile properties of rat single muscle fibers and myosin and troponin isoform expression after hypergravity J Appl Physiol, June 1, 2003; 94(6): 2398 - 2405. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |