Role of weight-bearing function on the expression of myosin
isoforms during regeneration of rat soleus muscles.
Bigard, Xavier A., Dani[grave]ele Merino, Bernard Serrurier, Francoise
Lienhard, Yannick C. Guezennec, Kathryn J. Bockhold, and Robert G.
Whalen.
D[acute]epartement de Physiologie Syst[acute]emique, CERMA, BP 73,
91223 Br[acute]etigny-sur-Orge Cedex, France and Department of
Molecular Biology, Pasteur Institute, 25, rue du Dr. Roux, 75724
Paris Cedex, France
APStracts 2:0441C, 1995.
The expression of myosin isoforms was studied in regenerated rat
soleus muscle during either normal or altered postural activity.
Regeneration was induced following injury by venom from the Notechis
scutatus scutatus snake. Immunohistochemical analysis showed that in
regenerating soleus muscle after 3 weeks of hindlimb suspension (HS),
nearly all fibers reacted positively with the fast myosin heavy chain
(MyHC) antibody. When 3 weeks of recovery with normal weight-bearing
activity followed HS, the regenerated soleus muscle exhibited a
nearly homogeneous staining with the slow MyHC antibody. These
findings were in accordance with quantitative analysis of the
electrophoretic separation of the native myosin isoforms.
Immunohistochemical data showed that removal of weight bearing in the
21-day-old regenerated soleus muscles resulted in an increase in fast
MyHC expression. Taken together, the results of the present study
clearly demonstrate that the postural load is an important component
in the induction of slow MyHC in regenerating muscle and that the
control of the expression of MyHC in muscle comprising a homogeneous
population of fibers deriving from satellite cells appears more
homogeneous and more complete than in non-degenerated one.
Received 18 April 1994; accepted in final form 28 November 1995.
APS Manuscript Number C208-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 December 95