| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Articles in PresS, published online ahead of print May 23, 2002
Am J Physiol Regu Physiol, 10.1152/ajpregu.00080.2002
Submitted on February 9, 2002
Accepted on May 17, 2002
1 Exercise and Sport Sciences, University of Florida, Gainesville, FL, USA
2 Biology, Williams College, Williamstown, MA, USA
3 Exercise and Sport Sciences, University of Florida, Gainesville, FL, USA; Physiology, University of Florida, Gainesville, FL, USA
* To whom correspondence should be addressed. E-mail: jstaib{at}ufl.edu.
MyoD is one of four myogenic regulatory factors found exclusively in skeletal muscle. In an effort to better understand the role that MyoD plays in determining muscle contractile properties, we examined the effects of MyoD deletion on both diaphragmatic contractile properties and myosin heavy chain (MHC) phenotype. Regions of the costal diaphragm from wild type (WT) and MyoD knockout (MyoD (-/-)) adult male Balb/C mice (n = 8/group) were removed and in vitro diaphragmatic contractile properties were measured. Diaphragmatic contractile measurements revealed that MyoD (-/-) animals exhibited a significant (p < 0.05) downward shift in the force-frequency relationship, a decrement in maximal specific tension (Po; -33%), a decline in maximal shortening velocity (Vmax; -37%), and concomitant decrease in peak power output (-47%). Determination of MHC isoforms in the diaphragm via gel electrophoresis revealed that MyoD elimination resulted in a fast-to-slow shift (p < 0.05) in the MHC phenotype toward MHC types IIA and IIX in MyoD (-/-) animals. These data indicate that MyoD deletion results in a decrease in diaphragmatic submaximal force generation and Po, along with decrements in both Vmax and peak power output. Hence, MyoD plays an important role in determining diaphragmatic contractile properties.
This article has been cited by other articles:
|
|
 |
|
  K. Maes, D. Testelmans, P. Cadot, K. DeRuisseau, S. K. Powers, M. Decramer, and G. Gayan-Ramirez Effects of Acute Administration of Corticosteroids during Mechanical Ventilation on Rat Diaphragm Am. J. Respir. Crit. Care Med., December 15, 2008; 178(12): 1219 - 1226. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-K. Kwon and K.-H. Cho Quantitative analysis of robustness and fragility in biological networks based on feedback dynamics Bioinformatics, April 1, 2008; 24(7): 987 - 994. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Degens, A. K. Swisher, Y. F. Heijdra, P. M. Siu, P. N. Richard Dekhuijzen, and S. E. Alway Apoptosis and Id2 expression in diaphragm and soleus muscle from the emphysematous hamster Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2007; 293(1): R135 - R144. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Matecki, G. H. Guibinga, and B. J. Petrof Regenerative capacity of the dystrophic (mdx) diaphragm after induced injury Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2004; 287(4): R961 - R968. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Rucker, T. J. Fraites Jr, S. L. Porvasnik, M. A. Lewis, I. Zolotukhin, D. A. Cloutier, and B. J. Byrne Rescue of enzyme deficiency in embryonic diaphragm in a mouse model of metabolic myopathy: Pompe disease Development, June 15, 2004; 131(12): 3007 - 3019. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Z. Racz, G. Gayan-Ramirez, D. Testelmans, P. Cadot, K. De Paepe, E. Zador, F. Wuytack, and M. Decramer Early Changes in Rat Diaphragm Biology with Mechanical Ventilation Am. J. Respir. Crit. Care Med., August 1, 2003; 168(3): 297 - 304. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
