Journal of Applied Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

J Appl Physiol (January 31, 2003). doi:10.1152/japplphysiol.00617.2002
This Article
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
94/5/1896    most recent
00617.2002v1
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
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 Sieck, G. C
Right arrow Articles by Zhan, W.-Z.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sieck, G. C
Right arrow Articles by Zhan, W.-Z.
Submitted on July 9, 2002
Accepted on January 23, 2003

CHANGES IN ACTOMYOSIN ATP CONSUMPTION RATE IN RAT DIAPHRAGM MUSCLE FIBERS DURING POSTNATAL DEVELOPMENT

Gary C Sieck1*, Y.S. Prakash1, Young-Soo Han1, Yun-Hua Fang1, Paige C Geiger1, and Wen-Zhi Zhan1

1 Departments of Anesthesiology and Physiology & Biophysics, Mayo Medical School, Rochester, MN, USA

* To whom correspondence should be addressed. E-mail: sieck.gary{at}mayo.edu.

Early postnatal development of rat diaphragm muscle (DIAm) is marked by dramatic transitions in myosin heavy chain (MHC) isoform expression. We hypothesized that the transition from MHCNeo to adult fast MHC isoform expression in DIAm fibers is accompanied by an increase in both the maximum velocity of the actomyosin ATPase reaction (Vmax ATPase) and the ATP consumption rate during maximum isometric activation (ATPiso). Rat DIAm fibers were evaluated at postnatal day 0, 14 and 28 (D-0, D-14 and D-28) and in adults (D-84). Across all ages, Vmax ATPase of fibers was significantly higher than ATPiso. The reserve capacity for ATP consumption [1- (ratio of ATPiso to Vmax ATPase)] was remarkably constant (~55-60%) across age groups, although at D-28 and in adults the reserve capacity for ATP consumption was slightly higher for fibers expressing MHCSlow compare to fast MHC isoforms. At D-28 and in adults, both Vmax ATPase and ATPiso were lower in fibers expressing MHCSlow followed in rank order by fibers expressing MHC2A, MHC2X and MHC2B. For fibers expressing MHCNeo, Vmax ATPase and ATPiso were comparable to values for adult fibers expressing MHCSlow, but significantly lower than values for fibers expressing fast MHC isoforms. We conclude that postnatal transitions from MHCNeo to adult fast MHC isoform expression in DIAm fibers are associated with corresponding but disproportionate changes in Vmax ATPase and ATPiso.




This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
J. G. Ryall, J. D. Schertzer, T. M. Alabakis, S. M. Gehrig, D. R. Plant, and G. S. Lynch
Intramuscular {beta}2-agonist administration enhances early regeneration and functional repair in rat skeletal muscle after myotoxic injury
J Appl Physiol, July 1, 2008; 105(1): 165 - 172.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
C. B. Mantilla and G. C. Sieck
Key aspects of phrenic motoneuron and diaphragm muscle development during the perinatal period
J Appl Physiol, June 1, 2008; 104(6): 1818 - 1827.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
C. B. Mantilla, R. V. Sill, B. Aravamudan, W.-Z. Zhan, and G. C. Sieck
Developmental effects on myonuclear domain size of rat diaphragm fibers
J Appl Physiol, March 1, 2008; 104(3): 787 - 794.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
G. C. Sieck, W.-Z. Zhan, Y.-S. Han, and Y. S. Prakash
Effect of denervation on ATP consumption rate of diaphragm muscle fibers
J Appl Physiol, September 1, 2007; 103(3): 858 - 866.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
P. C. Geiger, J. P. Bailey, C. B. Mantilla, W.-Z. Zhan, and G. C. Sieck
Mechanisms underlying myosin heavy chain expression during development of the rat diaphragm muscle
J Appl Physiol, December 1, 2006; 101(6): 1546 - 1555.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 1966 by the American Physiological Society.