Journal of Applied Physiology Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 88: 894-903, 2000;
8750-7587/00 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
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
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
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 ISI Web of Science (14)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Adams, G. R.
Right arrow Articles by Baldwin, K. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Adams, G. R.
Right arrow Articles by Baldwin, K. M.
Vol. 88, Issue 3, 894-903, March 2000

Effects of spaceflight and thyroid deficiency on hindlimb development. I. Muscle mass and IGF-I expression

G. R. Adams, S. A. McCue, P. W. Bodell, M. Zeng, and K. M. Baldwin

Department of Physiology and Biophysics, University of California, Irvine, California 92697-4560

Thyroid deficiency (TD) in neonatal rats causes reduced growth of skeletal muscle that is disproportionately greater than that for other tissues (G. R. Adams, S. A. McCue, M. Zeng, and K. M. Baldwin. Am. J. Physiol. Regulatory Integrative Comp. Physiol. 276: R954-R961, 1999). TD depresses plasma insulin-like growth factor I (IGF-I) levels, suggesting a mechanism for this effect. We hypothesized that TD and exposure to spaceflight (SF) would interact to reduce skeletal muscle growth via a reduction in IGF-I levels. Neonatal rats were flown in space for 16 days. There was a similar, nonadditive reduction in the growth of the body (~50%) and muscle weight (fast muscles, ~60%) with either TD or SF. In the soleus muscle, either SF or TD alone resulted in growth reductions that were augmented by SF-TD interactions. There were strong correlations between 1) muscle mass and muscle IGF-I levels and 2) circulating IGF-I and body weight. These results indicate that either hypothyroidism or exposure to SF will limit the somatic and muscle-specific growth of neonatal rats. The impact of these perturbations on skeletal muscle growth is relatively greater than the effect on somatic growth. The mechanisms by which either TD or SF impact growth appear to have a common pathway involving the control of plasma and muscle IGF-I concentrations.

skeletal muscle; microgravity; unweighting; fast twitch; slow twitch; hypothyroidism; insulin-like growth factor I


This article has been cited by other articles:


Home page
 J. Physiol.Home page
K. D. Walton, L. Benavides, N. Singh, and N. Hatoum
Long-term effects of microgravity on the swimming behaviour of young rats
J. Physiol., June 1, 2005; 565(2): 609 - 626.
[Abstract] [Full Text] [PDF]

Home page
 J. Physiol.Home page
K. D. Walton, S. Harding, D. Anschel, Y. T. Harris, and R. Llinas
The effects of microgravity on the development of surface righting in rats
J. Physiol., June 1, 2005; 565(2): 593 - 608.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
F. Haddad, F. Zaldivar, D. M. Cooper, and G. R. Adams
IL-6-induced skeletal muscle atrophy
J Appl Physiol, March 1, 2005; 98(3): 911 - 917.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
J. D. Fluckey, E. E. Dupont-Versteegden, M. Knox, D. Gaddy, P. A. Tesch, and C. A. Peterson
Insulin facilitation of muscle protein synthesis following resistance exercise in hindlimb-suspended rats is independent of a rapamycin-sensitive pathway
Am J Physiol Endocrinol Metab, December 1, 2004; 287(6): E1070 - E1075.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
G. R. Adams, F. Haddad, S. A. McCue, P. W. Bodell, M. Zeng, L. Qin, A. X. Qin, and K. M. Baldwin
Effects of spaceflight and thyroid deficiency on rat hindlimb development. II. Expression of MHC isoforms
J Appl Physiol, March 1, 2000; 88(3): 904 - 916.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. Inobe, I. Inobe, G. R. Adams, K. M. Baldwin, and S.'I. Takeda
Effects of microgravity on myogenic factor expressions during postnatal development of rat skeletal muscle
J Appl Physiol, May 1, 2002; 92(5): 1936 - 1942.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online