AJP - Endo Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Endocrinol Metab 267: E63-E67, 1994;
0193-1849/94 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
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 Katzeff, H. L.
Right arrow Articles by Klein, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Katzeff, H. L.
Right arrow Articles by Klein, I.

AJP - Endocrinology and Metabolism, Vol 267, Issue 1 E63-E67, Copyright © 1994 by American Physiological Society

ARTICLES

Effects of exercise on protein synthesis and myosin heavy chain gene expression in hypothyroid rats

H. L. Katzeff, K. M. Ojamaa and I. Klein
Department of Medicine, North Shore University Hospital-Cornell University Medical College, Manhasset, New York 10030.

Hypothyroidism suppresses muscle growth and alters myosin heavy chain (MHC) gene expression. To study the role of thyroid hormones in exercise-induced muscle growth and protein synthesis, we measured skeletal and cardiac muscle protein synthesis and MHC gene expression in hypothyroid rats allowed to exercise voluntarily. Female Sprague-Dawley rats (200-210 g) were separated into four groups for 28 days of treatment: control, hypothyroid (TX), hypothyroid plus running-wheel exercise (TX+Ex), and hypothyroid plus 25% overfed (TX+OF). Fractional protein synthesis rates (% incorporation/day) were measured using [3H]phenylalanine incorporation 10 min postinjection. The heart weight-to-body weight ratios of the TX and the TX+OF groups showed marked cardiac atrophy over the 28-day period (2.76 +/- 0.12 and 2.50 +/- 0.22 vs. 3.37 +/- 0.18 mg/g, respectively; P < 0.01). However, the TX+Ex group prevented heart, gastrocnemius, and soleus muscle atrophy over the same time period. Heart, gastrocnemius, and soleus muscles had markedly suppressed protein synthesis rates in the TX and TX+OF groups vs. the euthyroid controls (mean fall -72%; P < 0.01, analysis of variance). However, exercise increased protein synthesis rate by 50% (P < 0.05) compared with TX alone in all three muscle groups. Exercise did not modify hypothyroid-induced alterations of cardiac myosin isoform expression. Exercise-mediated effects on skeletal and cardiac muscle growth but not cardiac MHC gene expression appear to be independent of thyroid hormones.


This article has been cited by other articles:


Home page
 J. Thorac. Cardiovasc. Surg.Home page
T. Yeh Jr, A. S. Wechsler, L. Graham, K. E. Loesser, D. A. Sica, L. Wolfe, and E. R. Jakoi
Central sympathetic blockade ameliorates brain death-induced cardiotoxicity and associated changes in myocardial gene expression
J. Thorac. Cardiovasc. Surg., December 1, 2002; 124(6): 1087 - 1098.
[Abstract] [Full Text]

Home page
 J. Biol. Chem.Home page
R. Prabhakar, G. P. Boivin, B. Hoit, and D. F. Wieczorek
Rescue of High Expression beta -Tropomyosin Transgenic Mice by 5-Propyl-2-thiouracil. REGULATING THE alpha -MYOSIN HEAVY CHAIN PROMOTER
J. Biol. Chem., October 8, 1999; 274(41): 29558 - 29563.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
D. S. O'Neill, D. Zheng, W. K. Anderson, G. L. Dohm, and J. A. Houmard
Effect of endurance exercise on myosin heavy chain gene regulation in human skeletal muscle
Am J Physiol Regulatory Integrative Comp Physiol, February 1, 1999; 276(2): R414 - R419.
[Abstract] [Full Text] [PDF]


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