HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 286/5/H1696    most recent 00761.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (13) Citing Articles via Google Scholar Google Scholar Articles by Iemitsu, M. Articles by Yamaguchi, I. Search for Related Content PubMed PubMed Citation Articles by Iemitsu, M. Articles by Yamaguchi, I.

Exercise training improves cardiac function-related gene levels through thyroid hormone receptor signaling in aged rats

¹Cardiovascular Division, Department of Internal Medicine, Institute of Clinical Medicine, ²Institute of Health and Sport Sciences, and ³Center for Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki 305-0006, Japan

Submitted 8 August 2003 ; accepted in final form 22 December 2003

Exercise training improves the aging-induced downregulation of myosin heavy chain (MHC) and sarcoplasmic reticulum (SR) Ca²⁺-ATPase, which participate in the regulation of cardiac contraction and relaxation. Thyroid hormone receptor (TR), a transcriptional activator, affected the regulation of gene expression of MHC and SR Ca²⁺-ATPase. We hypothesized that myocardial TR signaling contributes to a molecular mechanism of exercise training-induced improvement of MHC and SR Ca²⁺-ATPase genes with cardiac function in old age. We investigated whether TR signaling and gene expression of MHC and SR Ca²⁺-ATPase in the aged heart are affected by exercise training, using the hearts of sedentary young rats (4 mo old), sedentary aged rats (23 mo old), and trained aged rats (23 mo old, swimming training for 8 wk). Trained aged rats showed improvement in cardiac function. Expression of TR-₁ and TR-₁ proteins in the heart were significantly lower in sedentary aged rats than in sedentary young rats and were significantly higher in trained aged rats than in sedentary aged rats. The activity of TR DNA binding to the transcriptional regulatory region in the -MHC and SR Ca²⁺-ATPase genes and the mRNA and protein expression of -MHC and SR Ca²⁺-ATPase in the heart and plasma 3,3'-triiodothyronine and thyroxine levels were altered in association with changes in the myocardial TR protein levels. These findings suggest that exercise training improves the aging-induced downregulation of myocardial TR signaling-mediated transcription of MHC and SR Ca²⁺-ATPase genes, thereby contributing to the improvement of cardiac function in trained aged hearts.

myosin heavy chain; sarcoplasmic reticulum Ca²⁺-ATPase; swimming training

This article has been cited by other articles:

				L. Groban, H. Jobe, M. Lin, T. Houle, D. A. Kitzman, and W. Sonntag Effects of Short-Term Treadmill Exercise Training or Growth Hormone Supplementation on Diastolic Function and Exercise Tolerance in Old Rats J. Gerontol. A Biol. Sci. Med. Sci., September 1, 2008; 63(9): 911 - 920. [Abstract] [Full Text] [PDF]

				M. Iemitsu, N. Shimojo, S. Maeda, Y. Irukayama-Tomobe, S. Sakai, T. Ohkubo, Y. Tanaka, and T. Miyauchi The benefit of medium-chain triglyceride therapy on the cardiac function of SHRs is associated with a reversal of metabolic and signaling alterations Am J Physiol Heart Circ Physiol, July 1, 2008; 295(1): H136 - H144. [Abstract] [Full Text] [PDF]

				D. S. Hydock, C.-Y. Lien, C. M. Schneider, and R. Hayward Effects of voluntary wheel running on cardiac function and myosin heavy chain in chemically gonadectomized rats Am J Physiol Heart Circ Physiol, December 1, 2007; 293(6): H3254 - H3264. [Abstract] [Full Text] [PDF]

				R. L. Schultz, J. G. Swallow, R. P. Waters, J. A. Kuzman, R. A. Redetzke, S. Said, G. M. de Escobar, and A. M. Gerdes Effects of Excessive Long-Term Exercise on Cardiac Function and Myocyte Remodeling in Hypertensive Heart Failure Rats Hypertension, August 1, 2007; 50(2): 410 - 416. [Abstract] [Full Text] [PDF]

				N. E. Buroker, M. E. Young, C. Wei, K. Serikawa, M. Ge, X.-H. Ning, and M. A. Portman The dominant negative thyroid hormone receptor beta-mutant {Delta}337T alters PPAR{alpha} signaling in heart Am J Physiol Endocrinol Metab, February 1, 2007; 292(2): E453 - E460. [Abstract] [Full Text] [PDF]

				M. Iemitsu, S. Maeda, S. Jesmin, T. Otsuki, Y. Kasuya, and T. Miyauchi Activation pattern of MAPK signaling in the hearts of trained and untrained rats following a single bout of exercise J Appl Physiol, July 1, 2006; 101(1): 151 - 163. [Abstract] [Full Text] [PDF]

				J. W. Starnes, A. M. Choilawala, R. P. Taylor, M. J. Nelson, and M. D. Delp Myocardial Heat Shock Protein 70 Expression in Young and Old Rats After Identical Exercise Programs J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2005; 60(8): 963 - 969. [Abstract] [Full Text] [PDF]

				T. A. Thomas, J. A. Kuzman, B. E. Anderson, S. M. K. Andersen, E. H. Schlenker, M. S. Holder, and A. M. Gerdes Thyroid hormones induce unique and potentially beneficial changes in cardiac myocyte shape in hypertensive rats near heart failure Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2118 - H2122. [Abstract] [Full Text] [PDF]