Journal of Applied Physiology AJP: Gastrointestinal and Liver Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

J Appl Physiol (August 9, 2002). doi:10.1152/japplphysiol.00304.2002
This Article
Right arrow Full Text (PDF) Free
Right arrow All Versions of this Article:
93/6/2095    most recent
00304.2002v1
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 Eynan, M.
Right arrow Articles by Horowitz, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Eynan, M.
Right arrow Articles by Horowitz, M.

Articles in PresS, published online ahead of print August 9, 2002
J Appl Physiol, 10.1152/jap.00304.2002
Submitted on April 8, 2002
Accepted on August 6, 2002

Elevated Glycogen and Glycolysis and Low Thyroxine Induced by Heat Acclimation Improve Heart Ischemic Tolerance

Mirit Eynan1, Tanya Knubuvetz2, Uri Meiri1, Gil Navon2, Gary Gerstenblith3, Zohar Bromberg1, Yonathan Hasin4, and Michal Horowitz1*

1 Division of Physiology, Hadassah Schools of Dental Medicine and Medicine, The Hebrew University, Jerusalem, Israel
2 Department of Physical Chemistry, Tel Aviv University, Tel Aviv, Israel
3 Department of Cardiology, Johns Hopkins University, Baltimore, Maryland, USA
4 Department of Cardiology, Hadassah University Hospital, Jerusalem, Israel

* To whom correspondence should be addressed. E-mail: horowitz{at}cc.huji.ac.il.

Based on our observations of energy sparing in heat-acclimated rat hearts, we investigated whether changes in pre-ischemic glycogen level, glycolytic rate and plasma thyroxine level mediate cardioprotection induced in these hearts during ischemic/reperfusion insults. Control (24°C, C), heat-acclimated (34°C, 30days, AC), acclimated-euthyroid (34°C+3ng/ml L-thyroxine, AT), and control hypothyroid (24°C +0.02% 6-n-propyl-2-thiouracil, CP) groups were studied. Pre-ischemic glycogen was higher in AC than in C hearts (39.0°8.5 vs 19.2°4.2(SEM) mmol glucose/g wet wt, p<0.0006) and the lactate produced vs glycogen level during total ischemia (13C NMR spectroscopy) was markedly slower (AC: -0.82X, r=0.98 vs C: -4.7X, r=0.9). Time to onset of ischemic contracture (IC) was lengthened and the fraction of hearts experiencing IC was lowered. Pulse pressure recovery was improved in AC compared to C animals before, but not after absolute Na-iodoacetate-induced glycolysis inhibition. AT hearts exhibited decreased ischemic tolerance, while induced hypothyroidism in controls improved cardiotolerance. Thus, higher pre-ischemic glycogen and slowed glycolysis are associated with hypothyroidism, are likely important mediators of the improved ischemic tolerance exhibited by AC hearts.




This article has been cited by other articles:


Home page
 Physiol. GenomicsHome page
A. Tetievsky, O. Cohen, L. Eli-Berchoer, G. Gerstenblith, M. D. Stern, I. Wapinski, N. Friedman, and M. Horowitz
Physiological and molecular evidence of heat acclimation memory: a lesson from thermal responses and ischemic cross-tolerance in the heart
Physiol Genomics, June 1, 2008; 34(1): 78 - 87.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
H. Schwimmer, L. Eli-Berchoer, and M. Horowitz
Acclimatory-phase specificity of gene expression during the course of heat acclimation and superimposed hypohydration in the rat hypothalamus
J Appl Physiol, June 1, 2006; 100(6): 1992 - 2003.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. GenomicsHome page
A. Maloyan, L. Eli-Berchoer, G. L. Semenza, G. Gerstenblith, M. D. Stern, and M. Horowitz
HIF-1{alpha}-targeted pathways are activated by heat acclimation and contribute to acclimation-ischemic cross-tolerance in the heart
Physiol Genomics, September 21, 2005; 23(1): 79 - 88.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. C. Ralphe, K. Bedell, J. L. Segar, and T. D. Scholz
Correlation between myocardial malate/aspartate shuttle activity and EAAT1 protein expression in hyper- and hypothyroidism
Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2521 - H2526.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
M. Horowitz, L. Eli-Berchoer, I. Wapinski, N. Friedman, and E. Kodesh
Stress-related genomic responses during the course of heat acclimation and its association with ischemic-reperfusion cross-tolerance
J Appl Physiol, October 1, 2004; 97(4): 1496 - 1507.
[Abstract] [Full Text] [PDF]

Home page
 PhysiologyHome page
M. Horowitz
Matching the Heart to Heat-Induced Circulatory Load: Heat-Acclimatory Responses
Physiology, December 1, 2003; 18(6): 215 - 221.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
J. E. Jordan, S. A. Simandle, C. D. Tulbert, D. W. Busija, and A. W. Miller
Fructose-Fed Rats Are Protected against Ischemia/Reperfusion Injury
J. Pharmacol. Exp. Ther., December 1, 2003; 307(3): 1007 - 1011.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. GenomicsHome page
M. Treinin, J. Shliar, H. Jiang, J. A. Powell-Coffman, Z. Bromberg, and M. Horowitz
HIF-1 is required for heat acclimation in the nematode Caenorhabditis elegans
Physiol Genomics, June 24, 2003; 14(1): 17 - 24.
[Abstract] [Full Text] [PDF]


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