AJP - Heart Myographs and Tissue organ baths
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 259: H849-H859, 1990;
0363-6135/90 $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 Gibbs, C. L.
Right arrow Articles by Woolley, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gibbs, C. L.
Right arrow Articles by Woolley, G.

AJP - Heart and Circulatory Physiology, Vol 259, Issue 3 849-H859, Copyright © 1990 by American Physiological Society

ARTICLES

Mechanical, energetic, and biochemical changes in long-term pressure overload of rabbit heart

C. L. Gibbs, I. R. Wendt, G. Kotsanas, I. R. Young and G. Woolley
Department of Physiology, Monash University, Clayton, Victoria, Australia.

The mechanical and energetic consequences of long-term pressure-overload (POL) hypertrophy have been investigated in rabbits and compared with sham-operated controls (SOC). Hypertrophy was induced by banding the pulmonary artery of young rabbits and examining the mechanical, biochemical, and energetic properties of the compensated heart 10-16 wk later. Experiments were undertaken on papillary muscles from the hypertrophic hearts. At 27 degrees C and a stimulus frequency of 1 Hz there was a modest depression of peak stress development but no significant changes in isometric rise times and one-half widths or in isotonic maximum velocity of shortening and power output. The inverse relationship between peak stress and cross-sectional area (CSA) was practically identical in the POL and SOC groups. Both polarographic and myothermic investigations were made on papillary muscles. Hypertrophy nearly halved basal metabolism, and in isometric contractions there was increased isometric economy due to a combination of a lower stress cost and a reduced activation heat. Hypertrophy did significantly depress the extent of shortening leading to a reduced work output per beat. In isotonic contractions the reduced work output was offset by a reduced energy output such that there was no significant change in suprabasal mechanical efficiency. Biochemical studies showed that the transition of myosin isoenzymes to the V3 form was essentially complete in the POL group, but that the SOC group was also predominantly V3 when the animals were killed. There was a significant 30% decline in the Ca2(+)-stimulated adenosinetriphosphatase activity of the sarcoplasmic reticulum. It is concluded that in long-term compensated hypertrophy of rabbit hearts there are only a few mechanical and energetic differences between control and hypertrophic muscles. The changes that can be detected appear to predominantly reflect disturbances in cellular Ca2+ regulation.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
T. Urashima, M. Zhao, R. Wagner, G. Fajardo, S. Farahani, T. Quertermous, and D. Bernstein
Molecular and physiological characterization of RV remodeling in a murine model of pulmonary stenosis
Am J Physiol Heart Circ Physiol, September 1, 2008; 295(3): H1351 - H1368.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
R. Brandes, L. S. Maier, and D. M. Bers
Regulation of Mitochondrial [NADH] by Cytosolic [Ca2+] and Work in Trabeculae From Hypertrophic and Normal Rat Hearts
Circ. Res., June 15, 1998; 82(11): 1189 - 1198.
[Abstract] [Full Text] [PDF]


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