| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
urbil, andDepartments of Medicine and Radiology and the Center for Magnetic Resonance Research, University of Minnesota Health Sciences Center, Minneapolis, Minnesota 55417
This study compared the transmural distribution
of high-energy phosphate (HEP) depletion during oxidative stress
induced by pacing- and dobutamine-induced tachycardia in myocardium
perfused by a flow-limiting coronary stenosis. Myocardial blood flow
(MBF) was measured with radioactive microspheres. Creatine phosphate (CrP), ATP, and Pi were measured
with transmurally localized 31P
NMR spectroscopy. In normal dogs a hydraulic occluder was used to
produce a left anterior descending coronary artery stenosis, which
maintained constant flow measured with a Doppler probe. Tachycardia was
induced by rapid pacing (200 beats/min,
n = 11) or by dobutamine infusion (20 µg · kg
1 · min1 iv,
n = 13) to produce a similar heart
rate. In the presence of stenosis, pacing and dobutamine caused similar
reductions of subendocardial (Endo)-to-subepicardial (Epi) MBF ratios
(0.66 ± 0.06 vs. 0.63 ± 0.08, respectively). Stenosis plus
pacing caused a decrease of the CrP-to-ATP ratio (CrP/ATP) in Endo from
2.00 ± 0.07 to 1.65 ± 0.08 (P < 0.05) with no significant
change in Epi. Stenosis plus dobutamine caused HEP changes across the
left ventricular wall, which were most marked in the outer myocardial layer (Epi CrP/ATP decreased from 2.33 ± 0.11 to 1.67 ± 0.12; Endo CrP/ATP decreased from 1.99 ± 0.09 to
1.64 ± 0.12). Thus HEP changes during oxidative stress that are
produced by pacing parallel the pattern of hypoperfusion and are most
severe in the subendocardium. In contrast, in response to inotropic
stimulation, the transmural metabolic changes did not correspond to the
pattern of the hypoperfusion.
myocardial blood flow; ischemia; phosphates; phosphorus-31 nuclear magnetic resonance spectroscopy; dobutamine
This article has been cited by other articles:
|
|
 |
|
  F. Wu, E. Y. Zhang, J. Zhang, R. J. Bache, and D. A. Beard Phosphate metabolite concentrations and ATP hydrolysis potential in normal and ischaemic hearts J. Physiol., September 1, 2008; 586(17): 4193 - 4208. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. N. Jameel, X. Wang, M. H. J. Eijgelshoven, A. Mansoor, and J. Zhang Transmural distribution of metabolic abnormalities and glycolytic activity during dobutamine-induced demand ischemia Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2680 - H2686. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Q. Hu, X. Wang, J. Lee, A. Mansoor, J. Liu, L. Zeng, C. Swingen, G. Zhang, J. Feygin, K. Ochiai, et al. Profound bioenergetic abnormalities in peri-infarct myocardial regions Am J Physiol Heart Circ Physiol, August 1, 2006; 291(2): H648 - H657. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. V. Naumova, R. G. Weiss, and V. P. Chacko Regulation of murine myocardial energy metabolism during adrenergic stress studied by in vivo 31P NMR spectroscopy Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H1976 - H1979. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Vendelin, P. H. M. Bovendeerd, J. Engelbrecht, and T. Arts Optimizing ventricular fibers: uniform strain or stress, but not ATP consumption, leads to high efficiency Am J Physiol Heart Circ Physiol, September 1, 2002; 283(3): H1072 - H1081. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
