|
|
||||||||
Department of Integrative Physiology, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas 76107-2699
The role of endogenous nitric oxide (NO)
in modulating myocardial oxygen consumption
(M
O2) is unclear, in part because of systemic and coronary hemodynamic effects of blocking NO release. This
study evaluated the effect of NO on right ventricular
M
O2 under controlled hemodynamic
conditions. In 12 open-chest dogs, N
-nitro-L-arginine methyl ester
(L-NAME, 150 µg/min), a NO synthase (NOS) blocker, was
infused into the right coronary artery. Heart rate and mean aortic
pressure were constant. Right coronary blood flow and right ventricular
M
O2 were measured at normal and elevated right coronary perfusion pressures (RCP) before and after
L-NAME. To avoid effects of NO synthesis blockade on right
coronary blood flow, which might have altered right ventricular
M
O2, experiments, were conducted during
adenosine-induced maximal coronary vasodilation. L-NAME did
not affect right coronary blood flow (P = 0.51). However, L-NAME significantly increased right ventricular
M
O2 (6% at RCP 100 mmHg, and 21% at
RCP 180 mmHg). Right coronary blood flow varied with perfusion pressure
(P < 0.02), and the elevation of M
O2 produced by L-NAME
increased at higher flows (P < 0.04), consistent with
the greater shear stress-mediated release of NO. These findings
indicate that endogenous NO limits right ventricular M
O2.
open-chest dogs; N
-nitro-L-arginine methyl ester; maximal vasodilation; right coronary perfusion pressure; right coronary
blood flow
This article has been cited by other articles:
![]() |
M. Shibata, K. Qin, S. Ichioka, and A. Kamiya Vascular wall energetics in arterioles during nitric oxide-dependent and -independent vasodilation J Appl Physiol, June 1, 2006; 100(6): 1793 - 1798. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Shibata, S. Ichioka, and A. Kamiya Nitric oxide modulates oxygen consumption by arteriolar walls in rat skeletal muscle Am J Physiol Heart Circ Physiol, December 1, 2005; 289(6): H2673 - H2679. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Zong, J. D. Tune, and H. F. Downey Mechanisms of Oxygen Demand/Supply Balance in the Right Ventricle Experimental Biology and Medicine, September 1, 2005; 230(8): 507 - 519. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. R. Martinez, S. Setty, P. Zong, J. D. Tune, and H. F. Downey Nitric oxide contributes to right coronary vasodilation during systemic hypoxia Am J Physiol Heart Circ Physiol, March 1, 2005; 288(3): H1139 - H1146. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Setty, J. D. Tune, and H. F. Downey Nitric oxide contributes to oxygen demand-supply balance in hypoperfused right ventricle Cardiovasc Res, December 1, 2004; 64(3): 431 - 436. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Setty, J. D. Tune, and H. F. Downey Nitric oxide modulates right ventricular flow and oxygen consumption during norepinephrine infusion Am J Physiol Heart Circ Physiol, February 1, 2002; 282(2): H696 - H703. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |