|
|
||||||||
NEUROHUMORAL CONTROL OF CARDIOVASCULAR FUNCTION
1Tulane Hypertension and Renal Center of Excellence and Department of Physiology, Tulane University Health Sciences Center, New Orleans, Louisiana; and 2Michael E. DeBakey, Department of Veterans Affairs Medical Center and Departments of Medicine and Pharmacology, Baylor College of Medicine, Houston, Texas
Submitted 20 February 2004 ; accepted in final form 2 November 2004
Vascular tissues express heme oxygenase (HO), which metabolizes heme to form carbon monoxide (CO). Heme-derived CO inhibits nitric oxide synthase and promotes endothelium-dependent vasoconstriction. After 4 wk of high-salt diet, Dahl salt-sensitive (Dahl-S) rats display hypertension, increased vascular HO-1 expression, and attenuated vasodilator responses to ACh that can be completely restored by acute treatment with an inhibitor of HO. In this study, we examined the temporal development of HO-mediated endothelial dysfunction in isolated pressurized first-order gracilis muscle arterioles, identified the HO product responsible, and studied the blood pressure effects of HO inhibition in Dahl-S rats on a high-salt diet. Male Dahl-S rats (56 wk) were placed on high-salt (8% NaCl) or low-salt (0.3% NaCl) diets for 04 wk. Blood pressure increased gradually, and responses to an endothelium-dependent vasodilator, ACh, decreased gradually with the length of high-salt diet. Flow-induced dilation was abolished in hypertensive Dahl-S rats. Acute in vitro pretreatment with an inhibitor of HO, chromium mesoporphyrin (CrMP), restored endothelium-dependent vasodilation and abolished the differences between groups. The HO product CO prevented the restoration of endothelium-dependent dilation by CrMP. Furthermore, administration of an HO inhibitor lowered blood pressure in Dahl-S rats with salt-induced hypertension but did not do so in low-salt control rats. These results suggest that hypertension and HO-mediated endothelial dysfunction develop gradually and simultaneously in Dahl-S rats on high-salt diets. They also suggest that HO-derived CO underlies the impaired endothelial dysfunction and contributes to hypertension in Dahl-S rats on high-salt diets.
salt-sensitive hypertension; vascular tone; arterioles; blood pressure
This article has been cited by other articles:
![]() |
N. G. Abraham, J. Cao, D. Sacerdoti, X. Li, and G. Drummond Heme oxygenase: the key to renal function regulation Am J Physiol Renal Physiol, November 1, 2009; 297(5): F1137 - F1152. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. Mingone, M. Ahmad, S. A. Gupte, J. L. Chow, and M. S. Wolin Heme oxygenase-1 induction depletes heme and attenuates pulmonary artery relaxation and guanylate cyclase activation by nitric oxide Am J Physiol Heart Circ Physiol, March 1, 2008; 294(3): H1244 - H1250. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Nath, L. V. d'Uscio, J. P. Juncos, A. J. Croatt, M. C. Manriquez, S. T. Pittock, and Z. S. Katusic An analysis of the DOCA-salt model of hypertension in HO-1-/- mice and the Gunn rat Am J Physiol Heart Circ Physiol, July 1, 2007; 293(1): H333 - H342. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Hill-Kapturczak and A. Agarwal Haem oxygenase-1--a culprit in vascular and renal damage? Nephrol. Dial. Transplant., June 1, 2007; 22(6): 1495 - 1499. [Full Text] [PDF] |
||||
![]() |
S. W. Ryter, J. Alam, and A. M. K. Choi Heme Oxygenase-1/Carbon Monoxide: From Basic Science to Therapeutic Applications Physiol Rev, April 1, 2006; 86(2): 583 - 650. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. K. Johnson, R. A. Johnson, W. Durante, K. E. Jackson, B. K. Stevenson, and K. J. Peyton Metabolic syndrome increases endogenous carbon monoxide production to promote hypertension and endothelial dysfunction in obese Zucker rats Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R601 - R608. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Morita Heme Oxygenase and Atherosclerosis Arterioscler Thromb Vasc Biol, September 1, 2005; 25(9): 1786 - 1795. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |