|
|
||||||||||
|
J Am Coll Cardiol, 2000; 36:213-218 © 2000 by the American College of Cardiology Foundation |
a Department of Cardiology, University Hospital, Zürich, Switzerland
Manuscript received August 5, 1999; revised manuscript received December 30, 1999, accepted February 28, 2000.
Reprint requests and correspondence: Dr. Georg Noll, Cardiology, University Hospital, CH-8091 Zürich, Switzerland
karnog{at}usz.unizh.ch
OBJECTIVES
We sought to investigate baroreceptor regulation of sympathetic nerve activity and hemodynamics after inhibition of nitric oxide (NO) synthesis.
BACKGROUND
Both the sympathetic nervous system and endothelium-derived substances play essential roles in cardiovascular homeostasis and diseases. Little is known about their interactions.
METHODS
In healthy volunteers, we recorded muscle sympathetic nerve activity (MSA) with microneurography and central hemodynamics measured at different levels of central venous pressure induced by lower body negative pressure.
RESULTS
After administration of the NO synthase inhibitor NG-monomethyl-L-arginine (L-NMMA, 1 mg/kg/min), systolic blood pressure increased by 24 mm Hg (p = 0.01) and diastolic blood pressure by 12 mm Hg (p = 0.009), while stroke volume index (measured by thermodilution) fell from 53 to 38 mL/min/m2 (p < 0.002). Administration of L-NMMA prevented the compensatory increase of heart rate, but not MSA, to orthostatic stress. The altered response of heart rate was not due to higher blood pressure, because heart rate responses were not altered during infusion of the alpha-1-adrenoceptor agonist phenylephrine (titrated to an equal increase of systolic blood pressure). In the presence of equal systolic blood pressure and central venous pressure, we found no difference in MSA during phenylephrine and L-NMMA infusion.
CONCLUSIONS
This study demonstrates a highly specific alteration of baroreceptor regulation of heart rate but not muscle sympathetic activity after inhibition of NO synthesis in healthy volunteers. This suggests an important role of NO in reflex-mediated heart rate regulation in humans.
| ||||||||||
This article has been cited by other articles:
![]() |
N. C Shah, S. Pringle, and A. Struthers Aldosterone Blockade Over and Above ACE-Inhibitors in Patients with Coronary Artery Disease but without Heart Failure Journal of Renin-Angiotensin-Aldosterone System, March 1, 2006; 7(1): 20 - 30. [Abstract] [PDF] |
||||
![]() |
I. Sudano, L. Spieker, C. Binggeli, F. Ruschitzka, T. F. Luscher, G. Noll, and R. Corti Coffee Blunts Mental Stress-Induced Blood Pressure Increase in Habitual but Not in Nonhabitual Coffee Drinkers Hypertension, September 1, 2005; 46(3): 521 - 526. [Abstract] [Full Text] [PDF] |
||||
![]() |
A M A Shehab, R J MacFadyen, M McLaren, R Tavendale, J J F Belch, and A D Struthers Sudden unexpected death in heart failure may be preceded by short term, intraindividual increases in inflammation and in autonomic dysfunction: a pilot study Heart, November 1, 2004; 90(11): 1263 - 1268. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Sim, J. B. Dick, and A. D Struthers Statin therapy increases vascular sensitivity to angiotensin II in hypercholesterolaemic patients Journal of Renin-Angiotensin-Aldosterone System, September 1, 2004; 5(3): 109 - 113. [Abstract] [PDF] |
||||
![]() |
K. D. Monahan, I. Eskurza, and D. R. Seals Ascorbic acid increases cardiovagal baroreflex sensitivity in healthy older men Am J Physiol Heart Circ Physiol, June 1, 2004; 286(6): H2113 - H2117. [Abstract] [Full Text] [PDF] |
||||
![]() |
W S Waring, S H Adwani, O Breukels, D J Webb, and S R J Maxwell Hyperuricaemia does not impair cardiovascular function in healthy adults Heart, February 1, 2004; 90(2): 155 - 159. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Cui, R. Zhang, T. E. Wilson, S. Witkowski, C. G. Crandall, and B. D. Levine Nitric oxide synthase inhibition does not affect regulation of muscle sympathetic nerve activity during head-up tilt Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H2105 - H2110. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. A. Ortiz and J. L. Garvin Cardiovascular and renal control in NOS-deficient mouse models Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2003; 284(3): R628 - R638. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Andreas, C. Bingeli, P. Mohacsi, T. F. Luscher, and G. Noll Nasal Oxygen and Muscle Sympathetic Nerve Activity in Heart Failure Chest, February 1, 2003; 123(2): 366 - 371. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Corti, C. Binggeli, I. Sudano, L. Spieker, E. Hanseler, F. Ruschitzka, W. F. Chaplin, T. F. Luscher, and G. Noll Coffee Acutely Increases Sympathetic Nerve Activity and Blood Pressure Independently of Caffeine Content: Role of Habitual Versus Nonhabitual Drinking Circulation, December 3, 2002; 106(23): 2935 - 2940. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. H. Cooke, R. Zhang, J. H. Zuckerman, J. Cui, T. E. Wilson, C. G. Crandall, and B. D. Levine Does nitric oxide buffer arterial blood pressure variability in humans? J Appl Physiol, October 1, 2002; 93(4): 1466 - 1470. [Abstract] [Full Text] [PDF] |
||||
![]() |
D Patterson, J B C Dick, and A D Struthers Intensive statin treatment improves baroreflex sensitivity: another cardioprotective mechanism for statins? Heart, October 1, 2002; 88(4): 415 - 416. [Full Text] [PDF] |
||||
![]() |
A. D Struthers Review: Aldosterone-induced vasculopathy: a new reversible cause of cardiac death Journal of Renin-Angiotensin-Aldosterone System, December 1, 2001; 2(4): 211 - 214. [PDF] |
||||
![]() |
K. L. Ryan, M. R. Tehrany, and J. R. Jauchem Nitric oxide does not contribute to the hypotension of heatstroke J Appl Physiol, March 1, 2001; 90(3): 961 - 970. [Abstract] [Full Text] [PDF] |
||||
| HOME | SUBSCRIPTIONS | CURRENT ISSUE | PAST ISSUES | CARDIOSOURCE | SEARCH | HELP | FEEDBACK |