(Hypertension. 2000;36:264.)
© 2000 American Heart Association, Inc.
Scientific Contributions |
Nitric Oxide and Cardiac Autonomic Control in Humans
From the Departments of Cardiovascular Medicine (S.C., J.C.V., J.N.T.) and Physiology (J.F., H.F.R., J.H.C.), University of Birmingham, UK.
Correspondence to Dr S. Chowdhary, Department of Cardiovascular Medicine, Queen Elizabeth Hospital, Birmingham B15 2TH, UK. E-mail S.Chowdhary{at}bham.ac.uk
Abstract—Cardiac
autonomic control is of prognostic significance in cardiac disease, yet
the control mechanisms of this system remain poorly defined. Animal
data suggest that nitric oxide (NO) modulates cardiac autonomic
control. We investigated the influence of NO on the baroreflex control
of heart rate in healthy human subjects. In 26 healthy male volunteers
(mean age, 23±5 years), we measured heart rate variability and
baroreflex sensitivity during inhibition of endogenous NO
production with
NG-monomethyl-L-arginine
(L-NMMA) (3 mg/kg per hour) and during exogenous NO donation with
sodium nitroprusside (1 to 3 mg/h). Increases from baseline (
) in
high-frequency (HF) indexes of heart rate variability were smaller with
L-NMMA in comparison to an equipressor dose of the control
vasoconstrictor phenylephrine (12 to 42 µg/kg per hour):
root mean square of successive RR interval differences
(RMSSD)=23±32 versus 51±48 ms (P<0.002);
percentage of successive RR interval differences >50 ms
(pNN50)=5±15% versus 14±12% (P<0.05); and HF
normalized power=-2±7 versus 9±8 normalized units
(P<0.01), respectively. Relative preservation of these
indexes was observed during unloading of the baroreflex with sodium
nitroprusside compared with a matched fall in blood pressure produced
by a control vasodilator, hydralazine (9 to 18 mg/h):
RMSSD=-8±8 versus -24±15 ms (P<0.001);
pNN50=-6±11% versus -15±19% (P<0.01); HF
normalized power=-7±13 versus -13±11 normalized units
(P<0.05), respectively. The change in cross-spectral
-index calculated as the square root of the ratio of RR interval
power to systolic spectral power in the HF band (although not
-index calculated in the same way for the low-frequency bands or
baroreflex sensitivity assessed by the phenylephrine bolus
method) was attenuated with L-NMMA compared with
phenylephrine (=4±8 versus 14±15 ms/mm Hg,
respectively; P<0.02) and with sodium nitroprusside
compared with hydralazine (=-7±6 and -9±7 ms/mm Hg,
respectively; P<0.05). In conclusion, these data
demonstrate that NO augments cardiac vagal control in humans.
Key Words: nitric oxide • heart rate • baroreceptors • autonomic nervous system • blood pressure
This article has been cited by other articles:
 |
|
 |
|
  S. Cook, M. Togni, M. C. Schaub, P. Wenaweser, and O. M. Hess High heart rate: a cardiovascular risk factor? Eur. Heart J., October 2, 2006; 27(20): 2387 - 2393. [Full Text] [PDF]
|
|
|
|
 |
|
 F. Iellamo, M. Tesauro, S. Rizza, S. Aquilani, C. Cardillo, M. Iantorno, M. Turriziani, and R. Lauro Concomitant Impairment in Endothelial Function and Neural Cardiovascular Regulation in Offspring of Type 2 Diabetic Subjects Hypertension, September 1, 2006; 48(3): 418 - 423. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H C Routledge, S Manney, R M Harrison, J G Ayres, and J N Townend Effect of inhaled sulphur dioxide and carbon particles on heart rate variability and markers of inflammation and coagulation in human subjects Heart, February 1, 2006; 92(2): 220 - 227. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M.-C. Irigoyen, J. Paulini, L. J. F. Flores, K. Flues, M. Bertagnolli, E. Dias Moreira, F. Consolim-Colombo, A. Bello-Klein, and K. De Angelis Exercise Training Improves Baroreflex Sensitivity Associated With Oxidative Stress Reduction in Ovariectomized Rats Hypertension, October 1, 2005; 46(4): 998 - 1003. [Abstract] [Full Text] [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]
|
|
|
|
|
|
S. Chowdhary, A. M. Marsh, J. H. Coote, and J. N. Townend Nitric Oxide and Cardiac Muscarinic Control in Humans Hypertension, May 1, 2004; 43(5): 1023 - 1028. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Fletcher, A. N. Buch, H. C. Routledge, S. Chowdhary, J. H. Coote, and J. N. Townend Acute aldosterone antagonism improves cardiac vagal control in humans J. Am. Coll. Cardiol., April 7, 2004; 43(7): 1270 - 1275. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Farias III, K. Jackson, M. Johnson, and J. L. Caffrey Cardiac enkephalins attenuate vagal bradycardia: interactions with NOS-1-cGMP systems in canine sinoatrial node Am J Physiol Heart Circ Physiol, November 1, 2003; 285(5): H2001 - H2012. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. D. Lipman, J. K. Salisbury, and J. A. Taylor Spontaneous Indices Are Inconsistent With Arterial Baroreflex Gain Hypertension, October 1, 2003; 42(4): 481 - 487. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Pitt, C. T Stier Jr, and S. Rajagopalan Mineralocorticoid receptor blockade: new insights into the mechanism of action in patients with cardiovascular disease Journal of Renin-Angiotensin-Aldosterone System, September 1, 2003; 4(3): 164 - 168. [Abstract] [PDF]
|
|
|
|
|
|
G. Piccirillo, M. Nocco, A. Moise, M. Lionetti, C. Naso, S. di Carlo, and V. Marigliano Influence of Vitamin C on Baroreflex Sensitivity in Chronic Heart Failure Hypertension, June 1, 2003; 41(6): 1240 - 1245. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Pitt Aldosterone Blockade in Patients With Acute Myocardial Infarction Circulation, May 27, 2003; 107(20): 2525 - 2527. [Full Text] [PDF]
|
|
|
|
|
|
P. J. Fadel, M. Stromstad, D. W. Wray, S. A. Smith, P. B. Raven, and N. H. Secher New insights into differential baroreflex control of heart rate in humans Am J Physiol Heart Circ Physiol, February 1, 2003; 284(2): H735 - H743. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. R. Claxton and M. W. Brands Nitric Oxide Opposes Glucose-Induced Hypertension by Suppressing Sympathetic Activity Hypertension, February 1, 2003; 41(2): 274 - 278. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Gori, J. S. Floras, and J. D. Parker Effects of nitroglycerin treatment on baroreflex sensitivity andshort-term heart rate variability in humans J. Am. Coll. Cardiol., December 4, 2002; 40(11): 2000 - 2005. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Chowdhary, S. L. Nuttall, J. H. Coote, and J. N. Townend L-Arginine Augments Cardiac Vagal Control in Healthy Human Subjects Hypertension, January 1, 2002; 39(1): 51 - 56. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. D. Katz, D. V. Parums, B. G. Phillips, M. Kato, C. A. Pesek, V. K. Somers, M. Winnicki, D. Davison, and K. Narkiewicz Sympathetic Activation by Sildenafil Response Circulation, November 27, 2001; 104 (22): e119 - e120. [Full Text] [PDF]
|
|
|
|
 |
|
 J. D. Lefrandt, M. C. Mulder, E. Bosma, A. J. Smit, and K. Hoogenberg Relation Between Autonomic Function and Blood Glucose in the Nondiabetic Range Diabetes Care, November 1, 2001; 24(11): 2017 - 2017. [Full Text] [PDF]
|
|