Journal article
Modulation of Baroreceptor Activity by Nitric Oxide and S-Nitrosocysteine
Circulation research, Vol.76(3), pp.426-433
03/1995
DOI: 10.1161/01.RES.76.3.426
PMID: 7859388
Abstract
The goal of this study was to determine whether nitric oxide (NO) and the NO donor, S-nitrosocysteine (cysNO), modulate the activity of carotid sinus baroreceptors. Baroreceptor activity was recorded from the vascularly isolated carotid sinus in anesthetized rabbits. Baroreceptor activity decreased in a dose-dependent manner after injection of either NO or cysNO as constant pressure was maintained, and activity recovered spontaneously over time, within seconds to minutes. The baroreceptor pressure-activity relation was shifted significantly to the right by cysNO, with a profound suppression of activity at high pressure. Baroreceptor activity at 160 mm Hg averaged 76 plus minus 8%, 60 plus minus 6%, and 36 plus minus 5% of the control maximum during exposure to 10 4, 2 to 3 times 10 4, and 10 3 mol/L cysNO, respectively. The inhibition of activity by the L and D isomers of cysNO was equivalent and was blocked by reduced hemoglobin, suggesting that the effect was mediated by NO. The suppression of baroreceptor activity by cysNO was not related to vascular relaxation as measured by videomicrometer. Inhibition of soluble guanylate cyclase with methylene blue or 6-anilinoquinoline-5,8-quinone (LY83583, 10 5 mol/L) did not attenuate and dibutyryl cGMP (10 3 mol/L) did not mimic the suppression of baroreceptor activity by cysNO, suggesting a cGMP-independent mechanism. Activation of endogenous NO formation with thimerosal (10 5 to 10 4 mol/L) reduced maximum baroreceptor activity in five of eight experiments to 59 plus minus 7% of the control maximum. The NO synthase inhibitor nitro-L-arginine methyl ester (L-NAME, 10 4 mol/L) by itself failed to influence baroreceptor activity but prevented thimerosal-induced suppression of activity. Addition of L-arginine (10 3 mol/L) after L-NAME restored the inhibitory influence of thimerosal. The results indicate that NO and cysNO suppress baroreceptor activity through a mechanism independent of guanylate cyclase activation and vascular relaxation and that endogenous NO released by chemical activation suppresses baroreceptor activity.(Circ Res. 1995;76:426-433.)
Details
- Title: Subtitle
- Modulation of Baroreceptor Activity by Nitric Oxide and S-Nitrosocysteine
- Creators
- Tadashi Matsuda - Received September 6, 1994; accepted November 21, 1994. From the Cardiovascular Center and the Departments of Internal Medicine, Physiology and Biophysics, Anesthesiology, and Pharmacology, University of Iowa, and the Department of Veterans Affairs Medical Center, Iowa City, Iowa. Correspondence to Mark W. Chapleau, PhD, Assistant Professor, Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, IA 52242James N BatesStephen J LewisFrancois M AbboudMark W Chapleau
- Resource Type
- Journal article
- Publication Details
- Circulation research, Vol.76(3), pp.426-433
- Publisher
- American Heart Association, Inc
- DOI
- 10.1161/01.RES.76.3.426
- PMID
- 7859388
- ISSN
- 0009-7330
- eISSN
- 1524-4571
- Language
- English
- Date published
- 03/1995
- Academic Unit
- Molecular Physiology and Biophysics; Cardiovascular Medicine; Anesthesia; Fraternal Order of Eagles Diabetes Research Center; Internal Medicine
- Record Identifier
- 9984007180602771
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