| Spontaneous Bursts of Muscle Sympathetic Nerve Activity Decrease Leg Vascular Conductance in Resting Humans. | |
| | |
MedLine Citation:
|
PMID: 23292718 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
Previous studies in humans attempting to assess sympathetic vascular transduction have related large reflex-mediated increases in muscle sympathetic nerve activity (MSNA) to associated changes in limb vascular resistance. However, such procedures do not provide insight into the ability of MSNA to dynamically control vascular tone on a beat-by-beat basis. Thus, we examined the influence of spontaneous MSNA bursts on leg vascular conductance (LVC) and how variations in MSNA burst pattern (single vs. multiple bursts) and burst size may affect the magnitude of the LVC response. In 11 young men, arterial blood pressure, common femoral artery blood flow, and MSNA were continuously recorded during 20 minutes of supine rest. Signal averaging was used to characterize percent changes in LVC for 15 cardiac cycles following heartbeats associated with and without MSNA bursts. LVC significantly decreased following MSNA bursts, reaching a nadir during the 6th cardiac cycle (single bursts: -2.9±1.1%; multiple bursts -11.0±1.4%; both P<0.001). Individual MSNA burst amplitudes and the total amplitude of consecutive bursts were related to the magnitude of peak decreases in LVC. In contrast, cardiac cycles without MSNA bursts were associated with a significant increase in LVC (+3.1±0.5%; P<0.001). Total vascular conductance decreased in parallel with LVC also reaching a nadir around the peak rise in arterial blood pressure following an MSNA burst. Collectively, these data are the first to assess beat-by-beat sympathetic vascular transduction in resting humans, demonstrating robust and dynamic decreases in LVC following MSNA bursts; an effect that was absent for cardiac cycles without MSNA bursts. |
| | |
Authors:
|
Seth T Fairfax; Jaume Padilla; Lauro C Vianna; Michael J Davis; Paul J Fadel |
Related Documents
:
|
2540928 - Aortic cyclic amp levels in hypertensive rats. 3591308 - Renovascular hypertension in a child with rett's syndrome. 6625638 - Expiration induced femoral flow in neonatal coarctation of aorta. 1685228 - Effect of intermittent blood pressure elevation on the growth of experimental saccular ... 11235498 - Best practices for the prevention and treatment of venous leg ulcers. 6489308 - Observations on structure and function of the equine mitral valve. |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2013-1-4 |
Journal Detail:
|
Title: American journal of physiology. Heart and circulatory physiology Volume: - ISSN: 1522-1539 ISO Abbreviation: Am. J. Physiol. Heart Circ. Physiol. Publication Date: 2013 Jan |
Date Detail:
|
Created Date: 2013-1-7 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 100901228 Medline TA: Am J Physiol Heart Circ Physiol Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Affiliation:
|
1University of Missouri. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Magnetic Resonance Imaging and Spectroscopy of the Murine Cardiovascular System.
Next Document: In vivo testing of a bioabsorbable magnesium alloy serving as total ossicular replacement prostheses...