Document Detail

Increased muscle sympathetic nerve activity acutely alters conduit artery shear rate patterns.
MedLine Citation:
PMID:  20154260     Owner:  NLM     Status:  MEDLINE    
Escalating evidence indicates that disturbed flow patterns, characterized by the presence of retrograde and oscillatory shear stress, induce a proatherogenic endothelial cell phenotype; however, the mechanisms underlying oscillatory shear profiles in peripheral conduit arteries are not fully understood. We tested the hypothesis that acute elevations in muscle sympathetic nerve activity (MSNA) are accompanied by increases in conduit artery retrograde and oscillatory shear. Fourteen healthy men (25 +/- 1 yr) performed three sympathoexcitatory maneuvers: graded lower body negative pressure (LBNP) from 0 to -40 Torr, cold pressor test (CPT), and 35% maximal voluntary contraction handgrip followed by postexercise ischemia (PEI). MSNA (microneurography; peroneal nerve), arterial blood pressure (finger photoplethysmography), and brachial artery velocity and diameter (duplex Doppler ultrasound) in the contralateral arm were recorded continuously. All maneuvers elicited significant increases in MSNA total activity from baseline (P < 0.05). Retrograde shear (-3.96 +/- 1.2 baseline vs. -8.15 +/- 1.8 s(-1), -40 LBNP, P < 0.05) and oscillatory shear index (0.09 +/- 0.02 baseline vs. 0.20 +/- 0.02 arbitrary units, -40 LBNP, P < 0.05) were progressively augmented during graded LBNP. In contrast, during CPT and PEI, in which MSNA and blood pressure were concomitantly increased (P < 0.05), minimal or no changes in retrograde and oscillatory shear were noted. These data suggest that acute elevations in MSNA are associated with an increase in conduit artery retrograde and oscillatory shear, an effect that may be influenced by concurrent increases in arterial blood pressure. Future studies should examine the complex interaction between MSNA, arterial blood pressure, and other potential modulatory factors of shear rate patterns.
Jaume Padilla; Colin N Young; Grant H Simmons; Shekhar H Deo; Sean C Newcomer; John P Sullivan; M Harold Laughlin; Paul J Fadel
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural     Date:  2010-02-12
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  298     ISSN:  1522-1539     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2010 Apr 
Date Detail:
Created Date:  2010-03-22     Completed Date:  2010-04-12     Revised Date:  2014-09-18    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H1128-35     Citation Subset:  IM    
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MeSH Terms
Blood Flow Velocity / physiology
Blood Pressure / physiology
Brachial Artery / physiology*
Cold Temperature
Endothelium, Vascular / innervation,  physiology
Hand Strength / physiology
Lower Body Negative Pressure
Muscle, Smooth, Vascular / innervation*,  physiology*
Regional Blood Flow / physiology*
Sympathetic Nervous System / physiology
Grant Support
Comment In:
Am J Physiol Heart Circ Physiol. 2010 Apr;298(4):H1126-7   [PMID:  20190101 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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