| Altered firing pattern of single-unit muscle sympathetic nerve activity during handgrip exercise in chronic heart failure. | |
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MedLine Citation:
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PMID: 19403612 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Sympathetic activation in chronic heart failure (CHF) is greatly augmented at rest but the response to exercise remains controversial. We previously demonstrated that single-unit muscle sympathetic nerve activity (MSNA) provides a more detailed description of the sympathetic response to physiological stress than multi-unit nerve recordings. The purpose of this study was to determine whether the reflex response and discharge properties of single-unit MSNA are altered during handgrip exercise (HG, 30% of maximum voluntary contraction for 3 min) in CHF patients (New York Heart Association functional class II or III, n = 16) compared with age-matched healthy control subjects (n = 13). At rest, both single-unit and multi-unit indices of sympathetic outflow were augmented in CHF compared with controls (P < 0.05). However, the percentage of cardiac intervals that contained one, two, three or four single-unit spikes were not different between the groups. Compared to the control group, HG elicited a larger increase in multi-unit total MSNA (Delta1002 +/- 50 compared with Delta636 +/- 76 units min(-1), P < 0.05) and single-unit MSNA spike incidence (Delta27 +/- 5 compared with Delta8 +/- 2 spikes (100 heart beats)(-1)), P < 0.01) in the CHF patients. More importantly, the percentage of cardiac intervals that contained two or three single-unit spikes was increased (P < 0.05) during exercise in the CHF group only (Delta8 +/- 2% and Delta5 +/- 1% for two and three spikes, respectively). These results suggest that the larger multi-unit total MSNA response observed during HG in CHF is brought about in part by an increase in the probability of multiple firing of single-unit sympathetic neurones. |
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Authors:
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Hisayoshi Murai; Masayuki Takamura; Michirou Maruyama; Manabu Nakano; Tatsunori Ikeda; Daisuke Kobayashi; Kan-ichi Otowa; Hiroshi Ootsuji; Masaki Okajima; Hiroshi Furusho; Shigeo Takata; Shuichi Kaneko |
Publication Detail:
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Type: Journal Article Date: 2009-04-29 |
Journal Detail:
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Title: The Journal of physiology Volume: 587 ISSN: 1469-7793 ISO Abbreviation: J. Physiol. (Lond.) Publication Date: 2009 Jun |
Date Detail:
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Created Date: 2009-06-01 Completed Date: 2009-08-03 Revised Date: 2013-06-02 |
Medline Journal Info:
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Nlm Unique ID: 0266262 Medline TA: J Physiol Country: England |
Other Details:
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Languages: eng Pagination: 2613-22 Citation Subset: IM |
Affiliation:
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Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan. sakurasoma1209@yahoo.co.jp |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials Aged Blood Pressure Case-Control Studies Chronic Disease Exercise* Exercise Tolerance Female Hand Strength* Heart Failure / physiopathology* Heart Rate Humans Kinetics Male Middle Aged Muscle Contraction* Muscle, Skeletal / blood supply, innervation* Peroneal Nerve / physiopathology Recruitment, Neurophysiological Reflex* Sympathetic Nervous System / physiopathology* Vasoconstriction |
| Comments/Corrections | |
Comment In:
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J Physiol. 2009 Jun 1;587(Pt 11):2421
[PMID:
19483249
]
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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