A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans

Lauro C Vianna; Paul J Fadel; Niels H Secher; James P Fisher

doi:10.1152/ajpregu.00236.2014

A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans

Lauro C Vianna, Paul J Fadel, Niels H Secher, James P Fisher

Department of Clinical Medicine

8 Citations (Scopus)

Abstract

A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular resistance (SVR) in young healthy males, while performing either 20 s of isometric handgrip contraction at 40% maximum voluntary contraction (protocol 1; n = 9) or 20 s of low-intensity leg cycling exercise (protocol 2; n = 8, 42 ± 8 W). Exercise trials were conducted under control (no drug) conditions and following cholinergic blockade (glycopyrrolate). Under control conditions, isometric handgrip elicited an initial increase in BP (+5 ± 2 mmHg at 3 s and +3 ± 1 mmHg at 10 s, P < 0.05), while SVR dropped after 3 s (-27 ± 6% at 20 s; P < 0.05). Cholinergic blockade abolished the isometric handgrip-induced fall in SVR and, thereby, augmented the pressor response (+13 ± 3 mmHg at 10 s; P < 0.05 vs. control). In contrast, cholinergic blockade had a nonsignificant effect on changes in BP and SVR at the onset of leg cycling exercise. These findings suggest that a cholinergic mechanism is important for the BP and SVR responses at the onset of isometric handgrip exercise in humans.

Original language	English
Journal	American Journal of Physiology: Regulatory, Integrative and Comparative Physiology
Volume	308
Issue number	7
Pages (from-to)	R597-604
ISSN	0363-6119
DOIs	https://doi.org/10.1152/ajpregu.00236.2014
Publication status	Published - 1 Apr 2015

Keywords

Adaptation, Physiological
Adult
Bicycling
Blood Pressure
Blood Vessels
Cardiac Output
Cholinergic Fibers
Exercise
Glycopyrrolate
Hand
Hand Strength
Healthy Volunteers
Heart Rate
Hemodynamics
Humans
Isometric Contraction
Lower Extremity
Male
Muscarinic Antagonists
Muscle, Skeletal
Regional Blood Flow
Time Factors
Vascular Resistance
Young Adult

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10.1152/ajpregu.00236.2014

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A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans. / Vianna, Lauro C; Fadel, Paul J; Secher, Niels H et al.
In: American Journal of Physiology: Regulatory, Integrative and Comparative Physiology, Vol. 308, No. 7, 01.04.2015, p. R597-604.

Research output: Contribution to journal › Journal article › Research › peer-review

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title = "A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans",

abstract = "A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular resistance (SVR) in young healthy males, while performing either 20 s of isometric handgrip contraction at 40% maximum voluntary contraction (protocol 1; n = 9) or 20 s of low-intensity leg cycling exercise (protocol 2; n = 8, 42 ± 8 W). Exercise trials were conducted under control (no drug) conditions and following cholinergic blockade (glycopyrrolate). Under control conditions, isometric handgrip elicited an initial increase in BP (+5 ± 2 mmHg at 3 s and +3 ± 1 mmHg at 10 s, P < 0.05), while SVR dropped after 3 s (-27 ± 6% at 20 s; P < 0.05). Cholinergic blockade abolished the isometric handgrip-induced fall in SVR and, thereby, augmented the pressor response (+13 ± 3 mmHg at 10 s; P < 0.05 vs. control). In contrast, cholinergic blockade had a nonsignificant effect on changes in BP and SVR at the onset of leg cycling exercise. These findings suggest that a cholinergic mechanism is important for the BP and SVR responses at the onset of isometric handgrip exercise in humans.",

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T1 - A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans

AU - Vianna, Lauro C

AU - Fadel, Paul J

AU - Secher, Niels H

AU - Fisher, James P

PY - 2015/4/1

Y1 - 2015/4/1

N2 - A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular resistance (SVR) in young healthy males, while performing either 20 s of isometric handgrip contraction at 40% maximum voluntary contraction (protocol 1; n = 9) or 20 s of low-intensity leg cycling exercise (protocol 2; n = 8, 42 ± 8 W). Exercise trials were conducted under control (no drug) conditions and following cholinergic blockade (glycopyrrolate). Under control conditions, isometric handgrip elicited an initial increase in BP (+5 ± 2 mmHg at 3 s and +3 ± 1 mmHg at 10 s, P < 0.05), while SVR dropped after 3 s (-27 ± 6% at 20 s; P < 0.05). Cholinergic blockade abolished the isometric handgrip-induced fall in SVR and, thereby, augmented the pressor response (+13 ± 3 mmHg at 10 s; P < 0.05 vs. control). In contrast, cholinergic blockade had a nonsignificant effect on changes in BP and SVR at the onset of leg cycling exercise. These findings suggest that a cholinergic mechanism is important for the BP and SVR responses at the onset of isometric handgrip exercise in humans.

AB - A cholinergic (muscarinic) contribution to the initial circulatory response to exercise in humans remains controversial. Herein, we posit that this may be due to exercise mode with a cholinergic contribution being important during isometric handgrip exercise, where the hyperemic response of the muscle is relatively small compared with the onset of leg cycling, where a marked increase in muscle blood flow rapidly occurs as a consequence of multiple redundant mechanisms. We recorded blood pressure (BP; brachial artery), stroke volume (pulse contour analysis), cardiac output, and systemic vascular resistance (SVR) in young healthy males, while performing either 20 s of isometric handgrip contraction at 40% maximum voluntary contraction (protocol 1; n = 9) or 20 s of low-intensity leg cycling exercise (protocol 2; n = 8, 42 ± 8 W). Exercise trials were conducted under control (no drug) conditions and following cholinergic blockade (glycopyrrolate). Under control conditions, isometric handgrip elicited an initial increase in BP (+5 ± 2 mmHg at 3 s and +3 ± 1 mmHg at 10 s, P < 0.05), while SVR dropped after 3 s (-27 ± 6% at 20 s; P < 0.05). Cholinergic blockade abolished the isometric handgrip-induced fall in SVR and, thereby, augmented the pressor response (+13 ± 3 mmHg at 10 s; P < 0.05 vs. control). In contrast, cholinergic blockade had a nonsignificant effect on changes in BP and SVR at the onset of leg cycling exercise. These findings suggest that a cholinergic mechanism is important for the BP and SVR responses at the onset of isometric handgrip exercise in humans.

KW - Adaptation, Physiological

KW - Adult

KW - Bicycling

KW - Blood Pressure

KW - Blood Vessels

KW - Cardiac Output

KW - Cholinergic Fibers

KW - Exercise

KW - Glycopyrrolate

KW - Hand

KW - Hand Strength

KW - Healthy Volunteers

KW - Heart Rate

KW - Hemodynamics

KW - Humans

KW - Isometric Contraction

KW - Lower Extremity

KW - Male

KW - Muscarinic Antagonists

KW - Muscle, Skeletal

KW - Regional Blood Flow

KW - Time Factors

KW - Vascular Resistance

KW - Young Adult

U2 - 10.1152/ajpregu.00236.2014

DO - 10.1152/ajpregu.00236.2014

M3 - Journal article

C2 - 25589014

SN - 0363-6119

VL - 308

SP - R597-604

JO - American Journal of Physiology: Regulatory, Integrative and Comparative Physiology

JF - American Journal of Physiology: Regulatory, Integrative and Comparative Physiology

IS - 7

ER -

A cholinergic contribution to the circulatory responses evoked at the onset of handgrip exercise in humans

Abstract

Keywords

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