Acupuncture effects on autonomic responses to cold pressor and handgrip exercise in healthy humans

Previous data support the idea of heightened sympathetically mediated cardiovascular reactivity in males. However, definitive conclusions cannot be made because of inconsistent reports, possibly stemming from imprecise measurement of sympathetic activity and/or failure to equate the stress stimuli between genders. The present study tested the hypothesis that males exhibit heightened sympathetic reactivity that is associated with heightened cardiovascular and plasma catecholamine responses. In 37 healthy adults (20 males, 17 females: age = 20-42 yr), direct recordings of skeletal muscle sympathetic nerve activity (MSNA), plasma catecholamines, heart rate, blood pressure, and perceived stress were measured before and during three laboratory stressors (isometric handgrip, cold pressor, and mental arithmetic). MSNA, catecholamine, and cardiovascular reactivity (defined as change from rest) were not consistently different between genders. For the isometric handgrip, when expressed as absolute unit changes, males had larger MSNA responses (P < 0.01), which were partially explained by greater contraction force; they did not differ in terms of percent change from baseline or in perceived stress. The responses to the cold pressor and mental arithmetic tasks were similar between genders. These findings indicate that stress-evoked vasoconstrictor neural excitation and the associated increases in blood pressure are not consistently influenced by gender.

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Naloxone augments muscle sympathetic nerve activity during isometric exercise in humans

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1991.260.3.e379 ◽

1991 ◽

Vol 260 (3) ◽

pp. E379-E388 ◽

Cited By ~ 3

Author(s):

P. A. Farrell ◽

T. J. Ebert ◽

J. P. Kampine

Keyword(s):

Sodium Nitroprusside ◽

Sympathetic Nerve ◽

Sympathetic Nerve Activity ◽

Muscle Sympathetic Nerve Activity ◽

Cold Pressor Test ◽

Cold Pressor ◽

Handgrip Exercise ◽

Isometric Handgrip ◽

Nerve Activity ◽

Cardiovascular Variables

The influence of an endogenous opioid peptide (EOP) antagonist (naloxone, 1.2 mg iv bolus) on muscle sympathetic nerve activity (MSNA, microneurography) was studied on 19 young male and female volunteers. Isometric handgrip, cold pressor test, and acute baroreceptor unloading with sodium nitroprusside (autonomic stresses) were carried out under two conditions, one group (n = 11) before (control responses) and after naloxone and another group (n = 8) before and after placebo saline. Monitored cardiovascular variables included heart rate, central venous pressure (jugular vein catheter), arterial blood pressure (radial artery catheter), circulating catecholamines, and forearm blood flow. At rest, cardiovascular variables and MSNA were not affected by either naloxone or saline. MSNA (total activity = burst frequency x burst amplitude/100 cardiac cycles) increased during isometric handgrip to a greater extent (30 +/- 6 vs. 16 +/- 5 arbitrary units) after naloxone compared with control trials (P less than 0.05). After naloxone, arterial systolic and diastolic blood pressures were higher during handgrip exercise. These augmented arterial pressures and MSNA responses were not evident during either the cold pressor test or the sodium nitroprusside stress. These data suggest that isometric muscle contraction elicits a sympathetic neural response that may be modified by EOP. This interaction is not evident during two other stresses, when sympathetic responses are equal to or greater than those provoked by isometric handgrip exercise.

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Determinants of myocardial blood flow response to cold pressor testing and pharmacologic vasodilation in healthy humans

European Journal of Nuclear Medicine and Molecular Imaging ◽

10.1007/s00259-006-0193-4 ◽

2006 ◽

Vol 34 (1) ◽

pp. 20-27 ◽

Cited By ~ 51

Author(s):

John O. Prior ◽

Thomas H. Schindler ◽

Alvaro D. Facta ◽

Miguel Hernandez-Pampaloni ◽

Roxana Campisi ◽

...

Keyword(s):

Blood Flow ◽

Myocardial Blood Flow ◽

Cold Pressor ◽

Blood Flow Response ◽

Healthy Humans ◽

Flow Response ◽

Cold Pressor Testing

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Cognitive Modulation of Psychophysical, Respiratory and Autonomic Responses to Cold Pressor Test

PLoS ONE ◽

10.1371/journal.pone.0075023 ◽

2013 ◽

Vol 8 (10) ◽

pp. e75023 ◽

Cited By ~ 15

Author(s):

Enrica L. Santarcangelo ◽

Giulia Paoletti ◽

Iacopo Chiavacci ◽

Carlo Palombo ◽

Giancarlo Carli ◽

...

Keyword(s):

Cold Pressor Test ◽

Cold Pressor ◽

Autonomic Responses ◽

Pressor Test ◽

Cognitive Modulation

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Increased cardiovascular reactivity to the cold pressor test is not associated with increased reactivity to isometric handgrip exercise

European Journal of Applied Physiology ◽

10.1007/s00421-009-1299-8 ◽

2009 ◽

Vol 108 (4) ◽

pp. 837-843 ◽

Cited By ~ 10

Author(s):

Kayo Moriyama ◽

Hirotoshi Ifuku

Keyword(s):

Cardiovascular Reactivity ◽

Cold Pressor Test ◽

Cold Pressor ◽

Handgrip Exercise ◽

Isometric Handgrip ◽

Pressor Test ◽

Isometric Handgrip Exercise

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Sympathetic neural reactivity to stress does not increase with age in healthy humans

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1994.267.1.h344 ◽

1994 ◽

Vol 267 (1) ◽

pp. H344-H353 ◽

Cited By ~ 44

Author(s):

A. V. Ng ◽

R. Callister ◽

D. G. Johnson ◽

D. R. Seals

Keyword(s):

Heart Rate ◽

Nervous System ◽

Arterial Pressure ◽

Cold Pressor Test ◽

Cold Pressor ◽

Handgrip Exercise ◽

Isometric Handgrip ◽

Isometric Handgrip Exercise ◽

Sympathetic Nervous ◽

Older Subjects

Sympathetic nervous system reactivity to stress is though to increase with age in humans. We tested this hypothesis by recording postganglionic sympathetic nerve activity to skeletal muscle (MSNA) (peroneal microneurography) and by measuring plasma norepinephrine concentrations (PNE), heart rate, and arterial pressure before (prestress control) and during cognitive challenge (mental arithmetic and colored word test), thermal stress (i.e., the cold pressor test), and exhaustive isometric handgrip exercise (40% of maximum voluntary force)/postexercise ischemia in 15 older (60-74 yr, mean +/- SE = 64 +/- 1) and 15 young (19–30 yr, mean +/- SE = 25 +/- 1) healthy men and women (8 males, 7 females each). The initial prestress control level of MSNA was higher in the older subjects (P < 0.01 vs. young), but there were no significant differences for PNE, heart rate, or arterial pressure. The MSNA and PNE responses to mental stress were small and not different in the two groups. MSNA and PNE increased markedly in response to the cold pressor test and isometric handgrip exercise/post exercise ischemia in both groups. The absolute unit increases in MSNA were similar in the two groups, but the relative (percentage) increases were actually smaller in the older subjects (P < 0.05 vs. young) due to their elevated baseline levels. The stress-evoked increases in arterial pressure were similar in the groups, but the older subjects tended to demonstrate smaller increases in heart rate. In general, no gender differences were noted in either age group. These findings fail to support the long-held concept that stress-induced sympathetic nervous system stimulation becomes exaggerated with age. Thus, sympathetic neural hyperreactivity does not appear to be a fundamental property of the aging process in humans.

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