scholarly journals Lack of effect of ovarian cycle and oral contraceptives on baroreceptor and nonbaroreceptor control of sympathetic nerve activity in healthy women

2012 ◽  
Vol 302 (12) ◽  
pp. H2560-H2566 ◽  
Author(s):  
Holly R. Middlekauff ◽  
Jeanie Park ◽  
Jeffrey A. Gornbein
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Total Activity ◽  
Ovarian Cycle ◽  
Nerve Activity ◽  
Oral Contraceptive Pills ◽  
Contraceptive Pills ◽  
Slope Change

Endogenous and exogenous female hormones regulate sympathetic nerve activity (SNA) in animal models, but their impact in humans is controversial. The purpose of this study is to investigate the effects of the ovarian cycle and oral contraceptive pills (OCPs) on SNA. We hypothesized that the effects of endogenous hormones were baroreflex (BR)-mediated and that these cyclical changes in BR control were blunted by OCPs. Furthermore, we hypothesized that the nocturnal fall in blood pressure (BP) (“dipping”), which is sympathetically mediated, also varied with the ovarian cycle. In 23 healthy females (13 OCP users, 10 age-matched, no OCPs), SNA was recorded (microneurography) at rest, during BR activation/deactivation, and cold pressor test (CPT) during low and high hormonal phases. Furthermore, 24-h BP monitoring was performed during low and high hormonal phases. SNA was lower during the low vs. high hormone phase in non-OCP users (17.3 ± 2.4 vs. 25.4 ± 3.2 bursts/min, P < 0.001) but was not different between phases in OCP users [15.5 ± 1.7 vs. 16.6 ± 2.0 bursts/min, P = not significant (NS)]. BR control of SNA was not different during the hormone phases in either group [SNA (total activity/min) mean slope %change from baseline, no OCP users, low vs. high hormone phase 35.4 ± 6.2 vs. 29.6 ± 3.4%, P = NS and OCP users, low vs. high hormone phase 35.7 ± 3.9 vs. 33.5 ± 3.5%, P = NS]. SNA activation during CPT was not impacted by hormonal phase or OCP use. Finally, nondipping was not different between OCP users and nonusers, although there was a trend for nondipping to occur more frequently in the OCP users. SNA varies during the ovarian cycle in women in the absence of OCPs. This modulation cannot be attributed to cyclical changes in the BR sensitivity.

scholarly journals Effects of the cold pressor test on muscle sympathetic nerve activity in humans.

Hypertension ◽  
1987 ◽  
Vol 9 (5) ◽  
pp. 429-436 ◽  
Author(s):  
R G Victor ◽  
W N Leimbach ◽  
D R Seals ◽  
B G Wallin ◽  
A L Mark
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Muscle Sympathetic Nerve Activity ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Nerve Activity ◽  
Pressor Test

scholarly journals Microneurography and sympathetic nerve activity: a decade-by-decade journey across 50 years

2019 ◽  
Vol 121 (4) ◽  
pp. 1183-1194 ◽  
Author(s):  
Jason R. Carter
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Lower Body Negative Pressure ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Isometric Handgrip ◽  
Nerve Activity ◽  
The Past ◽  
Thomson Reuters ◽  
The Impact

The technique of microneurography has advanced the field of neuroscience for the past 50 years. While there have been a number of reviews on microneurography, this paper takes an objective approach to exploring the impact of microneurography studies. Briefly, Web of Science (Thomson Reuters) was used to identify the highest citation articles over the past 50 years, and key findings are presented in a decade-by-decade highlight. This includes the establishment of microneurography in the 1960s, the acceleration of the technique by Gunnar Wallin in the 1970s, the international collaborations of the 1980s and 1990s, and finally the highest impact studies from 2000 to present. This journey through 50 years of microneurographic research related to peripheral sympathetic nerve activity includes a historical context for several of the laboratory interventions commonly used today (e.g., cold pressor test, mental stress, lower body negative pressure, isometric handgrip, etc.) and how these interventions and experimental approaches have advanced our knowledge of cardiovascular, cardiometabolic, and other human diseases and conditions.

Naloxone augments muscle sympathetic nerve activity during isometric exercise in humans

1991 ◽  
Vol 260 (3) ◽  
pp. E379-E388 ◽  
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.

scholarly journals Reproducibility of the neurocardiovascular responses to common laboratory-based sympathoexcitatory stimuli in young adults

2020 ◽  
Vol 129 (5) ◽  
pp. 1203-1213
Author(s):  
Gabrielle A. Dillon ◽  
Zachary S. Lichter ◽  
Lacy M. Alexander ◽  
Lauro C. Vianna ◽  
Jing Wang ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Young Adults ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Pressor Response ◽  
Muscle Sympathetic Nerve Activity ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Nerve Activity ◽  
Common Laboratory

The magnitude of the increases in blood pressure and muscle sympathetic nerve activity in response to sympathoexcitatory stimuli such as static handgrip, postexercise ischemia, and the cold pressor test are commonly used to assess neurocardiovascular responsiveness. However, limited studies have comprehensively examined the reproducibility of these responses. We demonstrate that the reproducibility of the pressor response to these perturbations was very good within an individual, whereas the reproducibility of the MSNA response was less consistent.

scholarly journals Ketamine Blunts Sympathetic Nerve Activity Responses to a Cold Pressor test

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Gilbert Moralez ◽  
Mu Huang ◽  
Matthew N Cramer ◽  
Joseph M Hendrix ◽  
Carmen Hinojosa‐Laborde ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Cold Pressor Test ◽  
Cold Pressor ◽  
Nerve Activity ◽  
Pressor Test
Sign in / Sign up

Export Citation Format

Share Document