Effects of +Gz Loads on Structural Organization of Central Autonomic Nuclei

Sukhoterin, A. F.; Pashchenko, P. S.

doi:10.1007/s10517-015-3044-0

Cited by 3 publications

(2 citation statements)

References 4 publications

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“…In this sense, the sympathetic predominance in FP is particularly important during the flight, proving a good circulatory tolerance to +Gz accelerations (Zenon et al, 2003). From an experimental point of view, +Gz chronic exposures increased the RNA content of neurons in the dorsal vagal complex in rats, inducing structural changes that may influence the autonomic control of the heart (Sukhoterin & Pashchenko, 2015).…”

Section: Discussionmentioning

confidence: 99%

Cardiovascular autonomic regulation in fighter pilots: Lessons from active standing tests

Sá

Rodrigues

Soares

2022

Clin Physio Funct Imaging

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Fighter pilots (FP) are exposed to flight accelerations and stressful situations that defy cardiovascular control during and after flight. FP presents a smaller adjustment in sympatho‐vagal balance during tilt test after flight compared to baseline, suggesting a huge impact of flight on autonomic modulation to the heart. We undertake to test the hypothesis that FP will have a smaller vagal reentrance and lower sympathetic withdrawal during the recovery at the supine position after a prolonged active standing test that mimics flight hemodynamic demands. Twenty‐one military personnel (20–34 years old), composed of 9 FP and 12 non‐pilots (NP) matched by age, V̉O2max and body mass index were enroled in the experimental protocol. R‐R intervals were continuously recorded in the supine position for 15 min (SUPbaseline), during the prolonged active standing test (45 min) windowed in six 5 min time frames (from ORT1 to ORT6), and a recovery period in the supine position for 15 min (SUPrecovery). Heart rate variability was performed by spectral analysis to obtain the normalized low (LFn) and high (HFn) frequency components. The variation (Δ) from baseline (Δ = ORT6 − SUPbaseline) and from recovery (Δ = SUPrecovery–ORT6) periods were calculated. FP had a smaller ΔLFn (sympathetic mediated) and ΔHFn (vagal meditated) during recovery after active standing as compared to NP. Both groups showed similar changes in ΔLFn and ΔHFn during orthostatic stress compared to baseline, with no differences over time. Therefore, FP show a smaller vagal reentrance and a lower sympathetic reduction during recovery at supine following active standing compared to NP.

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Section: Discussionmentioning

confidence: 99%

Cardiovascular autonomic regulation in fighter pilots: Lessons from active standing tests

Sá

Rodrigues

Soares

2022

Clin Physio Funct Imaging

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“…Besides the typical symptoms of loss of consciousness and visual function, which were reported by numerous studies [6–8], repeated +Gz exposure-induced cardiovascular diseases are also a key factor that threatens pilots’ health. A previous study by Martin et al .…”

Section: Introductionmentioning

confidence: 99%

Repeated positive acceleration exposure exacerbates endothelial dysfunction in high-fat-diet-induced hyperlipidemic rats

Zhang

Hua

Wang

et al. 2017

aoms

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IntroductionIt remains unclear whether exposure to repeated positive acceleration (+Gz) can exacerbate endothelial dysfunction on the basis of hyperlipidemia. The aim of this study was to investigate the effect of repeated +Gz exposure on endothelial function in high-fat-diet-induced hyperlipidemic rats.Material and methodsMale Sprague-Dawley rats were randomly divided into control, repeat +Gz exposure, high-fat diet (HFD), and +Gz + HFD groups. The rats in the +Gz group were exposed to +Gz and the rats in the HFD group were fed a diet with 2% cholesterol. The rats in the +Gz + HFD group received both the +Gz exposure and HFD. Eight weeks later, the endothelium-dependent relaxation of the aorta was tested and the ultrastructure of the endothelial cells was observed using transmission electron microscopy. Quantitative real-time polymerase chain reaction and Western blot were used to detect the mRNA and protein expression of endothelial function-associated proteins.ResultsRepeated +Gz exposure elevated the serum level of LDL-C in HFD rats. In the +Gz + HFD rats, the ACh-induced relaxation in the aorta rings was significantly attenuated and the endothelial cells of the aorta were dramatically damaged compared with HFD rats. Nitric oxide content and eNOS expression in the aortic tissue were markedly decreased and the oxidative stress was more serious in the +Gz + HFD rats compared with HFD rats. In addition, repeated +Gz exposure significantly increased serum ox-LDL level and LOX-1 expression in the aorta of HFD rats, thereby activating NF-κB p65 and upregulating the expression of interleukin 6, ICAM-1 and VAP-1.ConclusionsRepeated +Gz exposure promotes endothelial dysfunction in HFD-induced hyperlipidemic rats.

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Neuro-Cardiovascular Responses to Sympathetic Stimulation in Fighter Pilots

dos Santos Rangel,

de Sá,

Farinatti

et al. 2023

aerosp med hum perform

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INTRODUCTION: The chronic effects of regular exposure to high acceleration levels (G-force) on the neuro-cardiovascular system are unclear. We compared the mean arterial pressure (MAP) and cardiac autonomic modulation between nonpilots (NP) vs. military fighter (FP) and transport (TP) pilots. Additionally, we correlated the cardiac autonomic indices with the cardiorespiratory fitness and flight experience of FP.METHODS: A total of 21 FP, 8 TP, and 20 NP performed a tilt test (TT), during which beat-to-beat blood pressure and heart rate were recorded.RESULTS: No difference was detected between groups for changes in MAP and heart rate variability indices during the TT. However, the analysis of areas under the curves showed a greater increase in MAP in FP vs. TP and NP. Conversely, there was a greater decrease in indices reflecting vagal modulation in TP vs. FP and NP (rMSSD, pNN50, and SDNN), and a greater increase in heart rate and sympathovagal balance in TP vs. other groups (LF/HF). The maximal oxygen uptake was strongly correlated with the vagal reserve in FP (r = −0.74). Moreover, the total flying hours of FP were positively correlated with resting HFnu (r = 0.47) and inversely correlated with resting LFnu (r = −0.55) and LF/HF (r = −0.46).CONCLUSION: FP had a higher pressor response to TT than TP and NP. Vagal withdrawal and sympathovagal increase induced by TT in FP were similar vs. NP and attenuated vs. TP. Greater cardiorespiratory fitness and accumulated flying hours in FP seemed to favor lower sympathetic and greater vagal modulation at rest.dos Santos Rangel MV, de Sá GB, Farinatti P, Borges JP. Neuro-cardiovascular responses to sympathetic stimulation in fighter pilots. Aerosp Med Hum Perform. 2023; 94(10):761–769.

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Effects of +Gz Loads on Structural Organization of Central Autonomic Nuclei

Cited by 3 publications

References 4 publications

Cardiovascular autonomic regulation in fighter pilots: Lessons from active standing tests

Cardiovascular autonomic regulation in fighter pilots: Lessons from active standing tests

Repeated positive acceleration exposure exacerbates endothelial dysfunction in high-fat-diet-induced hyperlipidemic rats

Neuro-Cardiovascular Responses to Sympathetic Stimulation in Fighter Pilots

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