水静态梯度和昼间节律对大脑和眼睛血流的影响
Carmen Possnig1, Hendrik Mugele1, Ronja Mittermeier1
1Department of Sport Science, Division of Performance Physiology and Prevention, University of Innsbruck, Innsbruck, Austria.
European journal of applied physiology
|December 19, 2025
概括
大脑血流 (CBF) 和后动脉速度 (PCAv) 在坐着的位置下降,类似于微重力效应. 身体下部负压 (LBNP) 没有像预期的那样降低PCAv.
科学领域:
- 心血管生理学心血管生理学
- 神经眼科神经眼科
- 太空医学 太空医学
背景情况:
- 太空飞行相关的神经眼综合征 (SANS) 突出了在重力变化下了解眼睛和脑血管动态的必要性.
- 眼睛的自我调节能力受到质疑,在SANS中可能会增加血液流量或体积.
- 已知循环节律和睡眠会影响生理过程,可能影响大脑血流 (CBF) 和眼睛 perfusion.
研究的目的:
- 为了研究引力载体,昼夜节律和睡眠如何影响脑血流 (CBF) 和眼睛 perfusion.
- 为了测试眼睛缺乏自我调节的假设,以及增加的血流/体积驱动SANS中的胆道胀的假设.
- 评估下体负压 (LBNP) 作为后动脉速度 (PCAv) 变化的潜在对策.
主要方法:
- 16名参与者在坐着,仰卧,横卧和倾斜的姿势下进行了研究.
- 超声波用于测量内动脉和脊椎动脉的血液流动,以及PCAv和中脑动脉 (MCAv) 的速度.
- 测量包括CBF,PCAv,MCAv,心率,平均动脉压和氧气输送,有或没有LBNP.
主要成果:
- 与水平位置相比,CBF和PCAv在坐着的位置是最低的.
- 坐着时CBF导电性较低,但考虑到眼内和水静压,PCA导电性保持稳定.
- 睡眠降低了MCAv,心率和平均动脉压;LBNP意外增加了PCAv和眼 perfusion 压力.
结论:
- CBF和PCA速度对地球上的姿势变化表现出类似的反应.
- 眼睛的自我调节可能不如以前想象的那么有效,PCA导电性在不同位置保持稳定.
- 低水平的LBNP作为降低PCAv的对策是无效的.
相关概念视频
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
331
Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
331
Autoregulation of Blood Flow
7.4K
Autoregulation mechanisms are characterized by their inherent capacity for self-regulation without necessitating specific nervous stimulation or endocrine control. These mechanisms facilitate the adjustment of blood flow and, therefore, perfusion specific to each tissue region. This self-regulation encompasses chemical signals and myogenic controls.
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation....
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation....
7.4K
Blood Flow
75.4K
Blood is pumped by the heart into the aorta, the largest artery in the body, and then into increasingly smaller arteries, arterioles, and capillaries. The velocity of blood flow decreases with increased cross-sectional blood vessel area. As blood returns to the heart through venules and veins, its velocity increases. The movement of blood is encouraged by smooth muscle in the vessel walls, the movement of skeletal muscle surrounding the vessels, and one-way valves that prevent backflow.
75.4K
Neural Regulation of Blood Pressure
6.7K
The neural regulation of blood pressure involves intricate interactions between the autonomic nervous system (ANS) and cardiovascular system, ensuring adequate perfusion of tissues. This regulation primarily occurs through baroreceptor and chemoreceptor reflexes, involving both short-term and long-term mechanisms.
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
Baroreceptor Reflex
Baroreceptors, located in the carotid sinuses and aortic arch, detect changes in blood pressure. When blood pressure rises, these stretch-sensitive receptors...
6.7K
Disorders of the Autonomic Nervous System
1.4K
The autonomic nervous system (ANS) is an intricate network of nerves that controls functions such as the regulation of heart rate, digestion, and blood pressure regulation. When this system malfunctions, it can lead to various disorders that affect multiple bodily functions. One common feature of many autonomic disorders is the involvement of smooth blood vessels, which play a crucial role in regulating blood flow throughout the body.
Raynaud's disease, also known as Raynaud's...
Raynaud's disease, also known as Raynaud's...
1.4K
Fluid Movement Between Compartments
3.6K
The force applied by fluids against a surface, known as hydrostatic pressure, initiates the transfer of fluid among different compartments. Within our blood vessels, the blood's hydrostatic pressure is a result of the heart's pumping action. At the arteriolar end of capillaries, hydrostatic pressure (capillary blood pressure) exceeds the opposing colloid osmotic pressure created primarily by plasma proteins like albumin. This discrepancy in pressure propels plasma and nutrients from the...
3.6K


