期刊
JOURNAL OF APPLIED PHYSIOLOGY
卷 103, 期 3, 页码 959-962出版社
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/japplphysiol.00899.2006
关键词
-
Whenever the legs are lowered in humans, a venoarteriolar reflex is activated by the hydrostatic distension of the venules. Through local axon reflexes, the adjacent arterioles are contracted to decrease blood flow and prevent formation of edema. Because the venoarteriolar reflex is activated by gravity, we tested the hypothesis that long- term weightlessness would attenuate it. The reduction in subcutaneous blood flow was measured by the Xe-133 washout technique just proximal to the ankle joint in dependent lower legs of eight supine astronauts, where the knee joint was passively bent by 90. The measurements were conducted before spaceflight and 3 - 6 h on landing following 4 - 6.5 mo in space. Activation of the venoarteriolar reflex reduced subcutaneous blood flow by 37 +/- 9% ( P = 0.016) before flight and by 64 +/- 8% ( P < 0.001) following landing with no statistical significant difference between the two reductions ( P = 0.062). Therefore, our results show that the venoarteriolar reflex is not attenuated by weightlessness and therefore does not need the everyday stimulus of gravity to maintain efficiency.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据