Convertino V A, Doerr D F, Mathes K L, Stein S L, Buchanan P
Biomedical Operations and Research Office, NASA, Kennedy Space Center, FL 32899.
Aviat Space Environ Med. 1989 Jul;60(7):653-8.
The purpose of these experiments was to test the hypothesis that reduced size of the leg muscle compartment following exposure to long-duration microgravity would be associated with increased leg compliance. Eight men, 31-45 years of age, were measured for vascular compliance of the calf and serial circumferences of the thigh and calf before, during and after 30 d of continuous 6 degrees head-down bedrest. Cross-sectional areas (CSA) of muscle, fat, and bone compartments in the thigh and calf were determined pre- and post-bedrest by computed tomography. Calculated leg volumes decreased (p less than 0.05) in the calf by 9.9% and in the thigh by 4.5% from pre- to post-bedrest. Muscle compartment CSA also decreased (p less than 0.05) in both calf (-4.8%) and thigh (-8.1%); leg compliance (vol%/mm Hg x 100) increased (p less than 0.05) from 3.9 +/- 0.7 to 4.9 +/- 0.5. Calf compliance measured before and after bedrest was inversely related to calf muscle compartment CSA (r = -0.61, p less than 0.05) and the percent decrease in calf muscle compartment CSA from pre- to post-bedrest was inversely correlated with an increase in calf compliance (r = -0.72, p less than 0.05). Increased leg compliance following long-duration spaceflight is associated with reduced size of the leg muscle compartment.
长期暴露于微重力环境下腿部肌肉腔室尺寸减小与腿部顺应性增加有关。对8名年龄在31至45岁之间的男性，在连续30天6度头低位卧床休息前、期间和之后，测量其小腿的血管顺应性以及大腿和小腿的周长。通过计算机断层扫描确定卧床休息前后大腿和小腿肌肉、脂肪和骨腔室的横截面积（CSA）。从卧床休息前到卧床休息后，计算得出小腿的腿部体积减少了9.9%（p<0.05），大腿减少了4.5%。小腿和大腿的肌肉腔室CSA也均降低（p<0.05），小腿降低了4.8%，大腿降低了8.1%；腿部顺应性（每100毫米汞柱的体积百分比）从3.9±0.7增加到4.9±0.5（p<0.05）。卧床休息前后测量的小腿顺应性与小腿肌肉腔室CSA呈负相关（r = -0.61，p<0.05），并且从卧床休息前到卧床休息后小腿肌肉腔室CSA的百分比降低与小腿顺应性的增加呈负相关（r = -0.72，p<0.05）。长期太空飞行后腿部顺应性增加与腿部肌肉腔室尺寸减小有关。
