Cirillo Massimo, De Santo Natale G, Heer Martina, Norsk Peter, Elmann-Larsen Benny, Bellini Luigi, Stellato Davide, Drummer Christian
Nephrology, Second University of Naples, Naples, Italy.
Nephron Physiol. 2003;93(4):p102-5. doi: 10.1159/000070243.
Physiological changes occur in man during space missions also at the renal level. Proteinuria was hypothesized for space missions but research data are missing.
Urinary albumin, as an index of proteinuria, and other variables were analyzed in 4 astronauts during space missions onboard the MIR station and on the ground (control). Mission duration before first urine collection in the four astronauts was 4, 26, 26, and 106 days, respectively. On the ground, data were collected 2 months before mission in two astronauts, 6 months after in the other astronauts. A total of twenty-two 24-hour urine collections were obtained in space (n per astronaut = 1-14) and on the ground (n per astronaut = 2-12). Urinary albumin was measured by radioimmunoassay. For each astronaut, mean of data in space and on the ground was defined as individual average.
The individual averages of 24 h urinary albumin were lower in space than on the ground in all astronauts; the difference was significant (mean +/- SD, space and on the ground = 3.41 +/- 0.56 and 4.70 +/- 1.20 mg/24 h, p = 0.017). Dietary protein intake and 24-hour urinary urea were not significantly different between space and on the ground.
Urinary albumin excretion is low during space mission compared to data on the ground before or after mission. Low urinary albumin excretion could be another effect of exposure to weightlessness (microgravity).
在太空任务期间，人体在肾脏层面也会发生生理变化。曾有关于太空任务中蛋白尿的假设，但缺乏研究数据。
在和平号空间站执行太空任务期间及地面（对照），对4名宇航员的尿白蛋白（作为蛋白尿指标）及其他变量进行了分析。4名宇航员首次尿液采集前的任务持续时间分别为4天、26天、26天和106天。在地面上，两名宇航员在任务前2个月收集数据，其他宇航员在任务后6个月收集数据。在太空（每位宇航员收集次数 = 1 - 14次）和地面（每位宇航员收集次数 = 2 - 12次）共获得22次24小时尿液收集样本。通过放射免疫分析法测定尿白蛋白。对于每位宇航员，将太空和地面数据的平均值定义为个体平均值。
所有宇航员24小时尿白蛋白的个体平均值在太空时均低于地面；差异具有显著性（平均值±标准差，太空和地面分别为3.41±0.56和4.70±1.20 mg/24 h，p = 0.017）。太空和地面之间的膳食蛋白质摄入量及24小时尿尿素无显著差异。
与任务前或后的地面数据相比，太空任务期间尿白蛋白排泄量较低。低尿白蛋白排泄可能是暴露于失重状态（微重力）的另一个影响。
