模擬高度6,000m急性負荷実験における尿中N-Acetyl-β-D-Glucosaminidase, β2-microglobulinの変動

Abstract

模擬高度6, 000 m急性負荷実験施行時尿中NAG, BMGを測定した.1) 5症例1日目, 1群尿のNAGは1.96±0.53, BMGは128.6±121.9であった.2) NAGの変化については5症例中2例に3群において正常範囲を越える著明な上昇を認め, 5症例5日間の比較検討では3群は他群尿に対し有意の差の上昇を認めた.3) NAG 5日間の経時的変化は1～4群のいずれにおいても認められず, 連続負荷によるNAG排泄の増加傾向は認められなかった.4) BMGの変化は軽徴であり, 有意の上昇は認められなかった.5)高所負荷による反応は個人差が大きく作用していた

The changes in NAG and BMG concentration in the urine during sudden exposure to a simulated 6, 000 m altitude (354 mmHg) were studied. Subjects were 5 healthy male volunteers before a mountain climbing expedition (20-25 years old). Decompression was commenced at 11:00 and terminated at 17:00 (2-h ascent, 2-h sojourn, 2-h return) for 5 successive days. Urine was discarded at 9:00 and thereafter collected at 11:00 (group I), 14:00 (group II) 17:00 (group III), and 9:00 the next day (group IV) and urinary NAG and BMG was measured. The rate of NAG indicated elevation above 5.0 U/L in 2 cases in group III and elevation which was significantly different from that of the other 3 groups. In the other 3 cases, significant elevation was not observed, but for group III as a whole NAG excretion was significantly elevated compared of the other 3 groups. However, increased excretion of NAG was not observed on all 5 successive days. The change in BMG values was smaller than that of the NAG values and no significant elevation was observed in any of the 4 groups. Increasing urinary excretion of NAG by sudden exposure to a high altitude indicated excessive destroy of epithelium in the proximal tubules, but this change was reversible.