[Alterations in urinary N-Acetyl-beta-D-glucosaminidase (NAG), beta 2-microglobulin (BMG) under acute exposure to simulated 6,000 m altitude].
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.
D000118:Acetylglucosaminidase / Q000652:urine*; D000328:Adult; D000532:Altitude Sickness / Q000503:physiopathology / Q000652:urine*; D006596:Hexosaminidases / Q000652:urine*; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology / Q000652:urine*; D007668:Kidney / Q000503:physiopathology; D008297:Male; D001613:beta 2-Microglobulin / Q000652:urine*
D001613:beta 2-Microglobulin; D006596:Hexosaminidases; D000118:Acetylglucosaminidase