Hannon J P, Krabill L F, Wooldridge A, Schnakenberg D D
J Nutr. 1975 Mar;105(3):278-87. doi: 10.1093/jn/105.3.278.
Electrolyte excretion and balance were compared in meal-eating, adlibitum-fed rats maintained in Denver (1,600 m) and on Pikes Peak (4,300 m) and in meal-eating rats maintained in Denver but pair-fed to the Pikes Peak animals. Most of the changes in excretion and balance at Pikes Peak were attributable to hypophagia. At both elevations, equivalent decrements in mineral intake led to nearly equivalent decrements in mineral excretion. Comparisons of the Pikes Peak and Denver pair-fed animals, however, revealed certain changes that were unique to high altitude. These included a marked and sustained reduction in ammonia excretion over the 13-day period of exposure. The higher elevation also produced an enhanced sodium excretion on day 1 of exposure and a reduced sodium balance over the first 6 days. Potassium balance showed no changes unique to high altitude during the first 6 days on Pikes Peak but was significantly reduced during week 2 of exposure. The urinary sodium:potassium ratio was elevated during the first 4 days at 4,300 m, but this effect was attributable to altitude on day 1 only. Enhanced calcium and magnesium excretions, relative to those observed in the pair-fed rats, were observed over the middle and latter portions of the exposure period. The balance of these two minerals showed no altitude-dependent effects. Chloride and phosphate excretions showed an altitude-dependent reduction during day 1 and week 1 of exposure, respectively. These changes were associated with more positive balances. It is concluded that the altitude-dependent effects on mineral metabolism are largely, if not entirely, attributable to hypocapnia and associated alkalosis.
对在丹佛（海拔1600米）和派克斯峰（海拔4300米）维持的自由采食、进食的大鼠以及在丹佛维持但与派克斯峰动物配对饲养的进食大鼠的电解质排泄和平衡进行了比较。派克斯峰处排泄和平衡的大多数变化归因于摄食量减少。在两个海拔高度，矿物质摄入量的同等减少导致矿物质排泄量几乎同等减少。然而，对派克斯峰和丹佛配对饲养动物的比较揭示了一些高海拔特有的变化。这些变化包括在13天的暴露期内氨排泄显著且持续减少。较高海拔还在暴露第1天导致钠排泄增加，在前6天钠平衡减少。在派克斯峰的前6天，钾平衡没有显示出高海拔特有的变化，但在暴露第2周显著减少。在4300米处，尿钠：钾比值在最初4天升高，但这种影响仅在第1天归因于海拔高度。在暴露期的中后段，观察到相对于配对饲养大鼠，钙和镁排泄增加。这两种矿物质的平衡没有显示出海拔依赖性影响。氯化物和磷酸盐排泄分别在暴露第1天和第1周显示出海拔依赖性减少。这些变化与更正向的平衡相关。得出的结论是，海拔对矿物质代谢的影响在很大程度上（如果不是完全的话）归因于低碳酸血症和相关碱中毒。
