Effect of high altitude (14,100 Ft.) on nitrogenous components of human serum

Abstract

Serum free amino acids and nitrogenous metabolites were measured in 8 male subjects exposed to a high altitude of 14,100 feet for 14 days. The ratio of total essential amino acids to total nonessential amino acids was decreased at altitude. Glutamic acid increased and leucine, lysine, valine and threonine decreased significantly at altitude. The nitrogenous metabolites, taurine and urea were elevated at altitude. Serum water content increased slightly, i.e., about 1 per cent, and therefore changes in the nitrogenous components of serum at altitude cannot be explained by a dehydration effect. Alterations in serum free amino acid and nitrogenous metabolite concentrations in serum of subjects at 14,100 feet closely parallel changes in these serum components reported in subjects on protein deficient diets; however, protein intake at altitude was well above minimum requirements. This suggests that the changes in nitrogenous components of serum noted in 8 male subjects exposed to a high altitude of 14,100 feet are due to alterations in protein metabolism which affect protein utilization.