Renal Excretion of Bicarbonate in High Altitude Natives and in Natives with Chronic Mountain Sickness

Abstract
When compared with sea level controls, natives from high altitudes (4,300 m above sea level) have lower arterial PCo2 and the same renal maximal reabsorption (Tm) of bicarbonate. Natives with chronic mountain sickness have a high arterial Pco2 than their own native control group and a higher bicarbonate Tm. The results are interpreted as indicating that the normal high altitude native is in a new state of acid-base equilibrium. The possible roles of high arterial Pco2, hypokalemia, and anoxia in the elevation of bicarbonate Tm of patients with chronic mountain sickness are discussed.