Arnaud, J2026-03-222026-03-221979https://andeanlibrary.org/handle/123456789/18384Summary. The stress of chronic hypobaric hipoxia present at high altitudes induces a series of adaptive changes in the intermediate metabolism in erythrocytes of high-altitude natives. Aymaras of the high Andean Plateau are shown to have within erythrocytes: (a) increased activity of NADH₂ (GAPDH) generating stages, (b) decreased activity of NADH₂ (LDH) consuming steps, (c) significantly increased methaemoglobin content, and (d) a large increase in the level of reduced glutathione. These alterations occur also in persons of the same ethnic group residing at low altitude. There is, however, only a moderate elevation of classic haematological parameters (erythrocyte count, haemoglobin and haematocrit) in highland natives. The functional implications of these metabolic changes are discussed with respect to regulation of erythrocyte metabolism.enMETAHEMOGLOBINAALTURANATIVOS DE GRAN ALTURAArticle