title: Methaemoglobin and erythrocyte reducing systems in high-altitude natives.
abstract: The stress of chronic hypobaric hypoxia 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 metabolite changes are discussed with respect to regulation of erythrocyte metabolism.
mesh_terms: D000064:Acclimatization; D000328:Adult; D000531:Altitude; D001838:Bolivia; D008058:Dihydrolipoamide Dehydrogenase / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism*; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D005978:Glutathione / Q000097:blood; D005980:Glutathione Reductase / Q000097:blood; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000097:blood; D006801:Humans; D007199:Indians, South American; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008706:Methemoglobin / Q000378:metabolism*; D009252:NADPH Dehydrogenase / Q000097:blood
chemical_list: D008706:Methemoglobin; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D009252:NADPH Dehydrogenase; D008058:Dihydrolipoamide Dehydrogenase; D005980:Glutathione Reductase; D005978:Glutathione