Unchanged in vivo P50 at high altitude despite decreased erythrocyte age and elevated 2,3-diphosphoglycerate

摘要: We measured hematological and erythrocyte O2 transport parameters in whole blood density-separated erythrocytes 11 mountaineers before during 5 days of exposure to high altitude (4,559 m). determined the vivo (arterial pHblood PCO2) standard (pHblood = 7.4, PCO2 40 Torr) tension at 50% saturation hemoglobin (P50,vv P50,st) Bohr coefficients (BC) for fixed acid (H+) CO2 examined contribution altered average age circulating due stimulation erythropoiesis on 2,3-diphosphoglycerate (2,3-DPG) P50,st. At altitude, P50,vv remained almost unchanged, whereas P50,st 2,3-DPG increased significantly (+4 Torr; 3.5 mumol/g hemoglobin). BCCO2 was elevated altitude. Serum erythropoietin transiently fourfold, iron utilization increased, serum decreased by 66%. Reticulocyte counts but other were unchanged. In erythrocytes, with decreasing cell density higher fractions comparable reticulocyte cells prepared than those from control studies. Our data show that, despite increase decrease age, hemoglobin-O2 affinity remains values reflect elevation 2,3-DPG, approximately both can be ascribed number reticulocytes young erythrocytes.