Effect of age on oxygen-binding in normal human subjects.
1. Oxygen-binding, plasma and intra-erythrocytic pH, and haemoglobin, 2,3-diphosphoglycerate and inorganic phosphate concentrations were measured in sixty-two healthy non-smokers aged between 18 and 89 years. 2. P50 (oxygen tension at 50% oxygen saturation) expressed at plasma pH 7-40 and PCO2 5-33 kPa showed a positive correlation with age. 3. This correlation of P50 with age was closer when P50 was expressed at a constant intra-erythrocytic pH 7-20. On average P50 at intra-erythrocytic pH 7-20 increased from 3-59 kPa at 20 years to 3-96 kPa at 90 years of age. 4. 2,3-Diphosphoglycerate, inorganic phosphate, haemoglobin and mean corpuscular haemoglobin concentrations did not correlate with P50 or with age.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001769:Blood; D004163:Diphosphoglyceric Acids / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008706:Methemoglobin / Q000378:metabolism; D008875:Middle Aged; D010100:Oxygen / Q000097:blood*; D010313:Partial Pressure; D010710:Phosphates / Q000097:blood
D004163:Diphosphoglyceric Acids; D006454:Hemoglobins; D010710:Phosphates; D008706:Methemoglobin; D010100:Oxygen