Increased Blood Oxygen Affinity and Physical Work Capacity in Man

Abstract

Influence of altered blood oxygen affinity on work performance in man was investigated. Increased in vitro blood oxygen affinity was achieved in vivo by partial DPG depletion induced by 70 hours of acidosis followed by acute restoration of acid-base balance by intravenous NaHCO₃. Work performance tests with determination of submaximal and maximal oxygen uptake were performed at the two different DPG levels. Submaximal and maximal oxygen uptake remained unchanged when DPG decreased from 0.80 to 0.58 mol/mol Hb and P_{50 (7.4. BE=0)} (oxygen tension at half saturation of hemoglobin) decreased from 26.4 to 24.0 mm Hg. Thus a small increase of in vitro whole blood oxygen affinity does not impair work performance in man.

Key Words:

• 2,3-diphosphoglycerate
• exercise
• oxygen affinity of hemoglobin
• oxygen uptake