Induced low P 50 in anesthetized rats: Blood gas, circulatory and metabolic adjustments

• Published in: Respiration physiology Vol. 58; no. 3; pp. 335 - 344
• Main Authors: Teissiere, Bernard P., Soulard, Claude D., Teisseire, Liliane J., Herigault, Robert A., Laurent, Daniel N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1984
• Subjects: 2,3-Diphosphoglycerate; Hypoxia; Normoxia; Oxygen affinity; Oxygen consumption; Rat; Normoxia; Oxygen consumption; Hypoxia; Oxygen affinity; 2,3-Diphosphoglycerate; Rat
• ISSN: 0034-5687
• DOI: 10.1016/0034-5687(84)90009-4

In anesthetized, normoxic or hypoxic rats the hemodynamic, metabolic and O 2 transport characteristics following exchange transfusion with human erythrocytes containing a high O 2 affinity hemoglobin (Hemoglobin Creteil, β 89 Ser → Asp) have been studied. The in vivo oxygen partial pressure at 50% oxygen hemoglobin saturation (P 50) decreased from 37.4 ± 2.1 to 12.7 ± 0.7 mm Hg; the arterial oxygen tension was reduced significantly from 109.9 ± 7.7 to 87.3 ± 12.0 mm Hg. There was a decrease in right ventricular partial pressure of oxygen (Pv̄O 2), ( P < 0.001), oxygen consumption (V̇ O2), ( P< 0.001), arterio-venous difference, ( P < 0.001), and peripheral vascular resistance index, ( P < 0.01). Exchange transfusion with normal rat blood ( P 50 = 37.2±2.4 mm Hg) or with 2,3-diphosphaglycerate-enriched human red blood cells ( P 50 = 34.7±2.2 mm Hg), did not modify these variables in normoxic rats. In hypoxia, the reduction in P 50 was associated with a further decrease in Pv̄ O2 an increase in serum lactate concentration and a V̇ O2 decrease.