DISPLACEMENT OF OXYGEN DISSOCIATION CURVES AND RED CELL CATION EXCHANGE IN CHRONIC HYPERCAPNIA
Abstract
Guinea pigs were exposed to 15% CO2 in 21% 02 for periods up to seven days. Two separate oxygen dissociation curves were determined at a PCO2 of 40 mm Hg and a PCO2 of 115 mm Hg on pooled blood samples. Red cell pH and cation concentrations were also measured. P50 fell from 27.8 mm Hg to 18.6 at one day exposure and rose again to 24.7 after seven days of exposure to 15% CO2. Blood oxygen capacity decreased significantly with the return shift of the oxygen dissociation curve. In spite of the increase in oxygen affinity during the uncompensated phase of respiratory acidosis, delivery of oxygen to the tissues was not reduced due to an increase in the Bohr effect. Commensurate with the increase and decrease in oxygen affinity, cation concentrations of the red cells exhibited corresponding decreases and increases. The potassium concentrations showed a larger fall, while red cell content increased slightly during the uncompensated phase of respiratory acidosis. These changes were reversed during the compensated phase of respiratory acidosis without returning to control levels. The ratio of red cell cations/Hb showed a close correlation with the changes in P50 values. The pH gradients across the red cell were found to decrease during the uncompensated phase of respiratory acidosis and increase again during the compensated phase of respiratory acidosis.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1969
- Accession Number
- AD0708394
Entities
People
- Arthur A. Messier
- Carolyn C. Morgan
- Karl E. Schaefer
Organizations
- Naval Submarine Medical Research Laboratory