Effect of artificial carbon dioxide bathing on oxygen-dissociation curve of hemoglobin / 日本温泉気候物理医学会雑誌

ABSTRACT

Many researchers have pointed out that CO₂ bathing directly effects expanding dermal vessels. The authors have recently reported a decrease in red blood cell after CO₂ bathing. To clarify other effects of CO₂ bathing on RBC, the changes in the hemoglobinoxygen-dissociation curve (P50) were measured after single bathing (for 10 minutes at 40°C) with artificial CO₂ water made of sodium bicarbonate and citric acid dissolved in plain water. P50 was measured with an oxygen-dissociation analyzer (HEMO-O-SCAN^TM made by American Instrument Company) and 2, 3-diphosphoglycerate (2, 3-DPG) in RBC, with enzymatic analysis. The subjects of this study consisted of six male patients and four female patients, ranging from 53 to 80 years old.<br>The results are presented below.<br>1) Nine of ten patients showed an increase in P50 after 15 to 30 minutes of CO₂ bathing. The remainder showed a transient increase in P50.<br>2) No significant increase in 2, 3-DPG concentration in RBC was found in the group subjected to CO₂ bathing as compared to that of the controls who were subjected to plain water bathing. However, seven patients showed an increase in 2, 3-DPG after 15 to 30 minutes of CO₂ bathing, and three patients showed a decrease in 2, 3-DPG.<br>3) Partial pressures of oxygen (PO₂) and carbon dioxide (PCO₂) in the venous blood were measured. Elevation of PO₂, lowering of PCO₂, and increase in pH were observed in almost all patients after a single CO₂ bath.<br>From these results, we can conclude that a single CO₂ bath effectively decreases oxygen affinity of hemoglobin, presumably due to a rise in the blood temperature and partially due to an increase in 2, 3-DPG concentration in RBC.