Oxygen Affinity of Hemoglobin and Red Cell 2,3-Diphosphoglycerate in Hepatic Cirrhosis

Abstract

The level of 2,3-diphosphoglycerate (2,3-DPG) in erythrocytes was found to be increased in patients with cirrhosis of the liver, and as a consequence the oxygen affinity of hemoglobin was decreased. Part of the 2,3-DPG increase in the patients with cirrhosis was caused by a concomitant anemia. At all hemoglobin levels, however, patients with cirrhosis showed an additional 2,3-DPG increase in comparison with patients without cirrhosis. Red cell 2,3-DPG was positively correlated to pH in plasma and in erythrolysate. It is likely that pH changes contribute to the regulation of the red cell 2,3-DPG concentration in cirrhotic patients. In a group of these patients (n=48), the arterial pH and pCO₂ did not differ significantly from normal values. Other, as yet unknown, factors must presumably contribute to the increase in red cell 2,3-DPG. No direct effect of NH₄⁺ on red cell 2,3-DPG could be demonstrated in vitro. The plasma concentration of NH₄⁺ in vivo correlated positively to plasma pH. The lowered oxygen affinity does not contribute significantly to the decrease in oxygen saturation of arterial blood often found in patients with hepatic cirrhosis.

Key Words:

• 2,3-Diphosphoglycerate
• hepatic cirrhosis
• oxygen affinity