Effect of acute posthaemorrhagic anaemia on the level of 2,3-diphosphoglycerate (2,3-DPG) in the erythrocytes of sheep.

In 11 sheep anaemia was produced by one-time removal of from 17% to 20% total volume of blood. Blood samples for 2,3-DPG determinations in the erythrocytes were taken at 4-hour intervals during 72 hours. Posthaemorrhagic anaemic hypoxia caused in sheep a rise in the concentration of 2,3-DPG in the erythrocytes from a mean control value of about 0.13 microM/g Hb to 2.45 microM/g Hb during 20 hours after blood loss (primary rise). The return of this concentration to its control value occurred between 32 and 64 hours after blood loss. Between 36 and 56 hours after the blood loss a second (secondary) rise of 2,3-DPG concentration in the erythrocytes appeared reaching a peak level of about 0.6 microM/g Hb. Determinations of sodium and potassium in the erythrocytes of 5 low-potassium sheep demonstrated a fall in potassium concentration whose lowest values were observed 24 hours after blood loss. After 24 hours from blood removal potassium rose again to the initial value. The concentration of sodium in the erythrocytes showed changes opposite to those observed in the concentration of potassium.