Hemoglobin Function in Stored Blood: VII. Effects of Salts and Glutathione

摘要

The Valtis-Kennedy salt effect (rightward shift, toward normal, of the oxyhemoglobin dissociation curve produced by neutral salts in stored blood) was reported to remain normal after transfusion of treated blood. This has remained unexplained because the salts used are readily dialyzable and the normal mediator of hemoglobin function, 2,3-diphosphoglycerate (2,3-DPG), is not resynthesized for 8 to 24 hours after transfusion of stored blood. The separate observation that glutathione (GSH) shifts the oxyhemoglobin dissociation curve in stored or fresh blood to the right has also remained unexplained because glutathione is known to have no effect on the oxyhemoglobin dissociation curve of purified hemoglobin in solution. These phenomena have been restudied in two groups of experiments which were designed to explain the observations. In order to simulate the Valtis-Kennedy transfusion experiment, stored red cells, depleted of 2,3-DPG and therefore with left-shifted O2 curves, were treated with NaCl to improve the oxygen release capacity. Upon washing these treated cells with isotonic saline, the improvement was reversed and the O2 curves were again left-shifted. Glutathione solutions were found to lower the blood pH, which, of course, shifts the O2 curve to the right. If the pH change produced by GSH is either corrected for in the pO2 calculations or raised to 7.4 with tris buffer, GSH is seen to have no effect on the oxyhemoglobin dissociation curve. (Author)