Studies in red blood cell preservation. 6. Red cell membrane remodeling during rejuvenation

The purpose of this study was to examine whether vesiculation of RBC plays a significant role in their rejuvenation. Outdated units of Adsol blood, were divided into two aliquots and incubated with equal volumes of a solution of 100 mM pyruvate and inosine, 103 mM phosphate and 5 mM adenine (PIPA) or 0.9% saline. Following 1 h incubation, vesicles were isolated from the supernatants and quantitated for hemoglobin content. Restoration of RBC ATP, 2,3-DPG, morphology, and osmotic fragility after rejuvenation was satisfactory. The postrejuvenation mean corpuscular volumes (88.2 +/- 6.9 fl) were significantly lower (p less than 0.001) than the prerejuvenation (94.6 +/- 6.8 fl) and control (104.0 +/- 7.3 fl) volumes. The hemoglobin shed in vesicles during rejuvenation was significantly greater than in the saline controls (0.44 +/- 0.31 vs. 0.18 +/- 0.10 mg/dl RBCs; p = 0.026). These data suggest that the decreased MCV following rejuvenation is in part due to membrane loss in exocytic vesiculation.