BACKGROUND Blood banking procedures are associated with elevated adherence of red blood cells (RBCs) to blood vessel wall endothelial cells (ECs), which can introduce a circulatory risk to recipients. This study was undertaken to examine the possibility of repairing this damage by a poststorage "rejuvenation" procedure before transfusion. METHODS Stored RBCs were treated with rejuvenation solution (Rejuvesol, enCyte Systems, Inc.), and their adhesion to cultured human microvascular ECs was determined as a function of shear stress using a cell flow properties analyzer. The adherence of rejuvenation-treated stored RBCs (stRBCs) was compared to that of untreated stRBCs and of freshly donated RBCs. RESULTS Strong elevation of stRBC/EC adhesion was induced by cold storage and it correlated with translocation of phosphatidylserine (PS) to the RBC surface, a known mediator of RBC/EC adhesion. The role of RBC surface PS in stRBC/EC interaction was confirmed by the suppression of adhesion after the blocking of the stRBC surface PS with annexin V. Concomitantly, RBC storage elevated intracellular levels of reactive oxygen species (ROS) and Ca(2+), the latter known to facilitate PS externalization. Poststorage rejuvenation treatment of stRBCs reversed all the above changes (ROS, Ca(2+), PS), along with complete suppression of the enhanced RBC/EC adhesion, restoring it to that of normal, freshly collected RBCs. CONCLUSIONS Poststorage RBC rejuvenation treatment is effective in reversing the storage-induced RBC/EC interaction. This provides further documentation for the potential clinical benefit of poststorage rejuvenation.