Physico-chemical properties of membranes of recovered erythrocytes in blood autologous transfusion: a study using fluorescence technique.

Using fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its derivative trimethylammonium-1,6-diphenyl-1,3,5-hexatriene (TMA-DPH), we have investigated the fluidity in erythrocyte membranes isolated from intraoperatively and postoperatively recovered erythrocytes, compared to membranes isolated from untreated erythrocytes or stored red blood cells (RBCs). Fluorescence polarization (Pf) of DPH and TMA-DPH was not significantly modified in membranes isolated from intraoperatively and postoperatively recovered RBCs compared to membranes isolated from untreated fresh RBCs or stored RBCs. However, using 2-dimethyl-amino-6-lauroyl-naphtalene (Laurdan), a very sensitive molecule, a significant increase in polarity in membranes from stored RBCs compared to untreated, intraoperatively and postoperatively recovered RBCs was observed. Moreover, there was significantly higher susceptibility to oxidative stress in membranes isolated from stored RBCs, compared to untreated and intraoperatively or postoperatively recovered RBC membranes, both at baseline and after oxidative stress. Our results suggest that intraoperative and postoperative recovered RBCs are less damaged than stored RBCs.