The authors investigated the influence of vitamin E on leucocyte counts in preserved blood. Blood were obtained from 5 normal persons, with citrate・phosphate・dextrose system. To each blood, α-tocopherylacetate was added with the concentration of 10mg%, and its solvent was added to the control blood. Leucocyte were measured once or twice aweek for one month, using micro cell counter. As a result, leucocyte decrease was less marked in tocopherol group (E) than in the control (C), that is, the reductions in E and C were 16,41% at 7 day, 29,59% at 24th day, 33,69% at 31th day, respectively. From the results it was shown that α-tocopherylacetate had a preventive action for the spontaneous destruction of leucocytes in preserved blood.
