[Effect of vitamin D and vitamin E on the erythrocyte membrane. I. Effect on in vitro osmolar resistance and lysis].

As in the case of retinol, low doses of cholecalcipherol and alpha-tocopherol "in vitro" increase the osmotic resistance of red blood cells, while high doses have a lytic effect on the erythrocytes of various animal species (e.g.: man, sheep, rabbit, guinea-pig, mouse, rat) with the exception of the chicken. The haemolytic effect of cholecalcipherol is less intense than that of retinol; alpha-tochopherol, while causing even less haemolysis than cholecalcipherol, involves a remarkable loss of K+ from the red cells. Besides these quantitative differences, the mechanism of action of the three vitamins seems somewhat different, as shown by modifications of the suspension medium (e.g.: pH, temperature, presence of proteins and reducing substances) or by treatment of the red cells with trypsin. Our results therefore essentially confirm the hypothesis of Dingle and Lucy of common mechanism of action of liposoluble vitamins on biological membranes.