An experimental model has been developed for the study of recognition by cells of the reticuloendothelial system (RES).
A quantitative method employing Cr51 labeled cells has been devised for studying phagocytosis of homologous and heterologous erythrocytes.
Homologous and heterologous red blood cells are phagocytized at different rates. The spleen primarily takes up homologous (mouse) red cells and the liver removes foreign (human, guinea pig, rabbit) erythrocytes.
Genetic differences among strains of mice may be reflected in their ability to take up in the spleen red cells of nonrelated donor mice.
The ratio of recovery of radioactivity (RR ratio) between the blood, spleen and liver may be used to characterize a system employing erythrocytes of a particular donor in any given recipient. A comparison of RR ratios obtained under varying experimental conditions may be expected to reflect responses in the recognition mechanism of the RES.