[Age characteristics of the immune response in rats with multiple administraion of different doses of sheep erythrocytes].

A study was made of the number of antibody-forming cells and of the serum antibody titres in adult and old rats under conditions of a 10-fold immunization with "low" (4 X 10(8) cells) and "high" (4 X 10(10) cells) doses of sheep erythrocytes. The titres of antibodies (hemolysins and hemagglutinins) in the animals of both groups were either close to one another or greater in adult rats (hemolysins - in administration of "high" doses of the antigen). The content of the direct plaque-forming cells was greater in the spleen of old than of adult animals at all the immunization periods, of this period. The data obtained pointed to differences in the maturation of the immune response in the animals of various age.