The Influence of Immunization and Total Body X-Irradiation on Intracellular Digestion by Peritoneal Phagocytes

Total body x-irradiation suppresses intracellular digestion of chicken erythrocytes by the peritoneal phagocytes of mice and rabbits. Such digestive function was normal on the second and eighteenth postirradiation days but was depressed on the sixth through the fourteenth day following 350-r total body irradiation of mice. When the irradiation dose was increased to 450 r, digestion of chicken erythrocytes by mouse phagocytes did not return to normal until the twenty-sixth day. The inhibition of phagocyte digestion of Candida guilliermondi followed the same pattern as observed with chicken red blood cells. Immunization with chicken erythrocytes caused an increase in the digestion of these cells by the phagocytes from mice and rabbits. The immunization-induced increase in digestive capacity was reversed by irradiation procedures that did not appreciably alter serum antibody titers. In vitro tests carried out in the presence of serum from immunized and immunized-irradiated rabbits revealed that the beneficial effect of immunization and the detrimental effect of irradiation on phagocyte digestion were due to alterations in the phagocytic cell and not due to the humoral changes that follow irradiation or immunization.