Abstract
The phagocytic activity of polymorphonuclear leukocytes from irradiated rats was studied over a period of thirteen days following 550 r total body x-irradiation.
Leukocytes from irradiated rats showed slightly increased phagocytosis of plague bacilli during the first six days after irradiation, but on statistical analysis this increase proved to be insignificant.
From the seventh to the thirteenth day after irradiation, these cells showed a markedly reduced capacity to phagocytose plague bacilli.
Phagocytic studies on suspensions of normal cells in plasma from irradiated animals and on cells from irradiated animals in normal plasma showed that the deficient phagocytosis during the second week following irradiation was due mainly to a defect in the polymorphonuclear leukocytes themselves, though the fact that the addition of normal plasma to cells from irradiated animals did increase their phagocytic capacity by a small but definite degree suggests that there is also a defect in the plasma of irradiated animals.