Effects of in Vitro X-Irradiation on the Ameboid Migration of Human Leukocytes

Human venous blood was x irradiated in vitro, and the ameboid migration of polymorphonuclear leukocytes was measured by the capillary tube technique. Capillary tubes filled with heparinized blood were centrifuged, resulting in a basal layer of red cells, an intermediate buffy coat of leukocytes, and an uppermost layer of plasma. After irradiation, the tubes were incubated vertically, and the distance the leukocytes migrated into the plasma was measured by means of an ocular micrometer. The migration of leukocytes in blood x irradiated with doses ranging from 25 to 150,000 rads was not significantly altered. Irradiation with 200 krad, however, caused a marked inhibition of leukocyte migration. When nonirradiated cells were combined with plasma irradiated without cells, the same degree of inhibition occurred as when cells and plasma were irradiated together. This latter finding indicates that the observed inhibition resulted not from an effect of irradiation on the leukocytes directly, but indirectly through a change in the plasma. (auth)