CYTOTOXIC EFFECTS OF X-RAYS ON NORMAL AND LEUKEMIC LYMPHOCYTES.

Abstract

In normal rats and after total-body irradiation with 550 r of x rays, the fate in the bone marrow of labeled nucleated and red cells of transfused peripheral blood was observed autoradiographically. Labeled nucleated cells, most of which were lymphocyte-like cells, readily migrated into the marrow parenchyma in normal animals (2 cells/1,000 parenchymal cells/hr). Following irradiation to at least 27 to 51 hr, this migration appeared to be relatively increased. Beyond this time, parenchymal areas were more difflcult to be defined as such. Labeled red cells were rarely observed to enter parenchyma despite the presence of nonlabeled erythrocytes within the parenchymal structure after irradiation. The vascular bed following irradiation increased greatiy as the parenchyma diminished to a minimum of less than 10% control at 75 hr. Despite these changes in the architecture of the marrow, the average density of labeled cells per area of marrow corresponded to values expected on the assumption of a free-flowing circulation. The technique used at present did not allow us to distinguish, at all times, between a free-flowing circulation through intact sinusoids or through areas in which the sinusoidal wall, as such, was destroyed. (auth)