Effects of Adrenalectomy on Radiation Changes in Thymo-lymphatic Organs of Mice

In the present study, the effects of adrenalectomy upon the irradiation damage in the thymo-lymphatic organs were investigated. Young adult CF#1 male mice were used as experimental animals. The mice were divided into three groups : the first group received 300 R of total body X-irradiation immediately after bilateral adrenalectomy, the second group received only 300 R of total body X-irradiation and the third group was kept as nontreated controls. The experimental animals were killed at 2, 4, 6 and 24 hours after the X-irradiation. The weight of the thymo-lymphatic organs was precisely measured. Lymphocyte nuclei in smears of the thymus and of the mesenteric lymph node were stained with hematoxylin or fast green FCF, and the number of irradiation damaged cells were counted. The damaged cells were observed to be homogeneous in hematoxylin staining and cresent shaped in fast green staining. Changes in organ weight and damaged cell count were compared between these three groups. The loss in organ weight was less in the adrenalectomized irradiated mice than in animals given irradiation alone. The damaged cell count was significantly less in the adrenalectomized irradiated mice only at 2 hours after the irradiation. These findings were also confirmed by histological sections. Damaged cells were phagocytized by macrophages at 6 hours after the treatment, and most of the cell debris was gone by 24 hours after the treatment, suggesting the digestion of dead cells by macrophages. These findings indicate that the adrenalectomy may modify the effect of total body irradiation at the early stage after irradiation.