HISTOLOGICAL AND HISTOCHEMICAL CHANGES IN THE HEMATOPOIETIC TISSUES OF RATS AFTER TOTAL BODY X-IRRADIATION Ⅰ. THE SPLEEN / 解剖学报

ABSTRACT

Sixty-two adult rats were employed, 8 of them served as controls and the remainderwere exposed to whole body X-irradiation in a single dose of 500 r. The animals weresacrificed at intervals of 2, 6, 12 hours and 1, 3, 6, 10, 20, 30 days after irradiation.Specimens of the spleen were obtained from both the experimental and control groups forhistological and histochemical examinations. The data indicate that 1. A marked decrease in the spleen size and in the number of its Malpighian cor-puscles, and a severe destruction of its architecture with an extensive necrosis of lympho-cytes, occurred within 24 hours after irradiation. Regeneration began on the 6th day andthe spleen became almost normal at the end of the 30th day. Among the various cell-types of the spleen, the radiosensitivity was highest in the lymphocytes and lowest in theplasma cells. The reticular cells were apparently injured during the early stage afterirradiation, though they belonged to the radioresistant series. 2. The decrease in staining intensity of both desoxyribose-and ribose nucleic acidsof the spleen started as early as 2 hours after irradiation and continued to reach itsmaximum in a period of 1--3 days. This result was produced not only by the depletionin cell population, but also by the decrease in nucleic acid content of individual cells. 3. A marked increase in the activity of nonspecific alkaline phosphatase and ade-nosine triphosphatase occurred within 24 hours and it returned gradually to normal fromthe 3rd day to the 10th day after irradiation. 4. There was no significant change in the amount of protein-bound SH-groups ofvarious cell-types of the spleen in each post-irradiation period. 5. No difference was found in the changes produced by irradiation between theanimals fed with normal diet and those fed with phospholipides in addition.