Reaction of different functional zones in mouse thymus and spleen lymphoid tissue to γ-irradiation

Abstract

It is shown that immune organs respond to single ,f-radiation of 6.9 Gy in a cyclic manner. Acute reaction characterized by spontaneous lymphocyte lysis in the thymus and spleen develops on day 1 postirradiation and takes 3 and 7 days, respectively. This is followed by enhancement of thymoeyte mitotic activity and migration of young ceils to the thymic cortex and splenic lymphoid tissue. Twenty-one day postirradiation lymphoid cell populations in the thymus and spleen recover to 70-90 and 55-70%, respectively.