Cell Migration from the Thymus to Other Lymphoid Organs in Hamsters of Different Ages

Abstract

Abstract Hamsters of different ages were labeled intra thymus and intravenously with 3H-thymidine. After extraction of nucleic acids, measurements of DNA content and tritium activity, the specific activity of different organs was calculated. By comparing the pattern of label of different organs after these quantitative measurements, it could be concluded that a good local labeling was obtained in all intra thymus injected animals, and a quantitatively significant transport of label could be shown to occur from the thymus to the mesenteric lymph nodes and Peyer’s patches in animals of both sexes, and also to the spleen of male animals. This transport was shown in 23 day old hamsters in which the lymphatic organs except the thymus still are immature. No such transport could be demonstrated in adult animals. Autoradiographic examinations also showed a good local labeling in the intra thymus injected animals and a migration of heavily labeled cells to mesenteric lymph nodes in 7 days old animals, and to mesenteric lymph nodes, Peyer’s patches and the white pulp of the spleen in 23 days old animals. Only single heavily labeled cells were found in the "peripheral" lymphatic organs of adult animals.