The Effects of Ionizing Radiation on Growth and Regeneration of Intrarenal Thymus Grafts in Mice

Abstract

Observations have been made on growth and regeneration of intrarenal isologous thymus grafts in normal and irradiated C57BL mice. The growth of intrarenal thymus graft was found to be determined by the age of the donor thyIllus. No sex effect on thymus growth was demonstrated except for a partial male histoincompatibility effect. The autonomy of the thymus graft growth was demonstrated by refractoriness to environmental changes, due to irradiation in the host. Irradiation of newborn thymus graft reduced its growth rate. An adult intrarenal thymic graft, when irradiated, showed the same typical regeneration pattern established for the thymus in situ. Similarly, thigh shielding during irradiation and bone marrow injection after irradiation were also effective, enhancing intrarenal thymic graft regeneration. The rate of full recovery from radiation injury differed in the thymus in situ and in the intrarenal graft.