Effect of Thymic Irradiation on the Development of New-born Mice

Summary

An x-ray dose of 900 rads to new-born strain A mice with partial shielding of the inferior extremities, results in death from a fatal wasting disease before they are 6 weeks old. Shielding of the thymic area during irradiation prevents the development of the disease. In addition, the wasting disease can be prevented in a high percentage of animals by transplantation of fresh thymus from new-born animals within 48 hours after irradiation. Transplantation carried out 2 weeks after irradiation is ineffective. Animals 4 to 6 days old at the time of irradiation do not develop the wasting disease. On the basis of these findings, the role of the thymus in lymphopoiesis and immunological capacity is discussed.