Effect of Neonatal Thymectomy on Induction of Leukemia by Virus in Rats. ∗

Summary

1. Neonatal thymectomy reduced the induction rate of leukemia by virus from 74.3% to 13.2% in one experiment and from 93.0% to 19.0% in another. 2. This indicates that many non-thymic lymphomas occurring in rats thymectomized one month after virus-infection(1) originated in cells which have been transformed in the thymus and seeded in other lymphoid organs prior to thymectomy. 3. The data also suggest a) that non-thymic lymphomas may be induced by the virus and b) that stressful agents which cause corticoid discharge might lower not only the incidence of the thymic, but also the non-thymic lymphomas.