Experimental transfusion of lymphocytes

Lymphocytes, obtained from the intestinal lymph of rats and labeled with radiochromium or radiophosphate, were injected intravenously into rats. Both autogenous and homologous lymphocytes which were motile at the time of injection were used. No appreciable radioactivity became evident in the intestinal lymph until 4 hours after injection, but as much as half of the injected material was recovered in the lymph of the subsequent 24 hours. All the radioactivity disappeared from the blood within a half-hour, and began to reappear within 4 hours to reach maximal activity at about 24 hours. Tissue distribution determined at intervals indicated that 73% of the injected material was in the spleen at one-half hour, and that there was a gradual decrease to 7% by 72 hours. The content in bone marrow decreased from 4.5 to 1.3% at the same time. The thymus gland, lymph nodes, liver and small intestine showed increases over this same period. An active migratory process of lymphocytes is clearly indicated.