The circulatory behaviour of normal and enzyme altered thymocytes in rats.

The circulation of rat thymocytes and factors which may control their pathway were studied. Evidence was obtained that intravenously infused thymocytes migrate from blood to spleen and lymph nodes in a manner similar to lymphocytes, though in lesser amounts. Thymocytes, incubated with neuraminidase prior to intravenous infusion, exhibit markedly altered cell migration.

The effect of neuraminidase on the fate of transfused lymphocytes.

Evidence has been obtained that incubation of rat lymphocytes with neuraminidase, prior to intravenous transfusion into allogeneic or syngeneic recipients, alters the distribution of the cells. Many enzyme-treated lymphocytes initially become trapped in the liver, and there is a decrease in the selective accumulation of these cells in the lymph nodes and spleen. Subsequently, many enzyme-altered cells emigrate from the liver, concentrate in lymph nodes, and recirculate to the lymph.

Lymphocytes: circulation altered by trypsin.

Rat thoracic duct lymphocytes altered by trypsin in vitro do not circulate normally. At early intervals after transfusion of lymphocytes labeled with chromium-51 selective accumulation of radioactivity in the lymph nodes is abolished, while uptake in the spleen is not reduced. Later, the cells appear to "home" to lymph nodes and recirculate to the lymph.