Studies on T and B lymphocytes in rats bearing methylcholanthrene-induced tumor.

The authors have studied the influence of primary, methylcholanthrene-induced tumor on T and B lymphocytes of spleen, thymus, draining lymph nodes and peripheral blood of rats. Differences in weight of tumors were found to correlate with changes in proportionality of T and B lymphocytes of followed organs. Small tumors induced but insignificant changes. There was increased trapping of T lymphocytes in spleen and lymph nodes with simultaneous decrease in peripheral blood. The authors noted a high percentage of blasts. B lymphocytes showed a tendency to compensate for the loss of T cells. Large, progressively growing tumors caused evident exhaustion in the number of both cell types in lymph nodes and peripheral blood. In the spleen there was slower exhaustion. Reduction in the number of B lymphocytes correlated with the size of tumor. Blasts disappeared. Proportionality of T and B lymphocytes in thymus did not appear to be influenced by the size of tumor.