Cell proliferation in the thymus of Ehrlich ascites tumor bearing mice.

Thymic involution of Ehrlich ascites tumor bearing Swiss and NMRI mice was associated with an increased incorporation of 3H-thymidine into thymus DNA and an enhanced activity of adenosine deaminase. The apparent depletion time constants, which were determined by the following time course of the retention of 3H-DNA, indicated that the rate cell depletion was increased in the thymus of tumor bearing mice. The results suggest that the thymic involution was correlated with an increased proliferative activity and an accelerated depletion of thymic cells.