Treatment with 15-deoxyspergualin induces temporal suppression of hemopoiesis and changes thymocyte populations in mice.

Effects of the immunosuppressive agent, 15-deoxyspergualin (DSG) on hemopoiesis and thymocyte populations were examined in mice. The numbers of bone marrow (BM) cells decreased after the administration of DSG for up to 8 days, and the extent of this decrease was correlated inversely to the time of administration. Conversely, the BM cells of DSG-treated mice had enhanced proliferative responses in vitro and in viv. Deoxymethylspergualin, DSG analogue, directly suppressed the proliferation of BM cells in vitro in a time and dose-dependent manner. Total thymocyte counts decreased following the administration of DSG. The numbers of immature, peanut agglutinin-binding (PNA+) thymocytes decreased notably. Minor changes were observed in the mature thymocytes and spleen cells of DSG-treated mice.