[Cell division, cytolysis and regeneration after cyclophosphamide]

Cytokinetic effects of 5 or 20 mg cyclophosphamide/kg body weight on thoracic duct lymph and blood cells of calves were analyzed. The larger dose caused a temporary cessation of lymphoid cell division, reduced the output of nondividing small lymphoid cells and impaired proliferation of neutrophil precursors. Feedback mechanisms acting on GO/G1 cells controlled the proliferation of lymphoid cells.