[Dynamics of sister chromatid exchange after in vivo exposure to thiophosphamide]

Thiophosphamide (T) was i.v. administered into New Zealand rabbit (4 mg/kg). The rate of SCE in blood lymphocytes was increased up to 21st day after T administration. There are two phases in dynamics curve of SCE--a rapid phase and a slow one. The rapid decrease of SCE's rate depends on cell mortality. The slow decrease of SCE rate is connected with reparation of chromosome damages and selection of cells in lymphopoietic tissue. It was demonstrated that the special class of cells with intermediate number of SCE exists in blood after T administration.