Kinetic parameters of bone marrow stem cells using in vivo suicide by tritiated thymidine or by hydroxyurea.

The kinetics of colony-forming units (CFU) ment. A computer model helped to explain of the bone marrow in mice were studied the experimental results. The feedback using a method involving the suicide of mechanism seemed to be initiated by the cells in vivo by 3H-TdR or hydroxyurea. depletion of the compartment of maturing After selectively killing cells in S phase, cells. This hypothesis is supported by the the surviving cells traversed S phase in a fact that the CFU response to S-phase cyclic fashion. This enabled the duration cell killing was similar in two strains of of the cycle and of the S phase of CFU mice and was independent of the proporto be measured-8 hr and 4 hr. respection of CFU in S phase. which was approxtively. It was shown that quiescent stem mately 0#{176}/o in the C57B1 and 2O#{176}/o in the cells pass into the proliferative compartC3H mice.