ABSTRACT
In 1977, Frindel et al. reported the presence in fetal calf bone marrow of a low molecular factor, the tetrapeptide Ac-N-Ser-Asp-Lys-Pro (AcSDKP), capable of inhibiting in vivo the hematopoietic pluripotent stem cell (CFU-S) recruitment into DNA synthesis and to increase the survival of mice which had received lethal doses of cytosine arabinoside (AraC), a phase-specific drug. Considering the potential clinical importance of CFU-S proliferation inhibitor during anticancer chemotherapy and the importance of monitoring the inhibitor by immunological methods, we tried to determine if a similar inhibitor is present in humans. Preliminary results indicate the presence in human placenta of an inhibitor coeluted with AcSDKP and which is effective in inhibiting murine CFU-S.
