The influence of (+/-)-15-deoxyspergualin on experimental transplantation and its immunopharmacological mode of action.

15-Deoxyspergualin, a novel structure which was described to have anti-tumor activity, was tested on its influence on the survival time of transplanted organs. Prolongation of graft survival was demonstrated in rat skin (LEW----Fischer), islet cells heart and kidney transplantation (DA----LEW) as well as in allogeneic tumor transplantation in mice (C57Bl/6----Balb/c). Especially in the kidney transplantation a long-lasting transplant survival time was observed, indicating induction of tolerance. Examination of its immunopharmacological properties showed that the mononuclear phagocytes and not the lymphocytes are primarily affected by the substance, thus expressing a new mode of action for a substance being effective in transplantation immunology.