Transplantation of fetal liver of different ages in the rat.

This study investigates the effect of fetal liver transplantation in reconstituting hemopoiesis in supralethally irradiated rats. Different cell doses of fetuses at the embryonic age of 15 and 18 days were compared to equivalent cell doses of adult bone marrow cells. Although the frequency of engraftment ranged between 75 and 100% in all the groups of animals studied, the survival rate at 30 days after TBI did not show any significant difference between the fetal liver and the bone marrow treated recipients. The bone marrow transplants performed in littermate rats almost doubled the percentage of survivors at 30 days and showed a cell dose relationship suggesting that, in the closed colony of random-bred rats used, the mortality after bone marrow and fetal liver transplants was mainly due to graft-versus-host-disease. Antibiotic prophylaxis and treatment during the experiment did not modify the results in a separate group of fetal liver and bone marrow transplanted rats. In the rat model system used in this set of experiments fetal liver did not reveal any advantage over bone marrow transplantation.