[Transplacental passage of cells from mother to fetus: experimental approach and initial results in the rat].

The consequences of transfusion across the placenta of maternal cells to fetuses, supposed to elicit a Graft-Versus-Host-Reaction, are poorly investigated; the injection of pregnant rat whole blood cells to its own fetuses is proposed here as a convenient experimental model to improve the understanding of these consequences; indeed this technic is reliable as well as easy enough to carry out experiments on large samples. Preliminary results indicate that the injection is often followed by a runting disease, a thymic atrophy and a liver hypertrophy; splenomegaly does not occur. On the histologic level, the main features are as follows 1) modification of central lymphoïd organs, 2) blastic and/or granulocytic infiltrates of several other organs, namely the liver, the adrenal cortex and the thyroïd gland.