Rat granulated metrial gland cells differentiate in pregnant chimeric mice and may be cytotoxic for mouse trophoblast.

Shielding an ovary and part of the uterus of mice during irradiation allowed chimeric mice, reconstituted with rat or mouse bone marrow (respectively, RBM and MBM chimeras), to be studied in a subsequent pregnancy. Some of the granulated metrial gland (GMG) cells which differentiated in the RBM chimeric mice were rat GMG cells, showing the contribution of donor bone marrow precursors to the uterine response to pregnancy. Rat and mouse GMG cells were found in the maternal blood spaces of the placental labyrinth adjacent to the degenerate layer 1 trophoblast. This suggests that both rat and mouse GMG cells exhibit cytotoxic activity against the mouse trophoblast.