GRANULATED METRIAL GLAND-CELLS IN THE UTERINE WALL AND PLACENTA OF THE PREGNANT WOODMOUSE, APODEMUS-SYLVATICUS

The differentiation of the decidua and the fetal placenta in the woodm ouse, Apodemus sylvaticus, was studied with particular attention to th e differentiation and migration of granulated metrial gland cells. Num erous granulated metrial gland cells, characterised by their glycoprot ein-containing cytoplasmic granules, were found to differentiate in th e decidua basalis and metrial gland of the uterine wall during the fir st half of pregnancy. Many granulated metrial gland cells appeared to pass into the lumina of blood vessels in the uterine wall and reach th e maternal blood spaces of the fetal placenta. In the labyrinthine pla centa some granulated metrial gland cells were found associated with d egenerate cytotrophoblast lining the maternal blood spaces. This findi ng supports previous studies of the mouse, Mus musculus, suggesting th at the labyrinthine placenta is an important site for the function of the bone marrow-derived granulated metrial gland cell.