Mononuclear cell accumulations in the trophoblastic giant cell circulation in inbred strains of mice.

Marked accumulations of mononuclear cells in the trophoblastic giant cell layer of the pregnant mouse uterus have been investigated in the B10, B10.A, SWR/J and DBA/2J strains. Relatively low and approximately equal numbers of mononuclear cells in the trophoblastic giant cell layer were found throughout the ninth and eleventh days in conceptuses of both isogenically mated B10 female mice and those mated with B10.A males. Increased numbers of mononuclear cells in the trophoblastic giant cell layer were found throughout the tenth day in conceptuses of the former mating, while an even greater increase was found at approximately 9 am. on the tenth day in conceptuses of the latter. Conceptuses from B10.A females mated with B10 males have a higher number of mononuclear cells at about 9 am. on the tenth day than those from isogenically mated B10.A females, although the numbers are not as high as those found in conceptuses from B10 females mated with B10.A males. There appears to be no significant difference in numbers of mononuclear cells, at about 6 am, 9 am. and noon on the tenth day, between conceptuses from isogenically mated B10, B10.A, SWR/J and DBA/2J female mice.