Mucopolysaccharide histochemistry of the mink uterus during gestation.

Abstract

Histochemical localization of polysaccharide and protein-polysaccharide complexes (mucopolysaccharides or MPS) was studied in the uteri of female mink in three phases of gestation. These phases were the period of delay which precedes nidation, days 2 to 7 postimplantation, and days 13 to 16 postimplantation. Glycogen was found in uterine epithelial cells during delay, but appears to be depleted at nidation. This depletion may reflect the postnidation increases in progesterone observed in mink plasma. There is a general increase in MPS concentration in postimplantation uteri when compared with delay uteri. In addition, sulfated MPS are found in the uterine glands of postimplantation specimens, but not in the glands of delay specimens. The observed increase and shift in site of MPS production may reflect a perinidational increase in uterine protein.An acidic MPS layer is present between fetal and maternal placental components during postimplantation pregnancy. This coat appears to be synthesized by the trophoblast and may represent an immunoisolatory mechanism.