The decrease in endometrial glandular expression of PGRAB protein indicates a decline in PGRAB-mediated progesterone action in endometrial glands from days 14 to 30 of early pregnancy, which could influence secretion of histotroph
. Conversely, the increase in PGRAB expression in utero-placental blood vessels is associated with increased placental blood flow and angiogenesis in early pregnancy, and these are essential for establishment of pregnancy and healthy fetal growth.
Proteomic characterization of histotroph
during the preimplantation phase of the estrous cycle in cattle.
These membranes form the placenta that provides for histotrophic (uterine histotroph
) and hematotrophic (exchange of nutrients and gases between maternal to fetal-placental blood) nutrition of the embryo/fetus.
The secretory products of the endometrial glands are known collectively as histotroph
and consist of enzymes, growth factors, cytokines, lymphokines, hormones, transport proteins, and other substances.
Cycling endometrium provides a microenvironment in which molecules secreted by uterine cells, including glycoproteins mucin-1- (Muc 1-) and tumour-associated glycoprotein-72 (TAG-72), are transported into the uterine lumen, where they represent histotrophs
required for blastocyst growth and development .