Deficiency of IGF-2 in the trophoblast decreased the mean fetal placenta weight by 21%, and deficiency in the ICM derivatives decreased it by 14% (Table 4). There was no significant change in the DNA content in either case (Table 5), and thus wet weight and DNA content give different indicators of size. With IGF-2 in excess (Igf2r ko), the wet weight of the placenta is enlarged even if the type 1 IGF receptor is inactive (Igf1r ko; see ). It follows that this enlargement must depend on a novel receptor in the derivatives of the trophectoderm (XR see ) or on direct interactions between IGF-2 produced in the con-ceptus and the maternal component of the placenta. For instance, local high IGF-2 levels may influence maternal capillary permeability and blood flow (see below). buy flovent inhaler
Fluid Transport to the Conceptus and the Volume of the Exocoelom Plus Amniotic Cavities
During early postimplantation development, there is no defined site for fluid entry into the conceptus: fluid probably passes through the trophoblast layers, Reichert’s membrane, the parietal endoderm, and the visceral endoderm before reaching the fetal precursor cells in the epiblast.