Placental function in maternal-fetal fat transport in XXXX .

@entity6 @entity1674 @entity13688 @entity3839 @entity653 @entity6334 @entity35 @entity1718 @entity4722
High levels of @entity1674 (TG) and free @entity1718 ( @entity6334 ) in maternal plasma, in @entity6 , promote fat passage to the fetus. In the @entity3839 - @entity6 @entity35 a significant correlation exists between maternal plasma and fetal tissue lipid contents, as shown by the accretion of labeled @entity1718 or @entity4722 used as markers of maternal fat transfer. The passage of lipids through the placenta is not direct--this organ serves as an interim storage barrier with its lipid content increasing in proportion to the maternal TG and @entity6334 level. Very low density lipoprotein (VLDL) TG are taken up with the aid of @entity13688 as evident from TG = @entity653 exchange when doubly labeled VLDL-TG are presented to the placenta. Esterification rate of albumin-bound @entity6334 is considerably higher indicating that the rate of TG lipolysis is rate limiting and that the @entity6334 are the main precursor of the placental lipids. The uptake of both @entity6334 and VLDL-TG is associated with the retention of a substantial amount of @entity6334 in the placenta. The size of the @entity6334 pool corresponds to the size of the extracellular fluid space. The @entity6334 cannot be eluted by repeated washing, suggesting that they are membrane bound. Placental slices with prelabeled TG gradually release @entity6334 into the medium upon reincubation with @entity6334 -free albumin, indicating that TG and @entity6334 traverse the placenta in part by a sequential process of esterification and lipolysis and in part by diffusion as @entity6334 . The latter are probably moving from the maternal to the fetal side within the interfacial capillary membrane lipids.
