Biomaterial Database

[Dynamics and significance of transferrin receptors in various human placental cell membranes]. 1984

T Hirohashi

It has been postulated that the process of iron transfer to the human fetus begins with the binding of maternal transferrin-iron complexes to placental transferrin receptors. This presentation deals with the dynamics of transferrin receptors on the cell membrane of trophoblastic cells including normal placenta cells, molar trophoblasts and choriocarcinoma cell lines (GCH-1, GCH-2, ENAMI). Results were as follows. Receptors for transferrin were observed on all the trophoblastic cell membranes tested. The transferrin receptors increased with the gestational weeks. Transferrin receptors on molar trophoblasts were approximately one-half to twice as numerous as those on normal trophoblasts. The transferrin receptors on choriocarcinoma cell lines were five to ten times as numerous as those on normal trophoblast. Thymidine uptake and native hCG secretion in choriocarcinoma cell lines increased with transferrin-iron addition to these mediums (but no increase in the beta-hCG secretion in the medium was observed). On the other hand, the transferrin receptors on these membranes decreased.

UI	MeSH Term	Description	Entries
D010920	Placenta	A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).	Placentoma, Normal,Placentome,Placentas,Placentomes
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D011990	Receptors, Transferrin	Membrane glycoproteins found in high concentrations on iron-utilizing cells. They specifically bind iron-bearing transferrin, are endocytosed with its ligand and then returned to the cell surface where transferrin without its iron is released.	Transferrin Receptors,Transferrin Receptor,Receptor, Transferrin
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002822	Choriocarcinoma	A malignant metastatic form of trophoblastic tumors. Unlike the HYDATIDIFORM MOLE, choriocarcinoma contains no CHORIONIC VILLI but rather sheets of undifferentiated cytotrophoblasts and syncytiotrophoblasts (TROPHOBLASTS). It is characterized by the large amounts of CHORIONIC GONADOTROPIN produced. Tissue origins can be determined by DNA analyses: placental (fetal) origin or non-placental origin (CHORIOCARCINOMA, NON-GESTATIONAL).	Choriocarcinomas
D002824	Chorionic Villi	Threadlike vascular projections of the chorion. Chorionic villi may be free or embedded within the DECIDUA forming the site for exchange of substances between fetal and maternal blood (PLACENTA).	Placental Villi,Labyrinth of the Placenta,Labyrinthine Placenta,Placental Labyrinth Layer,Chorionic Villus,Labyrinth Layer, Placental,Placental Labyrinth Layers,Placental Villus,Villi, Chorionic,Villi, Placental,Villus, Chorionic,Villus, Placental
D005260	Female		Females
D006063	Chorionic Gonadotropin	A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).	Chorionic Gonadotropin, Human,HCG (Human Chorionic Gonadotropin),Biogonadil,Choriogonadotropin,Choriogonin,Chorulon,Gonabion,Human Chorionic Gonadotropin,Pregnyl,Gonadotropin, Chorionic,Gonadotropin, Human Chorionic