Aromatase P450 (P450arom), a product of the CYP19 gene, catalyzes the conversion of C19-steroids to estrogens. Human P450arom is expressed in placental syncytiotrophoblast, ovarian granulosa cells, and adipose stromal cells by use of tissue-specific promoters that are located 5' of unique untranslated first exons. Mononuclear cytotrophoblasts isolated from midterm human placenta spontaneously f...

A preparation of microvillous membrane vesicles from human placental syncytiotrophoblast binds transferrin to specific transferrin receptors. Transferrin binding to placental receptors is rapid, saturable, reversible, and specific. Approximately 2.5 X 10(13) receptors are present per milligram of membrane protein; the apparent association constant of transferrin for the placental receptor is 2....

Introduction Docosahexanoic (DHA) and arachidonic (ARA) acids are important for proper fetal development and accumulate in the fetus during gestation. They cannot be synthesized by the fetus and must be gained instead from the maternal blood supply via the syncytiotrophoblast, the transporting epithelium of the placenta. Cell biological experiments suggest that both membraneassociated placental...

It is now well established that human placenta secretes a protein hormone Human Placental Lactogen (HPL), also referred to as placental Somatomarnmotropin. It shows immunological crossreactivity with pituitary growth hormone and possesses both mammotropi.c and somatotropic effects (Jasiomovich and Maclaren, 1962, Kaplan and Grumbach 1968). This hormone is produced by syncytiotrophoblast layer o...

Through the use of immunohistochemical techniques, human chorionic gonadotropin has been localized to syncytiotrophoblastic cells of immature placenta, hydatidiform mole, chorioadenoma destruens, and choriocarcinoma. No gonadotropin has been detected in cytotrophoblast. Evidence is discussed which suggests that syncytiotrophoblast is the cell of origin of human chorionic gonadotropin. The obser...

Megalin and cubilin are multifunctional endocytic receptors associated with many transporting epithelia. They play an essential role in transport of nutrients through the visceral yolk sac of rodents during embryogenesis. Here, we immunolocalise them to the endodermal layer of the human yolk sac, and to the syncytiotrophoblast and cytotrophoblast cells of placental villi. In villi, the protein ...

Placental endoplasmic reticulum (ER) stress has been postulated in the pathophysiology of pre-eclampsia (PE) and intrauterine growth restriction (IUGR), but its activation remains elusive. Oxidative stress induced by ischaemia/hypoxia-reoxygenation activates ER stress in vitro. Here, we explored whether exposure to labour represents an in vivo model for the study of acute placental ER stress. E...