Sex hormone-binding globulin stimulates chorionic gonadotrophin secretion from human cytotrophoblasts in culture

The effects of sex hormone-binding globulin (SHBG) on the secretion of human chorionic gonadotrophin (HCG) and cAMP by cultured human cytotrophoblasts were investigated. Cytotrophoblasts obtained from normal term placentae were cultured in serum-free medium with or without the addition of human SHBG...

Full description

Saved in:
Bibliographic Details
Published in:Human reproduction (Oxford) 1998-05, Vol.13 (5), p.1368-1373
Main Authors: Queipo, G, Deas, M, Arranz, C, Cariño, C, González, R, Larrea, F
Format: Article
Language:English
Subjects:
8-Bromo Cyclic Adenosine Monophosphate - pharmacology
Animal cells
Biological and medical sciences
Cell cultures. Hybridization. Fusion
Chorionic Gonadotropin - metabolism
Culture Media, Serum-Free
Culture Techniques
Cyclic AMP - biosynthesis
Dihydrotestosterone - pharmacology
Estradiol - pharmacology
Female
Fundamental and applied biological sciences. Psychology
Humans
Molecular and cellular biology
Pregnancy
Sex Hormone-Binding Globulin - pharmacology
Trophoblasts - drug effects
Trophoblasts - metabolism
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The effects of sex hormone-binding globulin (SHBG) on the secretion of human chorionic gonadotrophin (HCG) and cAMP by cultured human cytotrophoblasts were investigated. Cytotrophoblasts obtained from normal term placentae were cultured in serum-free medium with or without the addition of human SHBG. The presence of SHBG in the medium increased the release of HCG and the accumulation of cAMP. Ligand-free SHBG was able to raise both HCG and cAMP concentrations and the maximal response was observed with 1 nM of the steroid-binding globulin. Addition of either oestradiol or 5alpha-dihydro-testosterone (DHT) to cultures previously incubated with SHBG in a final molar ratio of 1:10 resulted in a further increase of HCG and cAMP concentrations. This effect was blocked when cultured placental cells were exposed to SHBG that was previously saturated with DHT or when incubated in the presence of steroids only. The results of the present study provide evidence for the in-vitro regulation of HCG secretion by SHBG and further support the concept that this steroid-binding protein may act as a mediator of steroid action at the cellular level. Finally, the increase in cAMP suggests that SHBG receptor located in the surface of syncytiotrophoblast membranes is coupled to adenylate cyclase as part of the G-protein receptor family. Our results may provide new insights into the biological implications of extracellular steroid-binding proteins as well as new perspectives on the endocrinology of pregnancy.
ISSN:0268-1161
1460-2350
DOI:10.1093/humrep/13.5.1368