Endocrine Abstracts

We have earlier shown that treatment with gonadotropin releasing hormone antagonist blocked adrenocortical tumour progression through gonadotropin suppression in inhibin α/SV40 T-antigen (inhα/Tag) transgenic (TG) mice. Hereby, we investigated the molecular mechanisms underlying the GnRH antagonist (Cetrorelix acetate; GnRH-a) treatment induced potential antitumor effects on gonadal somatic cell and adrenocortical tumors in vivo and in vitro. In...

G protein-coupled receptors (GPCRs) are the largest family of mammalian receptors, modulating most aspects of endocrine homeostasis. GPCRs can associate to form dimers and higher order oligomers, acting to diversify receptor functionality. Most studies have explored the functional significance of GPCR dimerization in vitro and we have recently demonstrated the functional relevance of GPCR dimerization in vivo. Using the LH receptor (LHR), we have shown that t...

The gonadotrophin receptors, LH receptor (LHR) and FSH receptor (FSHR) are G-protein coupled receptors, vital in regulating reproductive functions. During the follicular phase of the ovarian cycle, FSHR and LHR are separately localised to discrete cellular compartments, granulosa and theca cells respectively, where they control steroidogenesis and follicle maturation. However, as the follicle develops, LHR expression is induced in granulosa cells, resulting in temporary co-exp...

The gonadotrophin receptors, LH receptor (LHR) and FSHR are G-protein coupled receptors, vital in mediating reproductive functions. During the follicular phase of the ovarian cycle, FSHR and LHR are separately localised to discrete cellular compartments, granulosa and theca cells respectively, where they control steroidogenesis and follicle maturation. However, as the follicle develops, LHR expression is induced in granulosa cells, resulting in co-expression of FSHR and LHR in...

Gonadotropin-releasing hormone (GnRH) analogues are now the standard hormonal treatment for prostate cancer. A fundamental difference between GnRH agonist and antagonist treatment is the permanent suppression of both gonadotropins (LH and FSH) by antagonist, while a rebound in FSH is associated with agonist treatment. The benefits of antagonist include the immediate onset of action and profound long-term suppression of FSH, suggested to be an independent growth factor in prost...

The classical model of GPCR activation entails the binding of a single ligand to a single receptor molecule, followed by transmembrane signal transduction to the appropriate G protein(s). The possibility of GPCRs functioning as dimers or oligomers still remains controversial, and is largely based on in vitro studies on transfected cells. The glycoprotein hormone receptors, including that of LH (LHCGR), differ from most GPCRs by their large extracellular ligand-binding...

G protein-coupled receptors (GPCRs) are one of the largest families of the mammalian genome, mediating the effects of approximately 40% of prescribed drugs. Until recently, accepted dogma stated that GPCRs exist as monomers, however, it is becoming evident that GPCRs can form higher order dimer/oligomer complexes which provide important mechanisms for the diversification of receptor function. The LHCGR is a class A family GPCR, primarily coupling to the Gαs pat...

Spermatozoa are dependent on the proximal epididymis environment to complete their maturation. However, no single specific factor crucial for this process has been identified. Rnase9 and Rnase10 are expressed specifically in the murine proximal epididymis. Located on chromosome 14C1 only 28 kb apart, they do not show high homology with each other. An orthologue of both genes exist in the rat and human, and ‘Train A’ (porcine orthologue) is the most abun...

A common polymorphism of the ERβ gene (AluI) located in 3′-UTR of exon 8 has been shown to be associated with clinical features of altered estrogen action in tissues where this gene is expressed. It has recently been shown that GnRH neurons express ERβ, indicating that this receptor may participate in the feedback regulation of gonadotrophin secretion. We therefore studied the association of gonadotrophin levels and the AluI polymorp...

Hypersecretion of hCG in transgenic mice produces profound alterations in the ovary, thus triggering failures in ovulation and affecting fertility. The objective of this study was to analyze the response of immature female mice overexpressing moderated (hCGβ+; 0.1 IU/ml) and elevated (hCGαβ+; 7 IU/ml) levels of hCG to an ovulation induction protocol (PMSG 7.5 IU i.p.; after 48 h, hCG 7.5 IU i.p). Wild-type (WT) females subjected to the same protocol were used as...