In many vertebrates, social interactions regulate reproductive capacity by altering the activity of the hypothalamic-pituitary-gonadal (HPG) axis. To better understand the mechanisms underlying social regulation of reproduction, we investigated the relationship between social status and one main component of the HPG axis: expression levels of gonadotropin-releasing hormone receptor (GnRH-R). So...

The hypothalamic-pituitary-gonadal (HPG) axis plays a critical role in the control of reproduction. Two key hormonal components of the HPG axis are gonadal steroids and gonadotropin-releasing hormone (GnRH). Gonadal steroids are known to organize the development of neural substrates which control adult reproductive behavior; GnRH is required for normal reproductive structure and function. The p...

The crucial role of pituitary GnRH receptors (GnRH-R) in the control of reproductive functions is well established. These receptors are the target of GnRH agonists (through receptor desensitization) and antagonists (through receptor blockade) for the treatment of steroid-dependent pathologies, including hormone-dependent tumors. It has also become increasingly clear that GnRH-R are expressed in...

About 50-64% of human breast cancers express receptors for GnRH-I. Direct antiproliferative effects of analogs of GnRH-I on human breast cancer cell lines have been shown. They are at least in part mediated by antagonizing growth promoting effects of estradiol, epidermal growth factor (EGF) or insulin-like growth factor. Recently, expression of a putative receptor for GnRH-II in human tissues w...

background: general concern is that the pregnancy rate is higher with gnrh-agonist as a protocol of pituitary suppression. gnrh-antagonist protocol provides a shorter period of administration and an easy flexible protocol. objective: in this study, the outcomes of gnrh agonist and antagonist in icsi cycles are compared in normo responder patients. materials and methods: in this randomized clini...

Gonadotropin-releasing hormone (GnRH) neurons integrate synaptic information in their dendrites in order to precisely control GnRH secretion and hence fertility. Recent discoveries concerning the structure and function of GnRH neuron dendrites have shed new light on the control of GnRH neuron excitability and GnRH secretion. This work suggests that GnRH neurons have a unique projection to the m...

A functional GnRH receptor (GnRH-R) in the anterior pituitary is critical for normal LH/FSH secretion, pubertal development and reproduction. Inactivating mutations of the GnRH-R have been identified in patients with idiopathic hypogonadotrophic hypogonadism. In this article we summarize phenotypic characteristics of these patients and focus on specific functional alterations of the human GnRH-...

BACKGROUND To test if early-cleavage was a strong predictor of pregnancy in patients receiving either a GnRH agonist long protocol or a GnRH antagonist protocol for in-vitro fertilization treatment (IVF) and intracytoplasmic sperm injection (ICSI). METHODS This retrospective study included 534 patients undergoing a fresh cycle of oocyte retrieval and the day-3 embryo transfer (from 22 to 46 y...

Mast cells occur in the brain and their number changes with reproductive status. While it has been suggested that brain mast cells contain the mammalian hypothalamic form of gonadotropin-releasing hormone (GnRH-I), it is not known whether mast cells synthesize GnRH-I de novo. In the present study, mast cells in the rat thalamus were immunoreactive to antisera generated against GnRH-I and the Gn...

Gonadotrophin-releasing hormone (GnRH) neurones located within the brain are the final neuroendocrine output regulating the reproductive hormone axis. Their small number and scattered distribution in the hypothalamus make them particularly difficult to study in vivo. The Cre/loxP system is a valuable tool to delete genes in specific cells and tissues. We report the production of two mouse lines...