Abstract Polycystic Ovarian Syndrome (PCOS) is a disease that characterized by an increased Gonadotropin-Releasing-Hormone (GnRH) pulsatile frequency, causing altered LH/FSH ratio. More precisely Luteinizing Hormone (LH) secretion compared to decreased Follicle-Stimulating (FSH) leads the development of hyperandrogenism and low-level concentration estrogens therefore negative estrogenic feedbac...

A case of a thirty-eight year old man with pseudohypoparathyroidism (PHP) type 1 associated with gonadotropin resistance and hypercalcitoninaemia was reported. The basal levels of the luteinizing hormone and follicle-stimulating hormone were elevated, and the responses to the luteinizing hormone-releasing hormone were exaggerated. The basal level of testosterone was normal, but the response to ...

We report on ovarian dysfunction in a 3-year-old girl with blepharophimosis, ptosis, and epicanthus inversus syndrome (BPES). A gonadotropin releasing hormone test showed hyperresponses of luteinizing hormone (<0.2-->7.2 mIU/ml) and follicle-stimulating hormone (7.1-->44.8 mIU/ml), and a human menopause gonadotropin test yielded no estradiol response (13-->11 pg/ml). The results suggest that pr...

Clinical findings and endocrine studies are reported concerning six subjects (from two pedigrees) suffering from isolated hypogonadotropic hypogonadism. Their complete lack of any gonadotropin response to clomiphene stimulation, together with positive responses of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to LH-releasing-hormone stimulation (LH-RH) provide evidence for a h...

The human gonadotropin-releasing hormone (GnRH) precursor consists of the GnRH sequence followed by a 59-amino acid carboxyl-terminal extension. A 56-amino acid peptide within this extension has been shown to stimulate gonadotropin release, and this activity has been localized to its amino-terminal region. A series of seven overlapping peptide fragments corresponding to the first 24 amino acids...

The hypothalamus regulates the secretion of anterior pituitary hormones via release of releasing hormones into the hypophysial portal vasculature. Additional neuromessengers act at the pituitary to modulate responses to the hypothalamic hormones. For example, neuropeptide Y enhances the effect of gonadotropin-releasing hormone and the response to the prolactin-inhibiting hormone dopamine.