The human gonadotropin-releasing hormone (GnRH) precursor comprises the GnRH sequence followed by an extension of 59 amino acids. Basic amino acid residues in the carboxyl terminal extension may represent sites of processing to biologically active peptides. A synthetic peptide comprising the first 13 amino acids (H X Asp-Ala-Glu-Asn-Leu-Ile-Asp-Ser-Phe-Gln-Glu-Ile-Val X OH) of the 59-amino acid peptide was found to stimulate the release of gonadotropic hormones from human and baboon anterior pituitary cells in culture. The peptide did not affect thyrotropin or prolactin secretion. A GnRH antagonist did not inhibit gonadotropin stimulation by the peptide, and the peptide did not compete with GnRH for GnRH pituitary receptors, indicating that the action of the peptide is independent of the GnRH receptor. The GnRH precursor contains two distinct peptide sequences capable of stimulating gonadotropin release from human and baboon pituitary cells.
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http://dx.doi.org/10.1126/science.3082009 | DOI Listing |
J Obstet Gynaecol India
December 2024
Nowrosjee Wadia Maternity Hospital, Mumbai, India.
Endometriosis affects about 10 percent women in the reproductive age group globally and approximately 42 million in India. Managing the patient's pain symptoms associated with endometriosis appears to be the cornerstone in endometriosis disease management. The ideal medical treatment in endometriosis would be suppressing estradiol enough to alleviate symptoms of endometriosis but maintain sufficient levels to mitigate hypoestrogenic side effects.
View Article and Find Full Text PDFJ Obes Metab Syndr
December 2024
Department of Obstetrics and Gynecology, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea.
The core pathophysiology of polycystic ovary syndrome involves an overproduction of androgens primarily originating from ovarian thecal cells. Two major external triggers promote androgen overproduction in the ovaries: the increased secretion of luteinizing hormone, a consequence of aberrant hypothalamic gonadotropin-releasing hormone secretion dynamics, and compensatory hyperinsulinemia resulting from insulin resistance. Obesity interacts with polycystic ovary syndrome in multiple ways, but a major role of obesity in its pathophysiology is the exacerbation of insulin resistance.
View Article and Find Full Text PDFBull Exp Biol Med
August 2024
Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
Poult Sci
July 2024
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450046, China; Henan Key Laboratory for Innovation and Utilization of Chicken Germplasm Resources, Zhengzhou 450046, China. Electronic address:
The "KNDy neurons" located in the hypothalamic arcuate nucleus (ARC) of mammals are known to co-express kisspeptin, neurokinin B (NKB), and dynorphin (DYN), and have been identified as key mediators of the feedback regulation of steroid hormones on gonadotropin-releasing hormone (GnRH). However, in birds, the genes encoding kisspeptin and its receptor GPR54 are genomic lost, leaving unclear mechanisms for feedback regulation of GnRH by steroid hormones. Here, the genes tachykinin 3 (TAC3) and prodynorphin (PDYN) encoding chicken NKB and DYN neuropeptides were successfully cloned.
View Article and Find Full Text PDFGen Comp Endocrinol
May 2024
Department of Biology, Faculty of Marine and Environmental Sciences, University of Cádiz, Puerto Real (Cádiz), Spain; Marine Research Institute (INMAR), Marine Campus of International Excellence (CEIMAR) and Agrifood Campus of International Excellence (ceiA3), Puerto Real (Cádiz), Spain; The European University of the Seas (SEA-EU), Cádiz, Spain. Electronic address:
Gonadotropin-inhibitory hormone (GnIH) was the first reported hypothalamic neuropeptide inhibiting reproduction in vertebrates. Since its discovery in the quail brain, its orthologs have been identified in a variety of vertebrate species and even protochordates. Depending on the species, the GnIH precursor polypeptides comprise two, three or four mature peptides of the RFamide family.
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