doi: 10.1046/j.ДЇruzzetti F, Bersi C, Parrini D, Ricci C, Genazzani AR. Evidence for a primary abnormality of thecal cell steroidogenesis in the polycystic ovary syndrome. Gilling-Smith C, Story H, Rogers V, Franks S. Inappropriate secretion of follicle-stimulating hormone and luteinizing hormone in polycystic ovarian disease. However, together with sex hormones, beta endorphin might play a key role in oocyte maturation.Д«eta endorphin Granulosa cells Opioids PCOS. In women with biochemical hyperandrogenemia, beta endorphin levels in FF correlated with testosterone levels.Д«eta Endorphin concentrations in serum and FF do not differ between PCOS- and non PCOS-women undergoing IVF. We found a significant correlation between the number of mature Metaphase II (MII) oocytes retrieved and beta endorphin concentration in FF. The concentration of the peptide was higher in serum than in FF, likely due to collection of FF after ovulation induction and corresponding to the early luteal phase. There was no difference in beta endorphin levels between PCOS- and non-PCOS women. Additionally, testosterone was measured before starting the stimulation protocol. Beta endorphin concentrations in serum and follicular fluid, serum levels of insulin, glucose, LH, estradiol and progesterone were measured. Follicular fluid was collected during oocyte retrieval and peripheral blood sampling was performed on the same day. The remaining 43 women served as controls.

Sixteen were stratified to the PCOS group using the Rotterdam criteria. Secondarily, to investigate associations between beta endorphin and other parameters.ДЇifty-nine women undergoing in vitro fertilization (IVF) were included in the study. Structural Biology Laboratory, The Salk Institute, La Jolla, CA, USA.To compare the concentrations of beta endorphin in serum and follicular fluid (FF) of PCOS- and non-PCOS women. Seuring, C.,В Gath, J.,В Verasdonck, J.,В Cadalbert, R.,В Rivier, J.,В Boeckmann, A.,В Meier, B.H.,В Riek, R. Solid-state NMR sequential assignment of the beta-endorphin peptide in its amyloid form.Analyses of ОІ-endorphin variants carrying mutations in Glu8 support the role of the protonation state of this residue in fibril disassembly, among other environmental changes. The secretory granule has an acidic pH but, on exocytosis, the ОІ-endorphin fibril would encounter neutral pH conditions (pHвЂ‰7.4) in the blood this pH change would result in deprotonation of Glu8 to release the hormone peptide from the amyloid. In the ОІ-endorphin amyloid, every layer of the ОІ-solenoid is composed of a single peptide and protonated Glu8 is located in the fibrillar core. We find that ОІ-endorphin fibrils are in a ОІ-solenoid conformation that is generally reminiscent of other functional amyloids. Here, we use solid-state NMR to determine the 3D structure of the amyloid fiber formed by the human hormone ОІ-endorphin. In the pituitary gland, peptide hormones can be stored as amyloid fibrils within acidic secretory granules before release into the blood stream. For amyloid disassembly in the blood, it is proposed that the pH change acts together with a buffer composition change and hormone dilution. During exocytosis of the hormone amyloid the pH increases from acidic in the secretory granule to neutral level in the blood, thus it is suggested-and supported with mutagenesis data-that the pH change in the cellular milieu acts through the deprotonation of glutamate 8 to release the hormone from the amyloid. We find that ОІ-endorphin fibrils are in a ОІ-solenoid conformation with a protonated glutamate residue in their fibrillar core. To gain a detailed understanding of the structure-function relationship of amyloids in hormone secretion, the three-dimensional (3D) structure of the amyloid fibril of the human hormone ОІ-endorphin was determined by solid-state NMR. In the pituitary gland, hormones are stored in a functional amyloid state within acidic secretory granules before they are released into the blood.

Beta-endorphin