Context: Ovarian hormones regulate pituitary gonadotropin secretion across the menstrual cycle via negative and positive feedback mechanisms. The contribution of individual hormones is complex and is a continuing area of research.
Objective: The aim of the study was to identify relationships between LH/FSH and estradiol, progesterone, inhibin A, inhibin B, and anti-Mullerian hormone (AMH) in ovulatory menstrual cycles across reproductive age.
Design: Serum ovarian and pituitary hormones were studied in a group of young (<35 yr; n = 21) and older (>45 yr; n = 55) women. The slopes of the regression lines relating the ovarian and pituitary hormones were determined by multiple linear regression analysis and expressed with 95% confidence intervals for each ovarian hormone, with FSH and LH as independent variables. Both simultaneous and delayed (time lagged) relationships were examined.
Results: Clear associations were evident for the lagged prediction of FSH, with significant negative associations being evident with inhibin B and AMH in the follicular phase and with estradiol, inhibin B, progesterone, and AMH in the luteal phase. For the lagged prediction of LH, significant positive and negative associations were observed with estradiol and inhibin B, respectively, in the follicular phase and a negative association with progesterone and inhibin B in the luteal phase.
Conclusions: It is concluded that in the follicular phase, inhibin B is a major feedback regulator of FSH and may also be a negative feedback regulator of LH. AMH may be indirectly involved in FSH regulation.
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http://dx.doi.org/10.1210/jc.2008-1684 | DOI Listing |
Endocrine
January 2025
Jagiellonian University Medical College, Faculty of Medicine, Chair of Gynecology and Obstetrics, Kopernika 23, 31-501, Krakow, Poland.
Purpose: To compare ovarian function measures in euthyroid women with normogonadotropic anovulation in subclinical hypothyroidism (SCH) or thyroid autoimmunity (TAI) to those without thyroid dysfunction.
Design: A prospective open-label cohort study analyzed anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), luteinizing hormone, estradiol and testosterone concentrations, ovarian volume, and polycystic ovarian morphology (PCOM) incidence between women with and without SCH or TAI in two study arms: polycystic ovary syndrome (PCOS) and hypothalamic-pituitary-ovarian dysfunction (HPOD).
Results: The prevalence of circulating thyroid peroxidase antibodies (TPOAb) was higher in the PCOS compared to the HPOD arm (p = 0.
Int J Gynaecol Obstet
December 2024
Department of Pediatrics, Division of Pediatric Emergency Medicine, Hacettepe University Faculty of Medicine, Ankara, Turkey.
Objective: Heavy menstrual bleeding (HMB) is a significant health concern that may lead to critical medical care and impaired quality of life. The aim of the present study was to identify the clinical indicators of common causes of HMB in adolescents and evaluate the factors influencing the treatment preferences of clinicians.
Methods: Between 2010 and 2022, the electronic medical records of adolescents between the ages of 10-18 with HMB were reviewed, and a final of 205 adolescents was included.
Front Cell Dev Biol
December 2024
Department of Oncology, The First Affiliated Hospital, College of Clinical Medicine, Henan University of Science and Technology, Luoyang, Henan, China.
Pseudouridine (Ψ) is a post-transcriptional modifier of RNA, often referred to as the 'fifth nucleotide' owing to its regulatory role in various biological functions as well as because of its significant involvement in the pathogenesis of human cancer. In recent years, research has revealed various Ψ modifications in different RNA types, including messenger RNA, transfer RNA, ribosomal RNA, small nuclear RNA, and long noncoding RNA. Pseudouridylation can significantly alter RNA structure and thermodynamic stability, as the Ψ-adenine (A) base pair is more stable than the typical uridine (U)-A base pair is due to its structural similarity to adenine.
View Article and Find Full Text PDFChemosphere
December 2024
Aquatic Science Center, Wisconsin Sea Grant, University of Wisconsin - Madison, Madison, WI, USA. Electronic address:
Aquatic herbicides are commonly used to control a variety of non-native plants. One common active ingredient used in commercial herbicide formulations globally is 2,4-dichlorophenoxyacetic acid (2,4-D). Though 2,4-D is used in aquatic ecosystems, no studies have investigated cellular, biochemical, and transcriptional effects or mechanisms of 2,4-D exposure on fathead minnows (Pimephales promelas) throughout juvenile development.
View Article and Find Full Text PDFHum Reprod
December 2024
Assisted Reproduction Center, Northwest Women's and Children's Hospital, Xi'an, China.
Study Question: Are live birth rates (LBRs) per woman following flexible progestin-primed ovarian stimulation (fPPOS) treatment non-inferior to LBRs per woman following the conventional GnRH-antagonist protocol in expected suboptimal responders undergoing freeze-all cycles in assisted reproduction treatment?
Summary Answer: In women expected to have a suboptimal response, the 12-month likelihood of live birth with the fPPOS treatment did not achieve the non-inferiority criteria when compared to the standard GnRH antagonist protocol for IVF/ICSI treatment with a freeze-all strategy.
What Is Known Already: The standard PPOS protocol is effective for ovarian stimulation, where medroxyprogesterone acetate (MPA) is conventionally administered in the early follicular phase for ovulatory suppression. Recent retrospective cohort studies on donor cycles have shown the potential to prevent premature ovulation and maintain oocyte yields by delaying the administration of MPA until the midcycle (referred to as fPPOS), similar to GnRH antagonist injections.
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