Gonadal hormones

Thyroid hormones (THs) play important roles in the regulation of many biological processes of vertebrates, such as growth, metabolism, morphogenesis and reproduction. An increasing number of studies have been focused on the involvement of THs in the male reproductive system of vertebrates, in particular of fish. Therefore, this mini-review aims to summarize the main findings on THs role in male reproductive system of fish, focusing on sex differentiation, testicular development and spermatogenesis. The existing data in the literature have demonstrated that THs exert their roles at the different levels of the hypothalamic-pituitary-gonadal (HPG) axis...

Background: Cisplatin is a potent antineoplastic agent for many cancers but causes several levels of gonadal damage. Ovarian toxicity is a major concern of young cancer patients undergoing chemotherapy. Objective: This study sought to examine the effect of Cisplatin and Resveratrol supplementation on ovarian function in Sprague-Dawley rats. Materials and Methods: In this experimental study, 45 cyclic Sprague-Dawley rats with an average weight of 160 gr were divided into 9 groups (n=5/group)...

BACKGROUND: Studies have shown that ghrelin plays an important role in the mammalian reproductive system, including the central, gonadal levels, and also during in vitro maturation of oocytes; however, the functions of ghrelin in bovine oocyte meiosis require further investigation. OBJECTIVE: We aimed to evaluate the effects of an n-octanoylated ghrelin peptide on oocyte meiotic resumption and the developmental competence of mature oocytes in vitro. EXPERIMENTAL: design: The expression of GHRL(encoding ghrelin) mRNA and its receptor (the growth hormone secretagogue receptor, GHSR) in the cumulus-oocyte complex (COCs), denuded oocytes (DOs), and cumulus cells (CCs) was assessed using quantitative real-time reverse transcription PCR (qRT-PCR), and the effects of the n-octanoylated ghrelin peptide on meiotic resumption were studied at four different doses (0, 10, 50, and 100 ng/mL) in a 6 h culture system...

Introduction: Withania somnifera (WS) also known as ashwagandha is a well-known medicinal plant used in traditional medicine in many countries for infertility treatment. The present study was aimed at systemically reviewing therapeutic effects of WS on the reproductive system. Methods: This systematic review study was designed in 2016. Required data were obtained from PubMed, Scopus, Google Scholar, Cochrane Library, Science Direct, Web of Knowledge, Web of Science, and manual search of articles, grey literature, reference checking, and expert contact...

Kisspeptin, a novel neuropeptide product of the Kiss1 gene, activates the G protein-coupled membrane receptor G protein-coupled receptor 54 (now termed Kiss1r). Over the last 15 years, the importance of the kisspeptin system has been the subject of much debate in the mammalian research field. At the heart of the debate is whether kisspeptin is an absolute upstream regulator of gonadotropin-releasing hormone secretion, as it has been proposed to be the master molecule in reproductive events and plays a special role not only during puberty but also in adulthood...

Aggression is an essential social behavior that promotes survival and reproductive fitness across animal systems. While research on the neuroendocrine mechanisms underlying this complex behavior has traditionally focused on the classic neuroendocrine model, in which circulating gonadal steroids are transported to the brain and directly mediate neural circuits relevant to aggression, recent studies have suggested that this paradigm is oversimplified. Work on seasonal mammals that exhibit territorial aggression outside of the breeding season, such as Siberian hamsters ( Phodopus sungorus ), has been particularly useful in elucidating alternate mechanisms...

Long non-coding RNAs (LncRNAs) have been identified as important regulators of testis development, however, their expression patterns and roles in sheep are not yet clear. Thus, we used stranded specific RNA-seq to profile the testis transcriptome (lncRNAs and mRNAs) in premature and mature sheep. Hormone levels and the testis index were examined, and histological analyses were performed at five stages of testis development, 5-day-old (D5), 3-month-old (3M), 6-month-old (6M), 9-month-old (9M) and 2-year-old (2Y), the results of which indicate a significant difference in hormone levels and testis morphometries between the 3M and 9M stages (P < 0...

BACKGROUND: The postnatal gonadotropin surge is sexually dimorphic: FSH levels predominate in girls and LH levels in boys. However, in preterm (PT) girls, both gonadotropin levels are higher than in PT boys. OBJECTIVE: To evaluate how gonadal maturation contributes to the sex differences in FSH and LH. DESIGN: Monthly follow-up of 58 full-term (FT, 29 boys) and 67 PT (33 boys) infants from one week (D7) to six months of age (M1-M6). Analyses were also done according to postmenstrual (PM) age in PT infants...

Fluctuations in gonadal hormones over the course of the menstrual cycle are known to cause functional brain changes and are thought to modulate changes in the balance of cortical excitation and inhibition. Animal research has shown this occurs primarily via the major metabolite of progesterone, allopregnanolone, and its action as a positive allosteric modulator of the GABAA receptor. Our study used EEG to record gamma oscillations induced in the visual cortex using stationary and moving gratings. Recordings took place during twenty females' mid-luteal phase when progesterone and estradiol are highest, and early follicular phase when progesterone and estradiol are lowest...

Originally discovered in elasmobranchs by Fritsh in 1878, the nervus terminalis has been found in virtually all species, including humans. After more than one-century debate on its nomenclature, it is nowadays recognized as cranial pair zero. The nerve mostly originates in the olfactory placode, although neural crest contribution has been also proposed. Developmentally, the nervus terminalis is clearly observed in human embryos; subsequently, during the fetal period loses some of its ganglion cells, and it is less recognizable in adults...

Benzophenones used as UV filters, in addition to the effects on the skin, can be absorbed into the blood and affect the function of certain organs. So far, their effects on the sex hormone receptors and gonadal function have been studied, but not much is known about their potential action on other systems. The aim of the present study was to determine the effect of benzophenone-2 (BP-2) on immune system activity, hypothalamic-pituitary-thyroid (HPT) axis activity and hematological parameters. BP-2 was administered dermally, twice daily at a dose of 100 mg/kg for 4-weeks to male Wistar rats...

Follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh), secreted from pituitary, stimulate gonadal function by binding to their cognate receptors FSH receptor (FSHR), and LH/ choriogonadotropin receptor (LHCGR). Rohu (Labeo rohita) is a commercially important seasonal breeder freshwater fish species, but till date, the regulation of expression of gonadotropins and their receptors gene during different phases of annual reproductive cycle has not been investigated. We envisaged the critical role of these molecules during seasonal gonadal development in this carp species...

Reproduction is an essential process for life and is regulated by complex hormone networks and environmental factors. To date, little is known about the contribution of epigenetic mechanisms to the regulation of reproduction, particularly in lower vertebrates. We used the zebrafish (Danio rerio) model to investigate the sex-specific transcription and DNA methylation profiles for genes involved in the regulation of reproduction and in epigenetic signalling in the livers and gonads. We found evidence for associations between DNA promotor methylation and transcription for esr1 (gonads and female livers), amh (gonads) and dnmt1 (livers)...

OBJECTIVES: Juvenile idiopathic arthritis (JIA) occurs during reproductive age, however, there are not systematic data regarding ovarian function in this disease. METHODS: Twenty-eight post-pubertal JIA patients and age-matched 28 healthy controls were studied. Complete ovarian function was assessed during the early follicular phase of the menstrual cycle including anti-Müllerian hormone (AMH), estradiol, luteinizing hormone (LH), follicle stimulating hormone (FSH) and antral follicle count (AFC) by ovarian ultrasound, and anti-corpus lutheum antibodies (anti-CoL)...

BACKGROUND: Male European seabass, already predominant (~ 70%) in cultured stocks, show a high incidence (20-30%) of precocious sexual maturation under current aquaculture practices, leading to important economic losses for the industry. In view of the known modulation of reproductive development by swimming exercise in other teleost species, we aimed at investigating the effects of sustained swimming on reproductive development in seabass males during the first year of life in order to determine if swimming could potentially reduce precocious sexual maturation...

In order to maintain the health and wellbeing of all mammals, numerous aspects of physiology are controlled by neuroendocrine mechanisms. These mechanisms ultimately enable communication between neurons and glands throughout the body and are centrally mediated by neuropeptides and/or steroid hormones. A recent session at the International Workshop in Neuroendocrinology highlighted essential roles for some of these neuropeptide and steroid hormone mediators in the neuroendocrine regulation of stress-, reproduction-, and behavior- related processes...

The presence of endocrine-derived compounds in the environment occurs due to a myriad of human or industrial activity and can disrupt the endocrine system of animals, including fish. One important group of endocrine disruptors are the estrogens, such as 17-β estradiol (E2 , estradiol). Estrogens are gonadal steroid hormones, able to be influential even in small concentrations. Here, we demonstrate that E2 is linked to female' decisions made by an important coral reef species, the cleaner fish Labroides dimidiatus, during interactions with other reef fishes (known as clients)...

Polycystic ovary syndrome (PCOS) is a heterogenous endocrine disorder with typical symptoms of oligomenorrhoea, hyperandrogenism, hirsutism, obesity, insulin resistance and increased risk of type 2 diabetes mellitus. Extensive evidence indicates that PCOS is a genetic disease and numerous biochemical pathways have been linked with its pathogenesis. A number of genes from these pathways have been investigated, which include those involved with steroid hormone biosynthesis and metabolism, action of gonadotropin and gonadal hormones, folliculogenesis, obesity and energy regulation, insulin secretion and action and many others...

Although several recent studies suggest endocrine disrupting compounds, such as polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p', DDE), and hexachlorobenzene (HCB), target different organs and systems in the body, their impact on female reproductive function in humans is not well characterized. We seek to determine the relationship between several known endocrine disrupting compounds and a marker of ovarian responsivity, the FSH:LH ratio (higher ratio indicates less ovarian responsivity)...

Phenanthrene is a tricyclic polycyclic aromatic hydrocarbon and environmental contaminant found in high concentrations around urban catchments and in the vicinity of oil extraction activities. Fish exposed to phenanthrene can exhibit altered reproductive hormone profiles and/or differences within gonadosomatic index and altered gamete proportions, but the mechanisms underlying these changes are not fully understood. In this study, we conducted a sub-chronic bioassay and measured transcriptional responses in the liver, the major tissue involved in generating lipids for oocyte growth...