Pulsatile Gonadotropin-releasing Hormone Research Articles

Paraventricular Dynorphin A Neurons Mediate LH Pulse Suppression Induced by Hindbrain Glucoprivation in Female Rats.

Malnutrition suppresses reproductive functions in mammals, which is considered to be mostly due to the inhibition of pulsatile gonadotropin-releasing hormone (GnRH)/gonadotropin secretion. Accumulating evidence suggests that kisspeptin neurons in the arcuate nucleus (ARC) play a critical role in the regulation of pulsatile GnRH/gonadotropin release. The present study aimed to examine if the hypothalamic dynorphin A (Dyn) neurons mediate the suppression of GnRH/luteinizing hormone (LH) pulses during malnutrition. Ovariectomized rats treated with a negative feedback level of estradiol-17β-treated (OVX+E2) were administered with intravenous (iv) or fourth cerebroventricle (4V) 2-deoxy-D-glucose (2DG), an inhibitor of glucose utilization, to serve as a malnutrition model. Central administration of a Dyn receptor antagonist blocked the iv- or 4V-2DG-induced suppression of LH pulses in OVX+E2 rats. The 4V 2DG administration significantly increased the number of Pdyn (Dyn gene)-positive cells co-expressing fos in the paraventricular nucleus (PVN), but not in the ARC and supraoptic nucleus (SON), and the iv 2DG treatment significantly increased the number of fos and Pdyn-co-expressing cells in the PVN and SON, but decreased it in the ARC. The E2 treatment significantly increased Pdyn expression in the PVN, but not in the ARC and SON. Double in situ hybridization for Kiss1 (kisspeptin gene) and Oprk1 (Dyn receptor gene) revealed that around 60% of ARC Kiss1-expressing cells co-expressed Oprk1. These results suggest that the PVN Dyn neurons, at least in part, mediate LH pulse suppression induced by the hindbrain or peripheral glucoprivation, and Dyn neurons may directly suppress the ARC kisspeptin neurons in female rats.

HIGH LIVE BIRTH RATES WITH LOW MULTIPLE BIRTH RATES: OVER TWO DECADES' EXPERIENCE OF PULSATILE GNRH PUMP USE FOR OVULATION INDUCTION IN PATIENTS WITH FUNCTIONAL HYPOTHALAMIC AMENORRHEA (FHA)

To analyze the experience of treating patients with FHA (functional hypothalamic amenorrhea) over the last 25 years using a subcutaneous pulsatile gonadotropin releasing hormone (GnRH) pump at a Swiss university-based tertiary referral center.

Facilitatory and inhibitory role of central amylin administration in the regulation of the gonadotropin-releasing hormone pulse generator activity in goats

Pulsatile gonadotropin-releasing hormone (GnRH) secretion is essential for regulating reproductive functions in mammals. GnRH pulses are governed by a neural mechanism that is termed the GnRH pulse generator. In the present study, we investigated the role of central calcitonin receptor (CTR) signaling in the regulation of the GnRH pulse generator activity in ovariectomized goats by administering amylin, an endogenous ligand for CTR, into the lateral ventricle. GnRH pulse generator activity was measured using multiple unit activity (MUA) recordings in the mediobasal hypothalamus. We analyzed changes in the interval of characteristic increases in MUA (MUA volleys). The MUA volley interval shortened immediately after amylin administration, followed by prolonged intervals. Double in situ hybridization for KISS1 (kisspeptin gene) and CALCR (CTR gene) revealed that low expression levels of CALCR were found in the arcuate kisspeptin neurons, which is suggested as the main population of neurons, involved in GnRH pulse generator activity. These results suggest that central amylin-CTR signaling has a biphasic role in the regulation of GnRH pulse generator activity by acting on cells other than the arcuate kisspeptin neurons in goats.

Spermatogenesis of Male Patients with Congenital Hypogonadotropic Hypogonadism Receiving Pulsatile Gonadotropin-Releasing Hormone Therapy Versus Gonadotropin Therapy: A Systematic Review and Meta-Analysis.

PurposePulsatile gonadotropin-releasing hormone (GnRH) therapy and gonadotropin therapy (GT) were widely used for male patients with congenital hypogonadotropic hypogonadism (CHH), but their efficacy was not well compared before. We conducted this meta-analysis to compare the efficacy of restoring fertility using these two therapies.Materials and MethodsPubMed, Web of Science, and Scopus were systematically searched for comparative studies evaluating the efficiency of GnRH therapy and GT for male patients with CHH. For continuous outcomes, the weighted mean difference (WMD) was used to measure the difference, whereas the risk ratio with 95% confidence interval was calculated for binary variables.ResultsOverall, eight articles from seven studies with 420 patients enrolled were included in the analysis. Patients from the two different groups were determined to be comparable in age, proportion with Kallmann syndrome, percentage of cryptorchidism and pretreatment hormones (follicular-stimulating hormone, luteinizing hormone, and testosterone). GnRH therapy was related to a larger testicular volume (standardized mean difference=−1.43; p=0.01) and earlier spermatogenesis (WMD=−5.30 months; p=0.004) compared to GT. However, the difference in the rate of positive sperm detection (p=0.08), sperm concentration (p=0.37), and pregnancy rate (p=0.11) were not significant. Allergic reactions mostly occurred during GnRH therapy, while GT was related to a higher incidence of gynecomastia and acne.ConclusionsCompared to GT, GnRH was related to earlier spermatogenesis and less estradiol-related adverse reactions, although there were no significant differences in spermatogenesis rate, sperm concentration, and pregnancy rate. High-quality randomized controlled trials are needed for future research.

Different dendritic domains of the GnRH neuron underlie the pulse and surge modes of GnRH secretion in female mice.

The gonadotropin-releasing hormone (GnRH) neurons exhibit pulse and surge modes of activity to control fertility. They also exhibit an unusual bipolar morphology comprised of a classical soma-proximal dendritic zone and an elongated secretory process that can operate as both a dendrite and an axon, termed a 'dendron'. We show using expansion microscopy that the highest density of synaptic inputs to a GnRH neuron exists at its distal dendron. In vivo, selective chemogenetic inhibition of the GnRH neuron distal dendron abolishes the luteinizing hormone (LH) surge and markedly dampens LH pulses. In contrast, inhibitory chemogenetic and optogenetic strategies targeting the GnRH neuron soma-proximal dendritic zone abolish the LH surge but have no effect upon LH pulsatility. These observations indicate that electrical activity at the soma-proximal dendrites of the GnRH neuron is only essential for the LH surge while the distal dendron represents an autonomous zone where synaptic integration drives pulsatile GnRH secretion.

SUN-LB57 Assessing the Requirement of Arcuate Nucleus Kisspeptin Neurons in Puberty Onset and Adult LH Secretion

Puberty is a critical developmental period marking the transition to adulthood and attainment of reproductive capability. A hallmark of puberty is increased pulsatile secretion of pituitary luteinizing hormone (LH) which is itself driven by increased gonadotropin-releasing hormone (GnRH) from the forebrain. The mechanisms governing GnRH neuron activation at puberty still remain unclear, but likely include enhanced stimulation from upstream reproductive neural circuits, including kisspeptin neurons. Kisspeptin is a potent stimulator of GnRH and is required for proper puberty onset. However, the specific brain site(s) from where kisspeptin signaling arises to trigger puberty remain unclarified. Kisspeptin is expressed in two primary nuclei in the hypothalamus, the arcuate nucleus (ARC) and anteroventral periventricular (AVPV) region. Studies suggest that, in adulthood, ARC Kiss1 neurons are involved in driving pulsatile secretion of GnRH (and hence, LH) in both sexes whereas AVPV Kiss1 neurons participate in the preovulatory GnRH/LH surge in females. However, the specific role of either kisspeptin neuron population in puberty onset still remains unknown. We previously showed that both kisspeptin populations show increased Kiss1 gene expression across the pubertal period, yet whether just one or both (or neither) population is needed for puberty to occur has not been determined. Here, we sought to tease out the role—if any—of ARC and AVPV Kiss1 neurons in the pubertal onset process. Since ARC Kiss1 neurons are abundant in both sexes and drive pulsatile GnRH secretion in adulthood, we hypothesized that ARC Kiss1 neurons are necessary for normal puberty onset and, conversely, that AVPV Kiss1 neurons are not sufficient on their own to induce normal puberty. To test this hypothesis, we used a Cre-specific diphtheria toxin approach to ablate just ARC Kiss1 neurons in juvenile mice (~ 2 weeks old) while leaving AVPV Kiss1 neurons intact. Preliminary data thus far indicates that site specific ablation of just ARC Kiss1 neurons during the juvenile period significantly delays puberty onset in both sexes, as measured by vaginal opening, first estrous, and preputial separation. In addition, selective ARC Kiss1 neuron ablation in juvenile life diminishes pulsatile LH secretion levels measured in adulthood, but does not alter LH surge generation in adult females. These preliminary findings empirically demonstrate that, in mice, ARC Kiss1 neurons are required for proper activation of the reproductive axis during puberty but not the LH surge in adulthood, and AVPV Kiss1 neurons are not sufficient to trigger normal pubertal onset.

Prevalence of lifetime eating disorders in infertile women seeking pregnancy with pulsatile gonadotropin-releasing hormone therapy.

Relationships between weight and fertility are well known. The aim of this study is to assess the prevalence of lifetime eating disorder (ED) in a sample of infertile women seeking a specific infertility treatment, pulsatile gonadotropin-releasing hormone (pGnRH) treatment, and to compare it to the prevalence of lifetime ED in a sample of infertile women seeking other types of assisted reproductive technology (ART) treatments. Non-randomized, observational study including infertile female patients. Two-group design including consecutive women treated with GnRH pump (pGnRH) or with other types of ART. Multi-centric infertility centers, France METHODS: Twenty one consecutive women treated with pGnRH treatment were compared to 21 consecutive women receiving other types of infertility treatment. Diagnosis of ED was based on DSM-IV and the Composite International Diagnostic Interview (CIDI). Twenty patients (95.2%) from the sample of women treated with pulsatile GnRH treatment and 5 patients (23.8%) from the patients receiving other types of infertility treatment met the criteria of lifetime ED diagnosis (p < 0.000). This study highlights the fact that the prevalence of ED is considerably higher in women receiving GnRH pulsatile treatment, when compared to women receiving other kinds of infertility treatment. In our study population ED were under-diagnosed, particularly in women receiving pulsatile GnRH treatment. Fertility clinicians should use reliable diagnostic tools to identify promptly ED in women presenting with hypothalamic amenorrhea and difficulties in conceiving. Level III: Evidence obtained from well-designed cohort or case-control analytic studies.

USE OF THE PULSATILE GnRH PUMP FOR OVULATION INDUCTION IN PATIENTS WITH FUNCTIONAL HYPOTHALAMIC AMENORRHEA (FHA): 5-YEAR EXPERIENCE FROM A SWISS UNIVERSITY HOSPITAL

Congenital or acquired hypogonadotropic hypogonadism (HH) is an important cause of anovulatory infertility. In functional hypothalamic amenorrhea (FHA), loss of function of the hypothalamichypopituitary axis occurs in catabolic states induced by eating disorders, compulsive exercise and high levels of somatic or psychological stress [1]. In patients with FHA attempting to conceive, in addition to addressing the underlying cause, a subcutaneous pulsatile gonadotropin releasing hormone (GnRH) pump may be used to induce ovulation [2].

FSH for the Treatment of Male Infertility.

Follicle-stimulating hormone (FSH) supports spermatogenesis acting via its receptor (FSHR), which activates trophic effects in gonadal Sertoli cells. These pathways are targeted by hormonal drugs used for clinical treatment of infertile men, mainly belonging to sub-groups defined as hypogonadotropic hypogonadism or idiopathic infertility. While, in the first case, fertility may be efficiently restored by specific treatments, such as pulsatile gonadotropin releasing hormone (GnRH) or choriogonadotropin (hCG) alone or in combination with FSH, less is known about the efficacy of FSH in supporting the treatment of male idiopathic infertility. This review focuses on the role of FSH in the clinical approach to male reproduction, addressing the state-of-the-art from the little data available and discussing the pharmacological evidence. New compounds, such as allosteric ligands, dually active, chimeric gonadotropins and immunoglobulins, may represent interesting avenues for future personalized, pharmacological approaches to male infertility.

Normosmic idiopathic hypogonadotropic hypogonadism due to a novel GNRH1 variant in two siblings.

SummaryHypogonadotropic hypogonadism is characterised by insufficient secretion of pituitary gonadotropins resulting in delayed puberty, anovulation and azoospermia. When hypogonadotropic hypogonadism occurs in the absence of structural or functional lesions of the hypothalamic or pituitary gland, the hypogonadism is defined as idiopathic hypogonadotropic hypogonadism (IHH). This is a rare genetic disorder caused by a defect in the secretion of gonadotropin releasing hormone (GNRH) by the hypothalamus or a defect in the action of GNRH on the pituitary gland. Up to 50% of IHH cases have identifiable pathogenic variants in the currently known genes. Pathogenic variants in the GNRHR gene encoding the GNRH receptor are a relatively common cause of normosmic IHH, but reports of pathogenic variants in GNRH1 encoding GNRH are exceedingly rare. We present a case of two siblings born to consanguineous parents who were found to have normosmic idiopathic hypogonadotropic hypogonadism due to homozygosity of a novel loss-of function variant in GNRH1. Case 1 is a male who presented at the age of 17 years with delayed puberty and under-virilised genitalia. Case 2 is a female who presented at the age of 16 years with delayed puberty and primary amenorrhea.Learning points:IHH is a genetically heterogeneous disorder which can be caused by pathogenic variants affecting proteins involved in the pulsatile gonadotropin-releasing hormone release, action, or both.Currently known genetic defects account for up to 50% of all IHH cases. GNRH1 pathogenic variants are a rare cause of normosmic IHH.IHH is associated with a wide spectrum of clinical manifestations.IHH can be challenging to diagnose, particularly when attempting to differentiate it from constitutional delay of puberty.Early diagnosis and gonadotrophin therapy can prevent negative physical sequelae and mitigate psychological distress with the restoration of puberty and fertility in affected individuals.

Congenital Hypogonadotropic Hypogonadism with Anosmia and Gorlin Features Caused by a PTCH1 Mutation Reveals a New Candidate Gene for Kallmann Syndrome

Background: Two loci (CHD7 and SOX10) underlying Kallmann syndrome (KS) were discovered through clinical and genetic analysis of CHARGE and Waardenburg syndromes, conditions that include congenital anosmia caused by olfactory bulb (CA/OBs) defects and congenital hypogonadotropic hypogonadism (CHH). We hypothesized that other candidate genes for KS could be discovered by analyzing rare syndromes presenting with these signs. Study Design, Size, Duration: We first investigated a family with Gorlin-Goltz syndrome (GGS) in which affected members exhibited clinical signs suggesting KS. Participants/Materials, Methods: Proband and family members underwent detailed clinical assessment. The proband received detailed neuroendocrine evaluation. Genetic analyses included sequencing the PTCH1 gene at diagnosis, followed by exome analyses of causative or candidate KS/CHH genes, in order to exclude contribution to the phenotypes of additional mutations. Exome analyses in additional 124 patients with KS/CHH probands with no additional GGS signs. Results: The proband exhibited CA, absent OBs on magnetic resonance imaging, and had CHH with unilateral cryptorchidism, consistent with KS. Pulsatile Gonadotropin-releasing hormone (GnRH) therapy normalized serum gonadotropins and increased testosterone levels, supporting GnRH deficiency. Genetic studies revealed 3 affected family members harbor a novel mutation of PTCH1 (c.838G> T; p.Glu280*). This unreported nonsense deleterious mutation results in either a putative truncated Ptch1 protein or in an absence of translated Ptch1 protein related to nonsense mediated messenger RNA decay. This heterozygous mutation cosegregates in the pedigree with GGS and CA with OBs aplasia/hypoplasia and with CHH in the proband suggesting a genetic linkage and an autosomal dominant mode of inheritance. No pathogenic rare variants in other KS/CHH genes cosegregated with these phenotypes. In additional 124 KS/CHH patients, 3 additional heterozygous, rare missense variants were found and predicted in silico to be damaging: p.Ser1203Arg, p.Arg1192Ser, and p.Ile108Met. Conclusion: This family suggests that the 2 main signs of KS can be included in GGS associated with PTCH1 mutations. Our data combined with mice models suggest that PTCH1 could be a novel candidate gene for KS/CHH and reinforce the role of the Hedgehog signaling pathway in pathophysiology of KS and GnRH neuron migration.

Insight Into the Ontogeny of GnRH Neurons From Patients Born Without a Nose.

The reproductive axis is controlled by a network of gonadotropin-releasing hormone (GnRH) neurons born in the primitive nose that migrate to the hypothalamus alongside axons of the olfactory system. The observation that congenital anosmia (inability to smell) is often associated with GnRH deficiency in humans led to the prevailing view that GnRH neurons depend on olfactory structures to reach the brain, but this hypothesis has not been confirmed. The objective of this work is to determine the potential for normal reproductive function in the setting of completely absent internal and external olfactory structures. We conducted comprehensive phenotyping studies in 11 patients with congenital arhinia. These studies were augmented by review of medical records and study questionnaires in another 40 international patients. All male patients demonstrated clinical and/or biochemical signs of GnRH deficiency, and the 5 men studied in person had no luteinizing hormone (LH) pulses, suggesting absent GnRH activity. The 6 women studied in person also had apulsatile LH profiles, yet 3 had spontaneous breast development and 2 women (studied from afar) had normal breast development and menstrual cycles, suggesting a fully intact reproductive axis. Administration of pulsatile GnRH to 2 GnRH-deficient patients revealed normal pituitary responsiveness but gonadal failure in the male patient. Patients with arhinia teach us that the GnRH neuron, a key gatekeeper of the reproductive axis, is associated with but may not depend on olfactory structures for normal migration and function, and more broadly, illustrate the power of extreme human phenotypes in answering fundamental questions about human embryology.

Type A insulin resistance syndrome misdiagnosed as polycystic ovary syndrome: a case report

BackgroundType A insulin resistance syndrome, one type of the hereditary insulin resistance syndromes, is a rare disorder. Patients with type A insulin resistance syndrome are nonobese and demonstrate severe hyperinsulinemia, hyperandrogenism, and acanthosis nigricans. The clinical features are more severe in affected females than in males, and they mostly become apparent at the age of puberty. In many cases, when severe insulin resistance is covered up by other signs or symptoms of type A insulin resistance syndrome, patients are often easily misdiagnosed with other diseases, such as polycystic ovary syndrome.Case presentationOur patient was a 27-year-old Han Chinese woman who sought treatment because of a menstrual disorder and hirsutism. Tests showed that her levels of insulin and testosterone were elevated, and gynecological color Doppler ultrasound suggested multiple cystic changes in the bilateral ovaries. After a diagnosis of polycystic ovary syndrome was made, pulsatile gonadotropin-releasing hormone therapy and metformin were administered, but the patient’s symptoms did not improve in 1 year of follow-up. Considering that the previous diagnosis might have been incorrect, venous blood samples were collected from the patient and her relatives for genetic analysis. Subsequently, using Illumina sequencing, it was found that the proband, her father, and two brothers all had the c.3601C>T heterozygous missense mutation in exon 20 of the insulin receptor gene. The diagnosis was corrected to type A insulin resistance syndrome, and the patient’s treatment was modified.ConclusionWe report a case of a young woman with type A insulin resistance syndrome that was misdiagnosed as polycystic ovary syndrome. We discuss the causes, clinical features, diagnosis, and treatment of type A insulin resistance syndrome to improve the recognition of the disease and reduce its misdiagnosis. Female patients with high androgen levels and severe hyperinsulinemia should be considered for the possibility of hereditary insulin resistance syndromes (such as type A insulin resistance syndrome). Gene sequencing helps in making an early diagnosis and developing a targeted treatment strategy.

Regulation and Function of C-Type Natriuretic Peptide (CNP) in Gonadotrope-Derived Cell Lines.

C-type natriuretic peptide (CNP) is the most conserved member of the mammalian natriuretic peptide family, and is implicated in the endocrine regulation of growth, metabolism and reproduction. CNP is expressed throughout the body, but is particularly abundant in the central nervous system and anterior pituitary gland. Pituitary gonadotropes are regulated by pulsatile release of gonadotropin releasing hormone (GnRH) from the hypothalamus, to control reproductive function. GnRH and CNP reciprocally regulate their respective signalling pathways in αT3-1 gonadotrope cells, but effects of pulsatile GnRH stimulation on CNP expression has not been explored. Here, we examine the sensitivity of the natriuretic peptide system in LβT2 and αT3-1 gonadotrope cell lines to continuous and pulsatile GnRH stimulation, and investigate putative CNP target genes in gonadotropes. Multiplex RT-qPCR assays confirmed that primary mouse pituitary tissue express Nppc, Npr2 (encoding CNP and guanylyl cyclase B (GC-B), respectively) and Furin (a CNP processing enzyme), but failed to express transcripts for Nppa or Nppb (encoding ANP and BNP, respectively). Pulsatile, but not continuous, GnRH stimulation of LβT2 cells caused significant increases in Nppc and Npr2 expression within 4 h, but failed to alter natriuretic peptide gene expression in αT3-1 cells. CNP enhanced expression of cJun, Egr1, Nr5a1 and Nr0b1, within 8 h in LβT2 cells, but inhibited Nr5a1 expression in αT3-1 cells. Collectively, these data show the gonadotrope natriuretic peptide system is sensitive to pulsatile GnRH signalling, and gonadotrope transcription factors are putative CNP-target genes. Such findings represent additional mechanisms by which CNP may regulate reproductive function.

Multiple failures in the lutenising hormone surge generating system in GABAB1KO female mice.

Female mice lacking GABAB receptors, GABAB1KO, show disrupted oestrous cycles, reduced pregnancies and increased hypothalamic Gnrh1 mRNA expression, whereas anteroventral periventricular/periventricular preoptic nucleus (AVPV/PeN) Kiss1 mRNA was not affected. In the present study, we characterise the important components of the gonadotrophic preovulatory surge, aiming to unravel the origin of this reproductive impairment. In GABAB1KO and wild-type (WT) females, we determined: (i) hypothalamic oestrogen receptor (ER)α and β and aromatase mRNA and protein expression; (ii) ovulation index and oestrus serum follicle-stimulating hormone (FSH) and pituitary Gnrh1r expression; (iii) in ovariectomised-oestradiol valerate-treated mice, we evaluated ex vivo hypothalamic gonadotrophin-releasing hormone (GnRH) pulsatility in the presence/absence of kisspeptin (Kiss-10, constant or pulsatile) and oestradiol (constant); and (iv) in ovariectomised-oestradiol silastic capsule-treated mice (proestrous-like environment), we evaluated morning and evening kisspeptin neurone activation (c-Fos+) and serum luteinising homrone (LH). In the medial basal hypothalamus of oestrus GABAB1KOs, aromatase and ERα mRNA and protein were increased, whereas ERβ was decreased. In GABAB1KOs, the ovulation index was decreased together with decreased first oestrus serum FSH and increased pituitary Gnrh1r mRNA. Under constant Kiss-10 stimulation, hypothalamic GnRH pulse frequency did not vary, although GnRH mass/pulse was increased in GABAB1KOs. In WTs, pulsatile Kiss-10 together with constant oestradiol significantly increased GnRH pulsatility, whereas, in GABAB1KOs, oestradiol alone increased GnRH pulsatility and this was reversed by pulsatile Kiss-10 addition. In GABAB1KOs AVPV/PeN kisspeptin neurones were similarly activated (c-Fos+) in the morning and evening, whereas WTs showed the expected, marked evening stimulation. LH correlated with activated kisspeptin cells in WT mice, whereas GABAB1KO mice showed high, similar LH levels both in the morning and evening. Taken together, all of these alterations point to impairment in the trigger of the preovulatory GnRH surge that entails the reproductive alterations described.

Pulsatile Gonadotropin-releasing Hormone for Infertility in Non-obese Patients With Polycystic Ovary Syndrome

Pulsatile Gonadotropin-releasing Hormone for Infertility in Non-obese Patients With Polycystic Ovary Syndrome

Central Mechanism Controlling Pubertal Onset in Mammals: A Triggering Role of Kisspeptin.

Pubertal onset is thought to be timed by an increase in pulsatile gonadotropin-releasing hormone (GnRH)/gonadotropin secretion in mammals. The underlying mechanism of pubertal onset in mammals is still an open question. Evidence accumulated in the last 15 years suggests that kisspeptin/neurokinin B/dynorphin A (KNDy) neurons in the hypothalamic arcuate nucleus play a key role in pubertal onset by triggering pulsatile GnRH/gonadotropin secretin in mammals. Specifically, KNDy neurons are now considered a part of GnRH pulse generator, in which neurokinin B facilitates and dynorphin A inhibits, the synchronized discharge of KNDy neurons in autocrine and/or paracrine manners. Kisspeptin serves as a potent secretagogue of GnRH secretion and thus its release is fundamental to pubertal increase in GnRH/gonadotropin secretion in mammals. Proposed mechanisms inhibiting Kiss1 (kisspeptin gene) expression during childhood to juvenile varies from species to species: we envisage that negative feedback action of estrogen plays a key role in the inhibition of Kiss1 expression in KNDy neurons in rodents and sheep, whereas estrogen-independent inhibition of kisspeptin secretion by γ-amino butyric acid or neuropeptide Y are suggested to be responsible for the pre-pubertal suppression of GnRH/gonadotropin secretion in primates. Taken together, the timing of pubertal onset is postulated to be controlled by upstream regulators for kisspeptin biosynthesis and secretion in mammals.

Arcuate Kisspeptin Neurons Coordinate Reproductive Activities with Metabolism.

Hypothalamic control of fertility is the quintessential homeostatic function. However, fertility is metabolically demanding; so, there must be coordination between energy states and reproductive functions. Because gonadotropin-releasing hormone (GnRH) neurons are devoid of many of the critical metabolic hormone receptors for sensing nutrient levels, it has long been recognized that the sensing of energy stores had to be done by neurons presynaptic to GnRH neurons. Some of the obvious players have been the anorexigenic proopiomelanocortin (POMC) and orexigenic neuropeptide Y (NPY)/agouti-related peptide (AgRP) neurons, both of which are in close apposition to the median eminence, a circumventricular organ. Indeed, POMC and NPY/AgRP neurons are inversely regulated by glucose and metabolic hormones including insulin and leptin. However, their synaptic connections with GnRH neurons are sparse and/or GnRH neurons are lacking the postsynaptic receptors to mediate the appropriate physiological response. Kisspeptin neurons were discovered in the early part of this century and subsequently shown to project to and control GnRH neuronal excitability. In fact, more recently the arcuate kisspeptin neurons have been identified as the command neurons driving pulsatile release of GnRH. Subsequently, it was shown that arcuate kisspeptin neurons express not only steroid hormone receptors but also metabolic hormone receptors such that similar to POMC neurons, they are excited by insulin and leptin. Therefore, based on the premise that arcuate kisspeptin neurons are the key neurons coordinating energy states with reproduction, we will review not only how these vital neurons control pulsatile GnRH release but how they control energy homeostasis through their synaptic connections with POMC and NPY/AgRP neurons and ultimately how E2 can regulate their excitability.

MON-LB051 Non-inferiority Clinical Trial on Gonadotropinversus Pulsatile Gonadotropin-releasing Hormone Infusion Therapy in Male Adolescent Patient with Congenital Hypogonadotropic Hypogonadism

Context We investigate the efficacy and safety of non-inferiority clinical trial for human chorionic gonadotropin/ human menopausal gonadotropin (HCG/HMG) versus pulsatile gonadotropin-releasing hormone (GnRH) which has not been evaluated on non-inferiority clinical trial in puberty boys with CHH. Objective To compare the efficacy and security of two different treatments in male adolescent patient with congenital hypogonadotropic hypogonadism (CHH) . To explore the standardization of early treatment and it is possible clinical recommended regimen. Methods For this prospective cohort nonrandomized controlled study, male adolescent CHH patients were recruited and categorized into HCG/HMG(group 1) and GnRH (group 2) groups. All patients were treated for 3-12months. The study was divided into research period (3 months of treatment) and extension period (3 to 12 months of treatment). Testicular volume (TV), penile length(PL), blood sex hormones levels, height, body weight, and other related laboratory indices were measured and evaluated. In this study, we observe the therapeutic effect within 3 months and also collect partial extended period data for providing further research experience. Results All CHH patients were treated for over 3 months. At the beginning, the average age of patients, the testicular volume, penile length, penile diameter in group 1 and group 2 were 15.3±1.9 years VS 14.2±1.5 years, 2.5±1.4ml VS 2.7±1.5ml, 4.8±1.3cm VS 4.2±1.4cm and 1.6±0.4cm VS 1.5±0.4cm. The difference of two groups was not statistically significant. After 3 months treatment, the testicular volume, penile length, penile diameter, the growth of testicular volume, the growth of penile length and the growth of penile diameter in group 1 and group 2 were 5.1±2.7ml VS 4.6±2.7ml , 6.9±1.7cm VS 5.1±1.6cm, 2.5±0.5cm VS 1.9±0.6cm,2.0±1.6 cm 和1.0±0.8cm, 0.9±0.5cmand0.3±0.4cm. The difference of two groups was not statistically significant. There was no significant difference in height, body weight, or BMI between the two treatments. Based on the principles of hypothesis-test, mean value M-0.25625, standard error(SE) = 0.69319,M±1.96, Se=-0.25625±1.3586524,(-1.161,1.10). The growth differential of testicular volume between group 1 and group 2 was less than 2ml in (P<0.05) . It can be inferred that group 1 is not inferior to group 2. There was no significant difference in efficacy comparison in some of the patients were treated after 6-12 months in both groups. There was no significant difference in side effects in both groups. Conclusions In this clinical trial, 3 months was an observation period. Short-term therapeutic indicated adolescent patients with CHH were effectively treated with HCG/HMG and GnRH. We discovered that the effect of HCG/HMG was as good as GnRH in treating adolescent boys with CHH. This therapeutic schedule can be used in more patients. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

SAT-414 Cytogenetic, Genomic, and Functional Characterization of Pituitary Gonadotrope Cell Lines

Cell lines have been widely used as models to characterize important intracellular and molecular mechanisms. Funding agencies and publishers – including the National Institutes of Health and Nature – have required researchers to authenticate human cell lines to establish their identity. Nevertheless, authentication of human cell lines has been poorly reported, let alone that of nonhuman species [1]. The use of different clones by diverse laboratories may lead to irreproducible results. Moreover, one should not assume that cell lines with the same name actually display identical characteristics, as differences in storage and culturing conditions may promote genomic variability and clonal divergence. In the reproductive field, the LβT2 [2] and αT3-1 [3] cell lines represent invaluable models for studying the regulation of pituitary gonadotropes by gonadotropin releasing hormone (GnRH) and other hormones. Both lines were produced by targeted oncogenesis in transgenic mice, with the LβT2 cells representing developmentally more mature gonadotropes than the αT3-1 cells. To establish a reference for each gonadotrope line, we requested early aliquots from the laboratory that generated them. Authentication by 27-dinucleotide and 9-tetranucleotide short tandem repeat (STR) genotyping was consistent with a mixed C57BL/6J x BALB/cJ genetic background. Spectral karyotyping revealed a variable number of chromosomes amongst cells, a result confirmed by shallow single-cell DNA sequencing in LβT2 cells. Interestingly, STR genotyping of several LβT2 batches obtained regularly throughout the past 20 years in our laboratory as well as in other laboratories identified a strain (#2) with a profile distinct from our reference line (#1). The two lines differed morphologically, with strain #2 exhibiting larger cells and extensions, whereas strain #1 displayed smaller uniform rounded cells. Moreover, the two lines showed variations in basal and GnRH-induced expression of early response and gonadotropin subunit genes. In line #1, under continuous GnRH stimulation, Egr1, Fos, and Lhb transcript levels were higher, whereas time course studies revealed lower Fos expression and no Fshb induction. Under a low-frequency regimen of pulsatile GnRH favoring Fshb induction, line #1 showed higher Egr1 transcript levels, but an absence of Fshb induction. Our results suggests that LβT2 strains exist that differ genetically and in their expression profiles. Our study demonstrates the importance of characterizing gonadotrope cell lines to improve data reproducibility, design and interpretation of gene expression experiments while continuing to use these cell lines that are important models for the study of gonadotrope physiology. [1] Almeida JL et al. PLoS Biol., 2016, 14(6):e1002476. [2] Thomas P et al. Endocrinology, 1996, 137(7): 2979-89. [3] Windle JJ et al. Mol. Endocrinology, 1990, 4(4): 597-603.