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Ethnopharmacological Relevance: Guilingji (GLJ), which has been used to treat male diseases in China for centuries, contains 28 Chinese herbs and was previously established as an effective treatment for male sexual dysfunction. However, its mechanism of action remains unclear., Aim of the Study: To explore the efficacy and mechanism of action of GLJ in improving senile sexual dysfunction (SSD) in aging rats., Materials and Methods: An aging rat model of SSD was induced by the subcutaneous injection of d-galactose (300 mg⋅kg -1 ) and used to analyse the effects of GLJ (different concentrations of 37.5, 75, and 150 mg⋅kg -1 ) on the mating of aging rats. At the end of the 8th week, histopathological analysis of testicular tissues, assessment of the hypothalamic-pituitary-gonadal (HPG) axis hormone levels in serum or brain, and metabonomics analysis of the brain and testicular tissue with liquid chromatography-mass spectrometry was performed to explore the mechanism of action of GLJ., Result: After treatment with GLJ, the mount and ejaculation latency levels were increased in the treatment group than those in model group (P < 0.05), moreover, the testicular morphology was improved. Gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) levels in rats were also improved significant (P < 0.05) compared with those in the model group. Furthermore, the metabonomics results in the testicular and brain tissue showed that GLJ improved SSD by adjusting amino acid and lipid metabolism., Conclusion: This study integrated the complementary metabolic profiles of the target tissues. GLJ might affect SSD rats by regulating amino acid and lipid metabolism and may modulate sensitivity to the signaling pathway in the HPG axis. This study provides an essential basis for the broad clinical application of GLJ., (Copyright © 2022 Elsevier B.V. All rights reserved.)

GnRH neurons are the final central neural output regulating fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (KNDy neurons) are considered the main regulator of GnRH output. GnRH and KNDy neurons are surrounded by astrocytes, which can modulate neuronal activity and communicate over distances. Prostaglandin E2 (PGE2), synthesized primarily by astrocytes, increases GnRH neuron activity and downstream pituitary release of luteinizing hormone (LH). We hypothesized that glial fibrillary acidic protein (GFAP)-expressing astrocytes play a role in regulating GnRH and/or KNDy neuron activity and LH release. We used adeno-associated viruses to target designer receptors exclusively activated by designer drugs (DREADDs) to GFAP-expressing cells to activate Gq- or Gi-mediated signaling. Activating Gq signaling in the preoptic area, near GnRH neurons, but not in the arcuate, increases LH release in vivo and GnRH firing in vitro via a mechanism in part dependent upon PGE2. These data suggest that astrocytes can activate GnRH/LH release in a manner independent of KNDy neurons., Competing Interests: CV, RD, CS, SM No competing interests declared, (© 2021, Vanacker et al.)

Background: Metformin reduced prolactin levels only in women with hyperprolactinemia., Objective: The purpose of this case-control study was to compare metformin action on lactoctrope function between women receiving oral contraceptive pills and women not using hormonal contraception., Methods: The study included two groups of matched women with elevated prolactin levels and new-onset prediabetes or diabetes. The first group consisted of 20 women using oral contraceptive pills for at least 12 months before entering the study, while the second group included 20 patients not using any hormonal contraception. Over the whole study period, all women were treated with metformin (1.7-3 g daily). Circulating levels of glucose, insulin, prolactin, thyrotropin, free thyroid hormones, adrenocorticotropic hormone, gonadotropins and insulin-like growth factor-1 were measured at the beginning and at the end of the study (16 weeks later)., Results: Thirty-eight patients completed the study. Metformin reduced plasma glucose levels and improved insulin sensitivity but the latter effect was stronger in women receiving oral contraceptive pills than in women not using any contraception. Although metformin treatment decreased plasma prolactin levels in both study groups, this effect was stronger in women taking oral contraceptive pills. Only in this group of women, metformin increased plasma luteinizing hormone levels. The changes in plasma prolactin correlated with their baseline insulin sensitivity and the effect of metformin on insulin sensitivity. Metformin did not affect plasma levels of thyrotropin, free thyroxine, free triiodothyronine, follicle-stimulating hormone, adrenocorticotropic hormone and insulin-like growth factor-1., Conclusions: The obtained results suggest that the effect of metformin on overactive lactotropes depends on estrogen levels., Competing Interests: The authors declare no conflict of interest., (Thieme. All rights reserved.)

Background: Hypogonadotropic hypogonadism (HH) is hypogonadism due to either hypothalamic or pituitary dysfunction. While gonadotropin-releasing hormone (GnRH) can directly test pituitary function, no specific test of hypothalamic function exists. Kisspeptin-54 (KP54) is a neuropeptide that directly stimulates hypothalamic GnRH release and thus could be used to specifically interrogate hypothalamic function. Congenital HH (CHH) is typically due to variants in genes that control hypothalamic GnRH neuronal migration or function. Thus, we investigated whether KP54 could accurately identify hypothalamic dysfunction in men with CHH., Methods: Men with CHH (n = 21) and healthy eugonadal men (n = 21) received an intravenous bolus of either GnRH (100 μg) or KP54 (6.4 nmol/kg), on 2 occasions, and were monitored for 6 h after administration of each neuropeptide., Results: Maximal luteinizing hormone (LH) rise after KP54 was significantly greater in healthy men (12.5 iU/L) than in men with CHH (0.4 iU/L; p < 0.0001). KP54 more accurately differentiated CHH men from healthy men than GnRH (area under receiver operating characteristic curve KP54: 1.0, 95% CI 1.0-1.0; GnRH: 0.88, 95% CI 0.76-0.99). Indeed, all CHH men had an LH rise <2.0 iU/L following KP54, whereas all healthy men had an LH rise >4.0 iU/L. Anosmic men with CHH (i.e., Kallmann syndrome) had even lower LH rises after KP54 than did normosmic men with CHH (p = 0.017). Likewise, men identified to have pathogenic/likely pathogenic variants in CHH genes had even lower LH rises after KP54 than other men with CHH (p = 0.035)., Conclusion: KP54 fully discriminated men with CHH from healthy men. Thus, KP54 could be used to specifically interrogate hypothalamic GnRH neuronal function in patients with CHH., (© 2020 S. Karger AG, Basel.)

Previous studies have suggested that human exposure to bisphenol A (BPA) and soy isoflavones (SIFs) can occur during pregnancy. The combination of these chemicals is hypothesized to have a toxic impact on the fetus. While BPA is an industrial chemical used widely in the manufacture of polycarbonate plastics and epoxy resins, SIFs are naturally occurring estrogen‑like phytoestrogens. To determine the impact of the combination of BPA and SIFs on fetal development, the body weight, organ weight, anogenital distance and histopathological changes in the testes of F1 offspring were assessed in mice. Hormonal effects were determined by measuring serum levels of estrogen receptor (ESR), follicle‑stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T). Additionally, mitochondrial DNA copy numbers, and the serum levels of malondialdehyde and superoxide dismutase, were determined to evaluate alterations in oxidative stress and potential toxicity. Exposure to BPA increased the body weight of the pups and reduced the ratio of anogenital distance to body weight, as well as testes weight. Moreover, BPA exposure also induced testicular lesions. The seminiferous tubules of testis were denatured in varying degrees and the lumen wall structure was disordered. The levels of ESR in all offspring and the T levels in male offspring significantly increased, compared with controls. Co‑exposure to BPA and SIFs exacerbated these changes in body weight, testicular lesions and hormonal levels, relative to BPA exposure alone. Additionally, oxidative damage was only induced by high‑dose BPA. Collectively, these findings suggested that BPA and SIFs could have synergistic effect on the reproductive system, which could be mediated by the regulation of ESR expression and testosterone release.

Vincetoxicum arnottianum (Wight) of family Apocynaceae is a rich source of therapeutic alkaloids, phenolics and flavonoids. Study aims to evaluate the protective potential of methanol extract of Vincetoxicum arnottianum (VAM) on bisphenol A (BPA)-induced testicular toxicity in male Sprague Dawley rat. Quantitative analysis of VAM for total phenolic (TPC), total flavonoid (TFC) and total alkaloid content (TAC) along with HPLC analysis for polyphenolics was carried out. BPA-induced testicular toxicity was determined through analysis of antioxidant enzymes, DNA damages and testicular histopathology along with reproductive hormones in serum of rat. VAM was constituted of TFC (382.50 ± 1.67 μg GAE/mg), TPC (291.17 ± 0.82 μg RE/mg), TAC (16.5 ± 0.5%), ferulic acid (2.2433 μg/mg) and vanillic acid (2.1249 μg/mg). VAM co-administration to BPA-treated rats attenuated the toxic effects of BPA and restored the body and testis weights. Altered level of luteinizing hormone (LH), testosterone and follicle-stimulating hormone (FSH) in serum, and level of antioxidants (GSH, POD, CAT and SOD) and nitric oxide in testis tissues of BPA-induced toxicity were significantly restored by VAM. Histological and comet assay studies also sanctioned the protective potential of VAM in BPA-intoxicated rats. The presence of polyphenols and alkaloids might contribute towards the scavenging and ameliorative potential of VAM in testicular toxicity induced by BPA., (© 2020 Blackwell Verlag GmbH.)

We have previously shown that systemic injection of erythropoietin-producing hepatocellular receptor A7 (EPHA7)-Fc raises serum luteinizing hormone (LH) levels before ovulation in female rats, indicating the induction of EPHA7 in ovulation. In this study, we aimed to identify the mechanism and hypothalamus-pituitary-ovary (HPO) axis level underlying the promotion of LH secretion by EPHA7. Using an ovariectomized (OVX) rat model, in conjunction with low-dose 17β-estradiol (E 2 ) treatment, we investigated the association between EPHA7-ephrin (EFN)A5 signaling and E 2 negative feedback. Various rat models (OVX, E 2 -treated OVX, and abarelix treated) were injected with the recombinant EPHA7-Fc protein through the caudal vein to investigate the molecular mechanism underlying the promotion of LH secretion by EPHA7. Efna5 was observed strongly expressed in the arcuate nucleus of the female rat by using RNAscope in situ hybridization. Our results indicated that E 2 , combined with estrogen receptor (ER)α, but not ERβ, inhibited Efna5 and gonadotropin-releasing hormone 1 ( Gnrh1) expressions in the hypothalamus. In addition, the systemic administration of EPHA7-Fc restrained the inhibition of Efna5 and Gnrh1 by E 2 , resulting in increased Efna5 and Gnrh1 expressions in the hypothalamus as well as increased serum LH levels. Collectively, our findings demonstrated the involvement of EPHA7-EFNA5 signaling in the regulation of LH and the E 2 negative feedback pathway in the hypothalamus, highlighting the functional role of EPHA7 in female reproduction.

Diabetes mellitus (DM) is a chronic endocrine disease characterized by persistent hyperglycemia. Oxidative damage, inflammatory cytokines, and apoptotic cell death play a major role in the induction and progression of male testicular damage. Plant-derived phytochemicals such as green coffee ( Coffea arabica ) can possess antidiabetic effects with little toxicity. The current study is aimed at investigating the therapeutic roles of green coffee in diabetic testicular injury stimulated by high-fat diet/streptozotocin administration. Diabetes mellitus was induced by a high-fat diet and a single dose of streptozotocin (STZ) (35 mg kg -1 ) in male albino rats. Diabetic animals were orally given two different concentrations of green coffee (50 mg kg -1 and 100 mg kg -1 ) for 28 days. The levels of testosterone, luteinizing hormone, and follicle-stimulating hormone and parameters of oxidative stress, inflammation, and apoptosis were measured. mRNAs and protein levels were detected quantitatively by real-time PCR and ELISA, respectively. In the diabetic group, the levels of testosterone, luteinizing hormone, and follicle-stimulating hormone showed a significant reduction while they increased significantly after green coffee treatment. A significant increase of antioxidant markers glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase along with decreased levels of lipid peroxides and nitric oxide was observed after green coffee treatment in the diabetic group. Finally, the levels of IL-1 β , TNF- α , Bax, and caspase-3 were also decreased in both treated groups (metformin and green coffee) when compared to the diabetic group. We conclude that testicular oxidative impairment induced by a high-fat diet (HFD) and STZ can be reversed by green coffee. Administration of green coffee could represent a promising therapeutic agent which can help the treatment of type 2 DM-induced testicular dysfunction., Competing Interests: The authors have no conflict of interest to declare., (Copyright © 2020 Wafa A. AL-Megrin et al.)

Background: Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disease with unknown pathogenesis. However, the treatment of Diane-35 combined with metformin can improve the endocrine and ovulation of PCOS. In this study, we investigated the effects of Diane-35 combined with metformin (DM) treatment on ovulation and glucose metabolism in a PCOS rat model., Methods: Sprague Dawley rats were divided into 3 groups, control group, model group (PCOS group) and Diane-35 combined with metformin (PCOS + DM group). The mRNA expression levels were determined by qRT-PCR. The hormone levels were determined by enzyme-linked immunosorbent assay. Immunostaining detected the protein levels of lactate dehydrogenase A (LDH-A), pyruvate kinase isozyme M2 (PKM2) and sirtuin 1 (SIRT1) in the ovarian tissues. TNUEL assay was performed to determine cell apoptosis in the PCOS rats. The metabolites in the ovarian tissues were analyzed by liquid chromatography with tandem mass spectrometry., Results: PCOS rats showed an increased in body weight, levels of luteinizing hormone and testosterone and insulin resistance, which was significantly attenuated by the DM treatment. The DM treatment improved disrupted estrous cycle and increased the granulosa cells of the ovary in the PCOS rats. The decreased proliferation and increased cell apoptosis of granulosa cells in the ovarian tissues of PCOS rats were significantly reversed by the DM treatment. The analysis of metabolics revealed that ATP and lactate levels were significantly decreased in PCOS rats, which was recovered by the DM treatment. Furthermore, the expression of LDH-A, PKM2 and SIRT1 was significantly down-regulated in ovarian tissues of the PCOS rats; while the DM treatment significantly increased the expression of LDH-A, PKM2 and SIRT1 in the ovarian tissues of the PCOS rats., Conclusion: In conclusion, our study demonstrated that Diane-35 plus metformin treatment improved the pathological changes in the PCOS rats. Further studies suggest that Diane-35 plus metformin can improve the energy metabolism of the ovary via regulating the glycolysis pathway. The mechanistic studies indicated that the therapeutic effects of Diane-35 plus metformin treatment in the PCOS rats may be associated with the regulation of glycolysis-related mediators including PKM2, LDH-A and SIRT1.

Context: Glucagon increases energy expenditure; consequently, glucagon receptor agonists are in development for the treatment of obesity. Obesity negatively affects the reproductive axis, and hypogonadism itself can exacerbate weight gain. Therefore, knowledge of the effects of glucagon receptor agonism on reproductive hormones is important for developing therapeutics for obesity; but reports in the literature about the effects of glucagon receptor agonism on the reproductive axis are conflicting., Objective: The objective of this work is to investigate the effect of glucagon administration on reproductive hormone secretion in healthy young men., Design: A single-blinded, randomized, placebo-controlled crossover study was conducted., Setting: The setting of this study was the Clinical Research Facility, Imperial College Healthcare NHS Trust., Participants: Eighteen healthy eugonadal men (mean ± SEM: age 25.1 ± 1.0 years; body mass index 22.5 ± 0.4 kg/m2; testosterone 21.2 ± 1.2 nmol/L) participated in this study., Intervention: An 8-hour intravenous infusion of 2 pmol/kg/min glucagon or rate-matched vehicle infusion was administered., Main Outcome Measures: Luteinizing hormone (LH) pulsatility; LH, follicle-stimulating hormone (FSH), and testosterone levels were measured., Results: Although glucagon administration induced metabolic effects (insulin area under the curve: vehicle 1065 ± 292 min.µU/mL vs glucagon 2098 ± 358 min.µU/mL, P < .001), it did not affect LH pulsatility (number of LH pulses/500 min: vehicle 4.7 ± 0.4, glucagon 4.2 ± 0.4, P = .22). Additionally, there were no significant differences in circulating LH, FSH, or testosterone levels during glucagon administration compared with vehicle administration., Conclusions: Acute administration of a metabolically active dose of glucagon does not alter reproductive hormone secretion in healthy men. These data are important for the continued development of glucagon-based treatments for obesity., (© Endocrine Society 2020.)

Accumulating evidence suggests that kisspeptin neurons in the arcuate nucleus (ARC), which coexpress neurokinin B and dynorphin, are involved in gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) pulse generation, while the anteroventral periventricular nucleus (AVPV) kisspeptin neurons are responsible for GnRH/LH surge generation. The present study aims to examine whether GnRH(1-5), a GnRH metabolite, regulates LH release via kisspeptin neurons. GnRH(1-5) was intracerebroventricularly injected to ovariectomized and estrogen-treated Wistar-Imamichi female rats. Immediately after the central GnRH(1-5) administration at 2 nmol, plasma LH concentration increased, resulting in significantly higher levels of the area under the curve and baseline of plasma LH concentrations compared to vehicle-injected controls. On the other hand, in Kiss1 knockout rats, GnRH(1-5) administration failed to affect LH secretion, suggesting that the facilitatory effect of GnRH(1-5) on LH release is mediated by kisspeptin neurons. Double in situ hybridization (ISH) for Kiss1 and Gpr101, a GnRH(1-5) receptor gene, revealed that few Kiss1-expressing cells coexpress Gpr101 in both ARC and AVPV. On the other hand, double ISH for Gpr101 and Slc17a6, a glutamatergic marker gene, revealed that 29.2% of ARC Gpr101-expressing cells coexpress Slc17a6. Further, most of the AVPV and ARC Kiss1-expressing cells coexpress Grin1, a gene encoding a subunit of NMDA receptor. Taken together, these results suggest that the GnRH(1-5)-GPR101 signaling facilitates LH release via indirect activation of kisspeptin neurons and that glutamatergic neurons may mediate the signaling. This provides a new aspect of kisspeptin- and GnRH-neuronal communication with the presence of stimulation from GnRH to kisspeptin neurons in female rats.

Objective: Doses of gonadotropin releasing hormone (GnRH) analogues used to treat idiopathic central precocious puberty (iCPP) vary among clinicians. Study aims were to evaluate the efficacy of a monthly 3.75 mg dose of leuprolide acetate (LA) to suppress the hypothalamo-pituitary-gonadal (HPG) axis in girls with iCPP and to determine factors that may have an impact on the supressing dose., Methods: Study subjects were 220 girls receiving LA for iCPP. LA was started at a dose of 3.75 mg/28 days. Suppression was assessed using the GnRH test at the third month. To assess clinical suppression signs and symptoms of puberty were also evaluated. The dose of LA was increased to 7.5 mg/28 days in those who had a peak luteinising hormone (LH) ≥2 IU/L and in whom adequate clinical suppression of puberty was absent. Receiver operating characteristic curves were used to determine thresholds for clinical and hormonal factors affecting the suppressing dose of LA. Logistic regression analyses were used to investigate thresholds which might differentiate between those requiring high dose for suppression and those in whom lower dose LA was adequate., Results: Peak stimulated LH <2 IU/L was achieved in 88.6% with a dose of LA of 3.75 mg (0.11±0.03 mg/kg). Significant variables for differentiating the two doses were body weight (Wt) of 36.2 kg and/or body mass index (BMI)-standard deviation scores (SDS) of 1.64 (p<0.001). Multiple logistic regressions showed that Wt and BMI-SDS values above thresholds indicated requirement of LA at a dose of 7.5 mg/28 days (p<0.001)., Conclusion: Monthly injections of 3.75 mg LA is an effective treatment in the majority of girls with iCPP. However, a higher initial dose may be preferred in patients with a Wt ≥36 kg or BMI-SDS ≥1.6 for effective suppression of the HPG axis.

This study was conducted to evaluate the effects of dietary polyunsaturated fatty acids (PUFA) sources and rosemary leaves powder (RLP) on the semen quality, fatty acid analysis, and some reproductive hormones of senescent broiler breeder roosters. Thirty-five 45-wk-old Ross breeder roosters were randomly divided into 7 groups (5 birds/group), and received following treatments including control group (basal diet), fish oil (2%), corn oil (2%), an equal (50:50%) proportion of fish oil and corn oil (50:50%), fish oil (2%) with 5 g/kg capsulated RLP, corn oil (2%) with 5 g/kg capsulated RLP, and an equal (50:50) proportion of fish oil and corn oil (50:50%) with 5 g/kg capsulated RLP of diet for 60 D, during which time their seminal characteristics were evaluated every 20 D. At the end of the trial (on day 60), semen samples were tested for determination of sperm fatty acid analysis, lipid peroxidation, and some reproductive hormones. Results showed that feeding fish oil and fish/corn oil with RLP was associated with an increase in docosahexaenoic acid (C22:6n-3) and docosatetraenoic acid (C22:4n-6) in sperm. The fish oil diet increased the proportion of n-3 fatty acids in sperm, and as a consequence, the (n-6)/(n-3) ratio also decreased (P < 0.05). RLP (5 g/kg) to the fish and fish/corn-oil (50:50%)-based diet resulted in improvement in sperm concentration, total motility (%), sperm progressive motility (%), membrane integrity, and viability in terms 0 to 60 day trial (P < 0.05). Diets and age interacted to positively affect sperm concentration and sperm membrane integrity. Also this herbal antioxidant decreased the seminal content of malondialdehyde (MDA) significantly (P < 0.05). Testosterone and LH serum levels of reproductive hormones were significantly higher in fish and fish/corn-oil with RPL (50:50%)-based diet than other groups (P < 0.05). It can be concluded that RLP as an antioxidant could remarkably improve the effects of n-3 and n-3/n-6 PUFA on sperm characteristics, seminal MDA, and hormones levels in aged breeder roosters. The susceptibility of semen to lipid peroxidation was increased in chickens fed without RLP. Future studies are needed to disclose the causal mechanisms involved., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)

Introduction: Two common responses to stress include elevated circulating glucocorticoids and impaired luteinizing hormone (LH) secretion. We have previously shown that a chronic stress level of corticosterone can impair ovarian cyclicity in intact mice by preventing follicular-phase endocrine events., Objective: This study is aimed at investigating if corticosterone can disrupt LH pulses and whether estradiol is necessary for this inhibition., Methods: Our approach was to measure LH pulses prior to and following the administration of chronic corticosterone or cholesterol in ovariectomized (OVX) mice treated with or without estradiol, as well as assess changes in arcuate kisspeptin (Kiss1) neuronal activation, as determined by co-expression with c-Fos., Results: In OVX mice, a chronic 48 h elevation in corticosterone did not alter the pulsatile pattern of LH. In contrast, corticosterone induced a robust suppression of pulsatile LH secretion in mice treated with estradiol. This suppression represented a decrease in pulse frequency without a change in amplitude. We show that the majority of arcuate Kiss1 neurons contain glucocorticoid receptor, revealing a potential site of corticosterone action. Although arcuate Kiss1 and Tac2 gene expression did not change in response to corticosterone, arcuate Kiss1 neuronal activation was significantly reduced by chronic corticosterone, but only in mice treated with estradiol., Conclusions: Collectively, these data demonstrate that chronic corticosterone inhibits LH pulse frequency and reduces Kiss1 neuronal activation in female mice, both in an estradiol-dependent manner. Our findings support the possibility that enhanced sensitivity to glucocorticoids, due to ovarian steroid milieu, may contribute to reproductive impairment associated with stress or pathophysiologic conditions of elevated glucocorticoids., (© 2019 S. Karger AG, Basel.)

Introduction: Many studies have reported that 5α-reductase inhibitors (finasteride and dutasteride) raise serum testosterone (T) levels, yet there is lack of consistency among studies on this point., Aim: To review and meta-analyze available studies reporting changes in serum T concentrations in men treated with 5α-reductase inhibitors (5α-RIs)., Methods: A Medline search using PubMed and EMBASE was performed including the following key words: "finasteride," "dutasteride," "testosterone and 5α-reductases.", Main Outcome Measure: Relevant studies were extracted, evaluated, and analyzed. Of these, 40 studies were analyzed qualitatively and 11 were included in the meta-analysis. A random effects model was used to conduct the meta-analysis., Results: In 11 studies comprising 1,784 patients with age ranging between 18 and 83 years and average treatment follow-up of 17 months, meta-analytic estimate of the mean baseline change was 27 (95% confidence interval 1-54). The meta-analysis did not demonstrate unequivocal significant increase in serum T levels. The increase was not uniform among all studies reported. Sensitivity analysis showed that no single study contributed decisively to the outcome or could be attributed to drug action. The reported increases in T levels with finasteride or dutasteride in men with low baseline serum T may be attributed, in part, to increased trapping of T by unsaturated sex hormone binding globulin (SHBG) due to dissociation of 5α-dihydrotestosterone. In men with high baseline T levels, there appears to be no change in serum T levels. 10 studies reported luteinizing hormone, follicle-stimulating hormone, SHBG, and estradiol values and none reported significant changes in their levels, suggesting that observed changes in serum T levels are unlikely mediated by gonadotropins levels or peripheral conversion of T to estradiol., Conclusion: 5α-RI therapy is not associated with consistent and significant increases in serum T levels. Traish AM, Krakowsky Y, Doros G, et al. Do 5α-reductase inhibitors raise circulating serum testosterone levels? A comprehensive review and meta-analysis to explaining paradoxical results. Sex Med Rev 2019;7:95-114., (Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To determine and compare effects of kisspeptin on serum prolactin, luteinizing hormone and follicle stimulating hormone levels in Balb-c mice with and without exposure to chronic restraint stress., Study Design: An animal experimental study., Place and Duration of Study: Shifa College of Medicine / Shifa International Hospital Islamabad, in collaboration with National Institute of Health, Islamabad and Centre for Research in Experimental and Applied Medicine Laboratory, Army Medical College, Rawalpindi, from April 2014 to June 2015., Methodology: Mice divided into three groups, each containing 30 mice. Control group (group A) received intraperitoneal injection of saline, group B was administered with intraperitoneal injection of saline and restrained stress, and group C was administered with both stress and kisspeptin 100 ng daily for four weeks. Restraint stress was applied to groups B and C for three hours per day by immobilising individual mice in wire-mesh restrainers. At the end of four weeks blood sampling was done. Serum luteinizing hormones (LH), serum follicular stimulating hormone (FSH) and serum prolactin (PRL) were analysed by ELISA., Results: Serum prolactin level increased in group B (stressed) and group C (stressed + kisspeptin treated) as compared to control group; and decreased in group C as compared to group B. Serum LH and FSH in group B was decreased as compared to control, and it was increased in group C as compared to control and group B., Conclusion: Administration of kisspeptin increases level of gonadotropins and reduces stress-induced hyperprolactinemia, which may improve fertility despite stress in animal.

Objective was to investigate the effect of different progesterone (P4) concentrations during early follicular development on luteinizing hormone (LH) secretion and oocyte characteristics in beef cows. Primiparous cows (n = 24) were estrous pre-synchronized and follicular ablation was performed (d 0) 6 days following the time of ovulation. At the time of follicular ablation, cows were assigned to either: 1) high P4 treatment - HiP4; a new CIDR was inserted on d 0 to supplement P4 from the existing corpus luteum [CL], or 2) low P4 treatment - LoP4; a previously-used CIDR and two doses of PGF 8 to 12 h apart were given on d 0. Concentrations of P4 were greater (P < 0.01) in the cows of the HiP4 than LoP4 group on d 1.5, 2.5, and 3.5. Peripheral concentrations of E2 were greater (P < 0.05) in the cows of the LoP4 than HiP4 group on d 2.5 and 3.5. Frequency of LH pulses was greater (P <  0.05) in the LoP4 than HiP4 group on d 2.5, but mean LH concentration and pulse amplitude did not differ between treatments. Number of follicles aspirated per cow, total oocytes recovered, recovery rate, percentage of oocytes graded 1 to 3, oocyte diameter, percentage BCB+ oocytes, and relative abundance of oocyte mRNA for FST did not differ (P >  0.10) between treatments. In conclusion, lower P4 concentrations during early follicular development resulted in increased LH pulse frequency and E2 concentrations, but did not affect characteristics of oocyte developmental competence., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: While there's a growing data on the comparison of GnRH agonist and GnRH antagonist protocols, no clear study exists on the effects of both protocols on the same patient. The aim of the present study was to compare the success rates of protocol shift and proceeding with the same protocol after an unsuccessful intracytoplasmic sperm injection (ICSI) cycle., Materials and Methods: Three hundred and forty-five normal responder patients who had a previously failed ICSI cycle between January 2011 and December 2015 were reviewed. The study (n = 73) and control (n = 93) groups in the first cohort were composed of patients whose protocol were shifted to antagonist and who proceeded with agonist. The study (n = 33) and control (n = 146) groups in the second cohort were composed of patients whose protocol were shifted to agonist and who proceeded with antagonist., Results: Total dose of gonadotropins, maximum estradiol levels, and number of oocytes collected were significantly higher in agonist protocol than in antagonist protocol (P = 0.021, P = 0.013, and P = 0.003, respectively). Cycle cancellation rates were significantly lower in agonist protocol than antagonist protocol (P = 0.005). The pregnancy rates in patients who shifted to antagonist and proceeded with agonist were 57.8% and 50.8%, respectively (P = 0.399). The pregnancy rates in patients who shifted to agonist and proceeded with antagonist were 33.3% and 47.9%, respectively (P = 0.202)., Conclusion: Protocol shift following a failed ICSI cycle with either agonist or antagonist protocol does not affect outcome., (Copyright © 2018. Published by Elsevier B.V.)

Background: The neuropeptide kisspeptin stimulates luteinizing hormone (LH) secretion in healthy adults but not in adults with idiopathic hypogonadotropic hypogonadism. We hypothesized that, in children presenting with delayed or stalled puberty, kisspeptin would elicit LH secretion in those children found on detailed nighttime neuroendocrine profiling to have evidence of emerging reproductive endocrine function., Methods: Eleven boys and four girls were admitted overnight to assess LH secretion at baseline, after a single intravenous bolus of kisspeptin, and after a single intravenous bolus of gonadotropin-releasing hormone (GnRH). Subjects then received exogenous pulsatile GnRH for 6 days and returned for a second visit to measure responses to kisspeptin and GnRH after this pituitary "priming." Responses to kisspeptin and GnRH were also measured in 5 healthy men., Results: Of the 15 children with delayed/stalled puberty, 6 exhibited at least one spontaneous LH pulse overnight; all of these subjects had clear responses to kisspeptin, as did one additional subject. Seven subjects had no response to kisspeptin, and one subject exhibited an intermediate response. In the children who responded to kisspeptin, the responses had features comparable to those of adult men., Conclusion: In this first report of kisspeptin administration to pediatric subjects to our knowledge, children with delayed/stalled puberty showed a wide range of responses, with some showing a robust response and others showing little to no response. Further follow-up will determine whether responses to kisspeptin predict future pubertal entry for children with delayed puberty., Trial Registration: ClinicalTrials.gov NCT01438034 and NCT01952782., Funding: NIH Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01 HD043341, R01 HD090071, P50 HD028138), NIH National Center for Advancing Translational (UL1 TR001102), NIH National Institute of Diabetes and Digestive and Kidney Diseases (T32 DK007028), the Massachusetts General Hospital Executive Committee on Research Fund for Medical Discovery, Harvard Catalyst, Doris Duke Charitable Foundation (award 2013110), Charles H. Hood Foundation, Robert and Laura Reynolds MGH Research Scholar Program, and Harvard University. These funding sources had no role in the design of this study and did not have any role in conducting the study, analyses, interpretation of the data, or the decision to submit results.

Promising initial data from our perspective clinical trial demonstrates that Natesto can not only increase serum testosterone but also maintain follicle-stimulating hormone, luteinizing hormone, and importantly, semen parameters., (Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Perfluorooctane sulfonate (PFOS) possibly delays male sexual development. However, its effects on pubertal Leydig cell development are unclear. The objective of the present study was to investigate the effects of in vivo PFOS exposure on rat Leydig cell development during puberty. Immature male Sprague Dawley rats were gavaged 5 or 10 mg/kg PFOS on postnatal day 35 for 21 days. Compared to the control (0 mg/kg), PFOS lowered serum testosterone levels without altering luteinizing hormone and follicle-stimulating hormone levels on postnatal day 56. PFOS in vivo downregulated mRNA or protein levels of Leydig cells (Lhcgr, Cyp11a1, and Cyp17a1). PFOS in vitro inhibited androgen secretion in immature Leydig cells at ≥ 50 nM, most possibly via downregulating Hsd17b3 mRNA level. At ≥ 500 nM, PFOS downregulated Lhcgr, inhibited BCL-2 and increased BAX levels to cause Leydig cell apoptosis. In conclusion, PFOS at a lower dose directly inhibited pubertal development of Leydig cells., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In rodents, the ovulation-inducing luteinizing hormone (LH) surge is sexually dimorphic, occurring only in females, but the reasons for this sex difference are unclear. Two neuropeptides, kisspeptin and RFamide-related peptide 3 (RFRP-3), are hypothesized to regulate the gonadotropin-releasing hormone (GnRH)/LH surge. In females, both of these systems show circadian changes coincident with the LH surge, but whether males show similar temporal changes under comparable hormonal conditions is unknown. Here, we evaluated circadian time (CT)-dependent changes in gene expression and neuronal activation of Kiss1 and Rfrp neurons of female and male mice given identical LH surge-inducing estrogen regimens. As expected, females, but not males, displayed a late afternoon LH surge and GnRH neuronal activation. Kiss1 expression in the anteroventral periventricular nucleus (AVPV) was temporally increased in females in the late afternoon, whereas males demonstrated no temporal changes in AVPV Kiss1 expression. Likewise, neuronal activation of AVPV Kiss1 neurons was dramatically elevated in the late afternoon in females but was low at all circadian times in males. Estrogen receptor α levels in AVPV Kiss1 neurons were sexually dimorphic, being higher in females than males. AVPV progesterone receptor levels were also higher in females than males. Hypothalamic Rfrp messenger RNA levels showed no CT-dependent changes in either sex. However, Rfrp neuronal activation was temporally diminished in the afternoon/evening in females but not males. Collectively, the identified sex differences in absolute and CT-dependent AVPV Kiss1 levels, AVPV sex steroid receptor levels, and circadian-timed changes in neuronal activation of both Kiss1 and Rfrp neurons suggest that multiple sexually dimorphic processes in the brain may underlie proper LH surge generation., (Copyright © 2017 Endocrine Society.)

Objective: To determine the effects of sevoflurane by inhalation on female reproductive hormones and ovarian tissues., Methods: This experimental study was conducted at the Gaziosmanpasa University, Tokat, Turkey, and comprised Wistar-Albino female rats. The rats were divided into six groups; one control and five study groups. The control group (C) received 2 L/min O2 in 18 min/day for seven days; the first study group (S1) received 1 minimum alveolar concentration sevoflurane + 2 L/min O2 in 18 min/day for seven days; the second group (S2) received 1 minimum alveolar concentration sevoflurane + 2 L/min O2 in 18 min/day for seven days and no treatment for the following seven days; the third group (S3) received 1 minimum alveolar concentration sevoflurane + 2 L/min O2 in 18 min/day for 14 days; the fourth group (S4) received 1 minimum alveolar concentration sevoflurane + 2 L/min O2 in 18 min/day for 14 days and no treatment for the following seven days; and the fifth group (S5) received 1 minimum alveolar concentration sevoflurane + 2 L/min O2 in 18 min/day for 14 days and no treatment for the following 14 days. The duration of the study was 28 days in February 2015. Reproductive system hormone levels were analysed and histological assessment of the ovaries was performed. SPSS 20 was used for data analysis., Results: Of the 30 rats, there were 5(16.7%) in each group. Histological injury scores in S2, S3, S4, and S5 were significantly higher than in C (p=0.016, p=0.008, p=0.016 and p=0.032, respectively). The hormone levels belonging to follicle stimulating hormone, luteinising hormone, estradiol and progesterone revealed significant alterations in all groups (p<0.05)., Conclusions: Chronic exposure to sevoflurane negatively affected the histological structure of the ovary and hormonal regulation.

Context: Kisspeptin stimulates the reproductive endocrine cascade in both men and women. Circulating sex steroids are thought to modulate the ability of kisspeptin to stimulate gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) release., Objective: To probe the effects of sex steroids on kisspeptin-stimulated GnRH-induced LH pulses., Participants: Eight healthy postmenopausal women., Intervention: Subjects underwent every-10-minute blood sampling to measure GnRH-induced LH secretion at baseline and in response to a continuous kisspeptin infusion (12.5 µg/kg/h) over 24 hours. A subset of the participants also received kisspeptin (0.313 µg/kg) and GnRH (75 ng/kg) intravenous boluses., Results: Postmenopausal women are resistant to the stimulatory effect of continuous kisspeptin on LH secretion. Postmenopausal women receiving estradiol replacement therapy are also resistant to kisspeptin initially, but they demonstrate a significant increase in LH pulse amplitude in direct proportion to the circulating estradiol concentration and duration of kisspeptin administration., Conclusions: Kisspeptin administration has complex effects on GnRH, and by extension, on LH secretion. The ability of kisspeptin to affect LH secretion can be modulated by the ambient sex-steroid milieu in a time- and dose-dependent manner., (Copyright © 2017 Endocrine Society)

Context: Elagolix is a nonpeptide, oral gonadotropin-releasing hormone (GnRH) antagonist being developed for sex-hormone-dependent diseases in women., Objective: We evaluated the pharmacokinetics and pharmacodynamics of elagolix., Design, Setting, and Participants: This study was a randomized, double-blind, placebo-controlled, multiple-ascending dose study in 45 healthy premenopausal women at a research unit., Interventions: Elagolix [150 mg once daily or 100, 200, 300, or 400 mg twice daily (BID)] or placebo was administered for 21 days., Main Outcome Measures: Main outcome measures were elagolix pharmacokinetics, suppression of gonadotropics [follicle-stimulating hormone (FSH), luteinizing hormone (LH)] and ovarian hormones [estradiol (E2), progesterone (P)], and adverse events., Results: Elagolix was rapidly absorbed after oral dosing, reaching maximum concentrations at 1.0 to 1.5 hours, with a half-life of 4 to 6 hours. FSH, LH, and E2 were suppressed within hours of elagolix administration on day 1. Dose-dependent suppression of E2 was observed, with maximum suppression achieved with elagolix 200 mg BID. Dose-dependent suppression of FSH and LH was also observed, with maximal or near-maximal suppression achieved at 300 mg BID and 200 mg BID, respectively. At elagolix doses ≥100 mg BID, P concentrations remained at anovulatory levels throughout 21 days of dosing. The most frequently reported adverse events were headache and hot flush., Conclusions: Elagolix administration allows for modulation of gonadotropin and ovarian hormone concentrations, from partial suppression at lower doses to nearly full suppression at higher doses. The results of this study provide a rationale for elagolix dose selection for treatment of sex hormone-dependent diseases in women., (Copyright © 2017 Endocrine Society)

Background: Gonadotropin-inhibitory hormone (GnIH, human homologue of RFRP-3) suppresses gonadotropin secretion in animal models, but its effects have not been studied in the human., Objective: We tested the hypotheses that exogenous GnIH inhibits LH secretion (i) in postmenopausal women and (ii) in men concurrently administered exogenous kisspeptin., Design: Following in vitro and in vivo preclinical studies to functionally characterize the GnIH peptide, a dose-finding study (human GnIH: 1·5-150 μg/kg/h, iv for 3 h) was undertaken, and 50 μg/kg/h selected for further evaluation. Five postmenopausal women were administered 50 μg/kg/h iv infusion for 3 h or vehicle on two separate days. Four men were administered kisspeptin-10 (0·3 μg/kg iv bolus) with simultaneous infusion of GnIH (50 μg/kg/h, iv for 3 h) or vehicle., Participants: Healthy postmenopausal women (mean age 58 ± 2 years, LH: 30·8 ± 2·9 IU/l, FSH: 78·7 ± 6·4 IU/l, oestradiol: <50 pmol/l) and men (39·8 ± 2·1 years, mean total testosterone 12·1 ± 1·8 nmol/l, LH 2·2 ± 0·2 IU/l)., Primary Outcome: Change in area under curve (AUC) of LH during GnIHvs vehicle., Results: During GnIH administration in postmenopausal women, LH secretion decreased (ΔAUC: -9·9 ± 1·8 IU/3 h) vs vehicle (ΔAUC: -0·5 ± 1·7 IU/3 h; P = 0·02). Kisspeptin-10-stimulated LH responses in men were not affected by GnIH co-administration (60-min AUC of LH 6·2 ± 0·8 IU/h with kisspeptin-10 alone, 6·3 ± 1·0 IU/h, kisspeptin-10 with GnIH, P = 0·72). Exogenous GnIH was well tolerated, with no adverse events reported., Conclusions: Gonadotropin-inhibitory hormone decreased LH secretion in postmenopausal women in this first-in-human study. Kisspeptin-stimulated LH secretion in men was not inhibited during concomitant administration of GnIH., (© 2017 John Wiley & Sons Ltd.)

Background: Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation., Methods: Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 μl of saline or atropine solution (62.5 ng) in the left or right POA-AHA; 2) removal (unilateral ovariectomty, ULO) of the left (L-ULO) or right (R-ULO) ovary, and 3) rats microinjected with atropine into the left or right POA-AHA plus L-ULO or R-ULO. The ovulation rate and the number of ova shed were measured during the predicted estrus, as well as the levels of estradiol, FSH and LH during the predicted proestrus and the effects of injecting synthetic LH-releasing hormone (LHRH) or estradiol benzoate (EB)., Results: Atropine in the left POA-AHA decreased both the ovulation rate and estradiol and LH levels on the afternoon of proestrus, also LHRH or EB injection restored ovulation. L- or R-ULO resulted in a lower ovulation rate and smaller number of ova shed, and only injection of LHRH restored ovulation. EB injection at diestrus-2 restored ovulation in animals with L-ULO only. The levels of estradiol, FSH and LH in rats with L-ULO were higher than in animals with unilateral laparotomy. In the group microinjected with atropine in the left POA-AHA, ovulation was similar to that in ULO rats. In contrast, atropine in the right POA-AHA of ULO rats blocked ovulation, an action that was restored by either LHRH or EB injection., Conclusions: These results indicated that the removal of a single ovary at noon on diestrus-2 day perturbed the neuronal pathways regulating LH secretion, which was mediated by the muscarinic system connecting the right POA-AHA and the ovaries.

Context: Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women, is characterized by high secretion levels of LH and T. Currently, there is no treatment licensed specifically for PCOS., Objective: The objective of this study was to investigate whether a targeted therapy would decrease LH pulse frequency in women with PCOS, subsequently reducing serum LH and T concentrations and thereby presenting a novel therapeutic approach to the management of PCOS., Design: This study is a double-blind, double-dummy, placebo-controlled, phase 2 trial., Settings: University hospitals and private clinical research centers were included., Participants: Women with PCOS aged 18-45 years participated., Intervention: Intervention included AZD4901 (a specific neurokinin-3 [NK3] receptor antagonist) at a dose of 20, 40, or 80 mg/day or matching placebo for 28 days., Main Outcome Measure: Change from baseline in the area under the LH serum concentration-time curve over 8 hours (area under the curve) on day 7 relative to placebo was measured., Results: Of a total 67 randomized patients, 65 were evaluable. On day 7, the following baseline-adjusted changes relative to placebo were observed in patients receiving AZD4901 80 mg/day: 1) a reduction of 52.0% (95% confidence interval [CI], 29.6-67.3%) in LH area under the curve; 2) a reduction of 28.7% (95% CI, 13.9-40.9%) in total T concentration; and 3) a reduction of 3.55 LH pulses/8 hours (95% CI, 2.0-5.1) (all nominal P < .05)., Conclusions: The NK3 receptor antagonist AZD4901 specifically reduced LH pulse frequency and subsequently serum LH and T concentrations, thus presenting NK3 receptor antagonism as a potential approach to treating the central neuroendocrine pathophysiology of PCOS.

The neonatal and/or prepubertal androgen milieu affects sexual maturation and reproductive function in adulthood. However, the effects of chronic dehydroepiandrosterone (DHEA) treatment on reproductive functions have not been fully elucidated. Therefore, the reproductive phenotypes and parameters of rats that had been subjected to chronic DHEA treatment were evaluated in this study. The chronic DHEA-treated (from postnatal day 23-12 weeks of age) rats exhibited earlier vaginal opening, indicating that DHEA treatment promotes sexual maturation. In addition, the estrus phase lasted longer in the DHEA-treated rats, suggesting that their estrous cycles had been disrupted. As the DHEA-treated rats' serum luteinizing hormone levels and hypothalamic Kiss1 mRNA expression levels were decreased and their uterine weight was increased, DHEA and/or estrogen might directly affect reproductive phenotypes. While DHEA treatment caused changes in body weight and body composition in chronic testosterone-treated models in previous studies, no such changes were seen in the present study.

Poor oocyte quality is a main concern for decreased reproductive outcomes in women with polycystic ovarian syndrome (PCOS) during controlled ovarian hyperstimulation (COH). A primary way to improve oocyte quality is to optimize the COH protocol. It was demonstrated that the viable embryo rate per oocyte retrieved in the Utrogestan and hMG protocol, a novel regimen based on frozen-thawed embryo transfer (FET), is statistically higher than that in the short protocol. Thus, a retrospective study was conducted to evaluate the endocrine characteristics and clinical outcomes in PCOS patients subjected to the Utrogestan and hMG protocol compared with those subjected to the short protocol.One hundred twenty three PCOS patients enrolled in the study group and were simultaneously administered Utrogestan and human menopausal gonadotropin (hMG) from cycle day 3 until the trigger day. When the dominant follicles matured, gonadotropin-releasing hormone agonist (GnRH-a) 0.1 mg was used as the trigger. A short protocol was applied in the control group including 77 PCOS women. Viable embryos were cryopreserved for later transfer in both groups. The primary outcome was the viable embryo rate per oocyte retrieved. The secondary outcomes included the number of oocytes retrieved, fertilization rate, and clinical pregnancy outcomes from FET cycles.The pituitary luteinizing hormone (LH) level was suppressed in most patients; however, the LH level in 13 women, whose basic LH level was more than 10 IU/L, surpassed 10 IU/L on menstruation cycle day (MC)9-11 and decreased subsequently. No significant between-group differences were observed in the number of oocytes retrieved (13.27 ± 7.46 vs 13.1 ± 7.98), number of viable embryos (5.57 ± 3.27 vs 5 ± 2.79), mature oocyte rate (90.14 ± 11.81% vs 93.02 ± 8.95%), and cleavage rate (97.69 ± 6.22% vs 95.89 ± 9.57%). The fertilization rate (76.11 ± 19.04% vs 69.34 ± 21.81%; P < 0.05), viable embryo rate per oocyte retrieved (39.85% vs 34.68%; P < 0.05), biochemical pregnancy rate (71.72% vs 56.67%; P < 0.05), clinical pregnancy rate (64.65% vs 51.65%; P < 0.05), and implantation rate (46.46% vs 31.35%; P < 0.05) in the study group were significant higher than those in the control group.This study shows that the Utrogestan and hMG protocol was feasible to improve the oocyte quality, possibly providing a new choice for PCOS patients undergoing IVF/ICSI treatments in combination with embryo cryopreservation.

GnRH sterilization vaccines have been developed for various practical and clinical reasons. However, conjugation of GnRH peptide to carrier protein has many drawbacks, hampering the further commercialization of GnRH vaccines. In this study, a new nonconjugated GnRH vaccine, D-Lys6-GnRH-tandem-dimer peptide (TDK), emulsified in Specol adjuvant was investigated for its immunocastration efficacy in young male rats. Prepubertal male rats were randomly allocated into three groups (n = 12): control (no treatment), surgically castrated or immunized against 100 μg TDK in Specol adjuvant at 6 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (18 weeks of age). Compared to intact controls, active immunization against TDK reduced (P < 0.05) serum concentrations of testosterone, inhibin B, LH and FSH, prevented the onset of spermatogenesis at puberty. Furthermore, mRNA expressions of GnRH receptor, LH-β and FSH-β in the pituitary, LH receptor, FSH receptor, inhibin α, βA and βB subunit in the testes were decreased in immunocastrated rats compared to intact controls (P < 0.05). These results demonstrate for the first time that GnRH-tandem-dimer peptide emulsified in Specol is a promising veterinary sterilization medicine.

Stress elicits activation of the hypothalamic-pituitary-adrenal axis, which leads to enhanced circulating glucocorticoids, as well as impaired gonadotropin secretion and ovarian cyclicity. Here, we tested the hypothesis that elevated, stress-levels of glucocorticoids disrupt ovarian cyclicity by interfering with the preovulatory sequence of endocrine events necessary for the LH surge. Ovarian cyclicity was monitored in female mice implanted with a cholesterol or corticosterone (Cort) pellet. Cort, but not cholesterol, arrested cyclicity in diestrus. Subsequent studies focused on the mechanism whereby Cort stalled the preovulatory sequence by assessing responsiveness to the positive feedback estradiol signal. Ovariectomized mice were treated with an LH surge-inducing estradiol implant, as well as Cort or cholesterol, and assessed several days later for LH levels on the evening of the anticipated surge. All cholesterol females showed a clear LH surge. At the time of the anticipated surge, LH levels were undetectable in Cort-treated females. In situ hybridization analyses the anteroventral periventricular nucleus revealed that Cort robustly suppressed the percentage of Kiss1 cells coexpressing cfos, as well as reduced the number of Kiss1 cells and amount of Kiss1 mRNA per cell, compared with expression in control brains. In addition, Cort blunted pituitary expression of the genes encoding the GnRH receptor and LHβ, indicating inhibition of gonadotropes during the blockage of the LH surge. Collectively, our findings support the hypothesis that physiological stress-levels of Cort disrupts ovarian cyclicity, in part, through disruption of positive feedback mechanisms at both the hypothalamic and pituitary levels which are necessary for generation of the preovulatory LH surge.

Cadmium (Cd) is a major environmental toxicant and an endocrine disruptor. We investigated the protective effects of methanol extract of Artocarpus altilis (AA) against Cd-induced testicular damage in rats while quercetin (Que) served as standard. The total flavonoids and phenolic contents (TFC and TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl (OH) radicals scavenging activities of AA were determined. In vivo, thirty male Wistar rats were assigned to six groups and orally treated with corn oil (control), Cd alone, Cd+Que, Cd+AA, Que and AA alone. Que and AA were given at doses of 25 and 200 mg kg(-1), respectively, for 3 weeks and challenged with two doses of Cd (1.5 mg kg(-1)). Results showed that TFC and TPC of AA increased with increase in concentration. AA scavenged DPPH and OH radicals in a dose-dependent manner. Administration of Cd significantly increased the relative weight of testis of rats. Lipid peroxidation was significantly increased while antioxidant parameters decreased in testis of Cd-treated rats. Also, Cd-treated rats had significantly reduced sperm count, motility, sialic acid, luteinising hormone and testosterone relative to controls. Pre-treatment with AA or Que significantly attenuated the biochemical alterations observed in Cd-treated rats. Overall, AA protects against Cd-induced testicular damage via antioxidative mechanism., (© 2015 Blackwell Verlag GmbH.)

Objectives: To determine, in a chronic dosing study, the oral toxicity potential of the test substances, enclomiphene citrate (ENC) and zuclomiphene citrate (ZUC), when administered to male mice by oral gavage., Materials and Methods: Mice were divided into five treatment groups. Group I, placebo; Group II, 40 mg/kg body weight/day ENC; Group III, 4 mg/kg/day ENC; Group IV, 40 mg/kg/day ZUC; Group V, 4 mg/kg/day ZUC. Serum samples and tissues were obtained from each mouse for analysis and body weights were measured., Results: In this chronic dosing study in mice, profound effects on Leydig cells, epididymis, seminal vesicles, and kidneys were seen, as well as effects on serum testosterone, follicle-stimulating hormone and luteinising hormone levels that were associated with ZUC treatment only. Treatment with the isolated enclomiphene isomer had positive effects on testosterone production and no effects on testicular histology., Conclusions: The present study suggests that an unopposed high dose of zuclomiphene can have pernicious effects on male mammalian reproductive organs. The deleterious effects seen when administering ZUC in male mice, justifies the case for a monoisomeric preparation and the development of ENC for clinical use in human males to increase serum levels of testosterone and maintain sperm counts., (© 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.)

RF9, a reported antagonist of the mammalian gonadotropin-inhibitory hormone receptor, stimulates gonadotropin secretion in mammals. Recent studies have suggested that the stimulatory effect of RF9 on gonadotropin secretion relies on intact kisspeptin receptor (KISS1R) signaling, but the underlying mechanisms remain to be elucidated. Using Chinese Hamster Ovary cells stably transfected with KISS1R, we show that RF9 binds specifically to KISS1R, with a Kd of 1.6 × 10(-5)M, and stimulates an increase in intracellular calcium and inositol phosphate accumulation in a KISS1R-dependent manner, with EC50 values of 3.0 × 10(-6)M and 1.6 × 10(-7)M, respectively. RF9 also stimulated ERK phosphorylation, with a time course similar to that of kisspeptin-10. RFRP-3, the putative endogenous ligand for NPFFR1, did not stimulate inositol phosphate accumulation or pERK, nor did it alter responses to of kisspeptin-10 or RF9. In agreement with these in vitro data, we found that RF9 stimulated a robust LH increase in Npffr1(-/-) mice, similar to that in wild-type littermates, whereas the stimulatory effect of RF9 was markedly reduced in Kiss1r(-/-) and double Kiss1r(-/-)/Npfrr1(-/-) mice. The stimulatory effect of RF9 on LH secretion was restored by the selective rescue of Kiss1r expression in GnRH neurons, in Kiss1r(-/-T) mice. Taken together, our study demonstrates that RF9 acts primarily as a KISS1R agonist, but not as an allosteric modulator, to stimulate LH secretion. Our findings raise questions regarding the utility of RF9 for assessing NPFF1R function and de-emphasize a predominant role of this signaling system in central regulation of reproduction.

Context: Tamoxifen, a selective estrogen receptor modulator, suppresses GH secretion in women but not in men. It increases testosterone levels in men. As GH and testosterone stimulate fat metabolism, the metabolic consequences of tamoxifen may be greater in women than in men., Objective: To determine whether tamoxifen suppresses fat oxidation (Fox) to a greater degree in women than in men., Design: An open-label study of ten healthy postmenopausal women and ten healthy men receiving 2-week treatment with tamoxifen (20  mg/day)., Endpoint Measures: GH response to arginine stimulation, serum levels of IGF1, testosterone and LH (men only), sex hormone binding globulin (SHBG) and whole body basal and postprandial Fox., Results: In women, tamoxifen significantly reduced the mean GH response to arginine stimulation (Δ -87%, P<0.05) and circulating IGF1 levels (Δ -23.5±5.4%, P<0.01). Tamoxifen reduced postprandial Fox in women (Δ -34.6±10.3%; P<0.05). In men, tamoxifen did not affect the GH response to arginine stimulation but significantly reduced mean IGF1 levels (Δ -24.8±6.1%, P<0.01). Tamoxifen increased mean testosterone levels (Δ 52±14.2%; P<0.01). Fox was not significantly affected by tamoxifen in men., Conclusion: Tamoxifen attenuated the GH response to stimulation and reduced postprandial Fox in women but not in men. We conclude that at a therapeutic dose, the suppressive effect of tamoxifen on fat metabolism is gender-dependent. Higher testosterone levels may mitigate the suppression of GH secretion and Fox during tamoxifen treatment in men., (© 2015 European Society of Endocrinology.)

Objective: To investigate the effects of Morina Officinalis How (MOH) on the abnormal levels of serum luteotrophic hormone (LH) and LH receptor (LHR) in the testis tissue induced by cellphone radiation (CPR) in rats., Methods: Fifty adult male SD rats were randomly divided into five groups of equal number: sham CPR, untreated CPR, negative double distilled water (DDW) control, aqueous MOH extract, and alcohol MOH extract. All the animals were exposed to mobile phone radiation except those of the sham CPR group. Then, the rats of the latter two groups were treated intragastrically with MOH at 20 g per kg of the body weight per day in water and alcohol, respectively. After 2. weeks of treatment, all the rats were sacrificed for measurement of the levels of serum LH and LHR in the testis tissue., Results: The levels of serum LH and LHR were 30.15 ± 8.71 and 33.28 ± 6.61 in the aqueous MOH group and 0.96 ± 0.06 and 0.94 ± 0.08 in the alcohol MOH group, both significantly decreased as compared with the negative DDW controls (P < 0.05), but with no remarkable difference between the two MOH groups (P > 0.05)., Conclusion: MOH can improve CPR-induced abnormality of LH and LHR in adult male rats.

Prenatal T excess induces maternal hyperinsulinemia, early puberty, and reproductive/metabolic defects in the female similar to those seen in women with polycystic ovary syndrome. This study addressed the organizational/activational role of androgens and insulin in programming pubertal advancement and periovulatory LH surge defects. Treatment groups included the following: 1) control; 2) prenatal T; 3) prenatal T plus prenatal androgen antagonist, flutamide; 4) prenatal T plus prenatal insulin sensitizer, rosiglitazone; 5) prenatal T and postnatal flutamide; 6) prenatal T and postnatal rosiglitazone; and 7) prenatal T and postnatal metformin. Prenatal treatments spanned 30-90 days of gestation and postnatal treatments began at approximately 8 weeks of age and continued throughout. Blood samples were taken twice weekly, beginning at approximately 12 weeks of age to time puberty. Two-hour samples after the synchronization with prostaglandin F2α were taken for 120 hours to characterize LH surge dynamics at 7 and 19 months of age. Prenatal T females entered puberty earlier than controls, and all interventions prevented this advancement. Prenatal T reduced the percentage of animals having LH surge, and females that presented LH surge exhibited delayed timing and dampened amplitude of the LH surge. Prenatal androgen antagonist, but not other interventions, restored LH surges without normalizing the timing of the surge. Normalization of pubertal timing with prenatal/postnatal androgen antagonist and insulin sensitizer interventions suggests that pubertal advancement is programmed by androgenic actions of T involving insulin as a mediary. Restoration of LH surges by cotreatment with androgen antagonist supports androgenic programming at the organizational level.

The objective of the present study was to investigate the effects of testosterone in recuperation of lead-induced suppressed reproduction in adult male rats. Lead acetate was administered orally to adult male rats (95 ± 5 days) at dosage level of 0.05 and 0.15% for 55 days through drinking water and injected intraperitoneally with either testoviron depot at a dose of 4.16 mg kg(-1) body weight or vehicle alone on days 1, 7 and 14 respectively. At the end of treatment, control and treated males were cohabited with untreated normal-cycling females. After cohabitation for 5 days, all the male rats were killed and weights of reproductive organs were determined. Significant increase in the indices of testis, epididymis, seminal vesicles, vas deferens and prostate glands was observed in testosterone (T)-treated rats when compared to those of lead-exposed rats. Testosterone treatment significantly increased epididymal sperm count, motile spermatozoa, viable spermatozoa and HOS tail-coiled spermatozoa and also the activity levels of testicular 3β- and 17β-hydroxysteroid dehydrogenases when compared to those of lead-exposed males. From the results, it can be hypothesised that supplementation of testosterone mitigated lead-induced suppressed reproduction in male rats., (© 2014 Blackwell Verlag GmbH.)

We tested the hypothesis that kisspeptin cells constitute the "pulse generator" for GnRH secretion. In ewes, we determined whether iv administered kisspeptin elicits a secretory pulse of LH in anaesthetized, sex-steroid suppressed ovariectomized ewes. A response was seen in both anaesthetized and conscious animals, which was not associated with induction of c-Fos labeling in GnRH cells, supporting the notion that kisspeptin acts on the neurosecretory GnRH terminals. Response was lower in the anaesthetized animals, suggesting that some nonkisspeptin elements may be involved in GnRH responses. Microinjection of kisspeptin (100 nmol) into the median eminence of conscious ewes elicited a pulse of LH, indicating that kisspeptin acts at this level to cause GnRH secretion. To determine which cells are activated at the time of GnRH secretion, we blood sampled 18 ewes during the luteal phase of the estrous cycle and harvested brains after 3 hours. Three of these ewes displayed a pulse of LH within 30 minutes of euthanasia. An increase in c-Fos labeling was seen in kisspeptin and glutamate cells of the arcuate nucleus but not in GnRH neurons, preoptic kisspeptin neurons, or preoptic glutamate neurons. Immunohistochemistry in 4 hypothalami showed that 72% of arcuate kisspeptin cells receive glutamatergic input. These data support the concept that the kisspeptin cells of the arcuate nucleus drive pulsatile secretion of GnRH at the level of the median eminence, but this may involve "upstream" input from glutamate cells. We conclude that the pulse generator for GnRH secretion involves more than 1 element.

A major cause of cycle cancellation during controlled ovarian hyperstimulation (COH) in women undergoing in vitro fertilization (IVF) is the occurrence of premature luteinizing hormone (LH) surges. Steroidal preparations can modulate the secretion of gonadotropins (Gn); however, few studies using progesterone to inhibit the premature LH surges in COH have been published. The purpose of the study was to evaluate the oral delivery of progesterone soft capsules (Utrogestan) to prevent LH surges from the follicular phase and to compare cycle characteristics as well as to evaluate pregnancy outcomes in subsequent frozen-thawed embryo transfer (FET) cycles. A total of 374 patients were enrolled in this retrospective study, among which 187 patients were simultaneously administered Utrogestan and human menopausal gonadotrophin (hMG) from cycle day 3 until the trigger day. A short protocol including 187 controls with comparable age, body mass index (BMI), infertility duration, and antral follicle count was also used. GnRH agonist (0.1 mg) or hCG (3000 IU) was used for a trigger when the dominant follicles matured. Viable embryos were cryopreserved for later transfer in both groups. The primary outcome was the number of oocytes retrieved. The secondary outcomes included the number of mature oocytes, incidence of premature LH surge, and clinical pregnancy outcomes from FET cycles. Consistent LH suppression was achieved during COH, with a range of 0.07 to 8.9 IU/L, and no premature LH surge was detected. The number of oocytes retrieved in the Utrogestan and hMG protocol was comparable with that in the short protocol (10.92 ± 5.74 vs 10.6 ± 6.22, P > 0.05), and the dose of hMG was higher than that used in the short protocol (1884.22 ± 439.47 IU vs 1446.26 ± 550.48 IU, P < 0.05). No significant between-group difference was observed in the mature oocyte rate (88.88% vs 90.12%), cleavage rate (96.58% vs 96.58%), clinical pregnancy rate (54.27% vs 51.65%), or implantation rate (33.59% vs 34.02%). The study shows that Utrogestan is an effective oral alternative for preventing premature LH surges in women undergoing COH, which will help to establish a convenient user regimen in combination with FET.

Objectives: Polymeric PEG-b-PLA nanoparticles (NPs) were developed for delivery of poorly water-soluble drugs via blood brain barrier into brain parenchyma. We analyzed neuroendocrine disrupting effects of neonatal exposure of female rats to PEG-b-PLA NPs and diethylstilbestrol (DES) on the function of adenohypophyseal gonadotrophs of infantile or adult rats by examining in vitro luteinizing hormone releasing hormone (LHRH)-induced luteinizing hormone (LH) release., Methods: Neonatal female Wistar rats were injected intraperitoneally, daily, from postnatal day (PND) 4 to PND7 with PEG-b-PLA NPs (20 mg.kg b.w.(-1)), DES (4 µg.kg b.w.(-1)) or vehicle. At the necropsy day (PND15 in infantile and the first estrus day after PND176 in adult rats), adenohypophyseal cells were isolated by enzymatic digestion, plated in 96-well plates (5×10(4) cells.well(-1)) in serum-supplemented medium and left to recover for 96 h. LHRH (10-7 mol.L(-1)) treatment was performed in serum-free medium for 60 min and LH levels in culture media were determined by radioimmunoassay., Results: In all experimental groups, in vitro LHRH treatment significantly stimulated LH release from pituitary cells of infantile but not adult female rats. Neonatal DES treatment increased basal LH secretion from cultured pituitary cells of adult but not infantile rats. In both, infantile and adult rats, neonatal treatment with PEG-b-PLA significantly increased basal and LHRH-induced LH release from pituitary cells compared to corresponding controls and DES-treated group., Conclusions: Data indicate that neonatal exposure to PEG-b-PLA NPs may alter pituitary LH release, and thereby modify reproductive system development in infantile female rats leading to reproductive dysfunctions in adult age.

The neural mechanisms controlling puberty onset remain enigmatic. Humans with loss of function mutations in TAC3 or TACR3, the genes encoding neurokinin B (NKB) or its receptor, neurokinin-3 receptor (NK3R), respectively, present with severe congenital gonadotrophin deficiency and pubertal failure. Animal studies have shown ambiguous actions of NKB-NK3R signalling with respect to controlling puberty onset. The present study aimed to determine the role of endogenous NKB-NK3R signalling in the control of pulsatile luteinising hormone (LH) secretion and the timing of puberty onset, and also whether precocious pubertal onset as a result of an obesogenic diet is similarly regulated by this neuropeptide system. Prepubertal female rats, chronically implanted with i.c.v. cannulae, were administered SB222200, a NK3R antagonist, or artificial cerebrospinal fluid via an osmotic mini-pump for 14 days. SB222200 significantly delayed the onset of vaginal opening and first oestrus (as markers of puberty) compared to controls in both normal and high-fat diet fed animals. Additionally, serial blood sampling, via chronic indwelling cardiac catheters, revealed that the increase in LH pulse frequency was delayed and that the LH pulse amplitude was reduced in response to NK3R antagonism, regardless of dietary status. These data suggest that endogenous NKB-NK3R signalling plays a role in controlling the timing of puberty and the associated acceleration of gonadotrophin-releasing hormone pulse generator frequency in the female rat., (© 2014 British Society for Neuroendocrinology.)

Our research was concentrated about physiological and structural aspects of metal complexes with GnRH, which were synthetized by Professor Henryk Kozłowski from the Uniwersity of Wrocław. We found that copper, nickel, zinc and cobalt complexes with GnRH stimulated the release of LH and FSH both in vivo and in vitro. The most stable and active was Cu-GnRH. It also exhibited the higher affinity to specific receptor than GnRH, had higher releasing power for LH and FSH and stimulated differently the intracellular signaling. We suggest, that this complex in highly promissive as a new analog of GnRH with possible application to further research.

The aims of this study were to evaluate the effects of administration of Vitamins C and E on fertilization capacity in rats exposed to noise stress. 40 adult male rats were randomly divided into 5 equal groups. Group 1 as controls who were not exposed to noise and groups 2-5 exposed to noise with 90-120 dB intensity and 300-350 Hz frequency from 7 pm to 7 am everyday for 50 days. Group 2 exposed to noise and did not receive Vitamins. Group 3 received vitamin C, Group 4 received Vitamin E. Group 5 received Vitamins C and E concomitantly. After 50 days, serum Follicle-stimulating hormone (FSH), Luteinizing hormone (LH) and testosterone were calculated. Then each rat was left with three female rats for mating. Pregnant females were sacrificed on the 19 th day of pregnancy and evaluated for the presence and number of viable, dead and absorbed fetuses. The level of FSH, LH and testosterone significantly decreased in rats exposed to noise (P < 0.05). By administration of Vitamins in groups 3-5 we observed that the level of hormones significantly increased in compared to group 2 (P < 0.05). The fertilization capacity of male rats in groups 3-5 significantly increased in compared to group 2 (P < 0.05). There was significant difference between groups 1 and 2 in case of fertilization capacity (P = 0.001). The data in this study strongly suggests a negative role for noise stress on level of FSH, LH and testosterone level and also fertilization capacity of male rats. To complement the information it is suggested that this research be done on human samples.

In female sheep, estradiol (E2) stimulates the preovulatory GnRH/LH surge and receptive behavior, whereas progesterone blocks these effects. Prenatal exposure to testosterone disrupts both the positive feedback action of E2 and sexual behavior although the mechanisms remain unknown. The current study tested the hypothesis that both prenatal and postnatal steroids are required to organize the surge and sex differences in reproductive behavior. Our approach was to characterize the LH surge and mating behavior in prenatally untreated (Control) and testosterone-treated (T) female sheep subsequently exposed to one of three postnatal steroid manipulations: endogenous E2, excess E2 from a chronic implant, or no E2 due to neonatal ovariectomy (OVX). All females were then perfused at the time of the expected surge and brains processed for estrogen receptor and Fos immunoreactivity. None of the T females exposed postnatally to E2 exhibited an E2-induced LH surge, but a surge was produced in five of six T/OVX and all Control females. No surges were produced when progesterone was administered concomitantly with E2. All Control females were mounted by males, but significantly fewer T females were mounted by a male, including the T/OVX females that exhibited LH surges. The percentage of estrogen receptor neurons containing Fos was significantly influenced in a brain region-, developmental stage-, and steroid-specific fashion by testosterone and E2 treatments. These findings support the hypothesis that the feedback controls of the GnRH surge are sensitive to programming by prenatal and postnatal steroids in a precocial species.

Doxazosin (Doxa) is an α1-selective adrenergic receptor (ADR) antagonist widely used, alone or in combination, to treat high blood pressure, benign prostatic hyperplasia symptoms, and recently has been suggested as a potential drug for prostate cancer prevention/treatment. This study was designed to evaluate the effect of in vivo Doxa po-application, in clinically relevant dose, on: (i) steroidogenic machinery homeostasis; (ii) cAMP/cGMP signalling; (iii) transcription profile of ADR in Leydig cells of adult rats. The results showed that po-application of Doxa for once (1×Doxa), or for two (2×Doxa) or 10 (10×Doxa) consecutive days significantly disturbed steroidogenic machinery homeostasis in Leydig cells. Doxa po-application significantly decreased circulating luteinizing hormone and androgens levels. The level of androgens in testicular interstitial fluid and that extracted from testes obtained from 1×Doxa/2×Doxa rats decreased, although it remained unchanged in 10×Doxa rats. Similarly, the ex vivo basal androgen production followed in testes isolated from 1×Doxa/2×Doxa rats decreased, while remained unchanged in 10×Doxa rats. Differently, ex vivo testosterone production and steroidogenic capacity of Leydig cells isolated from 1×Doxa/2×Doxa rats was stimulated, while 10×Doxa had opposite effect. In the same cells, cAMP content/release showed similar stimulatory effect, but back to control level in Leydig cells of 10×Doxa. 1×Doxa/2×Doxa decreased transcripts for cAMP specific phosphodiesterases Pde7b/Pde8b, whereas 10×Doxa increased Pde4d. All types of treatment reduced the expression of genes encoding protein kinase A (PRKA) regulatory subunit (Prkar2b), whereas only 10×Doxa stimulated catalytic subunit (Prkaca). Doxa application more affected cGMP signalling: stimulated transcription of constitutive nitric oxide synthases (Nos1, Nos3) in time-dependent manner, whereas reduced inducible Nos2. 10×Doxa increased guanylyl cyclase 1 transcript and PRKG1 protein in Leydig cells. Orally applied Doxa significantly disturbed the transcriptional 'signature' of steroidogenic machinery, cAMP/cGMP signalling and ADRs and β-ADRs kinases in Leydig cells, thus giving new molecular insights into the role of cAMP/cGMP/adrenalin signalling in Leydig cells homeostasis., (© 2012 American Society of Andrology and European Academy of Andrology.)

Background: Currently GnRH analogue injections are used to prevent premature LH surges in women undergoing assisted reproductive technology. This was a pilot study to determine the safety and effectiveness of nimodipine, an oral calcium channel blocker, to delay the mid-cycle spontaneous LH surge in women with regular menstrual cycles., Methods: Eight women with regular menstrual cycles self-monitored three consecutive cycles for the day of an LH surge by daily urine assay. The first and third cycles were observatory. In the second cycle, subjects took nimodipine 60 mg by mouth three times daily for four days, starting two days prior to the expected LH surge day based on cycle one., Results: The LH surge day in cycle 2 (nimodipine) was significantly delayed in comparison to both observatory cycle 1 (15.5+/-3.4 vs 14.0+/-2.8 days; p=0.033) and cycle 3 (15.1+/-3.5 vs 13.1+/-2.4 days; p=0.044). There was no difference in the LH surge day between the two observatory cycles (13.4+/-2.4 vs 13.1+/-2.4 days; p=0.457). Three patients experienced a mild headache., Conclusions: There was a statistically significant delay in the spontaneous LH surge day in the treatment cycle in comparison to both observatory cycles. Nimopidine should be further investigated as an oral alternative to delay a spontaneous LH surge.