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Ohkuma M, Maruyama T, Ishii T, Igarashi N, Azuma K, Inoue T, Obata R, Miyachi EI, Kaneda M. Effects of Progesterone and Other Gonadal Hormones on Glutamatergic Circuits in the Retina. J NIPPON MED SCH 2023; 90:333-345. [PMID: 37690823 DOI: 10.1272/jnms.jnms.2023_90-405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
BACKGROUND Gonadal hormones function in the retina; however, their targets have not yet been identified. Therefore, the present study examined the effects of progesterone and other gonadal hormones on glutamatergic circuits in the retina. METHODS Extracellular glutamate concentrations, which correspond to the amount of glutamate released, were examined using an enzyme-linked fluorescent assay system. The activity of glutamatergic synapses between bipolar cells and ganglion cells was investigated using a patch clamp technique. Changes in retinal thickness during pregnancy were assessed using optical coherence tomography (OCT) images. RESULTS Progesterone and pregnenolone sulfate increased extracellular glutamate concentrations, whereas estrogen and testosterone did not. Progesterone increased the activity of glutamatergic synapses between bipolar cells and ganglion cells. A temporal decrease in the thickness of the peripheral retina was observed in the 1st trimester. CONCLUSIONS Progesterone, but not estrogen or testosterone, activated glutamate release in the mouse retina. Increases in the concentration of progesterone during pregnancy did not induce any detectable change in retinal thickness.
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Affiliation(s)
| | - Takuma Maruyama
- Department of Physiology, Nippon Medical School
- Present address: Department of Physiology, Division of Neurophysiology, School of Medicine, Tokyo Women's Medical University
| | | | - Nozomi Igarashi
- Department of Ophthalmology, Faculty of Medicine, Tokyo University
| | - Keiko Azuma
- Department of Ophthalmology, Faculty of Medicine, Tokyo University
| | - Tatsuya Inoue
- Department of Ophthalmology, School of Medicine, Yokohama City University
| | - Ryo Obata
- Department of Ophthalmology, Faculty of Medicine, Tokyo University
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Xu XL, Huang ZY, Yu K, Li J, Fu XW, Deng SL. Estrogen Biosynthesis and Signal Transduction in Ovarian Disease. Front Endocrinol (Lausanne) 2022; 13:827032. [PMID: 35299973 PMCID: PMC8921451 DOI: 10.3389/fendo.2022.827032] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 02/03/2022] [Indexed: 12/01/2022] Open
Abstract
Estrogen mainly binds to estrogen receptors (ERs) to regulate menstrual cycles and reproduction. The expression of ERalpha (ERα), ERbeta (ERβ), and G-protein-coupled estrogen receptor (GPER) mRNA could be detected in ovary, suggesting that they play an important role in estrogen signal transduction in ovary. And many studies have revealed that abnormal expression of estrogen and its receptors is closely related to ovarian disease or malignant tumors. With the continuous development and research of animal models, tissue-specific roles of both ERα and ERβ have been demonstrated in animals, which enable people to have a deeper understanding of the potential role of ER in regulating female reproductive diseases. Nevertheless, our current understanding of ERs expression and function in ovarian disease is, however, incomplete. To elucidate the biological mechanism behind ERs in the ovary, this review will focus on the role of ERα and ERβ in polycystic ovary syndrome (PCOS), ovarian cancer and premature ovarian failure (POF) and discuss the major challenges of existing therapies to provide a reference for the treatment of estrogen target tissue ovarian diseases.
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Affiliation(s)
- Xue-Ling Xu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Zheng-Yuan Huang
- Department of Metabolism, Digestion and Reproduction, Chelsea and Westminster Hospital, Imperial College London, London, United Kingdom
| | - Kun Yu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Jun Li
- Department of Reproductive Medicine, The First Hospital of Hebei Medical University, Shijiazhuang, China
| | - Xiang-Wei Fu
- National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shou-Long Deng
- National Health Commission of China (NHC) Key Laboratory of Human Disease Comparative Medicine, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China
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Chuon T, Feri M, Carlson C, Ondrejik S, Micevych PE, Sinchak K. Progesterone receptor-Src kinase signaling pathway mediates neuroprogesterone induction of the luteinizing hormone surge in female rats. J Neuroendocrinol 2022; 34:e13071. [PMID: 34904297 PMCID: PMC8923351 DOI: 10.1111/jne.13071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/18/2021] [Accepted: 11/24/2021] [Indexed: 01/03/2023]
Abstract
Neural circuits in female rats are exposed to sequential estradiol and progesterone to regulate the release of luteinizing hormone (LH) and ultimately ovulation. Estradiol induces progesterone receptors (PGRs) in anteroventral periventricular nucleus (AVPV) kisspeptin neurons, and as estradiol reaches peak concentrations, neuroprogesterone (neuroP) synthesis is induced in hypothalamic astrocytes. This local neuroP signals to PGRs expressed in kisspeptin neurons to trigger the LH surge. We tested the hypothesis that neuroP-PGR signaling through Src family kinase (Src) underlies the LH surge. As observed in vitro, PGR and Src are co-expressed in AVPV neurons. Estradiol treatment increased the number of PGR immunopositive cells and PGR and Src colocalization. Furthermore, estradiol treatment increased the number of AVPV cells that had extranuclear PGR and Src in close proximity (< 40 nm). Infusion of the Src inhibitor (PP2) into the AVPV region of ovariectomized/adrenalectomized (ovx/adx) rats attenuated the LH surge in trunk blood collected 53 h post-estradiol (50 µg) injection that induced neuroP synthesis. Although PP2 reduced the LH surge in estradiol benzoate treated ovx/adx rats, activation of either AVPV PGR or Src in 2 µg estradiol-primed animals significantly elevated LH concentrations compared to dimethyl sulfoxide infused rats. Finally, antagonism of either AVPV PGR or Src blocked the ability of PGR or Src activation to induce an LH surge in estradiol-primed ovx/adx rats. These results indicate that neuroP, which triggers the LH surge, signals through an extranuclear PGR-Src signaling pathway.
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Affiliation(s)
- Timbora Chuon
- Department of Biological Sciences, California State
University, Long Beach, Long Beach, CA, USA
| | - Micah Feri
- Department of Biological Sciences, California State
University, Long Beach, Long Beach, CA, USA
| | - Claire Carlson
- Department of Biological Sciences, California State
University, Long Beach, Long Beach, CA, USA
| | - Sharity Ondrejik
- Department of Biological Sciences, California State
University, Long Beach, Long Beach, CA, USA
| | - Paul E Micevych
- Department of Neurobiology, David Geffen School of Medicine
at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University
of California, Los Angeles, Los Angeles, CA, USA
| | - Kevin Sinchak
- Department of Biological Sciences, California State
University, Long Beach, Long Beach, CA, USA
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4
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Brann DW, Lu Y, Wang J, Zhang Q, Thakkar R, Sareddy GR, Pratap UP, Tekmal RR, Vadlamudi RK. Brain-derived estrogen and neural function. Neurosci Biobehav Rev 2021; 132:793-817. [PMID: 34823913 PMCID: PMC8816863 DOI: 10.1016/j.neubiorev.2021.11.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/26/2021] [Accepted: 11/12/2021] [Indexed: 01/02/2023]
Abstract
Although classically known as an endocrine signal produced by the ovary, 17β-estradiol (E2) is also a neurosteroid produced in neurons and astrocytes in the brain of many different species. In this review, we provide a comprehensive overview of the localization, regulation, sex differences, and physiological/pathological roles of brain-derived E2 (BDE2). Much of what we know regarding the functional roles of BDE2 has come from studies using specific inhibitors of the E2 synthesis enzyme, aromatase, as well as the recent development of conditional forebrain neuron-specific and astrocyte-specific aromatase knockout mouse models. The evidence from these studies support a critical role for neuron-derived E2 (NDE2) in the regulation of synaptic plasticity, memory, socio-sexual behavior, sexual differentiation, reproduction, injury-induced reactive gliosis, and neuroprotection. Furthermore, we review evidence that astrocyte-derived E2 (ADE2) is induced following brain injury/ischemia, and plays a key role in reactive gliosis, neuroprotection, and cognitive preservation. Finally, we conclude by discussing the key controversies and challenges in this area, as well as potential future directions for the field.
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Affiliation(s)
- Darrell W Brann
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA.
| | - Yujiao Lu
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Jing Wang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Quanguang Zhang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Roshni Thakkar
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, FL, 33136, USA
| | - Gangadhara R Sareddy
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Uday P Pratap
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Rajeshwar R Tekmal
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA
| | - Ratna K Vadlamudi
- Department of Obstetrics and Gynecology, University of Texas Health, San Antoio TX, 78229, USA; Audie L. Murphy Division, South Texas Veterans Health Care System, San Antonio, TX, 78229, USA.
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Socha P, Bladowska K, Zduńczyk S, Janowski T. Aglepristone Administration in Mid-Proestrus Reduces the LH Peak but Does Not Prevent Ovulation in the Bitch. Animals (Basel) 2021; 11:ani11071922. [PMID: 34203449 PMCID: PMC8300317 DOI: 10.3390/ani11071922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary The role of preovulatory progesterone for LH release and ovulation in the bitch is not clear. The aim of the study was to evaluate the influence of administration of aglepristone in mid-proestrus on progesterone concentration, LH release, and occurrence of ovulation in the bitch. Experimental bitches (n = 7) were treated on days 4 and 5 of proestrus with aglepristone (Alizin®, Virbac) at the dose of 10 mg/kg body weight s.c. (i.e., the two treatments were 24 h apart). The progesterone concentration showed a similar pattern in both groups. The LH peak value and area under the curve for LH in bitches treated with aglepristone were significantly lower than those in control bitches. The ovulation occurred in all animals in both groups. The presented study showed that withdrawal of progesterone by administration of aglepristone in the mid-proestrus significantly reduced the preovulatory LH surge, but it had no effect on periovulatory progesterone concentration or the occurrence of ovulation. Abstract The aim of the study was to evaluate the influence of administration of aglepristone in mid-proestrus on progesterone concentration, LH release, and occurrence of ovulation in the bitch. Experimental bitches (n = 7) were treated on days 4 and 5 of proestrus with aglepristone at the dose of 10 mg/kg body weight s.c. (i.e., the two treatments were 24 h apart). Control animals (n = 7) received s.c. injections of saline. For progesterone determination, blood was collected daily until the first day of cytological diestrus. For LH determination, blood was collected daily and in the periovulatory phase every 8 h. The progesterone concentration showed a similar pattern in both groups. The LH peak value in bitches treated with aglepristone was significantly lower (p < 0.05) than that in control bitches (4.83 ± 1.20 vs. 13.66 ± 1.21 ng/mL). The area under the curve (AUC) for LH was significantly (p < 0.05) lower in treated than in control animals (6.85 ± 1.21 ng/mL/d vs. 12.25 ± 1.35 ng/mL/d). The ovulation occurred in all animals in both groups. The study showed that administration of aglepristone in the mid-proestrus significantly reduced the preovulatory LH surge, but it had no effect on progesterone concentration and the occurrence of ovulation.
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Nie H, Zhang R, Yu X, Zhang Y, Yan P, Li E, Wang R, Wu X. Molecular cloning, immunological characterization, and expression analysis of gonadotropin-releasing hormone (GnRH) in the brain of the Chinese alligator during different stages of reproductive cycle. Gene 2021; 789:145672. [PMID: 33882325 DOI: 10.1016/j.gene.2021.145672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 04/01/2021] [Accepted: 04/15/2021] [Indexed: 11/16/2022]
Abstract
The neurohormone gonadotropin-releasing hormone (GnRH) plays an essential role in the control of reproductive functions in vertebrates. However, the full-length complementary DNA (cDNA) encoding the GnRHs precursor and it role in the reproductive cycles regulating has not been illustrated in crocodilian species. In the present study, full-length cDNAs encoding GnRH1 forms, its predominant localization within brain and peripheral tissues, and GnRH1 peptide concentrations in the hypothalamus and pituitary in relation to seasonal gonadal development of Chinese alligator were investigated. The cDNA of GnRH1 is consisted of 282 bp open reading frame encoding 93 amino acids. The deduced amino acid sequence of alligator GnRH1 contains several conserved regions and shows a closer genetic relationship to the avian species than to other reptile species. The GnRH1 immunopositive cells were not only detected widely in cerebrum, diencephalon, medulla oblongata but also observed in peripheral tissues, these widespread distribution characteristics indicated that GnRH1 possibly possess the multi-functionality in Chinese Alligator. GnRH1 peptide concentration within hypothalamus were observed be the highest in RP group (P < 0.05), in association with an peak value in GSI and emerging of late vitellogenic follicles in the ovary. Taken together, our results suggested that GnRH1 was predominantly involved in the vitellogenesis process of seasonal gonadal development of Chinese Alligator.
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Affiliation(s)
- Haitao Nie
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Ruidong Zhang
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China; College of Life Sciences, Inner Mongolia Normal University, Hohhot, Inner Mongolia 010022, China
| | - Xiaoqin Yu
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Yuqian Zhang
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Peng Yan
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - En Li
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China
| | - Renping Wang
- Alligator Research Center of Anhui Province, Xuanzhou 242000, China
| | - Xiaobing Wu
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu, Anhui 241000, China.
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Zhou S, Wen S, Sheng Y, Yang M, Shen X, Chen Y, Kang D, Xu L. Association of Estrogen Receptor Genes Polymorphisms With Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis Based on Observational Studies. Front Endocrinol (Lausanne) 2021; 12:726184. [PMID: 34671317 PMCID: PMC8521002 DOI: 10.3389/fendo.2021.726184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 09/13/2021] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Controversial results existed in amounts of studies investigating the authentic association of estrogen receptor genes (ESR1 and ESR2) polymorphisms with the occurrence and progression of polycystic ovary syndrome (PCOS). The inconsistency might result from different loci, sample sizes, and ethnicities. To find the potential correlations between ESR1/ESR2 polymorphisms and PCOS risk, we conducted the first systematic review and meta-analysis to comprehensively summarize current studies in a large combined population. METHODS Eligible studies were retrieved from PubMed, MEDLINE, EMBASE, Cochrane Library, CBM, CNKI, WANFANG, and VIP up to February 28, 2021. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS) scoring system. Odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated to synthesize data in five genetic models. Subgroup analyses were conducted by ethnicity. Heterogeneity and publication bias were also assessed. The protocol was registered in PROSPERO under the number CRD42021239200. RESULTS A total of 8 studies involving 1,522 PCOS patients and 4,198 controls were included. No evidence demonstrated the association of ESR1 rs2234693 (OR=1.07 95%CI 0.98-1.18), ESR1 rs9340799 (OR=0.99 95%CI 0.69-1.43), or ESR2 rs4986938 (OR=1.06 95%CI 0.81-1.38) polymorphisms and PCOS risk in five genetic models. According to stratified subgroup analyses, ethnicity was considered the major source of heterogeneity. No publication bias was found in eligible studies. CONCLUSION The present meta-analysis found no significant associations between the variants of ESR1 rs2234693, ESR1 rs9340799, ESR2 rs4936938, and individual PCOS susceptibility, even if ethnicity was taken into account. SYSTEMATIC REVIEW REGISTRATION The protocol was registered in PROSPERO (available from https://www.crd.york.ac.uk/PROSPERO) with the ID number CRD42021239200.
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Affiliation(s)
- Siyu Zhou
- Department of Obstetrics and Gynaecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
- Reproductive Endocrinology and Regulation Laboratory, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Shu Wen
- Department of Obstetrics and Gynaecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
- Reproductive Endocrinology and Regulation Laboratory, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yongcheng Sheng
- Department of Evidence-based Medicine and Clinical Epidemiology, West China Hospital, Sichuan University, Chengdu, China
| | - Meina Yang
- Department of Obstetrics and Gynaecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
- Reproductive Endocrinology and Regulation Laboratory, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Xiaoyang Shen
- Department of Obstetrics and Gynaecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
- Reproductive Endocrinology and Regulation Laboratory, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Yan Chen
- Department of Obstetrics and Gynaecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
- Reproductive Endocrinology and Regulation Laboratory, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Deying Kang
- Department of Evidence-based Medicine and Clinical Epidemiology, West China Hospital, Sichuan University, Chengdu, China
- Center of Biostatistics, Design, Measurement and Evaluation (CBDME), West China Hospital, Sichuan University, Chengdu, China
| | - Liangzhi Xu
- Department of Obstetrics and Gynaecology, West China Second University Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
- Reproductive Endocrinology and Regulation Laboratory, West China Second University Hospital, Sichuan University, Chengdu, China
- *Correspondence: Liangzhi Xu,
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Sinchak K, Mohr MA, Micevych PE. Hypothalamic Astrocyte Development and Physiology for Neuroprogesterone Induction of the Luteinizing Hormone Surge. Front Endocrinol (Lausanne) 2020; 11:420. [PMID: 32670203 PMCID: PMC7333179 DOI: 10.3389/fendo.2020.00420] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/26/2020] [Indexed: 12/26/2022] Open
Abstract
Neural circuits in female rats sequentially exposed to estradiol and progesterone underlie so-called estrogen positive feedback that induce the surge release of pituitary luteinizing hormone (LH) leading to ovulation and luteinization of the corpus hemorrhagicum. It is now well-established that gonadotropin releasing hormone (GnRH) neurons express neither the reproductively critical estrogen receptor-α (ERα) nor classical progesterone receptor (PGR). Estradiol from developing ovarian follicles acts on ERα-expressing kisspeptin neurons in the rostral periventricular region of the third ventricle (RP3V) to induce PGR expression, and kisspeptin release. Circulating estradiol levels that induce positive feedback also induce neuroprogesterone (neuroP) synthesis in hypothalamic astrocytes. This local neuroP acts on kisspeptin neurons that express PGR to augment kisspeptin expression and release needed to stimulate GnRH release, triggering the LH surge. In vitro and in vivo studies demonstrate that neuroP signaling in kisspeptin neurons occurs through membrane PGR activation of Src family kinase (Src). This signaling cascade has been also implicated in PGR signaling in the arcuate nucleus of the hypothalamus, suggesting that Src may be a common mode of membrane PGR signaling. Sexual maturation requires that signaling between neuroP synthesizing astrocytes, kisspeptin and GnRH neurons be established. Prior to puberty, estradiol does not facilitate the synthesis of neuroP in hypothalamic astrocytes. During pubertal development, levels of membrane ERα increase in astrocytes coincident with an increase of PKA phosphorylation needed for neuroP synthesis. Currently, it is not clear whether these developmental changes occur in existing astrocytes or are due to a new population of astrocytes born during puberty. However, strong evidence suggests that it is the former. Blocking new cell addition during puberty attenuates the LH surge. Together these results demonstrate the importance of pubertal maturation involving hypothalamic astrocytes, estradiol-induced neuroP synthesis and membrane-initiated progesterone signaling for the CNS control of ovulation and reproduction.
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Affiliation(s)
- Kevin Sinchak
- Department of Biological Sciences, California State University, Long Beach, Long Beach, CA, United States
| | - Margaret A Mohr
- The Laboratory of Neuroendocrinology, Department of Neurobiology, David Geffen School of Medicine at UCLA, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
| | - Paul E Micevych
- The Laboratory of Neuroendocrinology, Department of Neurobiology, David Geffen School of Medicine at UCLA, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
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Edwards KL, Pilgrim M, Brown JL, Walker SL. Irregular ovarian cyclicity is associated with adrenal activity in female eastern black rhinoceros (Diceros bicornis michaeli). Gen Comp Endocrinol 2020; 289:113376. [PMID: 31881202 DOI: 10.1016/j.ygcen.2019.113376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 10/30/2019] [Accepted: 12/22/2019] [Indexed: 10/25/2022]
Abstract
To achieve self-sustaining and genetically diverse populations ex situ, captive breeding programmes must ensure good overall rates of reproduction, and equal contribution across individuals. Previous research in the critically endangered eastern black rhinoceros (Diceros bicornis michaeli) revealed a high incidence of irregular oestrous cyclicity; in particular extended cycle duration among nulliparous females and acyclic periods in parous females that have not bred for several years. Irregular ovarian activity could play a role in reduced reproductive output; however, the mechanisms underlying these anomalies are poorly understood. The aim of this study was to measure faecal glucocorticoid metabolite (fGCM) concentrations and variability prior to and during periods of regular and irregular ovarian activity, and determine if adrenal activity influences the occurrence of different cycle types in this species. Faecal samples were collected every other day from parous (N = 6) and nulliparous (N = 12) females at eight European institutions for periods of 9-15 months. Concentration and variability in fGCM were compared between periods of regular and irregular cyclicity and between different cycle types (<20 days, 20-40 days, >40 days, acyclic) using generalized linear mixed models. Concentrations of fGCM were influenced by season and higher during the luteal than the follicular phase of the oestrous cycle. Taking this into account, fGCMs were increased during periods of irregular cyclicity (all types combined and during cycles >40 days in length) compared to 20-40 day cycles. This was predominantly driven by nulliparous females. The variation in fGCM concentration also differed between periods of regular and irregular cyclicity; higher standard deviation in fGCM preceded irregular cycles and >40 day cycles compared to 20-40 day cycles. These results suggest that although fGCM concentrations fluctuate across the oestrous cycle in this species, changes in adrenal activity at specific times could be one factor associated with irregular ovarian activity in the black rhinoceros.
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Affiliation(s)
- Katie L Edwards
- North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK; Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA.
| | - Mark Pilgrim
- North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK
| | - Janine L Brown
- Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA
| | - Susan L Walker
- North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK
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Shu Y, Zhang H, Cai Q, Tang D, Wang G, Liu T, Lv B, Wu H. Integrated mRNA and miRNA expression profile analyses reveal the potential roles of sex-biased miRNA-mRNA pairs in gonad tissues of the Chinese concave-eared torrent frog (Odorrana tormota). JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2019; 332:69-80. [PMID: 30964604 DOI: 10.1002/jez.b.22851] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 02/21/2019] [Accepted: 03/20/2019] [Indexed: 12/20/2022]
Abstract
The Chinese concave-eared torrent frog (Odorrana tormota) is typically sexually dimorphic. Females are significantly less common than males in the wild. Until now, the molecular mechanisms of reproduction and sex differentiation of frogs remain unclear. Here, we integrated mRNA and microRNA (miRNA) expression profiles to reveal the molecular mechanisms of reproduction and sex differentiation in O. tormota. We identified 234 differentially expressed miRNAs (DEMs) and 18,551 differentially expressed transcripts. Of these, 12,053 mRNAs and 64 miRNAs were upregulated in testes, and 6,498 mRNAs and 170 miRNAs were upregulated in ovaries. Integrated analysis of the miRNA and mRNA expression profiles predicted 75,602 potential miRNA-mRNA interaction sites, with 42,065 negative miRNA-mRNA interactions. We found 36 differentially expressed genes (DEGs) related to reproduction and sex differentiation, of which 15 DEGs formed 92 negative miRNA-mRNA interactions with 34 known DEMs. Thus, miRNAs may play other important roles in O. tormota. Furthermore, Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed reproductive-related processes, such as the gonadotropinreleasing hormone signaling pathway and ovarian steroidogenesis. Based on functional annotation and the literature, the retinoic acid signaling pathway, the SOX9-AMH pathway, and the process of spermatogenesis may be involved in the molecular mechanisms of reproduction and sex differentiation in O. tormota, and may be regulated by miRNAs. The miRNA-mRNA pairs described may provide further understanding of the regulatory mechanisms associated with reproduction and sex differentiation, and the molecular mechanism of reproduction in O. tormota.
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Affiliation(s)
- Yilin Shu
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Huijuan Zhang
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Qijia Cai
- Key Laboratory of Algal Biology of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Dong Tang
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Gang Wang
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Ting Liu
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Bihua Lv
- Department of Pharmacy, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Hailong Wu
- Key Laboratory for the Conservation and Utilization of Important Biological Resources of Anhui Province, Wuhu, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
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11
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Edwards KL, Edes AN, Brown JL. Stress, Well-Being and Reproductive Success. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1200:91-162. [DOI: 10.1007/978-3-030-23633-5_5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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12
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Diotel N, Charlier TD, Lefebvre d'Hellencourt C, Couret D, Trudeau VL, Nicolau JC, Meilhac O, Kah O, Pellegrini E. Steroid Transport, Local Synthesis, and Signaling within the Brain: Roles in Neurogenesis, Neuroprotection, and Sexual Behaviors. Front Neurosci 2018; 12:84. [PMID: 29515356 PMCID: PMC5826223 DOI: 10.3389/fnins.2018.00084] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/02/2018] [Indexed: 01/18/2023] Open
Abstract
Sex steroid hormones are synthesized from cholesterol and exert pleiotropic effects notably in the central nervous system. Pioneering studies from Baulieu and colleagues have suggested that steroids are also locally-synthesized in the brain. Such steroids, called neurosteroids, can rapidly modulate neuronal excitability and functions, brain plasticity, and behavior. Accumulating data obtained on a wide variety of species demonstrate that neurosteroidogenesis is an evolutionary conserved feature across fish, birds, and mammals. In this review, we will first document neurosteroidogenesis and steroid signaling for estrogens, progestagens, and androgens in the brain of teleost fish, birds, and mammals. We will next consider the effects of sex steroids in homeostatic and regenerative neurogenesis, in neuroprotection, and in sexual behaviors. In a last part, we will discuss the transport of steroids and lipoproteins from the periphery within the brain (and vice-versa) and document their effects on the blood-brain barrier (BBB) permeability and on neuroprotection. We will emphasize the potential interaction between lipoproteins and sex steroids, addressing the beneficial effects of steroids and lipoproteins, particularly HDL-cholesterol, against the breakdown of the BBB reported to occur during brain ischemic stroke. We will consequently highlight the potential anti-inflammatory, anti-oxidant, and neuroprotective properties of sex steroid and lipoproteins, these latest improving cholesterol and steroid ester transport within the brain after insults.
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Affiliation(s)
- Nicolas Diotel
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
| | - Thierry D. Charlier
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
| | - Christian Lefebvre d'Hellencourt
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
| | - David Couret
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
- CHU de La Réunion, Saint-Denis, France
| | | | - Joel C. Nicolau
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
| | - Olivier Meilhac
- Université de La Réunion, Institut National de la Santé et de la Recherche Médicale, UMR 1188, Diabète athérothrombose Thérapies Réunion Océan Indien, Saint-Denis de La Réunion, France
- CHU de La Réunion, Saint-Denis, France
| | - Olivier Kah
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
| | - Elisabeth Pellegrini
- Univ Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, Rennes, France
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Mittelman-Smith MA, Rudolph LM, Mohr MA, Micevych PE. Rodent Models of Non-classical Progesterone Action Regulating Ovulation. Front Endocrinol (Lausanne) 2017; 8:165. [PMID: 28790975 PMCID: PMC5522857 DOI: 10.3389/fendo.2017.00165] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 06/27/2017] [Indexed: 11/13/2022] Open
Abstract
It is becoming clear that steroid hormones act not only by binding to nuclear receptors that associate with specific response elements in the nucleus but also by binding to receptors on the cell membrane. In this newly discovered manner, steroid hormones can initiate intracellular signaling cascades which elicit rapid effects such as release of internal calcium stores and activation of kinases. We have learned much about the translocation and signaling of steroid hormone receptors from investigations into estrogen receptor α, which can be trafficked to, and signal from, the cell membrane. It is now clear that progesterone (P4) can also elicit effects that cannot be exclusively explained by transcriptional changes. Similar to E2 and its receptors, P4 can initiate signaling at the cell membrane, both through progesterone receptor and via a host of newly discovered membrane receptors (e.g., membrane progesterone receptors, progesterone receptor membrane components). This review discusses the parallels between neurotransmitter-like E2 action and the more recently investigated non-classical P4 signaling, in the context of reproductive behaviors in the rodent.
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Affiliation(s)
- Melinda A. Mittelman-Smith
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
- *Correspondence: Melinda A. Mittelman-Smith,
| | - Lauren M. Rudolph
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
| | - Margaret A. Mohr
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
| | - Paul E. Micevych
- Department of Neurobiology, David Geffen School of Medicine at UCLA, The Laboratory of Neuroendocrinology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, United States
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14
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Aleknaviciute J, Tulen JHM, Timmermans M, de Rijke YB, van Rossum EFC, de Jong FH, Kushner SA. Adrenocorticotropic hormone elicits gonadotropin secretion in premenopausal women. Hum Reprod 2016; 31:2360-8. [PMID: 27591239 DOI: 10.1093/humrep/dew190] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 07/05/2016] [Indexed: 12/17/2022] Open
Abstract
STUDY QUESTION Does adrenocorticotropic hormone (ACTH) induce gonadotropin release in premenopausal women? SUMMARY ANSWER Administration of ACTH stimulates gonadotropin release, most likely by stimulation of the production of cortisol, in premenopausal women. WHAT IS KNOWN ALREADY In animal models, acute activation of the hypothalamic-pituitary-adrenal (HPA) axis has been shown to induce gonadotropin release in the presence of sufficiently high estrogen levels. However, it is unknown whether the HPA axis has a similar influence on gonadotropin release in humans. STUDY DESIGN, SIZE, DURATION This study had a mixed factorial design. A total of 60 healthy female participants participated in the experimental study. PARTICIPANTS/MATERIALS, SETTING, METHODS The study sample comprised three distinct hormonal-based populations according to their levels of progesterone (PROG) and estradiol (E2): (i) low-PROG-low-E2, (ii) low-PROG-high-E2 and (iii) high-PROG-high-E2 women. A low dose (1 µg) of ACTH was administered to all study participants. Serum steroid and gonadotropin concentrations were measured prior to, and at 30 and 90 minutes after, intravenous ACTH administration. MAIN RESULTS AND THE ROLE OF CHANCE Mean serum cortisol levels increased significantly following ACTH administration in all groups (P < 0.001). Similarly, the serum levels of 17-OH-PROG, androstenedione, dehydroepiandrosterone and testosterone increased significantly in all groups (P < 0.01). The low-PROG-high-E2 and high-PROG-high-E2 groups exhibited a significant increase in LH and FSH levels (P < 0.001), whereas the low-PROG-low-E2 group demonstrated blunted LH and FSH responses to ACTH administration (P < 0.05). LIMITATIONS, REASONS FOR CAUTION Testing was performed during the luteal phase of the natural menstrual cycle. Testing during the follicular phase might have elicited premature, or more pronounced, LH surges in response to ACTH administration. WIDER IMPLICATIONS OF THE FINDINGS Our findings suggest a novel mechanism by which the adrenal cortex functions as a mediator of gonadotropin release. These findings contribute to a greater understanding of the influence of acute stress on reproductive endocrinology. STUDY FUNDING/COMPETING INTERESTS Funding was received from the Erasmus University Medical Center. The authors have no conflicts of interest. TRIAL REGISTRATION NUMBER EudraCT Number 2012-005640-14.
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Affiliation(s)
- Jurate Aleknaviciute
- Department of Psychiatry, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Joke H M Tulen
- Department of Psychiatry, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Mirjam Timmermans
- Department of Psychiatry, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Yolanda B de Rijke
- Department of Clinical Chemistry, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Elisabeth F C van Rossum
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Frank H de Jong
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Steven A Kushner
- Department of Psychiatry, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
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15
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Hamed SA. The effect of epilepsy and antiepileptic drugs on sexual, reproductive and gonadal health of adults with epilepsy. Expert Rev Clin Pharmacol 2016; 9:807-19. [PMID: 26934627 DOI: 10.1586/17512433.2016.1160777] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Sherifa A. Hamed
- Department of Neurology and Psychiatry, Assiut University Hospital, Assiut, Egypt
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16
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Witorsch RJ. Effects of elevated glucocorticoids on reproduction and development: relevance to endocrine disruptor screening. Crit Rev Toxicol 2016; 46:420-36. [DOI: 10.3109/10408444.2016.1140718] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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17
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Fanson KV, Parrott ML. The value of eutherian-marsupial comparisons for understanding the function of glucocorticoids in female mammal reproduction. Horm Behav 2015; 76:41-7. [PMID: 26065733 DOI: 10.1016/j.yhbeh.2015.05.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 05/04/2015] [Accepted: 05/11/2015] [Indexed: 12/31/2022]
Abstract
This article is part of a Special Issue "SBN 2014". Chronic stress is known to inhibit female reproductive function. Consequently, it is often assumed that glucocorticoid (GC) concentrations should be negatively correlated with reproductive success because of the role they play in stress physiology. In contrast, a growing body of evidence indicates that GCs play an active role in promoting reproductive function. It is precisely because GCs are so integral to the entire process that disruptions to adrenal activity have negative consequences for reproduction. The goal of this paper is to draw attention to the increasing evidence showing that increases in adrenal activity are important for healthy female reproduction. Furthermore, we outline several hypotheses about the functional role(s) that GCs may play in mediating reproduction and argue that comparative studies between eutherian and marsupial mammals, which exhibit some pronounced differences in reproductive physiology, may be particularly useful for testing different hypotheses about the functional role of GCs in reproduction. Much of our current thinking about GCs and reproduction comes from research involving stress-induced levels of GCs and has led to broad assumptions about the effects of GCs on reproduction. Unfortunately, this has left a gaping hole in our knowledge about basal GC levels and how they may influence reproductive function, thereby preventing a broader understanding of adrenal physiology and obscuring potential solutions for reproductive dysfunction.
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Affiliation(s)
- Kerry V Fanson
- Centre for Integrative Ecology, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Marissa L Parrott
- Wildlife Conservation & Science, Zoos Victoria, Victoria 3052, Australia
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18
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Mizoguchi A, Kamimura M, Kiuchi M, Kataoka H. Positive feedback regulation of prothoracicotropic hormone secretion by ecdysteroid--a mechanism that determines the timing of metamorphosis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 58:39-45. [PMID: 25596092 DOI: 10.1016/j.ibmb.2015.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 01/02/2015] [Accepted: 01/06/2015] [Indexed: 06/04/2023]
Abstract
When insect larvae have fully grown, prothoracicotropic hormone (PTTH) is released from the brain, triggering the initiation of metamorphic development through stimulation of ecdysteroid secretion by the prothoracic glands. The present study analyzes the mechanism that regulates the occurrence of this PTTH surge. In the silkworm Bombyx mori, the PTTH surge occurs on day 6 of the fifth instar and is preceded by a small rise in hemolymph ecdysteroid titer, which occurs late on day 5. We therefore hypothesized that this rise of ecdysteroid titer is involved in the induction of the PTTH surge. To test this hypothesis, two experiments were conducted. First, a small amount of 20-hydroxyecdysone was injected on day 4, two days before the expected day of the PTTH surge, to simulate the small rise in hemolymph ecdysteroid titer on day 5. This injection led to a precocious surge of PTTH the next day. Next, the hemolymph ecdysteroid titer on day 5 was artificially lowered by injecting ecdysteroid-22-oxidase, which inactivates 20-hydroxyecdysone. After this treatment, the PTTH surge did not occur on day 6 in 80% of the animals. These results indicate that a small rise of the hemolymph ecdysteroid titer plays a critical role in the induction of the PTTH surge. Since basal ecdysteroidogenic activity of the prothoracic glands increases with larval growth, a circulating level of ecdysteroids may convey information about larval maturity to the brain, to coordinate larval growth and metamorphosis. This is the first report in invertebrates to demonstrate positive feedback regulation of the surge of a tropic hormone by a downstream steroid hormone.
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Affiliation(s)
- Akira Mizoguchi
- Division of Biological Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
| | - Manabu Kamimura
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan
| | - Makoto Kiuchi
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan
| | - Hiroshi Kataoka
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8562, Japan
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Impact of high serum progesterone during the late follicular phase on IVF outcome. Reprod Biomed Online 2014; 29:177-86. [DOI: 10.1016/j.rbmo.2014.03.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 03/19/2014] [Accepted: 03/20/2014] [Indexed: 11/24/2022]
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20
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Köves K, Kántor O, Lakatos A, Szabó E, Kirilly E, Heinzlmann A, Szabó F. Advent and recent advances in research on the role of pituitary adenylate cyclase-activating polypeptide (PACAP) in the regulation of gonadotropic hormone secretion of female rats. J Mol Neurosci 2014; 54:494-511. [PMID: 24696167 DOI: 10.1007/s12031-014-0294-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/20/2014] [Indexed: 02/06/2023]
Abstract
PACAP (ADCYAP1) was isolated from ovine hypothalami. PACAP activates three distinct receptor types: G-protein coupled PAC1, VPAC1, and VPAC2 with seven transmembrane domains. Eight splice variants of PAC1 receptor are described. A part of the hypothalamic PACAP is released into the hypophyseal portal circulation. Both hypothalamic and pituitary PACAP are involved in the dynamic control of gonadotropic hormone secretion. In female rats, PACAP in the paraventricular nucleus is upregulated in the morning and pituitary PACAP is upregulated in the late evening of the proestrus stage of the reproductive cycle. PACAP mRNA peak in the hypothalamic PVN precedes the LHRH release into the portal circulation. It is supposed that PACAP peak is evoked by the elevated estrogen on proestrous morning. At the beginning of the so-called critical period of the same day, PACAP level starts to decline allowing LHRH release into the portal circulation, resulting in the LH surge that evokes ovulation. Just before the critical period, icv-administered exogenous PACAP blocks the LH surge and ovulation. The blocking effect of PACAP is mediated through CRF and endogenous opioids. The effect of the pituitary-born PACAP depends on the intracellular cross-talk between PACAP and LHRH.
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Affiliation(s)
- Katalin Köves
- Department of Human Morphology and Developmental Biology, Faculty of Medicine, Semmelweis University, Tűzoltó u. 58, H-1094, Budapest, Hungary,
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Jayes FL, Burns KA, Rodriguez KF, Kissling GE, Korach KS. The naturally occurring luteinizing hormone surge is diminished in mice lacking estrogen receptor Beta in the ovary. Biol Reprod 2014; 90:24. [PMID: 24337314 DOI: 10.1095/biolreprod.113.113316] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Female ESR2-null mice (betaERKO) display defects in ovarian function and are subfertile. Follicular maturation is impaired and explains smaller litters, but betaERKO also produce fewer litters, which may be partially due to inadequate ovulatory signals. To test this, the amplitude and timing of the naturally occurring luteinizing hormone (LH) surge was measured in individual intact betaERKO and wild-type (WT) mice. Vaginal cytology was evaluated daily, and blood samples were taken from mice in proestrus. The amplitude of the LH surge was severely blunted in betaERKO mice compared to WT, but pituitary LH levels revealed no differences. The betaERKO mice did not produce a preovulatory estradiol surge. To determine if the smaller LH surges and the reduced number of litters in betaERKO were due to the lack of ESR2 in the hypothalamic-pituitary axis or due to the absence of ESR2 in the ovary, ovaries were transplanted from WT into betaERKO mice and vice versa. The size of the LH surge was reduced only in mice lacking ESR2 within the ovary, and these mice had fewer litters. Fertility and size of the LH surge were rescued in betaERKO mice receiving a WT ovary. These data provide the first experimental evidence that the LH surge is impaired in betaERKO females and may contribute to their reduced fertility. ESR2 is not necessary within the pituitary and hypothalamus for the generation of a normal LH surge and for normal fertility, but ESR2 is essential within the ovary to provide proper signals.
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Affiliation(s)
- Friederike L Jayes
- Receptor Biology Section, Laboratory of Reproductive and Developmental Toxicology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
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22
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Fanson KV, Keeley T, Fanson BG. Cyclic changes in cortisol across the estrous cycle in parous and nulliparous Asian elephants. Endocr Connect 2014; 3:57-66. [PMID: 24623735 PMCID: PMC3987288 DOI: 10.1530/ec-14-0025] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the context of reproduction, glucocorticoids (GCs) are generally considered to have negative effects. However, in well-studied model species, GCs fluctuate predictability across the estrous cycles, and short-term increases promote healthy ovarian function. Reproductive challenges have plagued captive elephant populations, which are not currently self-sustaining. Efforts to understand reproductive dysfunction in elephants have focused on the suppressive effects of cortisol, but the potential permissive or stimulatory effects of cortisol are unknown. In this study, we provide a detailed examination of cortisol patterns across the estrous cycle in Asian elephants (Elephas maximus). Time series analysis was used to analyze cortisol and progesterone data for a total of 73 cycles from eight females. We also compared cortisol profiles between females that successfully conceived and females that failed to conceive despite repeated mating attempts. Our results revealed that cortisol fluctuates predictably across the estrous cycle, with a peak during the second half of the follicular phase followed by low levels throughout the luteal phase. Furthermore, this pattern was significantly altered in nulliparous females; cortisol concentrations did not decline during the luteal phase to the same extent as in parous females. This study highlights the complexity of cortisol signaling and suggests future directions for understanding the role of cortisol in reproductive dysfunction.
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Affiliation(s)
- Kerry V Fanson
- Wildlife Reproductive Centre, Taronga Conservation Society AustraliaDubbo, New South WalesAustralia
- School of Life and Environmental Sciences, Deakin University75 Pigdons Road, Waurn Ponds, Victoria, 3217Australia
- Correspondence should be addressed to K V Fanson
| | - Tamara Keeley
- Wildlife Reproductive Centre, Taronga Conservation Society AustraliaDubbo, New South WalesAustralia
- School of Agriculture and Food Sciences, University of QueenslandGatton, QueenslandAustralia
| | - Benjamin G Fanson
- School of Life and Environmental Sciences, Deakin University75 Pigdons Road, Waurn Ponds, Victoria, 3217Australia
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Jahanfar S, Lye MS, Krishnarajah IS. Genetic and environmental effects on age at menarche, and its relationship with reproductive health in twins. INDIAN JOURNAL OF HUMAN GENETICS 2013; 19:245-50. [PMID: 24019629 PMCID: PMC3758734 DOI: 10.4103/0971-6866.116127] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
INTRODUCTION: Menarche or first menstrual period is a landmark in reproductive life span and it is the most prominent change of puberty. The timing of menarche can be under the influence of genes as well as individual environmental factors interacting with genetic factors. OBJECTIVE: Our study objectives were (a) to investigate the heritability of age of menarche in twins, (b) to obtain the association between age of menarche and childhood factors, and reproductive events/behavior, (c) to examine whether or not having a male co-twin affects early/late menarche. METHODOLOGY: A group of female-female identical (n = 108, 54 pairs), non-identical twins (n = 68, 34 pairs) and 17 females from opposite-sex twin sets were identified from twin registries of Malaysia and Iran. Genetic analysis was performed via two methods of Falconers’ formula and maximum likelihood. RESULTS: Heritability was found to be 66% using Falconers’ formula and 15% using univariate twin analysis. Model analysis revealed that shared environmental factors have a major contribution in determining the age of menarche (82%) followed by non-shared environment (18%). DISCUSSION: Result of this study is consistent with that of the literature. Timing of menarche could be under the influence of shared and non-shared environmental effects. Hirsutism was found to have a higher frequency among subjects with late menarche. There was no significant difference in age of menarche between females of opposite-sex twins and females of same-sex twins. CONCLUSION: It is concluded that twin models provide a powerful means of examining the total genetic contribution to age of menarche. Longitudinal studies of twins may clarify the type of environmental effects that determine the age of menarche.
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Affiliation(s)
- Shayesteh Jahanfar
- School of Population and Public Health, University of British Columbia, 2206 East Mall, Vancouver BC V6T 1Z3, Canada
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24
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Ferre C, Belluco S, Tinwell H, Bars R, Benahmed M, Rouquie D, Schorsch F. Comparison of early morphological and molecular changes induced by 17-alpha-methyltestosterone and estradiol benzoate in the rat ovary. ACTA ACUST UNITED AC 2013; 65:397-407. [DOI: 10.1016/j.etp.2011.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 11/11/2011] [Accepted: 12/18/2011] [Indexed: 11/24/2022]
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Stewart RA, Pelican KM, Crosier AE, Pukazhenthi BS, Wildt DE, Ottinger MA, Howard J. Oral progestin priming increases ovarian sensitivity to gonadotropin stimulation and improves luteal function in the cat. Biol Reprod 2012; 87:137. [PMID: 23100619 DOI: 10.1095/biolreprod.112.104190] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
As the only domesticated species known to exhibit both induced and spontaneous ovulation, the cat is a model for understanding the nuances of ovarian control. To explore ovarian sensitivity to exogenous gonadotropins and the influence of progestin priming, we conducted a study of queens that were down-regulated with oral progestin or allowed to cycle normally, followed by low or high doses of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG). Our metrics included 1) fecal steroid metabolite profiles before and after ovulation induction, 2) laparoscopic examination of ovarian follicles and corpora lutea (CL) on Days 2 and 17 (Day 0 = hCG administration), and 3) ovariohysterectomy (Day 17) to assess CL progesterone concentrations, morphometrics, and histology. Reproductive tracts from time-matched, naturally mated queens (n = 6) served as controls. Every progestin-primed cat (n = 12) produced the desired response of morphologically similar, fresh CL (regardless of eCG/hCG dose) by Day 2, whereas 41.7% of unprimed counterparts (n = 12) failed to ovulate or had variable-aged CL suggestive of prior spontaneous ovulation (P < 0.05). The ovarian response to low, but not high, eCG/hCG was improved (P < 0.05) in primed compared to unprimed cats, indicating increased sensitivity to gonadotropin in the progestin-primed ovary. Progestin priming prevented hyperelevated fecal steroid metabolites and normalized CL progesterone capacity, but only when combined with low eCG/hCG. However, priming failed to prevent ancillary CL formation, smaller CL mass, or abnormal luteal cell density, which were common to all eCG/hCG-treated cats. Thus, the domestic cat exposed to eCG/hCG produces CL with structural and functional aberrations. These anomalies can be partially mitigated by progestin priming, possibly due to a protective effect of progestin associated with enhanced ovarian sensitivity to gonadotropins.
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Affiliation(s)
- Rosemary A Stewart
- Center for Species Survival, Smithsonian Conservation Biology Institute, National Zoological Park, Front Royal, Virginia 22630, USA
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Sinchak K, Wagner EJ. Estradiol signaling in the regulation of reproduction and energy balance. Front Neuroendocrinol 2012; 33:342-63. [PMID: 22981653 PMCID: PMC3496056 DOI: 10.1016/j.yfrne.2012.08.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/18/2012] [Accepted: 08/22/2012] [Indexed: 12/14/2022]
Abstract
Our knowledge of membrane estrogenic signaling mechanisms and their interactions that regulate physiology and behavior has grown rapidly over the past three decades. The discovery of novel membrane estrogen receptors and their signaling mechanisms has started to reveal the complex timing and interactions of these various signaling mechanisms with classical genomic steroid actions within the nervous system to regulate physiology and behavior. The activation of the various estrogenic signaling mechanisms is site specific and differs across the estrous cycle acting through both classical genomic mechanisms and rapid membrane-initiated signaling to coordinate reproductive behavior and physiology. This review focuses on our current understanding of estrogenic signaling mechanisms to promote: (1) sexual receptivity within the arcuate nucleus of the hypothalamus, (2) estrogen positive feedback that stimulates de novo neuroprogesterone synthesis to trigger the luteinizing hormone surge important for ovulation and estrous cyclicity, and (3) alterations in energy balance.
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Affiliation(s)
- Kevin Sinchak
- Department of Biological Sciences, California State University, Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840-9502, United States.
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Shah PK, Song J, Kim S, Zhong H, Roy RR, Edgerton VR. Rodent estrous cycle response to incomplete spinal cord injury, surgical interventions, and locomotor training. Behav Neurosci 2012; 125:996-1002. [PMID: 22122153 DOI: 10.1037/a0026032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Estrous cycle disruption after spinal cord injury (SCI) in female rats is a common phenomenon. It remains unknown, however, if the aberrant estrous cycle is a result of an injury to the spinal cord itself or due to the general stress associated with surgical interventions. We addressed this issue by determining estrous cyclicality in female rats after a spinal cord hemisection (HX), implantation of EMG wires into selected hind limb muscles, and/or injections of tracer dyes into the spinal cord. Because it is known that aerobic exercise can enhance the recovery of locomotor function in rodents with an incomplete SCI, we also determined if locomotor training positively impacts the disrupted estrous cycle after an HX. Estrous cycle assessments were made during a 5-8 week period in 27 female rats before and after HX, EMG, and/or dye injection surgeries and in HX rats that recovered spontaneously or underwent locomotor training. Our results show that estrous cyclicality was disrupted (cycle length >5 days) in approximately 76%, 46%, and 50% of the rats after HX, EMG, and dye injection surgeries, respectively. The cyclicality, however, was disrupted for a longer period after HX than after EMG or dye injection surgeries. Furthermore, estrous cycle mean length was shorter in the trained than nontrained HX group. These results suggest that estrous cycle disruption after a major SCI is a consequence of both the direct injury to the spinal cord and to the associated stress. Moreover, moderate aerobic exercise initiated early after a spinal cord HX returns the duration of the estrous cycle toward normal.
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Affiliation(s)
- Prithvi K Shah
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA 90095-1527, USA
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Kuo J, Micevych P. Neurosteroids, trigger of the LH surge. J Steroid Biochem Mol Biol 2012; 131:57-65. [PMID: 22326732 PMCID: PMC3474707 DOI: 10.1016/j.jsbmb.2012.01.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 01/19/2012] [Accepted: 01/22/2012] [Indexed: 12/28/2022]
Abstract
Recent experiments from our laboratory are consistent with the idea that hypothalamic astrocytes are critical components of the central nervous system (CNS) mediated estrogen positive feedback mechanism. The "astrocrine hypothesis" maintains that ovarian estradiol rapidly increases free cytoplasmic calcium concentrations ([Ca(2+)](i)) that facilitate progesterone synthesis in astrocytes. This hypothalamic neuroprogesterone along with the elevated estrogen from the ovaries allows for the surge release of gonadotropin-releasing hormone (GnRH) that triggers the pituitary luteinizing hormone (LH) surge. A narrow range of estradiol stimulated progesterone production supports an "off-on-off" mechanism regulating the transition from estrogen negative feedback to estrogen positive feedback, and back again. The rapidity of the [Ca(2+)](i) response and progesterone synthesis support a non-genomic, membrane-initiated signaling mechanism. In hypothalamic astrocytes, membrane-associated estrogen receptors (mERs) signal through transactivation of the metabotropic glutamate receptor type 1a (mGluR1a), implying that astrocytic function is influenced by surrounding glutamatergic nerve terminals. Although other putative mERs, such as mERβ, STX-activated mER-Gα(q), and G protein-coupled receptor 30 (GPR30), are present and participate in membrane-mediated signaling, their influence in reproduction is still obscure since female reproduction be it estrogen positive feedback or lordosis behavior requires mERα. The astrocrine hypothesis is also consistent with the well-known sexual dimorphism of estrogen positive feedback. In rodents, only post-pubertal females exhibit this positive feedback. Hypothalamic astrocytes cultured from females, but not males, responded to estradiol by increasing progesterone synthesis. Estrogen autoregulates its own signaling by regulating levels of mERα in the plasma membrane of female astrocytes. In male astrocytes, the estradiol-induced increase in mERα was attenuated, suggesting that membrane-initiated estradiol signaling (MIES) would also be blunted. Indeed, estradiol induced [Ca(2+)](i) release in male astrocytes, but not to levels required to stimulate progesterone synthesis. Investigation of this sexual differentiation was performed using hypothalamic astrocytes from post-pubertal four core genotype (FCG) mice. In this model, genetic sex is uncoupled from gonadal sex. We demonstrated that animals that developed testes (XYM and XXM) lacked estrogen positive feedback, strongly suggesting that the sexual differentiation of progesterone synthesis is driven by the sex steroid environment during early development. This article is part of a Special Issue entitled 'Neurosteroids'.
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Affiliation(s)
- John Kuo
- Department of Neurobiology, Laboratory of Neuroendocrinology of the Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
| | - Paul Micevych
- Department of Neurobiology, Laboratory of Neuroendocrinology of the Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States
- Corresponding author at: Department of Neurobiology, David Geffen School of Medicine at UCLA, 10833 LeConte Avenue, 73-078 CHS, Los Angeles, CA 90095-1763, United States. Tel.: +1 310 206 8265; fax: +1 310 825 2224. (P. Micevych)
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Amorim JPA, Chuffa LGA, Teixeira GR, Mendes LO, Fioruci BA, Martins OA, Júnior WM, Anselmo-Franci JA, Pinheiro PFF, Martinez M, Martinez FE. Variations in maternal care alter corticosterone and 17beta-estradiol levels, estrous cycle and folliculogenesis and stimulate the expression of estrogen receptors alpha and beta in the ovaries of UCh rats. Reprod Biol Endocrinol 2011; 9:160. [PMID: 22192617 PMCID: PMC3265448 DOI: 10.1186/1477-7827-9-160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Accepted: 12/22/2011] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Variations in maternal care are associated with neonatal stress, hormonal disturbances and reproductive injuries during adulthood. However, the effects of these variations on sex hormones and steroid receptors during ovary development remain undetermined. This study aimed to investigate whether variations in maternal care are able to influence the hormonal profile, follicular dynamics and expression of AR, ER-alpha and ER-beta in the ovaries of UCh rat offspring. METHODS Twenty-four adult UCh rats, aged 120 days, were randomly divided into two groups (UChA and UChB) and mated. Maternal care was assessed from birth (day 0) to the 10th postnatal day (PND). In adulthood, twenty adult female rats (UChA and UChB offspring; n = 10/group), aged 120 days, were euthanized by decapitation during the morning estrus. RESULTS UChA females (providing high maternal care) more frequently displayed the behaviors of carrying pups, as well as licking/grooming and arched back nursing cares. Also, mothers providing high care had elevated corticosterone levels. Additionally, offspring receiving low maternal care showed the highest estrous cycle duration, increased corticosterone and 17beta-estradiol levels, overexpression of receptors ER-alpha and ER-beta, increased numbers of primordial, antral and mature follicles and accentuated granulosa cell proliferation. CONCLUSIONS Our study suggests that low maternal care alters corticosterone and 17beta-estradiol levels, disrupting the estrous cycle and folliculogenesis and differentially regulating the expression of ER-alpha and ER-beta in the ovaries of adult rats.
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Affiliation(s)
- João PA Amorim
- Department of Structural and Cellular Biology, Institute of Biology, Universidade Estadual de Campinas - UNICAMP, Campinas-SP 13083-863, Brazil
| | - Luiz GA Chuffa
- Department of Structural and Cellular Biology, Institute of Biology, Universidade Estadual de Campinas - UNICAMP, Campinas-SP 13083-863, Brazil
| | - Giovana R Teixeira
- Department of Anatomy, Bioscience Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP 18618-970, Brazil
| | - Leonardo O Mendes
- Department of Structural and Cellular Biology, Institute of Biology, Universidade Estadual de Campinas - UNICAMP, Campinas-SP 13083-863, Brazil
| | - Beatriz A Fioruci
- Department of Structural and Cellular Biology, Institute of Biology, Universidade Estadual de Campinas - UNICAMP, Campinas-SP 13083-863, Brazil
| | - Otávio A Martins
- Department of Anatomy, Bioscience Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP 18618-970, Brazil
| | - Wílson Mello Júnior
- Department of Anatomy, Bioscience Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP 18618-970, Brazil
| | - Janete A Anselmo-Franci
- Department of Morphology, Stomatology and Physiology, USP - Universidade de São Paulo, Ribeirão Preto-SP 14040-900, Brazil
| | - Patricia FF Pinheiro
- Department of Anatomy, Bioscience Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP 18618-970, Brazil
| | - Marcelo Martinez
- Department of Morphology and Pathology, UFSCar - Universidade Federal de São Carlos, São Carlos-SP 13565-905, Brazil
| | - Francisco E Martinez
- Department of Anatomy, Bioscience Institute, UNESP - Univ. Estadual Paulista, Botucatu-SP 18618-970, Brazil
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Verrotti A, Loiacono G, Laus M, Coppola G, Chiarelli F, Tiboni GM. Hormonal and reproductive disturbances in epileptic male patients: Emerging issues. Reprod Toxicol 2011; 31:519-27. [DOI: 10.1016/j.reprotox.2011.02.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 01/12/2011] [Accepted: 02/14/2011] [Indexed: 01/23/2023]
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31
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Crawford JL, Mester B, Thomson B, Lawrence SB, Eckery DC. Prolactin acts on the hypothalamic-pituitary axis to modulate follicle-stimulating hormone gene expression in the female brushtail possum (Trichosurus vulpecula). Gen Comp Endocrinol 2011; 171:39-45. [PMID: 21187096 DOI: 10.1016/j.ygcen.2010.12.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 12/03/2010] [Accepted: 12/20/2010] [Indexed: 11/26/2022]
Abstract
Brushtail possums exhibit a distinct preovulatory pattern of prolactin (Prl) secretion suggesting that Prl is involved in normal reproductive function. In some mammals, Prl is essential for corpus luteum (CL) function and/or modulation of steroidal effects on hypothalamic-pituitary activity. The aim of this study was to test the effects of biologically active recombinant possum Prl (recPosPrl) on both pituitary gland and CL function in possums. To confirm biological activity, administration of recPosPrl-N2C1 (10 μg) resulted in an 18-fold stimulation (P<0.05) of progesterone (P(4)) production by possum granulosa cells in vitro. Based on these findings, minipumps containing either recPosPrl-N2C1 (n=10) or saline (n=8) were inserted into lactating female possums. The expression levels of pituitary-derived PRL, LHB, FSHB and GNRHR and CL-derived LHR mRNA were quantified. Following a resumption of reproductive activity, no differences in ovulation incidence or plasma Prl concentrations were observed. Plasma Prl levels were less variable (P<0.001) in Prl-treated possums, confirming a self-regulatory role for Prl in this species. There was a marked down-regulation (P<0.001) of FSHB mRNA at the mid-luteal stage in Prl-treated possums, whereas mean PRL, LHB, GNRHR and LHR mRNA expression levels were not different between experimental groups. Plasma P(4) concentrations were not different (P=0.05) in Prl-treated possums, although tended to be higher in the peri-ovulatory and early-luteal phase. We conclude in the brushtail possum that Prl is self-regulated via a short-feedback loop common to all mammals studied and is able to modulate FSHB expression probably at the level of the hypothalamus and/or pituitary gland.
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Affiliation(s)
- J L Crawford
- Reproduction Group, AgResearch Ltd., Wallaceville Animal Research Centre, Ward Street, P.O. Box 40063, Upper Hutt, New Zealand.
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32
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Micevych P, Sinchak K. The Neurosteroid Progesterone Underlies Estrogen Positive Feedback of the LH Surge. Front Endocrinol (Lausanne) 2011; 2:90. [PMID: 22654832 PMCID: PMC3356049 DOI: 10.3389/fendo.2011.00090] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 11/16/2011] [Indexed: 01/25/2023] Open
Abstract
Our understanding the steroid regulation of neural function has rapidly evolved in the past decades. Not long ago the prevailing thoughts were that peripheral steroid hormones carried information to the brain which passively responded to these steroids. These steroid actions were slow, taking hours to days to be realized because they regulated gene expression. Over the past three decades, discoveries of new steroid receptors, rapid membrane-initiated signaling mechanisms, and de novo neurosteroidogenesis have shed new light on the complexity of steroids actions within the nervous system. Sexual differentiation of the brain during development occurs predominately through timed steroid-mediated expression of proteins and long term epigenetic modifications. In contrast across the estrous cycle, estradiol release from developing ovarian follicles initially increases slowly and then at proestrus increases rapidly. This pattern of estradiol release acts through both classical genomic mechanisms and rapid membrane-initiated signaling in the brain to coordinate reproductive behavior and physiology. This review focuses on recently discovered estrogen receptor-α membrane signaling mechanisms that estradiol utilizes during estrogen positive feedback to stimulate de novo progesterone synthesis within the hypothalamus to trigger the luteinizing hormone (LH) surge important for ovulation and estrous cyclicity. The activation of these signaling pathways appears to be coordinated by the rising and waning of estradiol throughout the estrous cycle and integral to the negative and positive feedback mechanisms of estradiol. This differential responsiveness is part of the timing mechanism triggering the LH surge.
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Affiliation(s)
- Paul Micevych
- Laboratory of Neuroendocrinology, Department of Neurobiology, David Geffen School of Medicine, Brain Research Institute, University of CaliforniaLos Angeles, CA, USA
- *Correspondence: Paul Micevych, Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095-1763, USA. e-mail:
| | - Kevin Sinchak
- Department of Biological Sciences, California State UniversityLong Beach, CA, USA
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Tarín JJ, Hamatani T, Cano A. Acute stress may induce ovulation in women. Reprod Biol Endocrinol 2010; 8:53. [PMID: 20504303 PMCID: PMC2890612 DOI: 10.1186/1477-7827-8-53] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 05/26/2010] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND This study aims to gather information either supporting or rejecting the hypothesis that acute stress may induce ovulation in women. The formulation of this hypothesis is based on 2 facts: 1) estrogen-primed postmenopausal or ovariectomized women display an adrenal-progesterone-induced ovulatory-like luteinizing hormone (LH) surge in response to exogenous adrenocorticotropic hormone (ACTH) administration; and 2) women display multiple follicular waves during an interovulatory interval, and likely during pregnancy and lactation. Thus, acute stress may induce ovulation in women displaying appropriate serum levels of estradiol and one or more follicles large enough to respond to a non-midcycle LH surge. METHODS A literature search using the PubMed database was performed to identify articles up to January 2010 focusing mainly on women as well as on rats and rhesus monkeys as animal models of interaction between the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes. RESULTS Whereas the HPA axis exhibits positive responses in practically all phases of the ovarian cycle, acute-stress-induced release of LH is found under relatively high plasma levels of estradiol. However, there are studies suggesting that several types of acute stress may exert different effects on pituitary LH release and the steroid environment may modulate in a different way (inhibiting or stimulating) the pattern of response of the HPG axis elicited by acute stressors. CONCLUSION Women may be induced to ovulate at any point of the menstrual cycle or even during periods of amenorrhea associated with pregnancy and lactation if exposed to an appropriate acute stressor under a right estradiol environment.
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Affiliation(s)
- Juan J Tarín
- Department of Functional Biology and Physical Anthropology, Faculty of Biological Sciences, University of Valencia, Burjassot, Valencia 46100, Spain
| | - Toshio Hamatani
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Antonio Cano
- Department of Pediatrics, Obstetrics and Gynecology, Faculty of Medicine, University of Valencia, Valencia 46010, Spain
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The generation of an array of clonal, immortalized cell models from the rat hypothalamus: analysis of melatonin effects on kisspeptin and gonadotropin-inhibitory hormone neurons. Neuroscience 2009; 162:1134-40. [DOI: 10.1016/j.neuroscience.2009.05.026] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 04/30/2009] [Accepted: 05/14/2009] [Indexed: 12/15/2022]
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Abstract
The best characterised oestrogen receptors (ERs) that are responsible for membrane-initiated oestradiol signalling are the classic ERs, ERalpha and ERbeta. When in the nucleus, these proteins are oestradiol activated transcription factors but, when trafficked to the cell membrane, ERalpha and ERbeta rapidly activate protein kinase pathways, alter membrane electrical properties, modulate ion flux and can mediate long-term effects through gene expression. To initiate cell signalling, membrane ERs transactivate metabotropic glutamate receptors (mGluRs) to stimulate Gq signalling through pathways using PKC and calcium. In this review, we discuss the interaction of membrane ERalpha with metabotropic glutamate receptor 1a (mGluR1a) to initiate rapid oestradiol cell signalling and its critical roles in female reproduction: sexual behaviour and oestrogen positive feedback of the luteinising hormone (LH) surge. Although long considered to be regulated by the long-term actions of oestradiol on gene transcription, recent results indicate that membrane oestradiol cell signalling is vital for a full display of sexual receptivity. Similarly, the source of pre-ovulatory progesterone necessary for initiating the LH surge is hypothalamic astrocytes. Oestradiol rapidly amplifies progesterone synthesis through the release of intracellular calcium stores. The ERalpha-mGluR1a interaction is necessary for critical calcium flux. These two examples provide support for the hypothesis that membrane ERs are not themselves G-protein receptors; rather, they use mGluRs to signal.
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Affiliation(s)
- P Micevych
- Department of Neurobiology, Laboratory of Neuroendocrinology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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36
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Affiliation(s)
- Suhail A R Doi
- Division of Endocrinology, Mubarak Al-Kabeer Hospital and Kuwait University, Kuwait.
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38
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Pelican KM, Wildt DE, Ottinger MA, Howard J. Priming with progestin, but not GnRH antagonist, induces a consistent endocrine response to exogenous gonadotropins in induced and spontaneously ovulating cats. Domest Anim Endocrinol 2008; 34:160-75. [PMID: 17369001 DOI: 10.1016/j.domaniend.2007.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 01/15/2007] [Accepted: 01/30/2007] [Indexed: 11/16/2022]
Abstract
Ovarian sensitivity to exogenous gonadotropin stimulation (equine chorionic gonadotropin [eCG] and human chorionic gonadotropin [hCG]) following pre-treatment with a progestin (levonorgestrel) versus GnRH antagonist (antide) was studied in cats known to be induced versus spontaneous ovulators. Queens were assigned to one of three treatments: (1) levonorgestrel implants+eCG/hCG (n=7 cats); (2) antide injections+eCG/hCG (n=7) or (3) eCG/hCG alone (control; n=7). Hormonal metabolites were assessed in fecal samples collected daily for 60 days before and during the 37 days inhibitory pre-treatment and for more than 60 days after eCG/hCG. Fecal metabolites of estradiol and progesterone were measured by radioimmunoassay. Females that maintained baseline progesterone were considered induced ovulators, whereas cats that exhibited a luteal phase before inhibition treatment were classified as spontaneous ovulators. Based on fecal hormone profiles, levonorgestrel thoroughly inhibited ovarian activity, whereas antide synchronized follicular phases but did not induce complete ovarian down-regulation. Both treatments prevented ovulation in spontaneous ovulators, but neither caused regression of existing corpora lutea (CL). Levonorgestrel, but not antide, pre-treatment resulted in a quiescent ovary at the time of eCG injection, yet endocrine responses to eCG/hCG were not different among treatments. Interestingly, spontaneously ovulating females exhibited a prolonged estradiol response to gonadotropin stimulation compared to induced ovulators, and this prolonged estradiol surge was replicated by levonorgestrel pre-treatment. Thus, the progestin levonorgestrel effectively suppresses follicular and luteal activity in the cat, resulting in a more consistent response to gonadotropin stimulation, even in females prone to spontaneous ovulation.
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Affiliation(s)
- Katharine M Pelican
- Conservation & Research Center, Smithsonian's National Zoological Park, Front Royal, VA 22630, United States.
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Micevych P, Soma KK, Sinchak K. Neuroprogesterone: key to estrogen positive feedback? ACTA ACUST UNITED AC 2007; 57:470-80. [PMID: 17850878 PMCID: PMC2647997 DOI: 10.1016/j.brainresrev.2007.06.009] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 05/31/2007] [Accepted: 06/03/2007] [Indexed: 11/28/2022]
Abstract
In the cycling female rat, estradiol and progesterone induce reproductive behavior and the surge of luteinizing hormone (LH) needed for ovulation. Circulating estradiol of ovarian origin induces progesterone receptors in the preoptic area and hypothalamus. Sequential activation of estrogen receptors (ER) and progesterone receptors coordinates reproductive physiology and behavior. In ovariectomized and adrenalectomized (ovx/adx) rats, administration of estradiol alone is sufficient to initiate an LH surge, and central infusion of aminoglutethimide (AGT), a blocker of the P450 side chain cleavage enzyme, disrupted the estrous cycle of intact rats without affecting peripheral estradiol levels, suggesting that an endogenous source of progesterone remains in these animals. In ovx/adx rats, progesterone levels in the hypothalamus increase prior to the LH surge, and inhibition of progesterone synthesis prevents the LH surge, suggesting that hypothalamic neuroprogesterone is necessary for estrogen positive feedback. In support of the idea that estradiol induces neuroprogesterone, estradiol increased expression of the progesterone-synthesizing enzyme 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the hypothalamus before the LH surge. Further, in vitro experiments demonstrate that estradiol stimulates progesterone synthesis in astrocytes, considered to be the most active steroidogenic cells in the CNS. To stimulate neurosteroidogenesis, estradiol acts through membrane ER and type 1a metabotropic glutamate receptors (mGluR1a) to increase free cytoplasmic calcium ([Ca(2+)](i)) via activation of the PLC-IP(3) pathway. Estradiol-induced progesterone synthesis is mimicked by thapsigargin-induced release of IP(3) receptor-sensitive Ca(2+) stores in astrocyte cultures. Thus, estradiol-induced progesterone synthesis is dependent on membrane ERs that act through mGluR1a to activate the PLC-IP(3) pathway. This neuroprogesterone also facilitated proceptive behavior. Blocking either progesterone synthesis or progesterone receptor in estrogen-primed ovx/adx prevented proceptive but not receptive behaviors.
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Affiliation(s)
- Paul Micevych
- Department of Neurobiology, David Geffen School of Medicine, Laboratory of Neuroendocrinology, Brain Research Institute at UCLA, Los Angeles, CA 90095-1763, USA.
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Hamed SA, Hamed EA, Shokry M, Omar H, Abdellah MM. The reproductive conditions and lipid profile in females with epilepsy. Acta Neurol Scand 2007; 115:12-22. [PMID: 17156261 DOI: 10.1111/j.1600-0404.2006.00740.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To explore the reproductive conditions in women with epilepsy. METHODS Eighty-eight women were included; 37.5% and 62.5% had generalized and partial epilepsies, respectively. Ovarian sonogram, reproductive hormone and lipid profiles were assessed. RESULTS Compared with the control group and in accordance with our laboratory reference values, irregular menses and polycystic ovaries (PCO(s)) were reported in 70.5% and 39.8% versus 21.7% and 16.7% of controls. Abnormalities in leutinizing hormone (LH), follicle-stimulating hormone (FSH), LH-to-FSH ratio, testosterone (T) and prolactin (PRL) were identified. High values of FSH, LH and FSH-to-LH ratio were common with carbamazepine while that of T and PRL were common in untreated patients and with valproate. Low levels of high-density lipoprotein cholesterol was identified in approximately 59% but neither associated with duration and type of antiepileptic drugs nor patients' age, hormonal profile or PCO(s). Significant correlation was identified between menatrual irregularities, T, PRL, hormonal, lipid profile alterations, PCO(s) and seizure frequency but neither with epilepsy type nor focus. CONCLUSION This is the first study in our country that aimed at evaluation of reproductive conditions in women with epilepsy. This study indicates that reproductive dysfunction is common, hence, characterization of seizure-associated neuroendocrine adverse effects is important while managing women particularly during choice of antiepileptic medications as initial step and during patients' follow-up.
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Affiliation(s)
- S A Hamed
- Department of Neurology, Assiut University, Assiut, Egypt.
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41
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Rebollar PG, Milanés A, Pereda N, Millán P, Cano P, Esquifino AI, Villarroel M, Silván G, Lorenzo PL. Oestrus synchronisation of rabbit does at early post-partum by doe–litter separation or ECG injection: Reproductive parameters and endocrine profiles. Anim Reprod Sci 2006; 93:218-30. [PMID: 16165333 DOI: 10.1016/j.anireprosci.2005.06.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 06/22/2005] [Accepted: 06/30/2005] [Indexed: 11/18/2022]
Abstract
Inseminating rabbit does at early post-partum, in combination with early weaning, can increase prolificacy (total kits born and still born per parturition) and decrease parturition intervals. Oestrus synchronisation increases fertility and prolificacy, while decreasing the number of inseminations required for gestation. However, little is known about the effectiveness of different oestrus synchronisation methods at early post-partum. In this study, does (n = 138) were artificially inseminated nine times (over a period of 1 year, kits weaned at 25 days), on day 4 post-partum after separation from the litter (for 48 or 24 h) or 48 h after 25 UI eCG injection. Plasma levels of prolactin and estradiol were also evaluated in a subsample of 12 multiparous lactating does per treatment, on days 2, 3 and 4 post-partum. The three treatments increased overall fertility of multiparous females compared to controls (which were not synchronised), but there were no differences among treatments in total kits born or stillborn. Does treated with eCG had a higher culling rate. The interval between parturitions and the number of inseminations required for gestation tended to decrease with increasing number of inseminations. In lactating does, there was an interaction between treatment and insemination order. Fertility decreased with increasing inseminations in eCG does but tended to increase above control values in the separated does until the fourth insemination. Control lactating does had significantly less kits per parturition compared to treatments, but eCG lactating does had more stillborn kits. Oestradiol levels increased on day 4 post-partum in all synchronised lactating does (and immediately before artificial insemination in 48 h doe-litter separation), so ovarian activity could be stimulated at early post-partum using all treatments. However, the increase could not be explained by prolactin levels, since there were no effects of suckling absence on plasma prolactin in separated does. In conclusion, separating does from the litter before insemination can be just as effective as eCG treatment, especially during for the first four inseminations.
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Affiliation(s)
- P G Rebollar
- Departamento de Producción Animal, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
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42
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Abstract
Hypothalamic astrocytes secrete TGF-beta and 3 alpha,5 alpha-tetrahydro progesterone (3 alpha,5 alpha-THP) in culture. When the astrocyte-conditioned medium (ACM) was incubated with the hypothalamic cell line GT1-7, it resulted in the secretion of GnRH. Immunoneutralization with TGF-beta antibody or ultra-filteration with a 10 kDa cut off filter resulted in attenuation of the GnRH releasing ability of ACM, indicating that TGF-beta was a major factor involved with GnRH release. Treatment with estrogens increases TGF-beta secretion. These observations indicate a significant role of astrocytes in GnRH secretion. Serum-deprivation results in the death of GT1-7 neurons in culture and addition of ACM or TGF-beta to the culture, attenuates cell death. The mechanism of protection from cell death appears to involve phosphorylation of MKK4, JNK, c-Jun(Ser63), and enhancement of AP-1 binding. Co-administration of JNK inhibitors, but not MEK inhibitors attenuated ACM or TGF-beta-induced c-Jun(Ser63) phosphorylation and their neuroprotective effects. These studies suggest that astrocytes can protect neurons, at least in part, by the release of TGF-beta and activation of a c-Jun/AP-1 protective pathway.
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Affiliation(s)
- Virendra B Mahesh
- Institute of Molecular Medicine and Genetics, Program in Neurobiology, and Department of Neurology, Medical College of Georgia, Augusta, GA 30912, USA.
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43
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Bodo C, Kudwa AE, Rissman EF. Both estrogen receptor-alpha and -beta are required for sexual differentiation of the anteroventral periventricular area in mice. Endocrinology 2006; 147:415-20. [PMID: 16239299 DOI: 10.1210/en.2005-0834] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Sexual dimorphisms in the hypothalamus are mediated in several cases by local aromatization of androgens to estrogens during the perinatal period. In this series of experiments, the contributions of the two estrogen receptors (ERs), ERalpha and ERbeta, to the differentiation of the sexually dimorphic subpopulation of dopaminergic neurons in the anteroventral periventricular area (AVPV) was examined. In the first experiment, numbers of tyrosine hydroxylase (TH) immunoreactive (-ir) AVPV neurons in ERbeta knockout and wild-type (WT) mice of both sexes were measured. In the second experiment, the average number of TH-ir neurons in the medial portion of the AVPV in ERalpha knockout, ERbeta knockout, double-ER knockout, and WT mice of both sexes was calculated. In both experiments TH-ir cell numbers were sexually dimorphic as expected, with female individuals of all genotypes exhibiting more TH-ir neurons than WT males. Interestingly the average number of TH-ir neurons in all knockout males was significantly higher than in WT male littermates. In fact, TH-ir cell numbers in all knockout males were equivalent to females. In a final experiment, C57BL/6J female mice were treated during the first 3 postnatal days with either estradiol, or a specific agonist for one of the two ERs. Additional male and female pups received vehicle injections. Treatments with estradiol or either ER-specific agonist significantly reduced the number of TH-ir AVPV neurons in female brains. Our data demonstrate that both ERalpha and ERbeta are involved in the sexual differentiation of the AVPV in mice.
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Affiliation(s)
- Cristian Bodo
- Program in Neuroscience (C.B., A.E.K., E.F.R.), University of Virginia, Charlottesville, Virginia 22908, USA
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Pelican KM, Brown JL, Wildt DE, Ottinger MA, Howard JG. Short term suppression of follicular recruitment and spontaneous ovulation in the cat using levonorgestrel versus a GnRH antagonist. Gen Comp Endocrinol 2005; 144:110-21. [PMID: 15979618 DOI: 10.1016/j.ygcen.2005.04.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Revised: 04/20/2005] [Accepted: 04/26/2005] [Indexed: 11/27/2022]
Abstract
Suppression and subsequent rebound of ovarian activity using a progestin (levonorgestrel; Norplant) versus a GnRH antagonist (antide) was assessed in the domestic cat via fecal estradiol and progesterone metabolite analyses. Following an initial dose-response trial, queens were assigned to one of four treatments: (1) antide, two 6 mg/kg injections 15 days apart (n = 8 cats); (2) levonorgestrel, six silastic rods (36 mg levonorgestrel/rod) implanted for 30 days (n = 8); (3) control injections (n = 5); and (4) control implants (n = 5). Steroid metabolites were quantified from daily fecal samples for 90 days before, 30 days during, and 90 days after treatment. Antide and levonorgestrel inhibited estrous cyclicity in contrast to continued cyclicity in controls. Cats already at estradiol baseline in antide (n = 7) and levonorgestrel (n = 4) groups remained inhibited during treatment. In females with elevated estradiol levels at treatment onset (Day 0), a normal estradiol surge was completed before concentrations declined to baseline (approximately Days 5-7) and remained suppressed throughout the remaining treatment period. Additionally, 56% of treatment animals exhibited at least one spontaneous ovulation during the pre-treatment period, but no female ovulated during treatment with levonorgestrel or antide. Antide-treated cats exhibited lower (P < 0.05) baseline estradiol concentrations during treatment compared to pre- and post-treatment. In contrast, levonorgestrel induced elevations in baseline estradiol following treatment compared to pre- and during treatment intervals. Control females showed no change (P > 0.05) in baseline estradiol throughout the study period. All levonorgestrel and antide cats returned to estrus after treatment withdrawal. Results demonstrate that: (1) both antide and levonorgestrel are effective for inducing short-term suppression of follicular recruitment and ovulation in the cat; (2) inhibition is reversible; and (3) GnRH antagonists and progestins differentially regulate basal estradiol secretion. This study also confirmed a relatively high incidence of spontaneous ovulation in the cat, a species generally considered to be an induced ovulator.
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Affiliation(s)
- K M Pelican
- Department of Reproductive Sciences, Conservation and Research Center, Smithsonian's National Zoological Park, Front Royal, VA 22630, USA.
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45
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Doi SAR, Al-Zaid M, Towers PA, Scott CJ, Al-Shoumer KAS. Ovarian steroids modulate neuroendocrine dysfunction in polycystic ovary syndrome. J Endocrinol Invest 2005; 28:882-92. [PMID: 16419490 DOI: 10.1007/bf03345319] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Neuroendocrine dysfunction in polycystic ovary syndrome (PCOS) was addressed by studying the steroid hormone changes in women with PCOS with either high or normal LH levels leading to inferences regarding the primacy of elevated LH in the pathophysiology of PCOS. METHODS A cross-sectional study was designed in an academic clinical facility involving 234 women with PCOS. Patients were divided into two groups based on an LH/FSH ratio < or >1 and hormonal and metabolic studies were performed in both groups. Factors were determined by binomial logistic regression that predicted group membership of these women. RESULTS Higher follicular phase estradiol (E2) and androstenedione (A4) levels as well as greater insulin sensitivity were the only factors that predicted the presence of neuroendocrine dysfunction with elevated A4 being necessary for neuroendocrine dysfunction. CONCLUSIONS It was concluded that uncoupling of hypothalamic E2 inhibition by elevated ovarian A4 associated with E2 related sensitization of pituitary LH leads to neuroendocrine dysfunction in PCOS.
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Affiliation(s)
- S A R Doi
- Division of Endocrinology, Mubarak Al-Kabeer Hospital and Department of Medicine, Faculty of Medicine, Kuwait University, Kuwait.
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Schirman-Hildesheim TD, Bar T, Ben-Aroya N, Koch Y. Differential gonadotropin-releasing hormone (GnRH) and GnRH receptor messenger ribonucleic acid expression patterns in different tissues of the female rat across the estrous cycle. Endocrinology 2005; 146:3401-8. [PMID: 15908340 DOI: 10.1210/en.2005-0240] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GnRH, the main regulator of reproduction, is produced in a variety of tissues outside of the hypothalamus, its main site of synthesis and release. We aimed to determine whether GnRH produced in the female rat pituitary and ovaries is involved in the processes leading to ovulation. We studied the expression patterns of GnRH and GnRH receptor (GnRH-R) in the same animals throughout the estrous cycle using real-time PCR. Hypothalamic levels of GnRH mRNA were highest at 1700 h on proestrus, preceding the preovulatory LH surge. No significant changes in the level of hypothalamic GnRH-R mRNA were detected, although fluctuations during the day of proestrus are evident. High pituitary GnRH mRNA was detected during the day of estrus, in the morning of diestrus 1, and at noon on proestrus. Pituitary GnRH-R displayed a similar pattern of expression, except on estrus, when its mRNA levels declined. Ovarian GnRH mRNA levels increased in the morning of diestrus 1 and early afternoon of proestrus. Here, too, GnRH-R displayed a somewhat similar pattern of expression to that of its ligand. To the best of our knowledge, this is the first demonstration of a GnRH expression pattern in the pituitary and ovary of any species. The different timings of the GnRH peaks in the three tissues imply differential tissue-specific regulation. We believe that the GnRH produced in the anterior pituitary and ovary could play a physiological role in the preparation of these organs for the midcycle gonadotropin surge and ovulation, respectively, possibly via local GnRH-gonadotropin axes.
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Xita N, Tsatsoulis A, Stavrou I, Georgiou I. Association of SHBG gene polymorphism with menarche. ACTA ACUST UNITED AC 2005; 11:459-62. [PMID: 15879463 DOI: 10.1093/molehr/gah178] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The age of menarche may be subject to hereditary influences but the specific determinants are unknown. Our aim was to investigate the possible association of a functional (TAAAA)n polymorphism in the promoter of the sex hormone-binding globulin (SHBG) gene with the timing of menarche. This polymorphism has been associated with polycystic ovary syndrome (PCOS) and is considered to contribute to SHBG levels. We studied 130 healthy normal-weight adolescent females from a closed community in North-Western Greece. Information on menarche was obtained through interviews. The BMI was recorded. Genomic DNA was isolated from peripheral blood leukocytes for genotyping the TAAAA repeat region. We subdivided our subjects into two groups based on median age of menarche: those with menarche <13 years and those with menarche > or =13 years. Genotype analysis revealed six (TAAAA)n alleles containing 5-10 TAAAA repeats. The distribution of alleles was different in the two groups. Girls with late menarche had more frequently longer TAAAA alleles (>8 repeats), while girls with early menarche had shorter alleles at a greater frequency (P=0.048). The major contribution to early menarche was by the 6 TAAAA repeat allele. Furthermore, carriers of the longer allele genotypes had later menarche (13.24+/-1.15 years) than those with shorter allele genotypes (12.67+/-1.15, P=0.018). These findings provide evidence for a genetic contribution of SHBG gene to the age of menarche.
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Affiliation(s)
- N Xita
- Department of Endocrinology and Laboratory of Reproductive Genetics, University of Ioannina, Ioannina, Greece
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48
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Zhao XF, Xu YQ, Wang YL, Leng Y, Cao L, Jin JD, Gu ZP. The effect of Nestorone on gonadotropic cells in pituitary of rats. Contraception 2004; 69:505-11. [PMID: 15157798 DOI: 10.1016/j.contraception.2004.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2003] [Revised: 01/20/2004] [Accepted: 01/20/2004] [Indexed: 11/15/2022]
Abstract
The implant containing Nestorone is a promising long-acting contraceptive especially suitable for lactating women. In this study, two experiments were designed to observe the effect of Nestorone on the gonadotropic cells in pituitary of rats for analyzing its antiovulation mechanism. In the first experiment, the ED50 of Nestorone on inhibiting ovulation was found to be 1.32 mg/kg. The serum luteinizing hormone (LH) levels were significantly lower 60 h after being treated with Nestorone at 8:30-9:00 a.m. on Day 2 (D2) of estrus. Image analysis showed that the average size of the LH cells in groups treated with Nestorone at 2 or 4 mg/kg was larger than that of the control. In the group treated with 4 mg/kg, most of gonadotropic cells were regular round in shape. And, abundant granules in cytoplasm were found in those cells, which indicated that the LH stored in cells was not released. In the second experiment, the rats were treated with Nestorone at 5 mg/kg at 11:30-12:00 a.m. on D2 of estrus. The normal or higher expression of LHbeta mRNA in pituitary suggested that the synthesis of LH was not inhibited by the treatment with Nestorone. The expression of PR mRNA in pituitary was significantly lower than that of the control at 33 h after treatment. This might be a direct effect of Nestorone, since there were no differences in the serum E2 and P4 levels between the treated and the control group. It is concluded that Nestorone prevents ovulation through inhibition of LH secretion and it has no effect on synthesis of LH. Progesterone receptors in pituitary might be involved in this process, but further study is needed to gain more evidence.
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MESH Headings
- Animals
- Contraceptive Agents, Female/pharmacology
- DNA Primers
- Dose-Response Relationship, Drug
- Drug Implants/pharmacology
- Female
- Gonadotropin-Releasing Hormone/blood
- Gonadotropin-Releasing Hormone/drug effects
- Gonadotropin-Releasing Hormone/genetics
- Luteinizing Hormone, beta Subunit/blood
- Luteinizing Hormone, beta Subunit/drug effects
- Luteinizing Hormone, beta Subunit/genetics
- Norprogesterones/pharmacology
- Ovulation/drug effects
- Pituitary Gland/cytology
- Pituitary Gland/drug effects
- RNA, Messenger/analysis
- Rats
- Rats, Sprague-Dawley
- Receptors, Progesterone/blood
- Receptors, Progesterone/drug effects
- Receptors, Progesterone/genetics
- Reverse Transcriptase Polymerase Chain Reaction
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Affiliation(s)
- Xiao-Feng Zhao
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing
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49
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Dong Y, Roberge JY, Wang Z, Wang X, Tamasi J, Dell V, Golla R, Corte JR, Liu Y, Fang T, Anthony MN, Schnur DM, Agler ML, Dickson JK, Lawrence RM, Prack MM, Seethala R, Feyen JHM. Characterization of a new class of selective nonsteroidal progesterone receptor agonists. Steroids 2004; 69:201-17. [PMID: 15072922 DOI: 10.1016/j.steroids.2003.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2003] [Revised: 11/21/2003] [Accepted: 12/04/2003] [Indexed: 11/28/2022]
Abstract
The identification of a new series of selective nonsteroidal progesterone receptor (PR) agonists is reported. Using a high-throughput screening assay based on the measurement of transactivation of a mouse mammary tumor virus promoter-driven luciferase reporter (MMTV-Luc) in human breast cancer T47D cells, a benzimidazole-2-thione analog was identified. Compound 1 showed an apparent EC50 of 53 nM and efficacy of 93% with respect to progesterone. It binds to PR with high affinity (Ki nM), but had no or very low affinity for other steroid hormone receptors. Structure-activity relationship studies of a series of benzimidazole-2-thione analogs revealed critical positions for high PR binding affinity and transactivation potency as well as receptor selectivity, as exemplified by 25. Compound 25 binds to human PR with high affinity (Ki nM) and had at least > 1000-fold selectivity for PR versus other steroid receptors. Molecular modeling studies suggested that these agonists overlap favorably with progesterone in the ligand-binding domain of PR. In T47D cells, compound 25 acted as a full agonist in the MMTV-Luc reporter assay, as well as in the induction of endogenous alkaline phosphatase activity with apparent EC50 values of 4 and 9 nM, respectively. In the immature rat model, compound 25 provided a significant suppression of estrogen-induced endometrium hypertrophy as measured by luminal epithelial height. In contrast, compound 25 was inactive in the luteinizing hormone release assay in young ovariectomized rats. These benzimidazole-2-thione analogs constitute a new series of nonsteroidal PR agonists with an excellent steroid receptor selectivity profile. The differential activities observed in the in vivo progestogenic assays in rat models suggest that these analogs can act as selective PR modulators.
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Affiliation(s)
- Yu Dong
- Department of Metabolic and Cardiovascular Drug Discovery, Bristol-Myers Squibb Company, Pennington, NJ 08543, USA
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50
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Cooke PS, Holsberger DR, Witorsch RJ, Sylvester PW, Meredith JM, Treinen KA, Chapin RE. Thyroid hormone, glucocorticoids, and prolactin at the nexus of physiology, reproduction, and toxicology. Toxicol Appl Pharmacol 2004; 194:309-35. [PMID: 14761686 DOI: 10.1016/j.taap.2003.09.016] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2003] [Accepted: 09/23/2003] [Indexed: 11/21/2022]
Abstract
A symposium at the 2003 Annual Meeting of the Society of Toxicology brought together an expert group of endocrinologists to review how non-reproductive hormones can affect the endocrine system. This publication captures the essence of those presentations. Paul Cooke and Denise Holsberger recapitulate the evidence of how thyroid hormones affect male and female reproduction, and reproductive development. Ray Witorsch summarizes the many effects of glucocorticoids on the reproductive system. Finally, Paul Sylvester reviews the mechanism of action of prolactin, and reminds us that this ancient hormone has many functions beyond lactation.
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Affiliation(s)
- Paul S Cooke
- Department of Veterinary Biosciences, University of Illinois at Urbana-Champaign, Urbana, IL 61802, USA
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