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Zhou XY, Ma JN, Shen YY, Xie XR, Ren W. Effects of Growth Hormone on Adult Human Gonads: Action on Reproduction and Sexual Function. Int J Endocrinol 2023; 2023:7492696. [PMID: 37064267 PMCID: PMC10104746 DOI: 10.1155/2023/7492696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 02/20/2023] [Accepted: 03/08/2023] [Indexed: 04/18/2023] Open
Abstract
Growth hormone (GH), which is commonly considered to be a promoter of growth and development, has direct and indirect effects on adult gonads that influence reproduction and sexual function of humans and nonhumans. GH receptors are expressed in adult gonads in some species including humans. For males, GH can improve the sensitivity of gonadotropins, contribute to testicular steroidogenesis, influence spermatogenesis possibly, and regulate erectile function. For females, GH can modulate ovarian steroidogenesis and ovarian angiogenesis, promote the development of ovarian cells, enhance the metabolism and proliferation of endometrial cells, and ameliorate female sexual function. Insulin-like growth factor-1 (IGF-1) is the main mediator of GH. In vivo, a number of the physiological effects of GH are mediated by GH-induced hepatic IGF-1 and local IGF-1. In this review, we highlight the roles of GH and IGF-1 in adult human gonads, clarify potential mechanisms, and explore the efficacy and the risk of GH supplementation in associated deficiency and assisted reproductive technologies. Besides, the effects of excess GH on adult human gonads are discussed as well.
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Affiliation(s)
- Xin-Yi Zhou
- Department of Endocrinology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Jia-Ni Ma
- Department of Endocrinology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Ya-Yin Shen
- Department of Endocrinology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Xue-Rui Xie
- Department of Endocrinology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Wei Ren
- Department of Endocrinology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
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Tenuta M, Carlomagno F, Cangiano B, Kanakis G, Pozza C, Sbardella E, Isidori AM, Krausz C, Gianfrilli D. Somatotropic-Testicular Axis: A crosstalk between GH/IGF-I and gonadal hormones during development, transition, and adult age. Andrology 2020; 9:168-184. [PMID: 33021069 DOI: 10.1111/andr.12918] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 07/31/2020] [Accepted: 09/28/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND The hypothalamic-pituitary-gonadal (HPG) and hypothalamic-pituitary-somatotropic (HPS) axes are strongly interconnected. Interactions between these axes are complex and poorly understood. These interactions are characterized by redundancies in reciprocal influences at each level of regulation and the combination of endocrine and paracrine effects that change during development. OBJECTIVES To comprehensively review the crosstalk between the HPG and HPS axes and related pathological and clinical aspects during various life stages of male subjects. MATERIALS AND METHODS A thorough search of publications available in PubMed was performed using proper keywords. RESULTS Molecular studies confirmed the expressions of growth hormone (GH) and insulin-like growth factor-I (IGF-I) receptors on the HPG axis and reproductive organs, indicating a possible interaction between HPS and HPG axes at various levels. Insulin growth factors participate in sexual differentiation during fetal development, indicating that normal HPS axis activity is required for proper testicular development. IGF-I contributes to correct testicular position during minipuberty, determines linear growth during childhood, and promotes puberty onset and pace through gonadotropin-releasing hormone activation. IGF-I levels are high during transition age, even when linear growth is almost complete, suggesting its role in reproductive tract maturation. Patients with GH deficiency (GHD) and insensitivity (GHI) exhibit delayed puberty and impaired genital development; replacement therapy in such patients induces proper pubertal development. In adults, few studies have suggested that lower IGF-I levels are associated with impaired sperm parameters. DISCUSSION AND CONCLUSION The role of GH-IGF-I in testicular development remains largely unexplored. However, it is important to evaluate gonadic development in children with GHD. Additionally, HPS axis function should be evaluated in children with urogenital malformation or gonadal development alterations. Correct diagnosis and prompt therapeutic intervention are needed for healthy puberty, attainment of complete gonadal development during transition age, and fertility potential in adulthood.
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Affiliation(s)
- Marta Tenuta
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | | | - Biagio Cangiano
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - George Kanakis
- Athens Naval and Veterans Affairs Hospital, Athens, Greece
| | - Carlotta Pozza
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Emilia Sbardella
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Andrea M Isidori
- Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Csilla Krausz
- Department of Experimental and Clinical Biomedical Sciences "Mario Serio", University of Florence, Florence, Italy
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Lee SH, Kim JW, Lee BC, Oh HJ. Age-specific variations in hematological and biochemical parameters in middle- and large-sized of dogs. J Vet Sci 2020; 21:e7. [PMID: 31940686 PMCID: PMC7000901 DOI: 10.4142/jvs.2020.21.e7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/15/2019] [Accepted: 11/21/2019] [Indexed: 01/28/2023] Open
Abstract
Aging triggers cellular and molecular alterations, including genomic instability and organ dysfunction, which increases the risk of disease in mammals. Recently, due to the markedly growing number of aging dogs in the world, as much as 49% in total number of pet dogs, it is necessary to improve and maintain their quality of life by understanding of the biological effects of aging. Therefore, the aim of this study was to determine specific biomarkers in aging dogs as a means of defining a set of hematological/biochemical biomarkers that influence the aging process. Blood samples were collected from younger (1-3 years) and older (7-10 years) dogs of middle/large size. The hematological/biochemistry analysis was performed to evaluate parameters significantly associated with age. Enzyme-linked immunosorbent assay was used to target growth hormone (GH)/insulin growth factor-1 (IGF-1), one of the main regulators of the aging process. Declining levels of total protein and increased levels of glucose in young dogs was observed regardless of their body size. Notably, a significantly high concentration of GH and IGF-1 in the younger dogs compared to the older dogs was found in middle/large-sized dogs. GH and IGF-1 were also found at significantly high levels in large-sized dogs compared to middle-sized dogs, suggesting a similar trend to that of elderly humans. Consequently, glucose, total protein, GH, and IGF-1 were identified as potential biomarkers for regulating the aging process in large/middle-sized dogs. These findings provide an invaluable insight into the mechanism of aging for the field of aging research.
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Affiliation(s)
- Seok Hee Lee
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Jin Wook Kim
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea
| | - Byeong Chun Lee
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
| | - Hyun Ju Oh
- Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul 08826, Korea.
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Abstract
The interrelationships of growth hormone (GH) actions and aging are complex and incompletely understood. The very pronounced age-related decline in GH secretion together with benefits of GH therapy in individuals with congenital or adult GH deficiency (GHD) prompted interest in GH as an anti-aging agent. However, the benefits of treatment of normal elderly subjects with GH appear to be marginal and counterbalanced by worrisome side effects. In laboratory mice, genetic GH deficiency or resistance leads to a remarkable extension of longevity accompanied by signs of delayed and/or slower aging. Mechanisms believed to contribute to extended longevity of GH-related mutants include improved anti-oxidant defenses, enhanced insulin sensitivity and reduced insulin levels, reduced inflammation and cell senescence, major shifts in mitochondrial function and energy metabolism, and greater stress resistance. Negative association of the somatotropic signaling and GH/insulin-like growth factor 1 (IGF-1)-dependent traits with longevity has also been shown in other mammalian species. In humans, syndromes of GH resistance or deficiency have no consistent effect on longevity, but can provide striking protection from cancer, diabetes and atherosclerosis. More subtle alterations in various steps of GH and IGF-1 signaling are associated with reduced old-age mortality, particularly in women and with improved chances of attaining extremes of lifespan. Epidemiological studies raise a possibility that the relationship of IGF-1 and perhaps also GH levels with human healthy aging and longevity may be biphasic. However, the impact of somatotropic signaling on neoplastic disease is difficult to separate from its impact on aging, and IGF-1 levels exhibit opposite associations with different chronic, age-related diseases.
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Affiliation(s)
- Andrzej Bartke
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, USA.
| | - Justin Darcy
- Department of Internal Medicine, Southern Illinois University School of Medicine, Springfield, IL, USA; Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois School of Medicine, Springfield, IL, USA
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Ding W, Cao L, Cao Z, Bing X, Zhao F. Molecular characterization and expression profile of the estrogen receptor α gene during different reproductive phases in Monopterus albus. Sci Rep 2016; 6:27924. [PMID: 27295422 PMCID: PMC4904739 DOI: 10.1038/srep27924] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 05/26/2016] [Indexed: 12/23/2022] Open
Abstract
To understand the molecular mechanism of estrogen and to evaluate the role of the estrogen receptor in mediating estrogen action, the full-length cDNA of estrogen receptor α (ERα) was cloned from Monopterus albus, and its expression pattern and distribution were investigated. The ERα cDNA of M. albus includes an open reading frame of 1863 bp, a 140-bp 5’-untranslated region and a 797-bp 3’-untranslated region. Amino acid sequence homology analysis showed that the Monopterus albus ERα has a moderate degree of similarity with Sebastes schlegelii, Zoarces viviparus and Haplochromis burtoni (81.1%, 80.7% and 80.4%, respectively). Quantitative PCR results showed that the highest level of ERα expression was in the liver; the next highest level of expression was observed in the gonads, where it was expressed at high levels particularly in the ovary in developmental stages IV and V and in the testis in developmental stage II/III. Immunohistochemistry analysis showed that ERα was present as slender particles distributed mainly in the membranes of spermatocytes and oocytes in the testis and ovary, whereas no positive signal was observed in the cytoplasm of sperm cells. This report describes the first molecular characterization of full-length ERα and its tissue-specific distribution in M. albus.
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Affiliation(s)
- Weidong Ding
- Wuxi Fisheries College, Nanjing Agricultural University, 9 East Shanshui Road, Wuxi 214081, China.,Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081,China
| | - Liping Cao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081,China
| | - Zheming Cao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081,China
| | - Xuwen Bing
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081,China
| | - Fazhen Zhao
- Wuxi Fisheries College, Nanjing Agricultural University, 9 East Shanshui Road, Wuxi 214081, China.,Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
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Ghrelin Actions on Somatotropic and Gonadotropic Function in Humans. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 138:3-25. [PMID: 26940384 DOI: 10.1016/bs.pmbts.2015.11.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin, a 28 amino-acid octanoylated peptide predominantly produced by the stomach, was discovered to be the natural ligand of the type 1a GH secretagogue receptor (GHS-R1a). It was thus considered as a natural GHS additional to GHRH, although later on ghrelin has mostly been considered a major orexigenic factor. The GH-releasing action of ghrelin takes place both directly on pituitary cells and through modulation of GHRH from the hypothalamus; some functional antisomatostatin action has also been shown. However, ghrelin is much more than a natural GH secretagogue. In fact, it also modulates lactotroph and corticotroph secretion in humans as well as in animals and plays a relevant role in the modulation of the hypothalamic-pituitary-gonadal function. Several studies have indicated that ghrelin plays an inhibitory effect on gonadotropin pulsatility, is involved in the regulation of puberty onset in animals, and may regulate spermatogenesis, follicular development and ovarian cell functions in humans. In this chapter ghrelin actions on the GH/IGF-I and the gonadal axes will be revised. The potential therapeutic role of ghrelin as a treatment of catabolic conditions will also be discussed.
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Murray PG, Higham CE, Clayton PE. 60 YEARS OF NEUROENDOCRINOLOGY: The hypothalamo-GH axis: the past 60 years. J Endocrinol 2015; 226:T123-40. [PMID: 26040485 DOI: 10.1530/joe-15-0120] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/03/2015] [Indexed: 12/19/2022]
Abstract
At the time of the publication of Geoffrey Harris's monograph on 'Neural control of the pituitary gland' 60 years ago, the pituitary was recognised to produce a growth factor, and extracts administered to children with hypopituitarism could accelerate growth. Since then our understanding of the neuroendocrinology of the GH axis has included identification of the key central components of the GH axis: GH-releasing hormone and somatostatin (SST) in the 1970s and 1980s and ghrelin in the 1990s. Characterisation of the physiological control of the axis was significantly advanced by frequent blood sampling studies in the 1980s and 1990s; the pulsatile pattern of GH secretion and the factors that influenced the frequency and amplitude of the pulses have been defined. Over the same time, spontaneously occurring and targeted mutations in the GH axis in rodents combined with the recognition of genetic causes of familial hypopituitarism demonstrated the key factors controlling pituitary development. As the understanding of the control of GH secretion advanced, developments of treatments for GH axis disorders have evolved. Administration of pituitary-derived human GH was followed by the introduction of recombinant human GH in the 1980s, and, more recently, by long-acting GH preparations. For GH excess disorders, dopamine agonists were used first followed by SST analogues, and in 2005 the GH receptor blocker pegvisomant was introduced. This review will cover the evolution of these discoveries and build a picture of our current understanding of the hypothalamo-GH axis.
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Affiliation(s)
- P G Murray
- Centre for Paediatrics and Child HealthInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UKDepartment of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UKDepartment of EndocrinologyThe Christie Hospital NHS Foundation Trust, Manchester, M20 4BX, UKCentre for Endocrinology and DiabetesInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UK Centre for Paediatrics and Child HealthInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UKDepartment of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UKDepartment of EndocrinologyThe Christie Hospital NHS Foundation Trust, Manchester, M20 4BX, UKCentre for Endocrinology and DiabetesInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UK
| | - C E Higham
- Centre for Paediatrics and Child HealthInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UKDepartment of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UKDepartment of EndocrinologyThe Christie Hospital NHS Foundation Trust, Manchester, M20 4BX, UKCentre for Endocrinology and DiabetesInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UK Centre for Paediatrics and Child HealthInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UKDepartment of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UKDepartment of EndocrinologyThe Christie Hospital NHS Foundation Trust, Manchester, M20 4BX, UKCentre for Endocrinology and DiabetesInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UK
| | - P E Clayton
- Centre for Paediatrics and Child HealthInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UKDepartment of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UKDepartment of EndocrinologyThe Christie Hospital NHS Foundation Trust, Manchester, M20 4BX, UKCentre for Endocrinology and DiabetesInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UK Centre for Paediatrics and Child HealthInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UKDepartment of Paediatric EndocrinologyRoyal Manchester Children's Hospital, Central Manchester Foundation Hospitals NHS Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UKDepartment of EndocrinologyThe Christie Hospital NHS Foundation Trust, Manchester, M20 4BX, UKCentre for Endocrinology and DiabetesInstitute of Human Development, Faculty of Medical and Human Sciences, University of Manchester, M13 9WL, UK
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Pena-Bello L, Pertega-Diaz S, Outeiriño-Blanco E, Garcia-Buela J, Tovar S, Sangiao-Alvarellos S, Dieguez C, Cordido F. Effect of oral glucose administration on rebound growth hormone release in normal and obese women: the role of adiposity, insulin sensitivity and ghrelin. PLoS One 2015; 10:e0121087. [PMID: 25782001 PMCID: PMC4363632 DOI: 10.1371/journal.pone.0121087] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 01/30/2015] [Indexed: 12/17/2022] Open
Abstract
Context Metabolic substrates and nutritional status play a major role in growth hormone (GH) secretion. Uncovering the mechanisms involved in GH secretion following oral glucose (OG) administration in normal and obese patients is a pending issue. Objective The aim of this study was to investigate GH after OG in relation with adiposity, insulin secretion and action, and ghrelin secretion in obese and healthy women, to further elucidate the mechanism of GH secretion after OG and the altered GH secretion in obesity. Participants and Methods We included 64 healthy and obese women. After an overnight fast, 75 g of OG were administered; GH, glucose, insulin and ghrelin were obtained during 300 minutes. Insulin secretion and action indices and the area under the curve (AUC) were calculated for GH, glucose, insulin and ghrelin. Univariate and multivariate linear regression analyses were employed. Results The AUC of GH (μg/L•min) was lower in obese (249.8±41.8) than in healthy women (490.4±74.6), P=0.001. The AUC of total ghrelin (pg/mL•min) was lower in obese (240995.5±11094.2) than in healthy women (340797.5±37757.5), P=0.042. There were significant correlations between GH secretion and the different adiposity, insulin secretion and action, and ghrelin secretion indices. After multivariate analysis only ghrelin AUC remained a significant predictor for fasting and peak GH.
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Affiliation(s)
- Lara Pena-Bello
- Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
| | - Sonia Pertega-Diaz
- Clinical Epidemiology and Biostatistics Unit, University Hospital A Coruña, A Coruña, Spain
| | | | - Jesus Garcia-Buela
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
| | - Sulay Tovar
- Department of Physiology (CIMUS), School of Medicine-Instituto de Investigaciones Sanitarias (IDIS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain, and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Susana Sangiao-Alvarellos
- Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
| | - Carlos Dieguez
- Department of Physiology (CIMUS), School of Medicine-Instituto de Investigaciones Sanitarias (IDIS), Universidad de Santiago de Compostela, Santiago de Compostela, Spain, and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain
| | - Fernando Cordido
- Department of Medicine, Faculty of Health Sciences, University of A Coruña, A Coruña, Spain
- Instituto de Investigación Biomedica (INIBIC), University Hospital A Coruña, A Coruña, Spain
- Department of Endocrinology, University Hospital A Coruña, A Coruña, Spain
- * E-mail:
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Veldhuis JD, Yang RJ, Wigham JR, Erickson D, Miles JC, Bowers CY. Estrogen-like potentiation of ghrelin-stimulated GH secretion by fulvestrant, a putatively selective ER antagonist, in postmenopausal women. J Clin Endocrinol Metab 2014; 99:E2557-64. [PMID: 25210881 PMCID: PMC4255109 DOI: 10.1210/jc.2014-2633] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Hyposomatotropism in healthy aging women reflects in part physiological estrogen (estradiol [E2]) depletion associated with menopause. OBJECTIVE AND DESIGN The purpose of this study was to test the hypothesis that low concentrations of endogenous E2 after menopause continue to drive GH secretion. SETTING The study was performed at the Mayo Center for Clinical and Translational Science. PARTICIPANTS The participants were 24 postmenopausal women (aged 50-77 years with body mass index of 19-32 kg/m(2)). INTERVENTIONS This was a randomized, double-blind, placebo-controlled, parallel-cohort treatment study with placebo (PL) (n = 14) or the antiestrogen fulvestrant (FUL) (n = 10) for 3 weeks, followed by infusion of l-arginine with saline, GHRH, ghrelin, or both peptide secretagogues. OUTCOMES GH concentrations were measured over 6 hours with 10-minute sampling and mass spectrometry measures of testosterone, E2, and estrone. RESULTS Concentrations of testosterone, E2, estrone, SHBG, IGF-I, LH, and FSH were not influenced by antiestrogen treatment. In contrast, GH rose from 0.096 ± 0.018 (PL) to 0.23 ± 0.063 μg/L (FUL, P = .033), and IGF-I binding protein type 3 (IGFBP-3) from 3.6 ± 0.18 to 4.0 ± 2.0 mg/L (P = .041). Conversely, prolactin fell from 7.1 ± 0.69 (PL) to 5.5 ± 0.57 μg/L (FUL) (P = .05), and IGF-I binding protein type 1 (IGFBP-1) fell from 44 ± 9.4 to 27 ± 4.3 μg/L (P = .048). Moreover, FUL vs PL potentiated mean GH responses to l-arginine/saline (P = .007), l-arginine/ghrelin (P = .008), and l-arginine/GHRH + ghrelin (P = .031), but not l-arginine/GHRH. CONCLUSION The potent antiestrogen, FUL, amplifies fasting and secretagogue-driven GH secretion and IGFBP-3 concentrations in postmenopausal women without altering SHBG or sex steroid levels. FUL also suppresses prolactin and IGFBP-1, without altering IGF-I. Thus, a major antiestrogen mediates 3 actions of estrogen: agonism (GH), neutral effects (sex steroids), and estrogen antagonism (prolactin and IGFBP-1).
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Affiliation(s)
- Johannes D Veldhuis
- Endocrine Research Unit (J.D.V., R.J.Y., J.R.W., D.E., J.C.M.), Mayo Clinic College of Medicine Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; and Tulane University Health Sciences Center (C.Y.B.), Endocrinology and Metabolism Section, Peptide Research Section, New Orleans, Louisiana 70112
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Norman C, Rollene N, Weist SM, Wigham JR, Erickson D, Miles JM, Bowers CY, Veldhuis JD. Short-term estradiol supplementation potentiates low-dose ghrelin action in the presence of GHRH or somatostatin in older women. J Clin Endocrinol Metab 2014; 99:E73-80. [PMID: 24203062 PMCID: PMC3879681 DOI: 10.1210/jc.2013-3043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Ghrelin is a potent gastric-derived GH-releasing peptide. How ghrelin interacts with sex steroids, GHRH, and somatostatin (SS) is not known. OBJECTIVE Our objective was to test the hypotheses that ghrelin's interactions with GHRH (synergistic) and SS (disinhibitory) are ghrelin dose-dependent and amplified by estrogen. SUBJECTS, SETTING, AND DESIGN: Healthy postmenopausal women were treated with placebo (n=12) or 17β-estradiol (E2) (n=12) at the Center for Translational Science Activities in a randomized double-blind prospective study. METHODS Ghrelin dose-dependence was assessed by nonlinear curve fitting of the relationship between deconvolved GH secretory-burst mass and 5 randomly ordered ghrelin doses (0, 0.03, 0.135, 0.6, and 2.7 μg/kg bolus iv) during saline, GHRH, and SS infusion. RESULTS Under placebo, neither GHRH nor SS altered the ED50 of ghrelin (range 0.64-0.67 μg/kg). Under E2 (median E2 88 pg/mL), the ED50 of ghrelin declined in the presence of GHRH to 0.52 μg/kg. In contrast, the efficacy of ghrelin rose markedly during GHRH vs saline exposure with and without E2: placebo and saline 52±1.0 vs GHRH 173±3.8 μg/L; and E2 and saline 56±0.90 vs GHRH 174±3.7 μg/L. Sensitivity to ghrelin was similar under all conditions. SUMMARY Short-term E2 supplementation in postmenopausal women reduces the ED50 (increases the potency) of ghrelin when GHRH is present, without altering ghrelin efficacy (maximal effect) or hypothalamo-pituitary sensitivity (slope of dose response) to ghrelin. The data suggest possible physiological interactions among sex steroids (endogenous), ghrelin, and GHRH during E2 replacement in postmenopausal women.
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Affiliation(s)
- Catalina Norman
- Endocrine Research Unit (C.N., S.M.W., J.R.W., D.E., J.M.M., J.D.V.), Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, Minnesota 55905; Naval Medical Center Portsmouth (N.R.), Division of Reproductive Endocrinology, Portsmouth, Virginia 23708; and Tulane University Health Sciences Center (C.Y.B.), Endocrinology and Metabolism Section, Peptide Research Section, New Orleans, Louisiana 70112
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Garin MC, Burns CM, Kaul S, Cappola AR. Clinical review: The human experience with ghrelin administration. J Clin Endocrinol Metab 2013; 98:1826-37. [PMID: 23533240 PMCID: PMC3644599 DOI: 10.1210/jc.2012-4247] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CONTEXT Ghrelin is an endogenous stimulator of GH and is implicated in a number of physiological processes. Clinical trials have been performed in a variety of patient populations, but there is no comprehensive review of the beneficial and adverse consequences of ghrelin administration to humans. EVIDENCE ACQUISITION PubMed was utilized, and the reference list of each article was screened. We included 121 published articles in which ghrelin was administered to humans. EVIDENCE SYNTHESIS Ghrelin has been administered as an infusion or a bolus in a variety of doses to 1850 study participants, including healthy participants and patients with obesity, prior gastrectomy, cancer, pituitary disease, diabetes mellitus, eating disorders, and other conditions. There is strong evidence that ghrelin stimulates appetite and increases circulating GH, ACTH, cortisol, prolactin, and glucose across varied patient populations. There is a paucity of evidence regarding the effects of ghrelin on LH, FSH, TSH, insulin, lipolysis, body composition, cardiac function, pulmonary function, the vasculature, and sleep. Adverse effects occurred in 20% of participants, with a predominance of flushing and gastric rumbles and a mild degree of severity. The few serious adverse events occurred in patients with advanced illness and were not clearly attributable to ghrelin. Route of administration may affect the pattern of adverse effects. CONCLUSIONS Existing literature supports the short-term safety of ghrelin administration and its efficacy as an appetite stimulant in diverse patient populations. There is some evidence to suggest that ghrelin has wider ranging therapeutic effects, although these areas require further investigation.
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Affiliation(s)
- Margaret C Garin
- Division of Endocrinology, Diabetes, and Metabolism, Perelman School of Medicine at the University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104-5160, USA
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Norman C, Miles J, Bowers CY, Veldhuis JD. Differential pulsatile secretagogue control of GH secretion in healthy men. Am J Physiol Regul Integr Comp Physiol 2013; 304:R712-9. [PMID: 23485864 DOI: 10.1152/ajpregu.00069.2013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pulsatile growth hormone (GH) secretion putatively reflects integrated regulation by GH-releasing hormone (GHRH), somatostatin (SST), and GH-releasing peptide (GHRP). GHRH and SST secretion is itself pulsatile. However, how GHRH and SST pulses act along with GHRP to jointly determine pulsatile GH secretion is unclear. Moreover, how testosterone (T) modulates such interactions is unknown. These queries were assessed in a prospectively randomized, placebo-controlled double-blind cohort comprising 26 healthy older men randomized to testosterone (T) vs. placebo supplementation. Pulses of GHRH, SST, or saline were infused intravenously at 90-min intervals for 13 h, along with either continuous saline or ghrelin analog (GHRP-2). The train of pulses was followed by a triple stimulus (combined l-arginine, GHRH, and GHRP-2) to estimate near-maximal GH secretion over a final 3 h. Testosterone vs. placebo supplementation doubled pulsatile GH secretion during GHRH pulses combined with continuous saline (GHRH/saline) (P < 0.01). Pulsatile GH secretion correlated positively with T concentrations (270-1,170 ng/dl) in the 26 men during saline pulses/saline (P = 0.015, R(2) = 0.24), GHRH pulses/saline (P = 0.020, R(2) = 0.22), and combined GHRH pulses/GHRP-2 (P = 0.016, R(2) = 0.25) infusions. Basal nonpulsatile GH secretion correlated with T during saline pulses/GHRP-2 drive (P = 0.020, R(2) = 0.16). By regression analysis, pulsatile GH secretion varied negatively with body mass index (BMI) during saline/GHRP-2 infusion (P = 0.001, R(2) = 0.36), as well as after the triple stimulus preceded by GHRH/GHRP-2 (P = 0.013, R(2) = 0.23). Mean (10-h) GH concentrations under GHRP-2 were predicted jointly by estradiol (positively) and BMI (negatively) (P < 0.001, R(2) = 0.520). These data indicate that estradiol, T, and BMI control pulsatile secretagogue-specific GH-regulatory mechanisms in older men.
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Affiliation(s)
- Catalina Norman
- Endocrine Research Unit, Mayo School of Graduate Medical Education, Center for Translational Science Activities, Mayo Clinic, Rochester, MN 55905, USA
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