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George BT, Jhancy M, Dube R, Kar SS, Annamma LM. The Molecular Basis of Male Infertility in Obesity: A Literature Review. Int J Mol Sci 2023; 25:179. [PMID: 38203349 PMCID: PMC10779000 DOI: 10.3390/ijms25010179] [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] [Received: 12/05/2023] [Revised: 12/12/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024] Open
Abstract
The rising incidence of obesity has coincided with rising levels of poor reproductive outcomes. The molecular basis for the association of infertility in obese males is now being explained through various mechanisms. Insulin resistance, hyperglycemia, and changes in serum and gonadal concentrations of adipokines, like leptin, adiponectin, resistin, and ghrelin have been implicated as causes of male infertility in obese males. The effects of obesity and hypogonadism form a vicious cycle whereby dysregulation of the hypothalamic-pituitary-testicular axis-due to the effect of the release of multiple mediators, thus decreasing GnRH release from the hypothalamus-causes decreases in LH and FSH levels. This leads to lower levels of testosterone, which further increases adiposity because of increased lipogenesis. Cytokines such as TNF-α and interleukins, sirtuins, and other inflammatory mediators like reactive oxygen species are known to affect fertility in obese male adults. There is evidence that parental obesity can be transferred through subsequent generations to offspring through epigenetic marks. Thus, negative expressions like obesity and infertility have been linked to epigenetic marks being altered in previous generations. The interesting aspect is that these epigenetic expressions can be reverted by removing the triggering factors. These positive modifications are also transmitted to subsequent generations.
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Affiliation(s)
- Biji Thomas George
- Department of Surgery, RAK College of Medical Sciences, RAKMHSU, Ras al Khaimah P.O. Box 11172, United Arab Emirates
| | - Malay Jhancy
- Department of Pediatrics, RAK College of Medical Sciences, RAKMHSU, Ras al Khaimah P.O. Box 11172, United Arab Emirates; (M.J.); (S.S.K.)
| | - Rajani Dube
- Department of Obstetrics and Gynecology, RAK College of Medical Sciences, RAKMHSU, Ras al Khaimah P.O. Box 11172, United Arab Emirates;
| | - Subhranshu Sekhar Kar
- Department of Pediatrics, RAK College of Medical Sciences, RAKMHSU, Ras al Khaimah P.O. Box 11172, United Arab Emirates; (M.J.); (S.S.K.)
| | - Lovely Muthiah Annamma
- Department of Clinical Sciences, Ajman University, Ajman P.O. Box 346, United Arab Emirates;
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Masule MV, Rathod S, Agrawal Y, Patil CR, Nakhate KT, Ojha S, Goyal SN, Mahajan UB. Ghrelin mediated regulation of neurosynaptic transmitters in depressive disorders. CURRENT RESEARCH IN PHARMACOLOGY AND DRUG DISCOVERY 2022; 3:100113. [PMID: 35782191 PMCID: PMC9240712 DOI: 10.1016/j.crphar.2022.100113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 06/07/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Ghrelin is a peptide released by the endocrine cells of the stomach and the neurons in the arcuate nucleus of the hypothalamus. It modulates both peripheral and central functions. Although ghrelin has emerged as a potent stimulator of growth hormone release and as an orexigenic neuropeptide, the wealth of literature suggests its involvement in the pathophysiology of affective disorders including depression. Ghrelin exhibits a dual role through the advancement and reduction of depressive behavior with nervousness in the experimental animals. It modulates depression-related signals by forming neuronal networks with various neuropeptides and classical neurotransmitter systems. The present review emphasizes the integration and signaling of ghrelin with other neuromodulatory systems concerning depressive disorders. The role of ghrelin in the regulation of neurosynaptic transmission and depressive illnesses implies that the ghrelin system modulation can yield promising antidepressive therapies. Ghrelin is the orexigenic type of neuropeptide. It binds with the growth hormone secretagogue receptor (GHSR). GHSR is ubiquitously present in the various brain regions. Ghrelin is involved in the regulation of depression-related behavior. The review focuses on the neurotransmission and signaling of ghrelin in neuropsychiatric and depressive disorders.
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Affiliation(s)
- Milind V. Masule
- Department of Pharmacology, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
| | - Sumit Rathod
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
| | - Yogeeta Agrawal
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
| | - Chandragouda R. Patil
- Department of Pharmacology, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
| | - Kartik T. Nakhate
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
| | - Shreesh Ojha
- Department of Pharmacology and Therapeutics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Sameer N. Goyal
- Shri Vile Parle Kelavani Mandal's Institute of Pharmacy, Dhule, 424001, Maharashtra, India
- Corresponding author.
| | - Umesh B. Mahajan
- Department of Pharmacology, R. C. Patel Institute of Pharmaceutical Education and Research, Shirpur, 425405, Maharashtra, India
- Corresponding author.
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Ferreira CER, Campos GS, Schmidt PI, Sollero BP, Goularte KL, Corcini CD, Gasperin BG, Lucia T, Boligon AA, Cardoso FF. Genome-wide association and genomic prediction for scrotal circumference in Hereford and Braford bulls. Theriogenology 2021; 172:268-280. [PMID: 34303226 DOI: 10.1016/j.theriogenology.2021.07.007] [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] [Received: 08/14/2020] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 11/19/2022]
Abstract
Scrotal circumference (SC) is widely used as a selection criterion for bulls in breeding programs, since it is easily assessed and correlated with several desirable reproductive traits. The objectives of this study were: to perform a genome-wide association study (GWAS) to identify genomic regions associated with SC adjusted for age (SCa) and for both age and weight (SCaw); to select Tag SNPs from GWAS to construct low-density panel for genomic prediction; and to compare the prediction accuracy of the SC through different methods for Braford and Hereford bulls from the same genetic breeding program. Data of SC from 18,172 bulls (30.4 ± 3.7 cm) and of genotypes from 131 sires and 3,545 animals were used. From GWAS, the top 1% of 1-Mb windows were observed on chromosome (BTA) 2, 20, 7, 8, 15, 3, 16, 27, 6 and 8 for SCa and on BTA 8, 15, 16, 21, 19, 2, 6, 5 and 10 for SCaw, representing 17.4% and 18.8% of the additive genetic variance of SCa and SCaw, respectively. The MeSH analysis was able to translate genomic information providing biological meanings of more specific gene functions related to the SCa and SCaw. The genomic enhancement methods, especially single step GBLUP, that combined phenotype and pedigree data with direct genomic values generated gains in accuracy in relation to pedigree BLUP, suggesting that genomic predictions should be applied to improve genetic gain and to narrow the generation interval compared to traditional methods. The proposed Tag-SNP panels may be useful for lower-cost commercial genomic prediction applications in the future, when the number of bulls in the reference population increases for SC in Hereford and Braford breeds.
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Affiliation(s)
- Carlos E R Ferreira
- ReproPel, Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brazil.
| | - Gabriel S Campos
- Departamento de Zootecnia, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Patricia I Schmidt
- Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual de São Paulo, Jaboticabal, SP, Brazil
| | | | - Karina L Goularte
- ReproPel, Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Carine D Corcini
- ReproPel, Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Bernardo G Gasperin
- ReproPel, Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Thomaz Lucia
- ReproPel, Faculdade de Veterinária, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Arione A Boligon
- Departamento de Zootecnia, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Pelotas, RS, Brazil
| | - Fernando F Cardoso
- Departamento de Zootecnia, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas, Pelotas, RS, Brazil; Embrapa Pecuária Sul, Bagé, RS, Brazil
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4
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Shati AA, Dallak M. Acylated Ghrelin Protects the Hearts of Rats from Doxorubicin-Induced Fas/FasL Apoptosis by Stimulating SERCA2a Mediated by Activation of PKA and Akt. Cardiovasc Toxicol 2020; 19:529-547. [PMID: 31093930 DOI: 10.1007/s12012-019-09527-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This study investigated if the cardioprotective effect of acylated ghrelin (AG) against doxorubicin (DOX)-induced cardiac toxicity in rats involves inhibition of Fas/FasL-mediated cell death. It also investigated if such an effect is mediated by restoring Ca+2 homeostasis from the aspect of stimulation of SERCA2a receptors. Adult male Wistar rats were divided into 4 groups (20 rats/each) as control, control + AG, DOX, and DOX + AG. AG was co-administered to all rats consecutively for 35 days. In addition, isolated cardiomyocytes were cultured and treated with AG in the presence or absence of DOX with or without pre-incubation with [D-Lys3]-GHRP-6 (a AG receptor antagonist), VIII (]an Akt inhibitor), or KT-5720 (a PKA inhibitor). AG increased LVSP, dp/dtmax, and dp/dtmin in both control and DOX-treated animals and improved cardiac ultrastructural changes in DOX-treated rats. It also inhibited ROS in control rats and lowered LVEDP, intracellular levels of ROS and Ca2+, and activity of calcineurin in LVs of DOX-treated rats. Concomitantly, it inhibited LV NFAT-4 nuclear translocation and downregulated their protein levels of Fas and FasL. Mechanistically, in control or DOX-treated hearts or cells, AG upregulated the levels of SERCA2a and increased the activities of PKA and Akt, leading to increase phosphorylation of phospholamban at Ser16 and Thr17. All these effects were abolished by D-Lys3-GHRP-6, VIII, or KT-5720 and were independent of food intake or GH/IGF-1. In conclusion, AG cardioprotection against DOX involves inhibition of extrinsic cell death and restoring normal Ca+2 homeostasis.
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Affiliation(s)
- Ali A Shati
- Department of Biology, College of Science, King Khalid University, Abha, Saudi Arabia.
| | - M Dallak
- Department of Physiology, College of Medicine, King Khalid University, Abha, Saudi Arabia
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5
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Vázquez-Borrego MC, Gahete MD, Martínez-Fuentes AJ, Fuentes-Fayos AC, Castaño JP, Kineman RD, Luque RM. Multiple signaling pathways convey central and peripheral signals to regulate pituitary function: Lessons from human and non-human primate models. Mol Cell Endocrinol 2018; 463:4-22. [PMID: 29253530 DOI: 10.1016/j.mce.2017.12.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 12/14/2017] [Accepted: 12/14/2017] [Indexed: 12/12/2022]
Abstract
The anterior pituitary gland is a key organ involved in the control of multiple physiological functions including growth, reproduction, metabolism and stress. These functions are controlled by five distinct hormone-producing pituitary cell types that produce growth hormone (somatotropes), prolactin (lactotropes), adrenocorticotropin (corticotropes), thyrotropin (thyrotropes) and follicle stimulating hormone/luteinizing hormone (gonadotropes). Classically, the synthesis and release of pituitary hormones was thought to be primarily regulated by central (neuroendocrine) signals. However, it is now becoming apparent that factors produced by pituitary hormone targets (endocrine and non-endocrine organs) can feedback directly to the pituitary to adjust pituitary hormone synthesis and release. Therefore, pituitary cells serve as sensors to integrate central and peripheral signals in order to fine-tune whole-body homeostasis, although it is clear that pituitary cell regulation is species-, age- and sex-dependent. The purpose of this review is to provide a comprehensive, general overview of our current knowledge of both central and peripheral regulators of pituitary cell function and associated intracellular mechanisms, focusing on human and non-human primates.
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Affiliation(s)
- M C Vázquez-Borrego
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain; Agrifood Campus of International Excellence (ceiA3), 14004 Cordoba, Spain
| | - M D Gahete
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain; Agrifood Campus of International Excellence (ceiA3), 14004 Cordoba, Spain
| | - A J Martínez-Fuentes
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain; Agrifood Campus of International Excellence (ceiA3), 14004 Cordoba, Spain
| | - A C Fuentes-Fayos
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain; Agrifood Campus of International Excellence (ceiA3), 14004 Cordoba, Spain
| | - J P Castaño
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain; Agrifood Campus of International Excellence (ceiA3), 14004 Cordoba, Spain
| | - R D Kineman
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA; Jesse Brown Veterans Affairs Medical Center, Research and Development Division, Chicago, IL, USA
| | - R M Luque
- Maimonides Institute of Biomedical Research of Cordoba (IMIBIC), 14004 Cordoba, Spain; Department of Cell Biology, Physiology and Immunology, University of Cordoba, 14004 Cordoba, Spain; Reina Sofia University Hospital (HURS), 14004 Cordoba, Spain; CIBER Physiopathology of Obesity and Nutrition (CIBERobn), 14004 Cordoba, Spain; Agrifood Campus of International Excellence (ceiA3), 14004 Cordoba, Spain.
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6
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Hyland L, Rosenbaum S, Edwards A, Palacios D, Graham MD, Pfaus JG, Woodside B, Abizaid A. Central ghrelin receptor stimulation modulates sex motivation in male rats in a site dependent manner. Horm Behav 2018; 97:56-66. [PMID: 29080670 DOI: 10.1016/j.yhbeh.2017.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/28/2017] [Accepted: 10/24/2017] [Indexed: 12/14/2022]
Abstract
Ghrelin, a hormone produced primarily by the stomach, has been associated with motivational processes that include reward-seeking behaviors. In male laboratory mice, elevation of ghrelin levels enhances some aspects of sexual motivation and behavior, whereas in other experiments with male mice, rats, and other species, ghrelin treatment or food deprivation decreases sexual motivation and/or behavior. The present tested the hypothesis that stimulation of ghrelin receptors in different brain regions have opposite effects on male sexual motivation and behavior. To do this we examined appetitive and consummatory sex behaviors of male rats with a truncated ghrelin receptor (FHH-GHSRm1/Mcwi), and that of their WT (FHH) littermates. We also examined the effects of ghrelin or the ghrelin antagonist D-Lys-GHRP6 delivered into the VTA or the MPOA on appetitive and consummatory sex behaviors in male Long Evans rats. Results demonstrate that rats with a truncated ghrelin receptor, or rats that are food deprived, show deficits in anticipatory sex. Furthermore, although ghrelin does not further stimulate sex anticipation in rats when infused into the VTA, intra-VTA infusions of D-Lys-GHRP6 into the VTA further decreases in sex anticipation in food deprived rats. In contrast, ghrelin delivery into the mPOA decreased sex anticipation compared to saline or D-Lys-GHRP6 infused rats. Overall, these data suggest that ghrelin receptor signalling is important for full expression of appetitive sex behaviors. Within the VTA, ghrelin may act to enhance sex motivation, while acting on the mPOA to decrease sex motivation and promote foraging.
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Affiliation(s)
- Lindsay Hyland
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | | | - Alexander Edwards
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada
| | - Daniel Palacios
- Centre for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - M Dean Graham
- Centre for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - James G Pfaus
- Centre for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - Barbara Woodside
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada; Centre for Studies in Behavioral Neurobiology, Concordia University, Montreal, Quebec, Canada
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, Ontario, Canada.
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Sominsky L, Hodgson DM, McLaughlin EA, Smith R, Wall HM, Spencer SJ. Linking Stress and Infertility: A Novel Role for Ghrelin. Endocr Rev 2017; 38:432-467. [PMID: 28938425 DOI: 10.1210/er.2016-1133] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 07/24/2017] [Indexed: 12/23/2022]
Abstract
Infertility affects a remarkable one in four couples in developing countries. Psychological stress is a ubiquitous facet of life, and although stress affects us all at some point, prolonged or unmanageable stress may become harmful for some individuals, negatively impacting on their health, including fertility. For instance, women who struggle to conceive are twice as likely to suffer from emotional distress than fertile women. Assisted reproductive technology treatments place an additional physical, emotional, and financial burden of stress, particularly on women, who are often exposed to invasive techniques associated with treatment. Stress-reduction interventions can reduce negative affect and in some cases to improve in vitro fertilization outcomes. Although it has been well-established that stress negatively affects fertility in animal models, human research remains inconsistent due to individual differences and methodological flaws. Attempts to isolate single causal links between stress and infertility have not yet been successful due to their multifaceted etiologies. In this review, we will discuss the current literature in the field of stress-induced reproductive dysfunction based on animal and human models, and introduce a recently unexplored link between stress and infertility, the gut-derived hormone, ghrelin. We also present evidence from recent seminal studies demonstrating that ghrelin has a principal role in the stress response and reward processing, as well as in regulating reproductive function, and that these roles are tightly interlinked. Collectively, these data support the hypothesis that stress may negatively impact upon fertility at least in part by stimulating a dysregulation in ghrelin signaling.
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Affiliation(s)
- Luba Sominsky
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria 3083, Australia
| | - Deborah M Hodgson
- School of Psychology, Faculty of Science and IT, The University of Newcastle, New South Wales 2308, Australia
| | - Eileen A McLaughlin
- School of Biological Sciences, Faculty of Science, The University of Auckland, Auckland 1010, New Zealand.,School of Environmental & Life Sciences, Faculty of Science and IT, The University of Newcastle, New South Wales 2308, Australia
| | - Roger Smith
- Mothers and Babies Research Centre, Hunter Medical Research Institute, Lookout Road, New Lambton Heights, New South Wales 2305, Australia.,Priority Research Centre in Reproductive Science, The University of Newcastle, New South Wales 2308, Australia
| | - Hannah M Wall
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria 3083, Australia
| | - Sarah J Spencer
- School of Health and Biomedical Sciences, RMIT University, Melbourne, Victoria 3083, Australia
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Messini CI, Malandri M, Anifandis G, Dafopoulos K, Georgoulias P, Sveronis G, Garas A, Daponte A, Messinis IE. Submaximal doses of ghrelin do not inhibit gonadotrophin levels but stimulate prolactin secretion in postmenopausal women. Clin Endocrinol (Oxf) 2017; 87:44-50. [PMID: 28397357 DOI: 10.1111/cen.13349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 03/24/2017] [Accepted: 04/06/2017] [Indexed: 11/29/2022]
Abstract
OBJECTIVE An inhibitory effect of ghrelin on gonadotrophin secretion has been reported in normally menstruating women possibly modulated by endogenous oestrogen. The aim of this study was to examine the effect of ghrelin on gonadotrophin and prolactin (PRL) secretion in oestrogen-deprived postmenopausal women. DESIGN Prospective intervention study. PATIENTS AND MEASUREMENTS Ten healthy postmenopausal volunteer women were studied during two 15-days periods of oestrogen treatment (A and B) a month apart. Four experiments (Exp) were performed in total, two on day 1 (Exp 1A and Exp 1B) and two on day 15 (Exp 15A and Exp 15B) of the two periods. The women received in Exp 1A and in Exp 15A two iv injections of ghrelin (0.15 μg/kg at time 0 minute and 0.30 μg/kg at time 90 minutes) and in Exp1B and in Exp 15B normal saline (2 mL), respectively. Blood samples were taken at -15, 0, 30, 60, 90, 120, 150 and 180 minutes. RESULTS After oestrogen treatment, late follicular phase serum oestradiol levels were attained on day 15 of periods A and B. Ghrelin administration did not affect serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), whereas it increased significantly those of growth hormone (GH) and PRL. In Exp 15A, serum PRL increment in response to ghrelin (area under the curve, net increment) was significantly greater than in Exp 1A (P<.05). CONCLUSIONS This study demonstrates for the first time that in oestrogen-deprived postmenopausal women, ghrelin administration affects neither FSH nor LH levels but stimulates PRL secretion, that is amplified by exogenous oestrogen administration.
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Affiliation(s)
- Christina I Messini
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Maria Malandri
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - George Anifandis
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Konstantinos Dafopoulos
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Panagiotis Georgoulias
- Department of Nuclear Medicine, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Georgios Sveronis
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Antonios Garas
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Alexandros Daponte
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
| | - Ioannis E Messinis
- Department of Obstetrics and Gynaecology, Faculty of Medicine, School of Health Sciences, University of Thessaly, Larissa, Greece
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Abstract
Anorexia nervosa is a psychiatric disorder characterized by altered body image, persistent food restriction and low body weight, and is associated with global endocrine dysregulation in both adolescent girls and women. Dysfunction of the hypothalamic-pituitary axis includes hypogonadotropic hypogonadism with relative oestrogen and androgen deficiency, growth hormone resistance, hypercortisolaemia, non-thyroidal illness syndrome, hyponatraemia and hypooxytocinaemia. Serum levels of leptin, an anorexigenic adipokine, are suppressed and levels of ghrelin, an orexigenic gut peptide, are elevated in women with anorexia nervosa; however, levels of peptide YY, an anorexigenic gut peptide, are paradoxically elevated. Although most, but not all, of these endocrine disturbances are adaptive to the low energy state of chronic starvation and reverse with treatment of the eating disorder, many contribute to impaired skeletal integrity, as well as neuropsychiatric comorbidities, in individuals with anorexia nervosa. Although 5-15% of patients with anorexia nervosa are men, only limited data exist regarding the endocrine impact of the disease in adolescent boys and men. Further research is needed to understand the endocrine determinants of bone loss and neuropsychiatric comorbidities in anorexia nervosa in both women and men, as well as to formulate optimal treatment strategies.
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Affiliation(s)
- Melanie Schorr
- Neuroendocrine Unit, Massachusetts General Hospital, 55 Fruit Street, Bulfinch 457B, Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Karen K Miller
- Neuroendocrine Unit, Massachusetts General Hospital, 55 Fruit Street, Bulfinch 457B, Boston, Massachusetts 02114, USA
- Harvard Medical School, 25 Shattuck Street, Boston, Massachusetts 02115, USA
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10
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Evans MC, Anderson GM. Neuroendocrine integration of nutritional signals on reproduction. J Mol Endocrinol 2017; 58:R107-R128. [PMID: 28057770 DOI: 10.1530/jme-16-0212] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 01/05/2017] [Indexed: 12/28/2022]
Abstract
Reproductive function in mammals is energetically costly and therefore tightly regulated by nutritional status. To enable this integration of metabolic and reproductive function, information regarding peripheral nutritional status must be relayed centrally to the gonadotropin-releasing hormone (GNRH) neurons that drive reproductive function. The metabolically relevant hormones leptin, insulin and ghrelin have been identified as key mediators of this 'metabolic control of fertility'. However, the neural circuitry through which they act to exert their control over GNRH drive remains incompletely understood. With the advent of Cre-LoxP technology, it has become possible to perform targeted gene-deletion and gene-rescue experiments and thus test the functional requirement and sufficiency, respectively, of discrete hormone-neuron signaling pathways in the metabolic control of reproductive function. This review discusses the findings from these investigations, and attempts to put them in context with what is known from clinical situations and wild-type animal models. What emerges from this discussion is clear evidence that the integration of nutritional signals on reproduction is complex and highly redundant, and therefore, surprisingly difficult to perturb. Consequently, the deletion of individual hormone-neuron signaling pathways often fails to cause reproductive phenotypes, despite strong evidence that the targeted pathway plays a role under normal physiological conditions. Although transgenic studies rarely reveal a critical role for discrete signaling pathways, they nevertheless prove to be a good strategy for identifying whether a targeted pathway is absolutely required, critically involved, sufficient or dispensable in the metabolic control of fertility.
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Affiliation(s)
- Maggie C Evans
- Centre for Neuroendocrinology and Department of AnatomyUniversity of Otago School of Medical Sciences, Dunedin, New Zealand
| | - Greg M Anderson
- Centre for Neuroendocrinology and Department of AnatomyUniversity of Otago School of Medical Sciences, Dunedin, New Zealand
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Ghrelin suppresses the GnRH-induced preovulatory gonadotropin surge in dairy heifers. Theriogenology 2016; 86:1615-1621. [DOI: 10.1016/j.theriogenology.2016.05.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 05/19/2016] [Accepted: 05/19/2016] [Indexed: 12/16/2022]
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12
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Wójcik-Gładysz A, Wańkowska M, Gajewska A, Misztal T, Zielińska-Górska M, Szlis M, Polkowska J. Effects of intracerebroventricular infusions of ghrelin on secretion of follicle-stimulating hormone in peripubertal female sheep. Reprod Fertil Dev 2016; 28:2065-2074. [DOI: 10.1071/rd16028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 04/23/2016] [Indexed: 12/18/2022] Open
Abstract
Reproduction depends on mechanisms responsible for the regulation of energy homeostasis and puberty is a developmental period when reproductive and somatic maturity are achieved. Ghrelin affects the activity of the hypothalamo–pituitary–gonadal axis under conditions of energy insufficiency. An in vivo model based on intracerebroventricular (i.c.v.) infusions was used to determine whether centrally administered acyl ghrelin affects transcriptional and translational activity of FSH in peripubertal lambs and whether ghrelin administration mimics the effects of short-term fasting. Standard-fed lambs received either Ringer–Lock (R-L) solution (120 µL h–1) or ghrelin (120 µL h–1, 100 µg day–1). Animals experiencing a short-term (72 h) fast were treated only with R-L solution. In each experimental group, i.c.v. infusions occurred for 3 consecutive days. Immunohistochemistry, in situ hybridisation and real-time reverse transcription quantitative polymerase chain reaction analyses revealed that short-term fasting, as well as exogenous acyl ghrelin administration to standard-fed peripubertal lambs, augmented FSHβ mRNA expression and immunoreactive FSH accumulation. In addition to the effects of ghrelin on FSH synthesis in standard-fed animals, effects on gonadotrophin release were also observed. Acyl ghrelin increased the pulse amplitude for gonadotrophin release, which resulted in an elevation in mean serum FSH concentrations. In conclusion, the present data suggest that ghrelin participates in an endocrine network that modulates gonadotrophic activity in peripubertal female sheep.
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Kluge M. Ghrelin directly affects GnRH neurons: Comment on the review article "Peptides: Basic determinants of reproductive functions". Peptides 2016; 75:121. [PMID: 26382063 DOI: 10.1016/j.peptides.2015.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/07/2015] [Indexed: 11/23/2022]
Affiliation(s)
- Michael Kluge
- Department of Psychiatry and Psychotherapy, University of Leipzig, Semmelweisstr. 10, 04103 Leipzig, Germany.
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Wittekind DA, Kluge M. Ghrelin in psychiatric disorders - A review. Psychoneuroendocrinology 2015; 52:176-94. [PMID: 25459900 DOI: 10.1016/j.psyneuen.2014.11.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 11/13/2014] [Accepted: 11/13/2014] [Indexed: 12/21/2022]
Abstract
Ghrelin is a 28-amino-acid peptide hormone, first described in 1999 and broadly expressed in the organism. As the only known orexigenic hormone secreted in the periphery, it increases hunger and appetite, promoting food intake. Ghrelin has also been shown to be involved in various physiological processes being regulated in the central nervous system such as sleep, mood, memory and reward. Accordingly, it has been implicated in a series of psychiatric disorders, making it subject of increasing investigation, with knowledge rapidly accumulating. This review aims at providing a concise yet comprehensive overview of the role of ghrelin in psychiatric disorders. Ghrelin was consistently shown to exert neuroprotective and memory-enhancing effects and alleviated psychopathology in animal models of dementia. Few human studies show a disruption of the ghrelin system in dementia. It was also shown to play a crucial role in the pathophysiology of addictive disorders, promoting drug reward, enhancing drug seeking behavior and increasing craving in both animals and humans. Ghrelin's exact role in depression and anxiety is still being debated, as it was shown to both promote and alleviate depressive and anxiety-behavior in animal studies, with an overweight of evidence suggesting antidepressant effects. Not surprisingly, the ghrelin system is also implicated in eating disorders, however its exact role remains to be elucidated. Its widespread involvement has made the ghrelin system a promising target for future therapies, with encouraging findings in recent literature.
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Affiliation(s)
| | - Michael Kluge
- Department of Psychiatry and Psychotherapy, University of Leipzig, Leipzig, Germany
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Abstract
Anorexia nervosa is prevalent in adolescents and young adults, and endocrine changes include hypothalamic amenorrhoea; a nutritionally acquired growth-hormone resistance leading to low concentrations of insulin-like growth factor-1 (IGF-1); relative hypercortisolaemia; decreases in leptin, insulin, amylin, and incretins; and increases in ghrelin, peptide YY, and adiponectin. These changes in turn have harmful effects on bone and might affect neurocognition, anxiety, depression, and the psychopathology of anorexia nervosa. Low bone-mineral density (BMD) is particularly concerning, because it is associated with changes in bone microarchitecture, strength, and clinical fractures. Recovery leads to improvements in many--but not all--hormonal changes, and deficits in bone accrual can persist. Oestrogen-replacement therapy, primarily via the transdermal route, increases BMD in adolescents, although catch-up is incomplete. In adults, oral oestrogen--combined with recombinant human IGF-1 in one study and bisphosphonates in another--increased BMD, but not to the normal range. More studies are necessary to investigate the optimum therapeutic approach in patients with, or recovering from, anorexia nervosa.
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Affiliation(s)
- Madhusmita Misra
- Neuroendocrine Unit and Pediatric Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
| | - Anne Klibanski
- Neuroendocrine Unit and Pediatric Endocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Gahete MD, Rincón-Fernández D, Villa-Osaba A, Hormaechea-Agulla D, Ibáñez-Costa A, Martínez-Fuentes AJ, Gracia-Navarro F, Castaño JP, Luque RM. Ghrelin gene products, receptors, and GOAT enzyme: biological and pathophysiological insight. J Endocrinol 2014; 220:R1-24. [PMID: 24194510 DOI: 10.1530/joe-13-0391] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ghrelin is a 28-amino acid acylated hormone, highly expressed in the stomach, which binds to its cognate receptor (GHSR1a) to regulate a plethora of relevant biological processes, including food intake, energy balance, hormonal secretions, learning, inflammation, etc. However, ghrelin is, in fact, the most notorious component of a complex, intricate regulatory system comprised of a growing number of alternative peptides (e.g. obestatin, unacylated ghrelin, and In1-ghrelin, etc.), known (GHSRs) and, necessarily unknown receptors, as well as modifying enzymes (e.g. ghrelin-O-acyl-transferase), which interact among them as well as with other regulatory systems in order to tightly modulate key (patho)-physiological processes. This multiplicity of functions and versatility of the ghrelin system arise from a dual, genetic and functional, complexity. Importantly, a growing body of evidence suggests that dysregulation in some of the components of the ghrelin system can lead to or influence the development and/or progression of highly concerning pathologies such as endocrine-related tumors, inflammatory/cardiovascular diseases, and neurodegeneration, wherein these altered components could be used as diagnostic, prognostic, or therapeutic targets. In this context, the aim of this review is to integrate and comprehensively analyze the multiple components and functions of the ghrelin system described to date in order to define and understand its biological and (patho)-physiological significance.
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Affiliation(s)
- Manuel D Gahete
- Department of Cell Biology, Physiology and Immunology, Campus Universitario de Rabanales, Edificio Severo Ochoa (C6), Planta 3, University of Córdoba, 14014-Córdoba; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), University of Córdoba; Reina Sofia University Hospital, Córdoba; and CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Córdoba, Spain
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Paslakis G, Buchmann AF, Westphal S, Banaschewski T, Hohm E, Zimmermann US, Laucht M, Deuschle M. Intrauterine exposure to cigarette smoke is associated with increased ghrelin concentrations in adulthood. Neuroendocrinology 2014; 99:123-9. [PMID: 24821310 DOI: 10.1159/000363325] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 04/29/2014] [Indexed: 11/19/2022]
Abstract
BACKGROUND The appetite-stimulating hormone ghrelin is a fundamental regulator of human energy metabolism. A series of studies support the notion that long-term appetite and weight regulation may be already programmed in early life and it could be demonstrated that the intrauterine environment affects the ghrelin system of the offspring. Animal studies have also shown that intrauterine programming of orexigenic systems persists even until adolescence/adulthood. METHODS We hypothesized that plasma ghrelin concentrations in adulthood may be associated with the intrauterine exposure to cigarette smoke. We examined this hypothesis in a sample of 19-year-olds followed up since birth in the framework of the Mannheim Study of Children at Risk, an ongoing epidemiological cohort study of the long-term outcome of early risk factors. RESULTS As a main finding, we found that ghrelin plasma concentrations in young adults who had been exposed to cigarette smoke in utero were significantly higher than in those without prenatal smoke exposure. Moreover, individuals with intrauterine nicotine exposure showed a significantly higher prevalence of own smoking habits and lower educational status compared to those in the group without exposure. CONCLUSION Smoking during pregnancy may be considered as an adverse intrauterine influence that may alter the endocrine-metabolic status of the offspring even until early adulthood.
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Affiliation(s)
- Georgios Paslakis
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany
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18
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Comninos AN, Jayasena CN, Dhillo WS. The relationship between gut and adipose hormones, and reproduction. Hum Reprod Update 2013; 20:153-74. [PMID: 24173881 DOI: 10.1093/humupd/dmt033] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Reproductive function is tightly regulated by nutritional status. Indeed, it has been well described that undernutrition or obesity can lead to subfertility or infertility in humans. The common regulatory pathways which control energy homeostasis and reproductive function have, to date, been poorly understood due to limited studies or inconclusive data. However, gut hormones and adipose tissue hormones have recently emerged as potential regulators of both energy homeostasis and reproductive function. METHODS A PubMed search was performed using keywords related to gut and adipose hormones and associated with keywords related to reproduction. RESULTS Currently available evidence that gut (ghrelin, obestatin, insulin, peptide YY, glucagon-like peptide-1, glucose-dependent insulinotropic peptide, oxyntomodulin, cholecystokinin) and adipose hormones (leptin, adiponectin, resistin, omentin, chemerin) interact with the reproductive axis is presented. The extent, site and direction of their effects on the reproductive axis are variable and also vary depending on species, sex and pubertal stage. CONCLUSIONS Gut and adipose hormones interact with the reproductive axis as well as with each other. While leptin and insulin have stimulatory effects and ghrelin has inhibitory effects on hypothalamic GnRH secretion, there is increasing evidence for their roles in other sites of the reproductive axis as well as evidence for the roles of other gut and adipose hormones in the complex interplay between nutrition and reproduction. As our understanding improves, so will our ability to identify and design novel therapeutic options for reproductive disorders and accompanying metabolic disorders.
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Affiliation(s)
- Alexander N Comninos
- Department of Investigative Medicine, Imperial College London, 6th Floor Commonwealth Building, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK
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Kluge M, Schmidt D, Uhr M, Steiger A. Ghrelin suppresses nocturnal secretion of luteinizing hormone (LH) and thyroid stimulating hormone (TSH) in patients with major depression. J Psychiatr Res 2013; 47:1236-9. [PMID: 23726373 DOI: 10.1016/j.jpsychires.2013.05.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 04/29/2013] [Accepted: 05/13/2013] [Indexed: 11/27/2022]
Abstract
Major depression is associated with various endocrine disturbances. Apart from the well-known hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, also the function of the hypothalamic-pituitary-gonadal (HPG) axis and of the hypothalamic-pituitary-thyroid (HPT) axis may be altered compared to healthy subjects. The orexigenic hormone ghrelin is involved in mood regulation and may have antidepressant effects. In addition, it has been shown to suppress secretion of luteinizing hormone (LH) and thyroid stimulating hormone (TSH) in healthy subjects. Aim of this study was therefore to test the effect of ghrelin on the activity of the HPG and HPT axis in patients with major depression. Therefore, secretion profiles of LH and TSH were determined in 14 unmedicated patients with major depression (7 women) twice, receiving 50 μg ghrelin or placebo at 2200, 2300, 0000, and 0100 h. LH secretion after ghrelin injection as assessed by the AUC (4.05 ± 1.18 mlIU min/ml) was significantly (P = 0.049) lower than after placebo injection (4.75 ± 1.33 mlIU min/ml) during the predefined intervention period (2220-0200 h). In addition, LH pulses occurred significantly (P = 0.045) less frequently after ghrelin injection (3.2 ± 1.4) than after placebo injection (3.9 ± 1.7). Mean TSH plasma levels were significantly lower at 0240 h and from 0320 until 0420 h after ghrelin injection than after placebo injection. In conclusion, ghrelin suppressed nocturnal secretion of LH and TSH in patients with major depression. However, these effects were weaker than previously shown in healthy subjects.
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Affiliation(s)
- Michael Kluge
- Max Planck Institute of Psychiatry, Munich, Germany.
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Human ghrelin decreases pituitary response to GnRH in superovulated ewes. Theriogenology 2013; 80:262-8. [PMID: 23664792 DOI: 10.1016/j.theriogenology.2013.04.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/07/2013] [Accepted: 04/08/2013] [Indexed: 12/16/2022]
Abstract
In addition to its metabolic role, ghrelin has been found to suppress luteinizing hormone secretion in many species acting mainly at the hypothalamic level. The objectives of the present study were to test the hypothesis that besides its effects on the hypothalamic level, ghrelin exerts a direct action on the pituitary. Twelve cycling ewes were synchronized, using progestagen intravaginal sponges and superovulated using eCG. At the time of sponge withdrawal, animals were allocated into two groups, ghrelin-treated (Gh) and control. Two days after the sponge removal, GnRH was given to synchronize ovulations. Simultaneously with GnRH treatment, animals of the Gh group received the first of four treatments of acylated human ghrelin at a dose of 6 μg/kg body weight iv; three additional treatments of ghrelin iv were given every 15 minutes thereafter. Control animals received saline iv. Blood samples were collected before challenge (-30 and 0 minutes) and at 30, 60, 75, 90, 105, 120, 135, 150, and 180 minutes after GnRH treatment, and were analyzed for LH, FSH, estradiol, progesterone, insulin, and insulin-like growth factor-I concentrations. Ghrelin treatment attenuated GnRH-induced a preovulatory surge of both gonadotrophins, with the effect being greater for LH. No difference was detected for insulin, estradiol, and progesterone concentrations, and insulin-like growth factor-I levels were increased in the Gh group. Our results imply that in sheep, ghrelin conducts specific regulatory effects on the GnRH/LH axis, and provide for the first time strong evidence that besides its central action, ghrelin might regulate gonadotrophin release acting at the pituitary level.
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21
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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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Ishitobi Y, Kohno K, Kanehisa M, Inoue A, Imanaga J, Maruyama Y, Ninomiya T, Higuma H, Okamoto S, Tanaka Y, Tsuru J, Hanada H, Isogawa K, Akiyoshi J. Serum ghrelin levels and the effects of antidepressants in major depressive disorder and panic disorder. Neuropsychobiology 2013; 66:185-92. [PMID: 22948519 DOI: 10.1159/000339948] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 06/08/2012] [Indexed: 11/19/2022]
Abstract
BACKGROUND Two opposing models for the action of ghrelin in the behavioral responses to stress were recently proposed. Some studies suggest that an increase in ghrelin contributes to the mechanisms responsible for the development of stress-induced depression and anxiety, while others suggest that it helps minimize what otherwise would be more severe manifestations of depression and anxiety following stress. METHODS We measured serum ghrelin levels, Profile of Mood States (POMS) scores and State-Trait Anxiety Inventory scores in nonresponders (treatment-resistant patients; 30) and responders (38) with major depressive disorder (MDD), nonresponders (29) and responders (51) with panic disorder and 97 healthy controls. RESULTS The ghrelin concentration in nonresponders with MDD was higher than that of responders with MDD and normal controls. The ghrelin concentration in nonresponders with panic disorder was higher than that of normal controls. POMS vigor scores in patients with MDD and panic disorder were significantly decreased compared with those in healthy controls. Other POMS scores in patients with MDD and panic disorder were significantly increased compared with those of healthy controls. Trait and state anxiety of the State-Trait Anxiety Inventory in MDD and panic disorder patients were higher than those in healthy controls. CONCLUSIONS These results indicate that decreased serum ghrelin levels might be associated with antidepressant treatment to confer the maximum therapeutic effect in patients with MDD and panic disorder.
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Affiliation(s)
- Yoshinobu Ishitobi
- Department of Neuropsychiatry, Oita University Faculty of Medicine, Oita, Japan
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Kluge M, Schüssler P, Schmidt D, Uhr M, Steiger A. Ghrelin suppresses secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in women. J Clin Endocrinol Metab 2012; 97:E448-51. [PMID: 22259063 DOI: 10.1210/jc.2011-2607] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Ghrelin has been shown to suppress secretion of LH and, less regularly, of FSH in male and female animals and human males. However, no such evidence exists for human females. OBJECTIVE The aim was to study the effect of ghrelin on secretion of LH and FSH in women. DESIGN/PARTICIPANTS/INTERVENTION: Nocturnal (2000-0700 h) secretion profiles of LH and FSH were determined in six healthy women (age, 25.5±2.9 yr) twice, receiving 50 μg ghrelin or placebo at 2200, 2300, 2400, and 0100 h in this single-blind, randomized, crossover study. RESULTS LH secretion after ghrelin injection as assessed by the area under the curve (4.01±1.37 mIU/min·ml) was significantly (P=0.031) lower than after placebo injection (5.46±1.33 mIU/min·ml). Also, FSH secretion after ghrelin injection (5.54±0.64 mIU/min·ml) was significantly (P=0.038) lower than after placebo injection (5.87±0.56 mIU/min·ml). LH pulses occurred significantly (P=0.007) less frequently after ghrelin injection (2.3±0.5) than after placebo injection (3.8±0.9). Accordingly, the interval between first and second LH pulse after treatment was significantly (P=0.002) longer after ghrelin injection (300±86 min) than after placebo injection (187±60 min). One of the six women exhibited clear FSH pulses, which overall paralleled LH pulses; two FSH and LH pulses occurred after ghrelin injection, but three occurred after placebo in this woman. CONCLUSIONS This is the first report that ghrelin suppresses the secretion of LH and FSH in women. These findings resemble those in male and female animals and in men.
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Affiliation(s)
- Michael Kluge
- Max Planck Institute of Psychiatry, Munich, Germany.
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Puechagut PB, Martini AC, Stutz G, Santillán ME, Luque EM, Fiol de Cuneo M, Ruiz RD, Vincenti LM. Reproductive performance and fertility in male and female adult mice chronically treated with hexarelin. Reprod Fertil Dev 2012; 24:451-60. [DOI: 10.1071/rd11009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Accepted: 07/06/2011] [Indexed: 01/08/2023] Open
Abstract
Hexarelin (HEXr), a synthetic ghrelin analogue, has been associated with modifications of reproductive physiology. In previous studies of adult mice, we detected that HEXr induced significantly reduced ovulation rate and significant correlation coefficients between sexual maturation and corporal weight in offspring. In this study, we investigated the effects of chronic HEXr administration on sperm concentration and functional activity, oestrous cyclicity and pregnancy index, in addition to the number of fetuses and its correlation with the number of corpora lutea. Adult Albino swiss mice were injected (sc) daily with HEXr: 100 μg kg–1 day–1 (HEXr D1) or 200 μg kg–1 day–1 (HEXr D2) for 53 days in males and 30 days in females. We detected a significantly decreased ratio in the number of fetuses per corpora lutea in females treated with HEXr D2 for 30 days before mating and during the first 6 days of pregnancy, in addition to a downward trend in the pregnancy index and percentage of females impregnated by each male treated with both doses of the analogue. Although we did not find any significant effect on additional parameters evaluated in both genders, we propose certain effects of HEXr on the implantation process and/or early development of embryos and over the in vivo reproductive capability of males.
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Muccioli G, Lorenzi T, Lorenzi M, Ghè C, Arnoletti E, Raso GM, Castellucci M, Gualillo O, Meli R. Beyond the metabolic role of ghrelin: a new player in the regulation of reproductive function. Peptides 2011; 32:2514-21. [PMID: 22074955 DOI: 10.1016/j.peptides.2011.10.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 10/23/2011] [Accepted: 10/23/2011] [Indexed: 11/30/2022]
Abstract
Ghrelin is a gastric peptide, discovered by Kojima et al. (1999) [55] as a result of the search for an endogenous ligand interacting with the "orphan receptor" GHS-R1a (growth hormone secretagogue receptor type 1a). Ghrelin is composed of 28 aminoacids and is produced mostly by specific cells of the stomach, by the hypothalamus and hypophysis, even if its presence, as well as that of its receptors, has been demonstrated in many other tissues, not least in gonads. Ghrelin potently stimulates GH release and participates in the regulation of energy homeostasis, increasing food intake, decreasing energy output and exerting a lipogenetic effect. Furthermore, ghrelin influences the secretion and motility of the gastrointestinal tract, especially of the stomach, and, above all, profoundly affects pancreatic functions. Despite of these previously envisaged activities, it has recently been hypothesized that ghrelin regulates several aspects of reproductive physiology and pathology. In conclusion, ghrelin not only cooperates with other neuroendocrine factors, such as leptin, in the modulation of energy homeostasis, but also has a crucial role in the regulation of the hypothalamic-pituitary gonadal axis. In the current review we summarize the main targets of this gastric peptide, especially focusing on the reproductive system.
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Affiliation(s)
- Giampiero Muccioli
- Department of Drug Science and Technology, Division of Medical Pharmacology, University of Torino, Via P. Giuria 13, 10125 Torino, Italy
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Homocysteine and ghrelin link with polcystic ovary syndrome in relation to obesity. J Pediatr Adolesc Gynecol 2011; 24:211-7. [PMID: 21458334 DOI: 10.1016/j.jpag.2011.02.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Revised: 02/03/2011] [Accepted: 02/04/2011] [Indexed: 01/01/2023]
Abstract
AIM Elevated levels of plasma homocysteine and depressed ghrelin levels have been found to be associated with insulin resistance in a number of clinical situations, such as polycystic ovary syndrome. This study was designed to determine the relationship of plasma homocysteine and ghrelin levels with obesity in polycystic ovary syndrome. MATERIAL AND METHODS Forty-four adolescents and young women (24 lean, 20 obese) 16-21 years old with polycystic ovary syndrome and age matched 20 healthy adolescents and young women were participated the study. Fasting samples were collected for serum vitamin B12, folate, plasma total homocysteine and ghrelin levels. Serum levels of follicle-stimulating hormone, luteinizing hormone, dehydroepiandrosterone sulfate, insulin, 17-hydroxyprogesterone, free testosterone, sex-hormone binding globulin were measured. Also, serum concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides were determined. Oral glucose tolerance test was done, and HOMA-IR index was used to define insulin resistance. RESULTS Plasma total homocysteine levels were significantly higher in women with polycystic ovary syndrome and their plasma ghrelin levels were depressed compared to control group (P < 0.05). Obese adolescents with polycystic ovary syndrome had more depressed plasma ghrelin levels compared to lean ones (P < 0.05). Homocysteine levels didn't correlate with body mass index, but positively correlated with insulin resistance (P < 0.05). CONCLUSION Elevated plasma homocysteine levels in polycystic ovary syndrome was independent from obesity. Adversely ghrelin levels were depressed with polycystic ovary syndrome in relation to obesity.
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Steiger A, Dresler M, Schüssler P, Kluge M. Ghrelin in mental health, sleep, memory. Mol Cell Endocrinol 2011; 340:88-96. [PMID: 21349316 DOI: 10.1016/j.mce.2011.02.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 02/15/2011] [Accepted: 02/15/2011] [Indexed: 01/06/2023]
Abstract
Ghrelin acts as a neuropeptide. It participates in sleep-wake regulation. After systemic ghrelin treatment nonREM sleep is promoted in male humans and mice. This effect is influenced by gender, time of administration and depression. Ghrelin does not modulate sleep in healthy women and during the early morning in male subjects. In depressed women REM sleep is diminished after ghrelin. In elderly men and depressed men sleep promotion by ghrelin was preserved. In rats after central ghrelin feeding and wakefulness increased. The nocturnal secretion pattern of cortisol, GH, LH, FSH and hypothalamo-pituitary-thyroid hormones are influenced by ghrelin. Furthermore ghrelin appears to be related to memory and to be involved in the pathophysiology of CNS disorders, particularly depression.
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Affiliation(s)
- Axel Steiger
- Max Planck Institute of Psychiatry, Munich, Germany.
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Unniappan S. Ghrelin: an emerging player in the regulation of reproduction in non-mammalian vertebrates. Gen Comp Endocrinol 2010; 167:340-3. [PMID: 20005227 DOI: 10.1016/j.ygcen.2009.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 12/04/2009] [Indexed: 11/16/2022]
Abstract
The endocrine regulation of vertebrate reproduction is achieved by the coordinated actions of multiple endocrine factors mainly produced from the brain, pituitary, and gonads. In addition to these, several other tissues including the fat and gut produce factors that have reproductive effects. Ghrelin is one such gut/brain hormone with species-specific effects in the regulation of mammalian reproduction. Recent studies have shown that ghrelin and ghrelin receptor mRNAs, and protein are expressed in the ovary and testis of mammals, indicating a direct effect for ghrelin in the control of reproduction. Ghrelin regulates mammalian reproduction by modulating hormone secretion from the brain and pituitary, and by acting directly on the gonads to influence reproductive tissue development and steroid hormone release. Based on the studies reported so far, ghrelin seems to have a predominantly inhibitory role on mammalian reproduction. The presence of ghrelin and ghrelin receptor has been found in the brain, pituitary and gonads of several non-mammalian vertebrates. In contrast to mammals, ghrelin seems to have a stimulatory role in the regulation of non-mammalian reproduction. The main objective of this review is to do a perspective analysis of the comparative aspects of ghrelin regulation of reproduction.
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Affiliation(s)
- Suraj Unniappan
- Laboratory of Integrative Neuroendocrinology, Department of Biology, York University, 221 Lumbers Building, 4700 Keele Street, Toronto, Ontario, Canada.
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Kluge M, Riedl S, Uhr M, Schmidt D, Zhang X, Yassouridis A, Steiger A. Ghrelin affects the hypothalamus-pituitary-thyroid axis in humans by increasing free thyroxine and decreasing TSH in plasma. Eur J Endocrinol 2010; 162:1059-65. [PMID: 20423986 DOI: 10.1530/eje-10-0094] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Ghrelin promotes a positive energy balance, e.g. by increasing food intake. Stimulation of the activity of the hypothalamus-pituitary-thyroid (HPT) axis promotes a negative energy balance, e.g. by increasing energy expenditure. We therefore hypothesized that ghrelin suppresses the HPT axis in humans, counteracting its energy-saving effect. DESIGN AND METHODS In this single-blind, randomized, cross-over study, we determined secretion patterns of free triiodothyronine (fT(3)), free thyroxine (fT(4)), TSH, and thyroid-binding globulin (TBG) between 2000 and 0700 h in 20 healthy adults (10 males and 10 females, 25.3+/-2.7 years) receiving 50 microg ghrelin or placebo at 2200, 2300, 0000, and 0100 h. RESULTS FT(4) plasma levels were significantly higher after ghrelin administration than after placebo administration from 0000 h until 0620 h except for the time points at 0100, 0520, and 0600 h. TSH plasma levels were significantly lower from 0200 until the end of the study at 0700 h except for the time points at 0540, 0600, and 0620 h. The relative increase of fT(4) (area under the curve (AUC) 0130-0700 h (ng/dl x min): placebo: 1.31+/-0.03; ghrelin: 1.39+/-0.03; P=0.001) was much weaker than the relative decrease of TSH (AUC 0130-0700 h (mIU/ml x min): placebo: 1.74+/-0.12; ghrelin: 1.32+/-0.12; P=0.007). FT(3) and TBG were not affected. CONCLUSIONS This is the first study to report that ghrelin affects the HPT axis in humans. The early fT(4) increase was possibly induced by direct ghrelin action on the thyroid where ghrelin receptors have been identified. The TSH decrease might have been caused by ghrelin-mediated inhibition at hypothalamic level by feedback inhibition through fT(4), or both.
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Affiliation(s)
- Michael Kluge
- Max-Planck Institute of Psychiatry, Kraepelinstrasse 2-10, Munich, Germany.
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Ghrelin increases slow wave sleep and stage 2 sleep and decreases stage 1 sleep and REM sleep in elderly men but does not affect sleep in elderly women. Psychoneuroendocrinology 2010; 35:297-304. [PMID: 19647945 DOI: 10.1016/j.psyneuen.2009.07.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Revised: 06/26/2009] [Accepted: 07/09/2009] [Indexed: 11/20/2022]
Abstract
Ghrelin increases non-REM sleep and decreases REM sleep in young men but does not affect sleep in young women. In both sexes, ghrelin stimulates the activity of the somatotropic and the hypothalamic-pituitary-adrenal (HPA) axis, as indicated by increased growth hormone (GH) and cortisol plasma levels. These two endocrine axes are crucially involved in sleep regulation. As various endocrine effects are age-dependent, aim was to study ghrelin's effect on sleep and secretion of GH and cortisol in elderly humans. Sleep-EEGs (2300-0700 h) and secretion profiles of GH and cortisol (2000-0700 h) were determined in 10 elderly men (64.0+/-2.2 years) and 10 elderly, postmenopausal women (63.0+/-2.9 years) twice, receiving 50 microg ghrelin or placebo at 2200, 2300, 0000, and 0100 h, in this single-blind, randomized, cross-over study. In men, ghrelin compared to placebo was associated with significantly more stage 2 sleep (placebo: 183.3+/-6.1; ghrelin: 221.0+/-12.2 min), slow wave sleep (placebo: 33.4+/-5.1; ghrelin: 44.3+/-7.7 min) and non-REM sleep (placebo: 272.6+/-12.8; ghrelin: 318.2+/-11.0 min). Stage 1 sleep (placebo: 56.9+/-8.7; ghrelin: 50.9+/-7.6 min) and REM sleep (placebo: 71.9+/-9.1; ghrelin: 52.5+/-5.9 min) were significantly reduced. Furthermore, delta power in men was significantly higher and alpha power and beta power were significantly lower after ghrelin than after placebo injection during the first half of night. In women, no effects on sleep were observed. In both sexes, ghrelin caused comparable increases and secretion patterns of GH and cortisol. In conclusion, ghrelin affects sleep in elderly men but not women resembling findings in young subjects.
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Kluge M. Evidence of a suppressive effect of ghrelin on FSH secretion in vivo: Comment on the review article “Ghrelin: A metabolic signal affecting the reproductive system”. Cytokine Growth Factor Rev 2009; 20:339-40. [DOI: 10.1016/j.cytogfr.2009.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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