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Ventura-Aquino E, Paredes RG. Being friendly: paced mating for the study of physiological, behavioral, and neuroplastic changes induced by sexual behavior in females. Front Behav Neurosci 2023; 17:1184897. [PMID: 37840548 PMCID: PMC10568070 DOI: 10.3389/fnbeh.2023.1184897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 09/14/2023] [Indexed: 10/17/2023] Open
Abstract
Paced mating in rats is an experimental condition that allows the evaluation of sexual behavior in a way that closely resembles what occurs in seminatural and natural conditions enabling the female to control the rate of the sexual interaction. In conventional non-paced mating tests, females cannot escape from male approaches, which may lead to an unrewarding overstimulation. Paced mating is an alternative laboratory procedure that improves animal welfare and has a higher ethological relevance. The use of this procedure contributed to the identification of physiological and behavioral factors that favor reproduction. Paced mating includes motivational and behavioral components differentiating quantitative and qualitative characteristics that are critical for the induction of the rewarding properties of mating. These positive consequences ensure that the behavior will be repeated, favoring the species' survival. Sexual reward is an immediate consequence of paced mating, mediated mainly by the endogenous opioid system. Paced mating also induces long-lasting neuroplastic changes, including gene expression, synthesis of proteins, and neurogenesis in sex-relevant brain areas. The interest in paced mating is growing since the complexity of its elements and consequences at different levels in a laboratory setting resembles what occurs in natural conditions. In this review, we analyze the classic studies and recent publications demonstrating the advantages of using paced mating to evaluate different aspects of sexual behavior in females.
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Affiliation(s)
- Elisa Ventura-Aquino
- Escuela Nacional de Estudios Superiores, Unidad Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Raúl G. Paredes
- Escuela Nacional de Estudios Superiores, Unidad Juriquilla, Universidad Nacional Autónoma de México, Querétaro, Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
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2
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Semple EA, Harberson MT, Xu B, Rashleigh R, Cartwright TL, Braun JJ, Custer AC, Liu C, Hill JW. Melanocortin 4 receptor signaling in Sim1 neurons permits sexual receptivity in female mice. Front Endocrinol (Lausanne) 2023; 14:983670. [PMID: 37033219 PMCID: PMC10080118 DOI: 10.3389/fendo.2023.983670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/14/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction Female sexual dysfunction affects approximately 40% of women in the United States, yet few therapeutic options exist for these patients. The melanocortin system is a new treatment target for hypoactive sexual desire disorder (HSDD), but the neuronal pathways involved are unclear. Methods In this study, the sexual behavior of female MC4R knockout mice lacking melanocortin 4 receptors (MC4Rs) was examined. The mice were then bred to express MC4Rs exclusively on Sim1 neurons (tbMC4RSim1 mice) or on oxytocin neurons (tbMC4ROxt mice) to examine the effect on sexual responsiveness. Results MC4R knockout mice were found to approach males less and have reduced receptivity to copulation, as indicated by a low lordosis quotient. These changes were independent of body weight. Lordosis behavior was normalized in tbMC4RSim1 mice and improved in tbMC4ROxt mice. In contrast, approach behavior was unchanged in tbMC4RSim1 mice but greatly increased in tbMC4ROxt animals. The changes were independent of melanocortin-driven metabolic effects. Discussion These results implicate MC4R signaling in Oxt neurons in appetitive behaviors and MC4R signaling in Sim1 neurons in female sexual receptivity, while suggesting melanocortin-driven sexual function does not rely on metabolic neural circuits.
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Affiliation(s)
- Erin A. Semple
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Mitchell T. Harberson
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Baijie Xu
- Center for Hypothalamic Research, University of Texas Southwestern, Dallas, TX, United States
| | - Rebecca Rashleigh
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Tori L. Cartwright
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Jessica J. Braun
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Amy C. Custer
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
| | - Chen Liu
- Center for Hypothalamic Research, University of Texas Southwestern, Dallas, TX, United States
| | - Jennifer W. Hill
- Department of Physiology and Pharmacology, University of Toledo College of Medicine, Toledo, OH, United States
- Center for Diabetes and Endocrine Research, University of Toledo, Toledo, OH, United States
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3
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Hall MAL, Kohut-Jackson AL, Peyla AC, Friedman GD, Simco NJ, Borland JM, Meisel RL. Melanocortin receptor 3 and 4 mRNA expression in the adult female Syrian hamster brain. Front Mol Neurosci 2023; 16:1038341. [PMID: 36910260 PMCID: PMC9995703 DOI: 10.3389/fnmol.2023.1038341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/07/2023] [Indexed: 02/25/2023] Open
Abstract
Melanocortin 3 receptors (MC3R) and melanocortin 4 receptors (MC4R) are vital in regulating a variety of functions across many species. For example, the dysregulation of these receptors results in obesity and dysfunction in sexual behaviors. Only a handful of studies have mapped the expression of MC3R and MC4R mRNA across the central nervous system, with the primary focus on mice and rats. Because Syrian hamsters are valuable models for functions regulated by melanocortin receptors, our current study maps the distribution of MC3R and MC4R mRNA in the Syrian hamster telencephalon, diencephalon, and midbrain using RNAscope. We found that the expression of MC3R mRNA was lowest in the telencephalon and greatest in the diencephalon, whereas the expression of MC4R mRNA was greatest in the midbrain. A comparison of these findings to previous studies found that MC3R and MC4R expression is similar in some brain regions across species and divergent in others. In addition, our study identifies novel brain regions for the expression of MC3Rs and MC4Rs, and identifies cells that co-express bothMC3 and MC4 receptors within certain brain regions.
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Affiliation(s)
- Megan A. L. Hall
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
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4
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Cipriani S, Alfaroli C, Maseroli E, Vignozzi L. An evaluation of bremelanotide injection for the treatment of hypoactive sexual desire disorder. Expert Opin Pharmacother 2023; 24:15-21. [PMID: 36242769 DOI: 10.1080/14656566.2022.2132144] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Female sexual response implies a deep intertwining between psychosocial and neurobiological mediators. Regulation of central melanocortin signaling may enhance sexual desire. In premenopausal women with hypoactive sexual desire disorder (HSDD), melanocortin receptor agonist bremelanotide (Vyleesi) has been hypothesized to trigger excitatory brain pathways. AREAS COVERED Hereby we summarize bremelanotide's proposed mechanism of action, pharmacokinetics, efficacy and safety data derived from clinical trials. A literature search of peer-reviewed publications on the current evidence on the pharmacotherapy with bremelanotide was performed using the PubMed database. EXPERT OPINION Bremelanotide appears to be moderately safe and well-tolerated; the most common adverse reaction is nausea (40%). Although data from clinical trials demonstrated a significant change in validated questionnaires, the overall clinical benefit appears to be modest. However, these results should be interpreted in the light of the dramatic challenges in conducting well-designed clinical trials for female sexual dysfunction, due to the significant placebo effect of pharmacotherapy, and the frequent use of outcome measures that are likely to be highly susceptible to expectation biases, such as long periods of recall of sexual and emotional response.
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Affiliation(s)
- Sarah Cipriani
- Department of Experimental Clinical and Biomedical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Chiara Alfaroli
- Department of Experimental Clinical and Biomedical Sciences Mario Serio, University of Florence, Florence, Italy
| | - Elisa Maseroli
- Andrology, Women's Endocrinology and Gender Incongruence Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
| | - Linda Vignozzi
- Department of Experimental Clinical and Biomedical Sciences Mario Serio, University of Florence, Florence, Italy.,Andrology, Women's Endocrinology and Gender Incongruence Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy.,I.N.B.B. (Istituto Nazionale Biostrutture e Biosistemi), Rome, Italy
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5
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Karigo T, Deutsch D. Flexibility of neural circuits regulating mating behaviors in mice and flies. Front Neural Circuits 2022; 16:949781. [PMID: 36426135 PMCID: PMC9679785 DOI: 10.3389/fncir.2022.949781] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 07/28/2022] [Indexed: 11/11/2022] Open
Abstract
Mating is essential for the reproduction of animal species. As mating behaviors are high-risk and energy-consuming processes, it is critical for animals to make adaptive mating decisions. This includes not only finding a suitable mate, but also adapting mating behaviors to the animal's needs and environmental conditions. Internal needs include physical states (e.g., hunger) and emotional states (e.g., fear), while external conditions include both social cues (e.g., the existence of predators or rivals) and non-social factors (e.g., food availability). With recent advances in behavioral neuroscience, we are now beginning to understand the neural basis of mating behaviors, particularly in genetic model organisms such as mice and flies. However, how internal and external factors are integrated by the nervous system to enable adaptive mating-related decision-making in a state- and context-dependent manner is less well understood. In this article, we review recent knowledge regarding the neural basis of flexible mating behaviors from studies of flies and mice. By contrasting the knowledge derived from these two evolutionarily distant model organisms, we discuss potential conserved and divergent neural mechanisms involved in the control of flexible mating behaviors in invertebrate and vertebrate brains.
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Affiliation(s)
- Tomomi Karigo
- Kennedy Krieger Institute, Baltimore, MD, United States,The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States,*Correspondence: Tomomi Karigo,
| | - David Deutsch
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel,David Deutsch,
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6
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Yuan XC, Tao YX. Ligands for Melanocortin Receptors: Beyond Melanocyte-Stimulating Hormones and Adrenocorticotropin. Biomolecules 2022; 12:biom12101407. [PMID: 36291616 PMCID: PMC9599618 DOI: 10.3390/biom12101407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
The discovery of melanocortins in 1916 has resulted in more than 100 years of research focused on these peptides. Extensive studies have elucidated well-established functions of melanocortins mediated by cell surface receptors, including MSHR (melanocyte-stimulating hormone receptor) and ACTHR (adrenocorticotropin receptor). Subsequently, three additional melanocortin receptors (MCRs) were identified. Among these five MCRs, MC3R and MC4R are expressed primarily in the central nervous system, and are therefore referred to as the neural MCRs. Since the central melanocortin system plays important roles in regulating energy homeostasis, targeting neural MCRs is emerging as a therapeutic approach for treating metabolic conditions such as obesity and cachexia. Early efforts modifying endogenous ligands resulted in the development of many potent and selective ligands. This review focuses on the ligands for neural MCRs, including classical ligands (MSH and agouti-related peptide), nonclassical ligands (lipocalin 2, β-defensin, small molecules, and pharmacoperones), and clinically approved ligands (ACTH, setmelanotide, bremelanotide, and several repurposed drugs).
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Affiliation(s)
- Xiao-Chen Yuan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230061, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Correspondence:
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Pfaus JG. Politics of Sexual Desire. CURRENT SEXUAL HEALTH REPORTS 2022. [DOI: 10.1007/s11930-022-00335-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women. CNS Spectr 2022; 27:281-289. [PMID: 33455598 DOI: 10.1017/s109285292100002x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hypoactive sexual desire disorder (HSDD) is a common female sexual dysfunction and is estimated to affect approximately 10% of women in the United States. It has been suggested that HSDD is associated with an imbalance of hormone and neurotransmitter levels in the brain, resulting in decreased excitation, increased inhibition, or a combination of both. Evidence suggests neurotransmitters, including dopamine (DA), norepinephrine, and serotonin, as well as hormones such as estradiol and testosterone, contribute to female sexual desire and response. Current treatments for HSDD include psychotherapy, and two US Food and Drug Administration-approved medications for premenopausal women: flibanserin, a serotonin mixed agonist and antagonist, and bremelanotide, a melanocortin receptor (MCR) agonist. Melanocortins are endogenous neuropeptides associated with the excitatory pathway of the female sexual response system. MCRs are found throughout the body, including the brain. Bremelanotide is an MCR agonist that nonselectively activates several of the receptor subtypes, of which subtype 4 (MC4R) is the most relevant at therapeutic doses. MC4R is predominantly expressed in the medial preoptic area (mPOA) of the hypothalamus in the brain, and is important for female sexual function. Animal studies suggest that bremelanotide may affect female sexual desire by activating presynaptic MC4Rs on neurons in the mPOA of the hypothalamus, leading to increased release of DA, an excitatory neurotransmitter that increases sexual desire. This review presents what is known about the mechanism of action of bremelanotide in the context of treating HSDD.
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9
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Ågmo A, Laan E. Sexual incentive motivation, sexual behavior, and general arousal: Do rats and humans tell the same story? Neurosci Biobehav Rev 2022; 135:104595. [PMID: 35231490 DOI: 10.1016/j.neubiorev.2022.104595] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 01/28/2022] [Accepted: 02/24/2022] [Indexed: 12/13/2022]
Abstract
Sexual incentive stimuli activate sexual motivation and heighten the level of general arousal. The sexual motive may induce the individual to approach the incentive, and eventually to initiate sexual acts. Both approach and the ensuing copulatory interaction further enhance general arousal. We present data from rodents and humans in support of these assertions. We then suggest that orgasm is experienced when the combined level of excitation surpasses a threshold. In order to analyze the neurobiological bases of sexual motivation, we employ the concept of a central motive state. We then discuss the mechanisms involved in the long- and short-term control of that state as well as those mediating the momentaneous actions of sexual incentive stimuli. This leads to an analysis of the neurobiology behind the interindividual differences in responsivity of the sexual central motive state. Knowledge is still fragmentary, and many contradictory observations have been made. Nevertheless, we conclude that the basic mechanisms of sexual motivation and the role of general arousal are similar in rodents and humans.
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Affiliation(s)
- Anders Ågmo
- Department of Psychology, University of Tromsø, Norway.
| | - Ellen Laan
- Department of Sexology and Psychosomatic Gynaecology, Amsterdam UMC, University of Amsterdam, The Netherlands
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10
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Clayton AH, Kingsberg SA, Portman D, Sadiq A, Krop J, Jordan R, Lucas J, Simon JA. Safety Profile of Bremelanotide Across the Clinical Development Program. J Womens Health (Larchmt) 2022; 31:171-182. [PMID: 35147466 DOI: 10.1089/jwh.2021.0191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Bremelanotide, a melanocortin receptor agonist, is Food and Drug Administration (FDA)-approved for the treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder. Methods: Review of bremelanotide's safety profile from the clinical development program (phases 1 through 3). Results: The clinical development program comprised 3500 subjects in 43 completed studies. In the phase 3 studies, subjects took bremelanotide for up to 18 months. The most common adverse events (AEs) were nausea (40.0% vs. 1.3%), flushing (20.3% vs. 1.3%), headache (11.3% vs. 1.9%), and injection site reactions (5.4 vs. 0.5), bremelanotide versus placebo groups, respectively, in the integrated double-blind portion of the phase 3 studies (N = 1247). Nausea was the most common reason for bremelanotide discontinuation. There were no deaths; a few subjects experienced serious AEs. Focal hyperpigmentation was rare when bremelanotide was dosed in accordance with label recommendations, but it occurred in more than one-third of subjects following up to 16 consecutive daily dosings. Small and transient but statistically significant blood pressure increases were observed during ambulatory blood pressure monitoring. Most drug-drug interactions were not clinically significant, except for interactions that lowered plasma concentrations of indomethacin and naltrexone. In the double-blind portion of the integrated phase 3 studies, 70% of the bremelanotide group proceeded to the open-label phase of the studies versus 87% of those on placebo. Conclusions: The AEs associated with bremelanotide are mostly mild to moderate. Although not deemed clinically important, bremelanotide should be used with caution in patients at risk of cardiovascular disease, and blood pressure should be well controlled during treatment. Clinical Trial Registration number: NCT02333071 [Study 301] and NCT02338960 [Study 302].
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Affiliation(s)
- Anita H Clayton
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia, USA
| | - Sheryl A Kingsberg
- Department of Reproductive Biology and Department of Psychiatry, University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA
| | | | - Amama Sadiq
- AMAG Pharmaceuticals, Inc., Waltham, Massachusetts, USA
| | - Julie Krop
- AMAG Pharmaceuticals, Inc., Waltham, Massachusetts, USA
| | - Robert Jordan
- Palatin Technologies, Inc., Cranbury, New Jersey, USA
| | - Johna Lucas
- Palatin Technologies, Inc., Cranbury, New Jersey, USA
| | - James A Simon
- George Washington University and IntimMedicine™ Specialists, Washington, District of Columbia, USA
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11
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Oestrogen engages brain MC4R signalling to drive physical activity in female mice. Nature 2021; 599:131-135. [PMID: 34646010 PMCID: PMC9113400 DOI: 10.1038/s41586-021-04010-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 09/09/2021] [Indexed: 12/30/2022]
Abstract
Oestrogen depletion in rodents and humans leads to inactivity, fat accumulation and diabetes1,2, underscoring the conserved metabolic benefits of oestrogen that inevitably decrease with age. In rodents, the preovulatory surge in 17β-oestradiol (E2) temporarily increases energy expenditure to coordinate increased physical activity with peak sexual receptivity. Here we report that a subset of oestrogen-sensitive neurons in the ventrolateral ventromedial hypothalamic nucleus (VMHvl)3-7 projects to arousal centres in the hippocampus and hindbrain, and enables oestrogen to rebalance energy allocation in female mice. Surges in E2 increase melanocortin-4 receptor (MC4R) signalling in these VMHvl neurons by directly recruiting oestrogen receptor-α (ERα) to the Mc4r gene. Sedentary behaviour and obesity in oestrogen-depleted female mice were reversed after chemogenetic stimulation of VMHvl neurons expressing both MC4R and ERα. Similarly, a long-term increase in physical activity is observed after CRISPR-mediated activation of this node. These data extend the effect of MC4R signalling - the most common cause of monogenic human obesity8 - beyond the regulation of food intake and rationalize reported sex differences in melanocortin signalling, including greater disease severity of MC4R insufficiency in women9. This hormone-dependent node illuminates the power of oestrogen during the reproductive cycle in motivating behaviour and maintaining an active lifestyle in women.
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Yeo GSH, Chao DHM, Siegert AM, Koerperich ZM, Ericson MD, Simonds SE, Larson CM, Luquet S, Clarke I, Sharma S, Clément K, Cowley MA, Haskell-Luevano C, Van Der Ploeg L, Adan RAH. The melanocortin pathway and energy homeostasis: From discovery to obesity therapy. Mol Metab 2021; 48:101206. [PMID: 33684608 PMCID: PMC8050006 DOI: 10.1016/j.molmet.2021.101206] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 02/28/2021] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
Background Over the past 20 years, insights from human and mouse genetics have illuminated the central role of the brain leptin-melanocortin pathway in controlling mammalian food intake, with genetic disruption resulting in extreme obesity, and more subtle polymorphic variations influencing the population distribution of body weight. At the end of 2020, the U.S. Food and Drug Administration (FDA) approved setmelanotide, a melanocortin 4 receptor agonist, for use in individuals with severe obesity due to either pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency. Scope of review Herein, we chart the melanocortin pathway's history, explore its pharmacology, genetics, and physiology, and describe how a neuropeptidergic circuit became an important druggable obesity target. Major conclusions Unravelling the genetics of the subset of severe obesity has revealed the importance of the melanocortin pathway in appetitive control; coupling this with studying the molecular pharmacology of compounds that bind melanocortin receptors has brought a new obesity drug to the market. This process provides a drug discovery template for complex disorders, which for setmelanotide took 25 years to transform from a single gene into an approved drug.
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Affiliation(s)
- Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | | | - Anna-Maria Siegert
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Zoe M Koerperich
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Mark D Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Stephanie E Simonds
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Courtney M Larson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, Paris, France.
| | - Iain Clarke
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia.
| | | | - Karine Clément
- Assistance Publique Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, Paris, France, Sorbonne Université, INSERM, Nutrition and Obesity: Systemic Approaches (NutriOmics) Research Unit, Paris, France.
| | - Michael A Cowley
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | | | - Roger A H Adan
- Department of Translational Neuroscience, UMCU Brain Centre, University Medical Centre Utrecht, Utrecht University, the Netherlands; Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden.
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13
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Kling JM, Faubion SS, Kapoor E. Sexual Health in Women. J Womens Health (Larchmt) 2020; 30:301-304. [PMID: 32898453 DOI: 10.1089/jwh.2020.8730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Juliana M Kling
- Division of Women's Health Internal Medicine, Mayo Clinic, Scottsdale, Arizona, USA.,Center for Women's Health, Mayo Clinic, Rochester, Minnesota, USA
| | - Stephanie S Faubion
- Center for Women's Health, Mayo Clinic, Rochester, Minnesota, USA.,Divisions of General Internal Medicine and Diabetes, Metabolism, and Nutrition, Mayo Clinic, Jacksonville, Florida, USA
| | - Ekta Kapoor
- Center for Women's Health, Mayo Clinic, Rochester, Minnesota, USA.,Divisions of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Jacksonville, Florida, USA.,Division of General Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA
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14
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Prescott H, Khan I. Medicinal plants/herbal supplements as female aphrodisiacs: Does any evidence exist to support their inclusion or potential in the treatment of FSD? JOURNAL OF ETHNOPHARMACOLOGY 2020; 251:112464. [PMID: 31881322 DOI: 10.1016/j.jep.2019.112464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/15/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Female Sexual Dysfunction is a complex condition with biopsychosocial origins. Plants traditionally used as aphrodisiacs may be promising as routes to develop therapeutic options which are lacking. AIM To distinguish the plants commonly used in (AP) on the market in the United States, and to evaluate their ethnobotanical and clinical evidence as a basis for their inclusion. METHODS This study is a narrative review of 53 species commonly found in AP on the market in the United States. Most species listed have anecdotal use as aphrodisiacs throughout history; therefore, a systematic search was done for clinical evidence. The primary outcome assessed is the clinical efficacy of plants in the treatment of libido desire disorders. RESULTS There is little to no evidence from the literature to substantiate claims of plants currently on the market as AP for female libido desire disorders. CONCLUSIONS The biggest problem in the literature is the lack of botanical verification and consistency in material across studies. Any botanical, commercial or otherwise must be tested for chemical markers exhibited by individual species; however, if no markers exist, work must first be done to determine these. Appropriate analytical techniques for this would include high pressure liquid chromatography, and mass spectroscopy. It would also be sufficient to taxonomically authenticate species provided the plant material. Further research should aim to standardize plant material and extraction methods utilized in order to compare studies effectively and allow for reproducibility to draw conclusions. While clear interest into investigation the aphrodisiac potential of plants exists, a translatable in vivo animal model does not. Clinical trials rely on patient reported outcomes to determine efficacy but cost and length of such trials deem a necessity for development of an animal model to first screen botanicals. We suggest development of screening tools utilizing the evident neurobiological underpinnings of FSD as the first step. In general, studies of plants currently used as ingredients for AP are severely lacking, and even so the evidence that exists is weak.
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Affiliation(s)
- Hayley Prescott
- The University of Mississippi, School of Pharmacy, 1558 University Circle, P.O. Box 1848, University, MS, 38677, United States.
| | - Ikhlas Khan
- The University of Mississippi, School of Pharmacy, 1558 University Circle, P.O. Box 1848, University, MS, 38677, United States.
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Abstract
Bremelanotide significantly improves sexual desire and related distress in premenopausal women with hypoactive sexual distress disorder and has a favorable safety profile. To evaluate the safety and efficacy of bremelanotide for the treatment of premenopausal women with hypoactive sexual desire disorder.
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Abstract
The 52-week open-label extension of the RECONNECT studies demonstrates bremelanotide's favorable safety profile, with sustained efficacy in treating hypoactive sexual desire disorder in premenopausal women. To evaluate the long-term safety and efficacy of bremelanotide as treatment for hypoactive sexual desire disorder in premenopausal women.
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Abstract
Erectile dysfunction is a common condition of men in middle and older ages. Twin studies suggest that about one-third of the risk is due to genetic factors, independent of other known erectile dysfunction risk factors. However, studies that have searched for specific genetic contributors have been limited due to small sample sizes, candidate gene approaches, and weak phenotyping. As a result, there are no confirmed genetic risk factors for erectile dysfunction. This study finds a specific genetic cause for erectile dysfunction. Erectile dysfunction affects millions of men worldwide. Twin studies support the role of genetic risk factors underlying erectile dysfunction, but no specific genetic variants have been identified. We conducted a large-scale genome-wide association study of erectile dysfunction in 36,649 men in the multiethnic Kaiser Permanente Northern California Genetic Epidemiology Research in Adult Health and Aging cohort. We also undertook replication analyses in 222,358 men from the UK Biobank. In the discovery cohort, we identified a single locus (rs17185536-T) on chromosome 6 near the single-minded family basic helix-loop-helix transcription factor 1 (SIM1) gene that was significantly associated with the risk of erectile dysfunction (odds ratio = 1.26, P = 3.4 × 10−25). The association replicated in the UK Biobank sample (odds ratio = 1.25, P = 6.8 × 10−14), and the effect is independent of known erectile dysfunction risk factors, including body mass index (BMI). The risk locus resides on the same topologically associating domain as SIM1 and interacts with the SIM1 promoter, and the rs17185536-T risk allele showed differential enhancer activity. SIM1 is part of the leptin–melanocortin system, which has an established role in body weight homeostasis and sexual function. Because the variants associated with erectile dysfunction are not associated with differences in BMI, our findings suggest a mechanism that is specific to sexual function.
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Tecamachaltzi-Silvaran MB, Barradas-Moctezuma M, Herrera-Covarrubias D, Carrillo P, Corona-Morales AA, Perez CA, García LI, Manzo J, Coria-Avila GA. Olfactory conditioned same-sex partner preference in female rats: Role of ovarian hormones. Horm Behav 2017; 96:13-20. [PMID: 28867385 DOI: 10.1016/j.yhbeh.2017.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/09/2017] [Accepted: 08/29/2017] [Indexed: 11/22/2022]
Abstract
The dopamine D2-type receptor agonist quinpirole (QNP) facilitates the development of conditioned same-sex partner preference in males during cohabitation, but not in ovariectomized (OVX) females, primed with estradiol benzoate (EB) and progesterone (P). Herein we tested the effects of QNP on OVX, EB-only primed females. Females received a systemic injection (every four days) of either saline (Saline-conditioned) or QNP (QNP-conditioned) and then cohabited for 24h with lemon-scented stimulus females (CS+), during three trials. In test 1 (female-female) preference was QNP-free, and females chose between the CS+ female and a novel female. In test 2 (male-female) they chose between the CS+ female and a sexually experienced male. In test 1 Saline-conditioned females displayed more hops & darts towards the novel female, but QNP-conditioned females displayed more sexual solicitations towards the CS+ female. In test 2 Saline-conditioned females displayed a clear preference for the male, whereas QNP-conditioned females displayed what we considered a bisexual preference. We discuss the effect of dopamine and ovarian hormones on the development of olfactory conditioned same-sex preference in females.
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Affiliation(s)
| | | | | | - P Carrillo
- Instituto de Neuroetología, Universidad Veracruzana, Mexico
| | | | - C A Perez
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Mexico
| | - L I García
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Mexico
| | - J Manzo
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Mexico
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Usefulness of ambulatory blood pressure monitoring to assess the melanocortin receptor agonist bremelanotide. J Hypertens 2017; 35:761-768. [PMID: 27977473 PMCID: PMC5338879 DOI: 10.1097/hjh.0000000000001221] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Supplemental Digital Content is available in the text Background: Melanocortin receptor agonists that bind to the melanocortin receptor 4 may cause increases in blood pressure (BP). Bremelanotide is an on-demand, subcutaneous melanocortin-receptor agonist that binds to the melanocortin receptor 4 and is being developed for the treatment of female sexual dysfunction. Methods: We studied the effects of bremelanotide administration on ambulatory BP and heart rate (HR), in a randomized, double-blind, placebo-controlled, and parallel-arm trial of three doses of bremelanotide (0.75, 1.25, and 1.75 mg) in 397 premenopausal women with female sexual dysfunction with normotension or controlled hypertension. Pharmacokinetic exposure was assessed in conjunction with ambulatory BP measurements. Results: Increases in ambulatory SBP relative to placebo of 2.4 and 3.0 mmHg (1.25 mg; P values: 0.029 and 0.076) and 3.1 and 3.2 mmHg (1.75 mg; P values: 0.006 and 0.027), respectively, occurred following two doses, separated by 24 h at the 0 to 4-h postdose interval; peak increases typically lasted less than 15 min. Similar increases in the DBP were observed. Increases in BP were accompanied by reductions in HR during the 0–4-h interval for the 1.75-mg dose (−4.6 to −4.7 bpm; P < 0.001). Twenty-six participants discontinued after randomization due to prespecified increases in BP but the proportions were similar among the four treatment groups. Conclusion: These data show that ambulatory monitoring was a useful methodology to detect small, transient increases in ambulatory BP accompanied by reductions in HR following bremelanotide. Results of this trial led to appropriate in-clinic BP monitoring during the larger clinical development trials of this agent for female sexual dysfunction.
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McCarthy MM. Probing the neural circuits of sex and aggression with precision genetics: Commentary on "Estrogen receptor alpha is required in GABAergic but not glutamatergic, neurons to masculinize behavior" by Wu and Tollkuhn. Horm Behav 2017; 95:1-2. [PMID: 28733175 DOI: 10.1016/j.yhbeh.2017.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Margaret M McCarthy
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201.
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Meerts SH, Anderson KS, Farry-Thorn ME, Johnson EG, Taxier L. Prepubertal ovariectomy modulates paced mating behavior but not sexual preference or conditioned place preference for mating in female rats. Physiol Behav 2017; 171:142-148. [PMID: 28082246 DOI: 10.1016/j.physbeh.2017.01.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 01/07/2017] [Accepted: 01/07/2017] [Indexed: 11/24/2022]
Abstract
The present study investigated whether the presence or absence of peripubertal ovarian hormones affects sexual preference and conditioned place preference for paced mating in adult female rats primed with 10μg estradiol benzoate and 1mg progesterone. Ovariectomy (OVX) occurred either before or after pubertal development, and 4weeks later rats began a series of behavioral tests. Rats with ovaries removed before the pubertal timeframe (Prepubertal OVX) were more active, more likely to withdrawal from the male compartment, and did not discriminate between mounts and intromissions during paced mating relative to rats with ovaries during puberty (Adult OVX). Both Adult OVX and Prepubertal OVX rats showed a higher preference for the male when hormone primed vs. oil treated and a conditioned place preference for paced mating behavior. The results of the present study demonstrate that some, but not all, aspects of female sexual behavior require ovarian hormones during puberty.
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Affiliation(s)
- Sarah H Meerts
- Department of Psychology, Carleton College, Northfield, MN 55057, United States.
| | - Kelly S Anderson
- Department of Psychology, Carleton College, Northfield, MN 55057, United States
| | - Molly E Farry-Thorn
- Department of Psychology, Carleton College, Northfield, MN 55057, United States
| | - Elliott G Johnson
- Department of Psychology, Carleton College, Northfield, MN 55057, United States
| | - Lisa Taxier
- Department of Psychology, Carleton College, Northfield, MN 55057, United States
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Clayton AH, Lucas J, DeRogatis LR, Jordan R. Phase I Randomized Placebo-controlled, Double-blind Study of the Safety and Tolerability of Bremelanotide Coadministered With Ethanol in Healthy Male and Female Participants. Clin Ther 2017; 39:514-526.e14. [PMID: 28189361 DOI: 10.1016/j.clinthera.2017.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 01/05/2017] [Accepted: 01/10/2017] [Indexed: 10/20/2022]
Abstract
PURPOSE This was a Phase I study to evaluate the safety, tolerability, and hemodynamic and pharmacokinetic effects of bremelanotide (BMT) coadministered with ethanol to healthy male and female participants. METHODS This was a randomized, placebo-controlled, double-blind, 3-period, 3-way crossover study. Individuals meeting the inclusion/exclusion criteria received BMT or placebo with or without ethanol at the research facility for 7 consecutive days. Participants were randomized to receive 1 of 6 treatment paths; each participant received single intranasal doses of BMT (20 mg) or placebo on days 1, 4, and 7, with or without oral ethanol (0.6 g/kg) while in a fasted state. The intranasal 20-mg dose of BMT has an exposure equivalent to ~1 to 2 times the subcutaneous dose currently being evaluated in Phase III studies. Vital signs, self-rated sedation scores, nursing and medical observations, and spontaneous reporting by participants provided the basis for evaluation of adverse events. A physical examination and a resting 12-lead electrocardiogram were performed at baseline and on study day 7. Blood and urine samples were obtained for clinical safety profile laboratory tests. FINDINGS A total of 24 participants were enrolled (12 men; 12 women) and completed the study. Single doses of 20 mg intranasal BMT, administered with or without 0.6 g/kg ethanol, were found to be safe and generally well tolerated with mean maximum ethanol concentrations exceeding 80 mg/dL in women. No clinically significant pharmacokinetic interactions were found between ethanol and BMT either overall or by sex. No significant drug-related hypotensive or orthostatic hypotensive effects were noted. Treatment with BMT did not result in an increased frequency of treatment-emergent adverse events, and no participants discontinued the study because of adverse events. Physical examination, electrocardiography, and laboratory tests disclosed no clinically significant changes. IMPLICATIONS Female sexual dysfunction is a multifactorial condition with anatomic, physiologic, medical, psychological, and social components. BMT is a synthetic peptide analogue of the naturally occurring hormone α-melanocyte-stimulating hormone and a melanocortin receptor agonist that is being developed for the treatment of hypoactive sexual desire disorder. Its mechanism of action involves activation of endogenous melanocortin hormone pathways involved in the sexual desire and arousal response. The results of this Phase I study found that BMT and ethanol can be safely coadministered and are generally well tolerated with no reports of drug-related serious adverse events. Phase III trials of subcutaneous BMT for the treatment of hypoactive sexual desire disorder in premenopausal women are in progress. ClinicalTrials.gov identifiers NCT02338960 and NCT02333071.
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Affiliation(s)
- Anita H Clayton
- Department of Psychiatry and Neurobehavioral Sciences, University of Virginia, Charlottesville, Virginia.
| | - Johna Lucas
- Palatin Technologies, Inc., Cranbury, New Jersey
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Future Targets for Female Sexual Dysfunction. J Sex Med 2016; 13:1147-65. [DOI: 10.1016/j.jsxm.2016.05.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/22/2016] [Accepted: 05/27/2016] [Indexed: 12/18/2022]
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Clayton AH, Althof SE, Kingsberg S, DeRogatis LR, Kroll R, Goldstein I, Kaminetsky J, Spana C, Lucas J, Jordan R, Portman DJ. Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. ACTA ACUST UNITED AC 2016; 12:325-37. [PMID: 27181790 PMCID: PMC5384512 DOI: 10.2217/whe-2016-0018] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Aim: Evaluate efficacy/safety of bremelanotide (BMT), a melanocortin-receptor-4 agonist, to treat female sexual dysfunctions in premenopausal women. Methods: Patients randomized to receive placebo or BMT 0.75, 1.25 or 1.75 mg self-administered subcutaneously, as desired, over 12 weeks. Primary end point was change in satisfying sexual events/month. Secondary end points included total score changes on female sexual function index and female sexual distress scale-desire/arousal/orgasm. Results: Efficacy data, n = 327. For 1.25/1.75-mg pooled versus placebo, mean changes from baseline to study end were +0.7 versus +0.2 satisfying sexual events/month (p = 0.0180), +3.6 versus +1.9 female sexual function index total score (p = 0.0017), −11.1 versus −6.8 female sexual distress scale-desire/arousal/orgasm total score (p = 0.0014). Adverse events: nausea, flushing, headache. Conclusion: In premenopausal women with female sexual dysfunctions, self-administered, as desired, subcutaneous BMT was safe, effective, and well tolerated (NCT01382719).
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Affiliation(s)
- Anita H Clayton
- University of Virginia, 2955 Ivy Road, Northridge Suite 210, Charlottesville, VA 22903, USA
| | - Stanley E Althof
- Case Western Reserve University School of Medicine, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | - Sheryl Kingsberg
- University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | - Leonard R DeRogatis
- Maryland Center for Sexual Health, 1300 York Road, Lutherville, MD 21093, USA
| | - Robin Kroll
- Seattle Women's Health, Research, Gynecology, 3216 NE 45th Place, Seattle, WA 98105, USA
| | - Irwin Goldstein
- San Diego Sexual Medicine/Alvarado Hospital & Medical Center, 6655 Alvarado Road, San Diego, CA 92120, USA
| | - Jed Kaminetsky
- Manhattan Medical Research, 215 Lexington Avenue, New York, NY 10016, USA
| | - Carl Spana
- Palatin Technologies, Inc., 4C Cedar Brook Drive, Cranbury, NJ 08512, USA
| | - Johna Lucas
- Palatin Technologies, Inc., 4C Cedar Brook Drive, Cranbury, NJ 08512, USA
| | - Robert Jordan
- Palatin Technologies, Inc., 4C Cedar Brook Drive, Cranbury, NJ 08512, USA
| | - David J Portman
- Columbus Center for Women's Health Research, 99 North Brice Road, Columbus, OH 43213, USA
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The Female Sexual Response: Current Models, Neurobiological Underpinnings and Agents Currently Approved or Under Investigation for the Treatment of Hypoactive Sexual Desire Disorder. CNS Drugs 2015; 29:915-33. [PMID: 26519340 DOI: 10.1007/s40263-015-0288-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
How a woman responds to sexual cues is highly dependent on a number of distinct, yet related, factors. Researchers have attempted to explain the female sexual response for decades, but no single model reigns supreme. Proper female sexual function relies on the interplay of somatic, psychosocial and neurobiological factors; misregulation of any of these components could result in sexual dysfunction. The most common sexual dysfunction disorder is hypoactive sexual desire disorder (HSDD). HSDD is a disorder affecting women across the world; a recent in-person diagnostic interview study conducted in the USA found that an estimated 7.4% of US women suffer from HSDD. Despite the disorder's prevalence, it is often overlooked as a formal diagnosis. In a survey of primary care physicians and obstetrics/gynaecology specialists, the number one reason for not assigning an HSDD diagnosis was the lack of a safe and effective therapy approved by the US Food and Drug Administration (FDA). This changed with the recent FDA approval of flibanserin (Addyi™) for the treatment of premenopausal women with acquired, generalized HSDD; there are still, however, no treatments approved outside the USA. HSDD is characterized by a marked decrease in sexual desire, an absence of motivation (also known as avolition) to engage in sexual activity, and the condition's hallmark symptom, marked patient distress. Research suggests that HSDD may arise from an imbalance of the excitatory and inhibitory neurobiological pathways that regulate the mammalian sexual response; top-down inhibition from the prefrontal cortex may be hyperactive, and/or bottom-up excitation to the limbic system may be hypoactive. Key neuromodulators for the excitatory pathways include norepinephrine, oxytocin, dopamine and melanocortins. Serotonin, opioids and endocannabinoids serve as key neuromodulators for the inhibitory pathways. Evolving treatment strategies have relied heavily on these crucial research findings, as many of the agents currently being investigated as treatment options for HSDD target and influence key players within these excitatory and inhibitory pathways, including various hormone therapies and centrally acting drugs, such as buspirone, bupropion and bremelanotide.
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Marson L, Giamberardino MA, Costantini R, Czakanski P, Wesselmann U. Animal Models for the Study of Female Sexual Dysfunction. Sex Med Rev 2015; 1:108-122. [PMID: 27784584 DOI: 10.1002/smrj.14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Significant progress has been made in elucidating the physiological and pharmacological mechanisms of female sexual function through preclinical animal research. The continued development of animal models is vital for the understanding and treatment of the many diverse disorders that occur in women. AIM To provide an updated review of the experimental models evaluating female sexual function that may be useful for clinical translation. METHODS Review of English written, peer-reviewed literature, primarily from 2000 to 2012, that described studies on female sexual behavior related to motivation, arousal, physiological monitoring of genital function and urogenital pain. MAIN OUTCOMES MEASURES Analysis of supporting evidence for the suitability of the animal model to provide measurable indices related to desire, arousal, reward, orgasm, and pelvic pain. RESULTS The development of female animal models has provided important insights in the peripheral and central processes regulating sexual function. Behavioral models of sexual desire, motivation, and reward are well developed. Central arousal and orgasmic responses are less well understood, compared with the physiological changes associated with genital arousal. Models of nociception are useful for replicating symptoms and identifying the neurobiological pathways involved. While in some cases translation to women correlates with the findings in animals, the requirement of circulating hormones for sexual receptivity in rodents and the multifactorial nature of women's sexual function requires better designed studies and careful analysis. The current models have studied sexual dysfunction or pelvic pain in isolation; combining these aspects would help to elucidate interactions of the pathophysiology of pain and sexual dysfunction. CONCLUSIONS Basic research in animals has been vital for understanding the anatomy, neurobiology, and physiological mechanisms underlying sexual function and urogenital pain. These models are important for understanding the etiology of female sexual function and for future development of pharmacological treatments for sexual dysfunctions with or without pain. Marson L, Giamberardino MA, Costantini R, Czakanski P, and Wesselmann U. Animal models for the study of female sexual dysfunction. Sex Med Rev 2013;1:108-122.
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Affiliation(s)
- Lesley Marson
- University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | | | | | - Peter Czakanski
- University of Alabama at Birmingham-Departments of Anesthesiology and Obstetrics & Gynecology, Birmingham, AL, USA
| | - Ursula Wesselmann
- University of Alabama at Birmingham-Departments of Anesthesiology and Neurology, Birmingham, AL, USA
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Lam DD, Attard CA, Mercer AJ, Myers MG, Rubinstein M, Low MJ. Conditional expression of Pomc in the Lepr-positive subpopulation of POMC neurons is sufficient for normal energy homeostasis and metabolism. Endocrinology 2015; 156:1292-302. [PMID: 25594696 PMCID: PMC4399319 DOI: 10.1210/en.2014-1373] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Peptides derived from the proopiomelanocortin (POMC) precursor are critical for the normal regulation of many physiological parameters, and POMC deficiency results in severe obesity and metabolic dysfunction. Conversely, augmentation of central nervous system melanocortin function is a promising therapeutic avenue for obesity and diabetes but is confounded by detrimental cardiovascular effects including hypertension. Because the hypothalamic population of POMC-expressing neurons is neurochemically and neuroanatomically heterogeneous, there is interest in the possible dissociation of functionally distinct POMC neuron subpopulations. We used a Cre recombinase-dependent and hypothalamus-specific reactivatable PomcNEO allele to restrict Pomc expression to hypothalamic neurons expressing leptin receptor (Lepr) in mice. In contrast to mice with total hypothalamic Pomc deficiency, which are severely obese, mice with Lepr-restricted Pomc expression displayed fully normal body weight, food consumption, glucose homeostasis, and locomotor activity. Thus, Lepr+ POMC neurons, which constitute approximately two-thirds of the total POMC neuron population, are sufficient for normal regulation of these parameters. This functional dissociation approach represents a promising avenue for isolating therapeutically relevant POMC neuron subpopulations.
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Affiliation(s)
- Daniel D Lam
- Department of Molecular and Integrative Physiology (D.D.L., C.A.A., A.J.M., M.R., M.J.L.), and Department of Internal Medicine (M.G.M.), Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105; and Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (M.R.), Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
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Ückert S, Bannowsky A, Albrecht K, Kuczyk MA. Melanocortin receptor agonists in the treatment of male and female sexual dysfunctions: results from basic research and clinical studies. Expert Opin Investig Drugs 2014; 23:1477-83. [DOI: 10.1517/13543784.2014.934805] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Ågmo A. Animal models of female sexual dysfunction: Basic considerations on drugs, arousal, motivation and behavior. Pharmacol Biochem Behav 2014; 121:3-15. [DOI: 10.1016/j.pbb.2013.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 10/04/2013] [Indexed: 12/19/2022]
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Argiolas A, Melis MR. Neuropeptides and central control of sexual behaviour from the past to the present: a review. Prog Neurobiol 2013; 108:80-107. [PMID: 23851261 DOI: 10.1016/j.pneurobio.2013.06.006] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 06/28/2013] [Accepted: 06/29/2013] [Indexed: 12/23/2022]
Abstract
Of the numerous neuropeptides identified in the central nervous system, only a few are involved in the control of sexual behaviour. Among these, the most studied are oxytocin, adrenocorticotropin, α-melanocyte stimulating hormone and opioid peptides. While opioid peptides inhibit sexual performance, the others facilitate sexual behaviour in most of the species studied so far (rats, mice, monkeys and humans). However, evidence for a sexual role of gonadotropin-releasing hormone, corticotropin releasing factor, neuropeptide Y, galanin and galanin-like peptide, cholecystokinin, substance P, vasoactive intestinal peptide, vasopressin, angiotensin II, hypocretins/orexins and VGF-derived peptides are also available. Corticotropin releasing factor, neuropeptide Y, cholecystokinin, vasopressin and angiotensin II inhibit, while substance P, vasoactive intestinal peptide, hypocretins/orexins and some VGF-derived peptide facilitate sexual behaviour. Neuropeptides influence sexual behaviour by acting mainly in the hypothalamic nuclei (i.e., lateral hypothalamus, paraventricular nucleus, ventromedial nucleus, arcuate nucleus), in the medial preoptic area and in the spinal cord. However, it is often unclear whether neuropeptides influence the anticipatory phase (sexual arousal and/or motivation) or the consummatory phase (performance) of sexual behaviour, except in a few cases (e.g., opioid peptides and oxytocin). Unfortunately, scarce information has been added in the last 15 years on the neural mechanisms by which neuropeptides influence sexual behaviour, most studied neuropeptides apart. This may be due to a decreased interest of researchers on neuropeptides and sexual behaviour or on sexual behaviour in general. Such a decrease may be related to the discovery of orally effective, locally acting type V phosphodiesterase inhibitors for the therapy of erectile dysfunction.
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Affiliation(s)
- Antonio Argiolas
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
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Anatomie et physiologie de la sexualité. Prog Urol 2013; 23:547-61. [DOI: 10.1016/j.purol.2012.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 11/16/2012] [Indexed: 01/08/2023]
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Aubert Y, Allers KA, Sommer B, de Kloet ER, Abbott DH, Datson NA. Brain region-specific transcriptomic markers of serotonin-1A receptor agonist action mediating sexual rejection and aggression in female marmoset monkeys. J Sex Med 2013; 10:1461-75. [PMID: 23551660 DOI: 10.1111/jsm.12131] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION In a marmoset model of hypoactive female sexual function, we have shown that repeated administration of the serotonin (5-HT)-1A agonist R-(+)-8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT) inhibits sexual receptivity in female marmoset monkeys and increases aggression toward the male pairmate. AIM The aims of this study are to investigate gene expression changes induced by 8-OH-DPAT in laser-microdissected brain areas that regulate female sexual function and to identify genes, functional gene classes, and pathways associated with 8-OH-DPAT-mediated inhibition of female sexual receptivity. METHODS Gene expression was measured in the medial prefrontal cortex (mPFC), medial preoptic area (mPOA), cornu ammonis-1 (CA1) area of the hippocampus (CA1), and dorsal raphé nucleus (DRN) of four 8-OH-DPAT-treated (0.1 mg/kg; daily administration for 16 weeks) and four vehicle-treated female marmosets using a marmoset-specific microarray (European Marmoset Microarray [EUMAMA]) and validated by real-time quantitative polymerase chain reaction (RTqPCR). Enriched functional gene classes were determined. In a parallel candidate gene approach, the expression of serotonergic candidate genes, i.e., the 5-HT1A, 5-HT2A, and 5-HT7 receptors and the 5-HT transporter (5-HTT), was measured by RTqPCR. MAIN OUTCOME MEASURES The main outcome is the differential expression of genes between 8-OH-DPAT- and vehicle-treated marmosets. RESULTS 8-OH-DPAT affected the gene classes important to neural development (mPFC, mPOA, and DRN), neurotransmission (mPOA), energy production (mPFC and mPOA), learning and memory (CA1), and intracellular signal transduction (DRN). Oxytocin (OXT) in the mPOA and 5-HTT in the DRN were strongly increased by 8-OH-DPAT. 5-HT1A tended to increase in the mPFC, while 5-HT7 was decreased in the CA1. CONCLUSIONS Brain region-specific alterations of gene expression regulating neural circuitries, energy demands, and learning processes are associated with 8-OH-DPAT-induced decrease in female sexual receptivity and increase in pairmate aggression. The role of OXT in the serotonergic regulation of female sexual behavior and partner interactions warrants attention in future studies.
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Affiliation(s)
- Yves Aubert
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden University Medical Center, Leiden, The Netherlands.
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Gautron L, Cravo RM, Elmquist JK, Elias CF. Discrete melanocortin-sensitive neuroanatomical pathway linking the ventral premmamillary nucleus to the paraventricular hypothalamus. Neuroscience 2013; 240:70-82. [PMID: 23485805 DOI: 10.1016/j.neuroscience.2013.02.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 02/14/2013] [Accepted: 02/15/2013] [Indexed: 11/16/2022]
Abstract
The physiological effects of melanocortin-4 receptor (MC4-R) on metabolism have been hypothesized to be mediated individually or collectively by neuronal groups innervating the paraventricular nucleus of the hypothalamus (PVH). The present study was designed to identify MC4-R-expressing neurons that innervate the PVH using retrograde tract tracing techniques in the MC4-R-GFP reporter mice. Our initial mapping identified very limited projections from MC4-R-expressing neurons to the PVH. This included a defined population of MC4-R-positive neurons located in the ventral premmamillary nucleus (PMv). Anterograde tracing experiments confirmed projections from PMv neurons to the medial parvicellular subdivision of the PVH, in close proximity to oxytocin neurons and β-endorphin-containing fibers. Given the known stimulatory effects of leptin and sexual odorants exposure on many PMv neurons, it was expected that MC4-R-expressing neurons in the PMv might be responsive to leptin and activated by odors exposure. Contrary to expectation, MC4-R-GFP neurons in the PMv do not respond to leptin as demonstrated by double labeling for GFP and leptin-induced phosphorylated STAT3. However, we found that Fos expression is induced in a large subset of MC4-R-GFP neurons in the PMv in response to opposite sex odors. Collectively, these results provide evidence for a previous unrecognized role of MC4-R expressed by neurons innervating the PVH that are also sensitive to reproductive cues.
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Affiliation(s)
- L Gautron
- Department of Internal Medicine, Division of Hypothalamic Research, The University of Texas Southwestern Medical Center at Dallas, USA.
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Gelez H, Greggain-Mohr J, Pfaus JG, Allers KA, Giuliano F. Flibanserin treatment increases appetitive sexual motivation in the female rat. J Sex Med 2013; 10:1231-9. [PMID: 23421417 DOI: 10.1111/jsm.12094] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Flibanserin is a mixed 5-HT1A agonist/5-HT2A antagonist that has been developed for the treatment of hypoactive sexual desire disorder in women. AIM To assess the acute and chronic dose-response effects of flibanserin on measures of sexual desire and copulation in ovariectomized rats primed with estradiol benzoate (EB) alone or in combination with progesterone (P). METHODS In Experiment 1, sexually experienced ovariectomized (OVX) rats at one testing site were rendered fully sexually receptive with EB + P priming and tested weekly with a sexually active male in bi-level pacing chambers following daily flibanserin treatment for 28 days. In Experiment 2, sexually experienced OVX rats at a different testing site received EB alone and were tested weekly with sexually active males following daily flibanserin treatment. MAIN OUTCOME MEASURES Female appetitive behaviors (solicitations, hops and darts, anogenital investigations), defensive behaviors, pacing, lordosis, and male copulatory responses (intromissions and ejaculations) were measured during each 30-minute copulation test. RESULTS Acute flibanserin or 1 week of chronic flibanserin treatment did not modify sexual responses in fully (EB + P) or partially (EB-alone) primed females. After 2 weeks of chronic treatment, fully primed females displayed significantly more solicitations than the three other groups. After 3 weeks of chronic treatment, a significant increase in female solicitations was observed in both hormone-treatment groups. CONCLUSION This study shows the first evidence that chronic, but not acute, flibanserin treatment augments appetitive sexual behaviors in OVX female rats primed with EB + P or EB alone. Given the positive effect of flibanserin in clinical trials, these results confirm previous reports that solicitations in the female rat are a predictive animal model of human female sexual desire.
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Affiliation(s)
- Hélène Gelez
- Pelvipharm, University of Versailles Saint Quentin en Yvelines, Montigny le Bretonneux, France.
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Cibrian-Llanderal T, Rosas-Aguilar V, Triana-Del Rio R, Perez CA, Manzo J, Garcia LI, Coria-Avila GA. Enhaced D2-type receptor activity facilitates the development of conditioned same-sex partner preference in male rats. Pharmacol Biochem Behav 2012; 102:177-83. [PMID: 22564860 DOI: 10.1016/j.pbb.2012.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Revised: 04/07/2012] [Accepted: 04/21/2012] [Indexed: 11/25/2022]
Abstract
Animal models have shown that the neural bases of social attachment, sexual preference and pair bonds, depend on dopamine D2-type receptor and oxytocin activity. In addition, studies have demonstrated that cohabitation can shape partner preference via conditioning. Herein, we used rats to explore the development of learned same-sex partner preferences in adulthood as a result of cohabitation during enhanced D2 activity. Experimental Wistar males (N=20), received saline or the D2 agonist (quinpirole) and were allowed to cohabitate during 24 h, with a stimulus male partner that bore almond scent on the back as conditioned stimulus. This was repeated every 4 days, for a total of three trials. Four days later they were drug-free tested for partner preference between the scented male partner and a sexually receptive female. Sexual partner preference was analyzed by measuring frequency and latency for appetitive and consummatory sexual behaviors, as well as non-contact erections. Social preference was also analyzed by measuring the frequency and latency of visits, body contacts and time spent together. Results indicated that only quinpirole-treated males displayed sexual and social preference for the scented male over the sexually receptive female. They spent more time together, displayed more body contacts, more female-like proceptive behaviors, and more non-contact erections. Accordingly, conditioned males appeared to be more sexually aroused and motivated by the known male than by a receptive female. We discuss the implications of this animal model on the formation of learned homosexual partner preferences.
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Coria-Avila GA. The role of conditioning on heterosexual and homosexual partner preferences in rats. SOCIOAFFECTIVE NEUROSCIENCE & PSYCHOLOGY 2012; 2:17340. [PMID: 24693350 PMCID: PMC3960032 DOI: 10.3402/snp.v2i0.17340] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Partner preferences are expressed by many social species, including humans. They are commonly observed as selective contacts with an individual, more time spent together, and directed courtship behavior that leads to selective copulation. This review discusses the effect of conditioning on the development of heterosexual and homosexual partner preferences in rodents. Learned preferences may develop when a conditioned stimulus (CS) is associated in contingency with an unconditioned stimulus (UCS) that functions as a reinforcer. Consequently, an individual may display preference for a partner that bears a CS. Some UCS may be more or less reinforcing, depending on when they are experienced, and may be different for males and females. For example, it could be that, only during periods of early development, that stimuli associated with nurture and juvenile play become conditioned. In adulthood, other stimuli such as sexual reward, cohabitation, mild stress, or even pharmacological manipulations may function as reinforcers to condition partner preferences. Evolutionary biologists and psychologists must take into consideration the idea that an individual's experience with reward (i.e. sexual and pharmacological) can override presumably 'innate' mate choices (e.g. assortativeness and orientation) or mate strategies (e.g. monogamy or polygamy) by means of Pavlovian and operant contingencies. In fact, it is likely as innate to learn about the environment in ways that maximize reward and minimize aversive outcomes, making so-called 'proximate' causes (e.g. pleasure) ultimately more powerful predictors of social behavior and choice than so-called 'ultimate' causes (e.g. genetic or reproductive fitness).
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Affiliation(s)
- Genaro A. Coria-Avila
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Xalapa, Veracruz, Mexico
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Early onset of obesity induces reproductive deficits in female rats. Physiol Behav 2012; 105:1104-11. [DOI: 10.1016/j.physbeh.2011.12.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 11/18/2011] [Accepted: 12/05/2011] [Indexed: 11/20/2022]
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Juvenile play conditions sexual partner preference in adult female rats. Physiol Behav 2011; 104:1016-23. [DOI: 10.1016/j.physbeh.2011.06.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 05/25/2011] [Accepted: 06/28/2011] [Indexed: 11/17/2022]
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Conde-Frieboes K, Ankersen M, Breinholt J, Hansen BS, Raun K, Thøgersen H, Wulff BS. Serendipitous discovery of a new class of agonists for the melanocortin 1 and 4 receptors and a new class of cyclophanes. Bioorg Med Chem Lett 2011; 21:1459-63. [DOI: 10.1016/j.bmcl.2011.01.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 01/03/2011] [Accepted: 01/04/2011] [Indexed: 11/16/2022]
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Burnett AL, Goldstein I, Andersson KE, Argiolas A, Christ G, Park K, Xin ZC. Future sexual medicine physiological treatment targets. J Sex Med 2011; 7:3269-304. [PMID: 21029380 DOI: 10.1111/j.1743-6109.2010.02025.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
INTRODUCTION Sexual function in men and women incorporates physiologic processes and regulation of the central and peripheral nervous systems, the vascular system, and the endocrine system. There is need for state-of-the-art information as there is an evolving research understanding of the underlying molecular biological factors and mechanisms governing sexual physiologic functions. AIM To develop an evidence-based, state-of-the-art consensus report on the current knowledge of the major cellular and molecular targets of biologic systems responsible for sexual physiologic function. METHODS State-of-the-art knowledge representing the opinions of seven experts from four countries was developed in a consensus process over a 2-year period. MAIN OUTCOME MEASURES Expert opinion was based on the grading of evidence-based medical literature, widespread internal committee discussion, public presentation, and debate. RESULTS Scientific investigation in this field is needed to increase knowledge and foster development of the future line of treatments for all forms of biological-based sexual dysfunction. This article addresses the current knowledge of the major cellular and molecular targets of biological systems responsible for sexual physiologic function. Future treatment targets include growth factor therapy, gene therapy, stem and cell-based therapies, and regenerative medicine. CONCLUSIONS Scientific discovery is critically important for developing new and increasingly effective treatments in sexual medicine. Broad physiologic directions should be vigorously explored and considered for future management of sexual disorders.
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Affiliation(s)
- Arthur L Burnett
- The James Buchanan Brady Urological Institute, The Johns Hopkins Hospital, Baltimore, MD, USA.
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Gelez H, Poirier S, Facchinetti P, Allers KA, Wayman C, Bernabé J, Alexandre L, Giuliano F. Neuroanatomical distribution of the melanocortin-4 receptors in male and female rodent brain. J Chem Neuroanat 2010; 40:310-24. [DOI: 10.1016/j.jchemneu.2010.09.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 09/16/2010] [Accepted: 09/20/2010] [Indexed: 11/29/2022]
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Giuliano F, Pfaus J, Balasubramanian S, Hedlund P, Hisasue SI, Marson L, Wallen K. Experimental Models for the Study of Female and Male Sexual Function. J Sex Med 2010; 7:2970-95. [DOI: 10.1111/j.1743-6109.2010.01960.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Abstract
The melanocortin-4 receptor (MC4R) was cloned in 1993 by degenerate PCR; however, its function was unknown. Subsequent studies suggest that the MC4R might be involved in regulating energy homeostasis. This hypothesis was confirmed in 1997 by a series of seminal studies in mice. In 1998, human genetic studies demonstrated that mutations in the MC4R gene can cause monogenic obesity. We now know that mutations in the MC4R are the most common monogenic form of obesity, with more than 150 distinct mutations reported thus far. This review will summarize the studies on the MC4R, from its cloning and tissue distribution to its physiological roles in regulating energy homeostasis, cachexia, cardiovascular function, glucose and lipid homeostasis, reproduction and sexual function, drug abuse, pain perception, brain inflammation, and anxiety. I will then review the studies on the pharmacology of the receptor, including ligand binding and receptor activation, signaling pathways, as well as its regulation. Finally, the pathophysiology of the MC4R in obesity pathogenesis will be reviewed. Functional studies of the mutant MC4Rs and the therapeutic implications, including small molecules in correcting binding and signaling defect, and their potential as pharmacological chaperones in rescuing intracellularly retained mutants, will be highlighted.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, Auburn University, Alabama 36849-5519, USA.
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Fridmanis D, Petrovska R, Kalnina I, Slaidina M, Peculis R, Schiöth HB, Klovins J. Identification of domains responsible for specific membrane transport and ligand specificity of the ACTH receptor (MC2R). Mol Cell Endocrinol 2010; 321:175-83. [PMID: 20206229 DOI: 10.1016/j.mce.2010.02.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 02/23/2010] [Accepted: 02/23/2010] [Indexed: 12/26/2022]
Abstract
The adrenocorticotropic hormone (ACTH) receptor has highly specific membrane expression that is limited to adrenal cells; in other cell types the polypeptide fails to be transported to the cell surface. Unlike other evolutionarily related members of the melanocortin receptor family (MC1R-MC5R) that recognize different melanocortin peptides, ACTHR (MC2R) binds only ACTH. We used a mutagenesis approach involving systematic construction of chimeric ACTHR/MC4R receptors to identify the domains determining the selectivity of ACTHR membrane transport and ACTH binding. In total 15 chimeric receptors were created by replacement of selected domains of human ACTHR with the corresponding regions of human MC4R. We developed an analytical method to accurately quantify cell-membrane localization of recombinant receptors fused with enhanced green fluorescent protein by confocal fluorescence microscopy. The chimeric receptors were also tested for their ability to bind ACTH (1-24) and the melanocyte-stimulating hormone (MSH) analog, Nle4, DPhe7-alpha-MSH, and to induce a cAMP response. Our results indicate that substitution of the MC4R N-terminal segment with the homologous segment of ACTHR significantly decreased membrane transport. We also identified another signal localized in the third and fourth transmembrane regions as the main determinant of ACTHR intracellular retention. In addition, we found that the fourth and fifth transmembrane domains of the ACTHR are involved in ACTH binding selectivity. We discuss the mechanisms involved in bypassing these arrest signals via an interaction with melanocortin 2 receptor accessory protein (MRAP) and the possible mechanisms that determine the high ligand-binding specificity of ACTHR.
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Gelez H, Poirier S, Facchinetti P, Allers KA, Wayman C, Alexandre L, Giuliano F. Neuroanatomical Evidence for a Role of Central Melanocortin-4 Receptors and Oxytocin in the Efferent Control of the Rodent Clitoris and Vagina. J Sex Med 2010; 7:2056-2067. [DOI: 10.1111/j.1743-6109.2010.01760.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Korda JB, Pfaus JG, Kellner CH, Goldstein I. Persistent Genital Arousal Disorder (PGAD): Case Report of Long-Term Symptomatic Management with Electroconvulsive Therapy. J Sex Med 2009; 6:2901-9. [DOI: 10.1111/j.1743-6109.2009.01421.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Amphetamine pretreatment facilitates appetitive sexual behaviors in the female rat. Psychopharmacology (Berl) 2009; 205:35-43. [PMID: 19283363 DOI: 10.1007/s00213-009-1511-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 03/02/2009] [Indexed: 10/25/2022]
Abstract
RATIONALE Intermittent treatment of rats with psychomotor stimulants induces behavioral sensitization to their motor-stimulating effects. This sensitization involves an increase in mesolimbic and nigrostriatal dopamine release, and in male rats, facilitates sexual behavior. OBJECTIVES The aim of this study is to investigate the effect of repeated injections of D-amphetamine on appetitive and consummatory sexual behaviors in female rats. MATERIALS AND METHODS Sexually experienced or naïve females were injected with either D-amphetamine (1 mg/kg, i.p.) or saline every other day for three injections each. After each amphetamine injection, females were placed either in a bilevel testing chamber or in their home cages. After saline injections, females were placed in bilevel chambers. Following a 3-week washout period, females were tested for sexual behavior in bilevel chambers in a drug-free state. RESULTS Amphetamine pre-exposure facilitated the display of solicitations, hops and darts, and female-male mounting (FMM), regardless of whether the drug was paired with the testing environment. CONCLUSION Intermittent amphetamine pretreatment that induces behavioral sensitization facilitates appetitive sexual behaviors in female rats, as has been shown previously in male rats. This suggests that the physiological substrates that modulate sensitized responses to psychomotor stimulants also mediate sensitized appetitive responses to sexual cues, including solicitation, hops and darts, and FMM. As in male rats, this facilitation was a direct consequence of amphetamine sensitization and not due to conditioned associations between drug and test environment.
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Simon S, Young TJ, Nickolls SA. The effect of assay formats on the estimation of melanocortin agonist affinity and efficacy using the operation model of agonism. Eur J Pharmacol 2009; 615:33-9. [PMID: 19446549 DOI: 10.1016/j.ejphar.2009.04.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 04/27/2009] [Accepted: 04/29/2009] [Indexed: 01/29/2023]
Abstract
Melanocortin MC(3) and MC(4) receptor agonists have pharmaceutical benefit in the regulation of energy homeostasis. These agonists are defined by two parameters, their potency and their efficacy. However, these parameters are dependent upon the system in which they are measured. Herein, we have used the operational model of agonism to define agonist properties. We have used two different assay formats, cAMP accumulation and a cAMP response element (CRE)-beta-lactamase gene reporter to measure melanocortin MC(3) and MC(4) receptor agonist profiles, in the presence and absence of the irreversible receptor inactivator N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) and fitted these data to the operational model of agonism to define agonist affinity and efficacy. Data generated using the cAMP accumulation assay fitted well to assumptions made in the operational model and provided estimations of affinity and efficacy in line with those expected. However, data generated in the gene reporter assays showed over a 100-fold increase in agonist affinity compared with cAMP data and unexpectedly low values for efficacy. These data show that the operational model can be used to determine the efficacies of melanocortin agonists which appear as full agonists in cAMP assays, but that this is not the case for gene reporter assays in which agonist efficacies cannot be distinguished.
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Affiliation(s)
- Sylvie Simon
- Discovery Biology, Pfizer Inc, Ramsgate Road, Sandwich, Kent, CT13 9NJ, UK
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Wilson LA, Wayman CP, Jackson VM. Neuropeptide modulation of a lumbar spinal reflex: potential implications for female sexual function. J Sex Med 2009; 6:947-957. [PMID: 19170864 DOI: 10.1111/j.1743-6109.2008.01150.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Neuropeptides are known to modulate female receptivity. However, even though receptivity is a spinal reflex, the role of neuropeptides within the spinal cord remains to be elucidated. AIM The aims were to (i) investigate neuropeptides in the lumbosacral region; and (ii) determine how neuropeptides modulate glutamate release from stretch Ia fibers, touch sensation Abeta fibers and Adelta/C pain fibers. MAIN OUTCOME MEASURES Neuropeptide modulation of the lumbosacral dorsal-root ventral-root reflex in vitro. METHODS Spinal cords were removed from Sprague-Dawley rats in compliance with UK Home Office guidelines. Hemisected cords were superfused with aCSF and the dorsal root (L4-S1) was stimulated to evoke glutamate release. A biphasic reflex response was evoked from the opposite ventral root consisting of a monosynaptic (Ia fibers) and polysynaptic (Abeta, Adelta/C fibers) component. RESULTS The micro opioid receptor (MOR) agonist DAMGO inhibited the monosynaptic (EC(50) 0.02 +/- 0.02 nM) and polysynaptic area (EC(50) 125 +/- 167 nM) but not polysynaptic amplitude. Oxytocin and corticotrophin releasing factor (CRF) inhibited the monosynaptic amplitude (EC(50), 1.4 +/- 1.0 nM and EC(50) 4.3 +/- 3.5 nM, respectively), polysynaptic amplitude (EC(50) 18.2 +/- 28.0 nM and EC(50), 9.5 +/- 13.3 nM, respectively), and area (EC(50) 11.6 +/- 13.0 nM and EC(50), 2.8 +/- 3.3 nM, respectively); effects that were abolished by oxytocin and CRF(1) antagonists, L-368899 and 8w. Melanocortin agonists solely inhibited the monosynaptic component, which were blocked by the MC(3/4) receptor antagonist SHU9119. CONCLUSION These data suggest endogenous neuropeptides are released within the lumbosacral spinal cord. Melanocortin agonists, oxytocin, CRF, and DAMGO via MC(4), oxytocin, CRF(1), and MOR inhibit glutamate release but with differing effects on afferent fiber subtypes. Melanocortins, oxytocin, CRF, and DAMGO have the ability to modulate orgasm whereas oxytocin, CRF and DAMGO can increase pain threshold. Oxytocin and CRF may dampen touch sensation.
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Affiliation(s)
- Lesley A Wilson
- Pfizer Global Research & Development-Discovery Biology, Sandwich, Kent, UK
| | - Chris P Wayman
- Pfizer Global Research & Development-Discovery Biology, Sandwich, Kent, UK
| | - V Margaret Jackson
- Pfizer Global Research & Development-Discovery Biology, Sandwich, Kent, UK.
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