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Comerma-Steffensen S, Kun A, Prat-Duran J, Mogensen S, Alan Albayrak E, Fais R, Munro G, Peters D, Simonsen U. A novel reuptake inhibitor, IP2015, induces erection by increasing central dopamine and peripheral nitric oxide release. Br J Pharmacol 2024; 181:2566-2582. [PMID: 38604613 DOI: 10.1111/bph.16362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/07/2024] [Accepted: 02/12/2024] [Indexed: 04/13/2024] Open
Abstract
BACKGROUND AND PURPOSE An estimated 40% of patients with erectile dysfunction have a poor prognosis for improvement with currently available treatments. The present study investigated whether a newly developed monoamine transport inhibitor, IP2015, improves erectile function. EXPERIMENTAL APPROACH We investigated the effects of IP2015 on monoamine uptake and binding, erectile function in rats and diabetic mice and the effect on corpus cavernosum contractility. KEY RESULTS IP2015 inhibited the uptake of 5-HT, noradrenaline and dopamine by human monoamine transporters expressed in cells and in rat brain synaptosomes. Intracavernosal pressure measurement in anaesthetized rats revealed that IP2015 dose-dependently increased the number and the duration of spontaneous erections. Whereas pretreatment with the dopamine D2-like receptor antagonists, clozapine and (-)-sulpiride, or cutting the cavernosal nerve inhibited IP2015-induced erectile responses, the phosphodiesterase type 5 inhibitor sildenafil further enhanced the IP2015-mediated increase in intracavernosal pressure. IP2015 also increased the number of erections in type 2 diabetic db/db mice. Direct intracavernosal injection of IP2015 increased penile pressure, and in corpus cavernosum strips, IP2015 induced concentration-dependent relaxations. These relaxations were enhanced by sildenafil and blunted by endothelial cell removal, a nitric oxide synthase inhibitor, NG-nitro-l-arginine and a D1-like receptor antagonist, SCH23390. Quantitative polymerase chain reaction (qPCR) showed the expression of the dopamine transporter in the rat corpus cavernosum. CONCLUSION AND IMPLICATIONS Our findings suggest that IP2015 stimulates erectile function by a central mechanism involving dopamine reuptake inhibition and direct NO-mediated relaxation of the erectile tissue. This novel multi-modal mechanism of action could offer a new treatment approach to erectile dysfunction.
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Affiliation(s)
- Simon Comerma-Steffensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Department of Biomedical Sciences/Animal Physiology, Faculty of Veterinary, Central University of Venezuela, Caracas, Venezuela
- Initiator Pharma A/S, Copenhagen, Denmark
| | - Attila Kun
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Judit Prat-Duran
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Susie Mogensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Elif Alan Albayrak
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Türkiye
| | - Rafael Fais
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | - Dan Peters
- Initiator Pharma A/S, Copenhagen, Denmark
- DanPET AB, Malmö, Sweden
| | - Ulf Simonsen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Initiator Pharma A/S, Copenhagen, Denmark
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Argiolas A, Argiolas FM, Argiolas G, Melis MR. Erectile Dysfunction: Treatments, Advances and New Therapeutic Strategies. Brain Sci 2023; 13:802. [PMID: 37239274 PMCID: PMC10216368 DOI: 10.3390/brainsci13050802] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/08/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Erectile dysfunction (ED) is the inability to get and maintain an adequate penile erection for satisfactory sexual intercourse. Due to its negative impacts on men's life quality and increase during aging (40% of men between 40 and 70 years), ED has always attracted researchers of different disciplines, from urology, andrology and neuropharmacology to regenerative medicine, and vascular and prosthesis implant surgery. Locally and/or centrally acting drugs are used to treat ED, e.g., phosphodiesterase 5 inhibitors (first in the list) given orally, and phentolamine, prostaglandin E1 and papaverine injected intracavernously. Preclinical data also show that dopamine D4 receptor agonists, oxytocin and α-MSH analogues may have a role in ED treatment. However, since pro-erectile drugs are given on demand and are not always efficacious, new strategies are being tested for long lasting cures of ED. These include regenerative therapies, e.g., stem cells, plasma-enriched platelets and extracorporeal shock wave treatments to cure damaged erectile tissues. Although fascinating, these therapies are laborious, expensive and not easily reproducible. This leaves old vacuum erection devices and penile prostheses as the only way to get an artificial erection and sexual intercourse with intractable ED, with penile prosthesis used only by accurately selected patients.
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Affiliation(s)
- Antonio Argiolas
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Monserrato, Italy; (F.M.A.); (M.R.M.)
| | - Francesco Mario Argiolas
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Monserrato, Italy; (F.M.A.); (M.R.M.)
| | - Giacomo Argiolas
- General Medicine Unit, Hospital San Michele, ARNAS“G. Brotzu”, Piazzale Ricchi 1, 09100 Cagliari, Italy;
| | - Maria Rosaria Melis
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Monserrato, Italy; (F.M.A.); (M.R.M.)
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Melis MR, Sanna F, Argiolas A. Dopamine, Erectile Function and Male Sexual Behavior from the Past to the Present: A Review. Brain Sci 2022; 12:brainsci12070826. [PMID: 35884633 PMCID: PMC9312911 DOI: 10.3390/brainsci12070826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/08/2022] [Accepted: 06/21/2022] [Indexed: 11/16/2022] Open
Abstract
Early and recent studies show that dopamine through its neuronal systems and receptor subtypes plays different roles in the control of male sexual behavior. These studies show that (i) the mesolimbic/mesocortical dopaminergic system plays a key role in the preparatory phase of sexual behavior, e.g., in sexual arousal, motivation and reward, whereas the nigrostriatal system controls the sensory-motor coordination necessary for copulation, (ii) the incertohypothalamic system is involved in the consummatory aspects of sexual behavior (penile erection and copulation), but evidence for its role in sexual motivation is also available, (iii) the pro-sexual effects of dopamine occur in concert with neural systems interconnecting the hypothalamus and preoptic area with the spinal cord, ventral tegmental area and other limbic brain areas and (iv) D2 and D4 receptors play a major role in the pro-sexual effects of dopamine. Despite some controversy, increases or decreases, respectively, of brain dopamine activity induced by drugs or that occur physiologically, usually improves or worsens, respectively, sexual activity. These findings suggest that an altered central dopaminergic tone plays a role in mental pathologies characterized by aberrant sexual behavior, and that pro-erectile D4 receptor agonists may be considered a new strategy for the treatment of erectile dysfunction in men.
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Zhang T, Yuan P, Cui Y, Yuan W, Jiang D. Convergent and Divergent Structural Connectivity of Brain White Matter Network Between Patients With Erectile Dysfunction and Premature Ejaculation: A Graph Theory Analysis Study. Front Neurol 2022; 13:804207. [PMID: 35273555 PMCID: PMC8902049 DOI: 10.3389/fneur.2022.804207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/20/2022] [Indexed: 11/13/2022] Open
Abstract
Background Sexual dysfunction, namely, erectile dysfunction (ED) and premature ejaculation (PE), has been found to be associated with abnormal structural connectivity in the brain. Previous studies have mainly focused on a single disorder, however, convergent and divergent structural connectivity patterns of the brain network between ED and PE remain poorly understood. Methods T1-weighted structural data and diffusion tensor imaging data of 28 patients with psychological ED, 28 patients with lifelong PE (LPE), and 28 healthy controls (HCs) were obtained to map the white matter (WM) brain networks. Then, the graph-theoretical method was applied to investigate the differences of network properties (small-world measures) of the WM network between patients with ED and LPE. Furthermore, nodal segregative and integrative parameters (nodal clustering coefficient and characteristic path length) were also explored between these patients. Results Small-world architecture of the brain networks were identified for both psychological ED and LPE groups. However, patients with ED exhibited increased average characteristic path length of the brain network when compared with patients with LPE and HCs. No significant difference was found in the average characteristic path length between patients with LPE and HCs. Moreover, increased nodal characteristic path length was found in the right middle frontal gyrus (orbital part) of patients with ED and LPE when compared with HCs. In addition, patients with ED had increased nodal characteristic path length in the right middle frontal gyrus (orbital part) when compared with patients with LPE. Conclusion Together, our results demonstrated that decreased integration of the right middle frontal gyrus (orbital part) might be a convergent neuropathological basis for both psychological ED and LPE. In addition, patients with ED also exhibited decreased integration in the whole WM brain network, which was not found in patients with LPE. Therefore, altered integration of the whole brain network might be the divergent structural connectivity patterns for psychological ED and LPE.
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Affiliation(s)
- Tielong Zhang
- Department of Urology, The Affiliated Jianhu Hospital of Nantong University, Jianhu People's Hospital, Yancheng, China
| | - Peng Yuan
- Department of Intervention, The Affiliated Jianhu Hospital of Nantong University, Jianhu People's Hospital, Yancheng, China
| | - Yonghua Cui
- Department of Neurosurgery, The Affiliated Jianhu Hospital of Nantong University, Jianhu People's Hospital, Yancheng, China
| | - Weibiao Yuan
- Department of Radiology, The Affiliated Jianhu Hospital of Nantong University, Jianhu People's Hospital, Yancheng, China
| | - Daye Jiang
- Department of Urology, The Affiliated Jianhu Hospital of Nantong University, Jianhu People's Hospital, Yancheng, China
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Melis MR, Argiolas A. Erectile Function and Sexual Behavior: A Review of the Role of Nitric Oxide in the Central Nervous System. Biomolecules 2021; 11:biom11121866. [PMID: 34944510 PMCID: PMC8699072 DOI: 10.3390/biom11121866] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 12/06/2021] [Accepted: 12/08/2021] [Indexed: 12/21/2022] Open
Abstract
Nitric oxide (NO), the neuromodulator/neurotransmitter formed from l-arginine by neuronal, endothelial and inducible NO synthases, is involved in numerous functions across the body, from the control of arterial blood pressure to penile erection, and at central level from energy homeostasis regulation to memory, learning and sexual behavior. The aim of this work is to review earlier studies showing that NO plays a role in erectile function and sexual behavior in the hypothalamus and its paraventricular nucleus and the medial preoptic area, and integrate these findings with those of recent studies on this matter. This revisitation shows that NO influences erectile function and sexual behavior in males and females by acting not only in the paraventricular nucleus and medial preoptic area but also in extrahypothalamic brain areas, often with different mechanisms. Most importantly, since these areas are strictly interconnected with the paraventricular nucleus and medial preoptic area, send to and receive neural projections from the spinal cord, in which sexual communication between brain and genital apparatus takes place, this review reveals that central NO participates in concert with neurotransmitters/neuropeptides to a neural circuit controlling both the consummatory (penile erection, copulation, lordosis) and appetitive components (sexual motivation, arousal, reward) of sexual behavior.
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Oxytocin, Erectile Function and Sexual Behavior: Last Discoveries and Possible Advances. Int J Mol Sci 2021; 22:ijms221910376. [PMID: 34638719 PMCID: PMC8509000 DOI: 10.3390/ijms221910376] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/20/2021] [Accepted: 09/23/2021] [Indexed: 12/30/2022] Open
Abstract
A continuously increasing amount of research shows that oxytocin is involved in numerous central functions. Among the functions in which oxytocin is thought to be involved are those that play a role in social and sexual behaviors, and the involvement of central oxytocin in erectile function and sexual behavior was indeed one of the first to be discovered in laboratory animals in the 1980s. The first part of this review summarizes the results of studies done in laboratory animals that support a facilitatory role of oxytocin in male and female sexual behavior and reveal mechanisms through which this ancient neuropeptide participates in concert with other neurotransmitters and neuropeptides in this complex function, which is fundamental for the species reproduction. The second part summarizes the results of studies done mainly with intranasal oxytocin in men and women with the aim to translate the results found in laboratory animals to humans. Unexpectedly, the results of these studies do not appear to confirm the facilitatory role of oxytocin found in male and female sexual behavior in animals, both in men and women. Possible explanations for the failure of oxytocin to improve sexual behavior in men and women and strategies to attempt to overcome this impasse are considered.
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Giorgioni G, Del Bello F, Pavletić P, Quaglia W, Botticelli L, Cifani C, Micioni Di Bonaventura E, Micioni Di Bonaventura MV, Piergentili A. Recent findings leading to the discovery of selective dopamine D 4 receptor ligands for the treatment of widespread diseases. Eur J Med Chem 2020; 212:113141. [PMID: 33422983 DOI: 10.1016/j.ejmech.2020.113141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 12/14/2022]
Abstract
Since its discovery, the dopamine D4 receptor (D4R) has been suggested to be an attractive target for the treatment of neuropsychiatric diseases. Novel findings have renewed the interest in such a receptor as an emerging target for the management of different diseases, including cancer, Parkinson's disease, alcohol or substance use disorders, eating disorders, erectile dysfunction and cognitive deficits. The recently resolved crystal structures of D4R in complexes with the potent ligands nemonapride and L-745870 strongly improved the knowledge on the molecular mechanisms involving the D4R functions and may help medicinal chemists in drug design. This review is focused on the recent development of the subtype selective D4R ligands belonging to classical or new chemotypes. Moreover, ligands showing functional selectivity toward G protein activation or β-arrestin recruitment and the effects of selective D4R ligands on the above-mentioned diseases are discussed.
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Affiliation(s)
- Gianfabio Giorgioni
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy
| | - Fabio Del Bello
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy.
| | - Pegi Pavletić
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy
| | - Wilma Quaglia
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy.
| | - Luca Botticelli
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna Delle Carceri 9, 62032, Camerino, Italy
| | - Carlo Cifani
- School of Pharmacy, Pharmacology Unit, University of Camerino, Via Madonna Delle Carceri 9, 62032, Camerino, Italy
| | | | | | - Alessandro Piergentili
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy
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Sanna F, Bratzu J, Serra MP, Leo D, Quartu M, Boi M, Espinoza S, Gainetdinov RR, Melis MR, Argiolas A. Altered Sexual Behavior in Dopamine Transporter (DAT) Knockout Male Rats: A Behavioral, Neurochemical and Intracerebral Microdialysis Study. Front Behav Neurosci 2020; 14:58. [PMID: 32372926 PMCID: PMC7185326 DOI: 10.3389/fnbeh.2020.00058] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/25/2020] [Indexed: 12/15/2022] Open
Abstract
Central dopamine plays a key role in sexual behavior. Recently, a Dopamine Transporter knockout (DAT KO) rat has been developed, which displays several behavioral dysfunctions that have been related to increased extracellular dopamine levels and altered dopamine turnover secondary to DAT gene silencing. This prompted us to characterize the sexual behavior of these DAT KO rats and their heterozygote (HET) and wild type (WT) counterparts in classical copulatory tests with a sexually receptive female rat and to verify if and how the acquisition of sexual experience changes along five copulatory tests in these rat lines. Extracellular dopamine and glutamic acid concentrations were also measured in the dialysate obtained by intracerebral microdialysis from the nucleus accumbens (Acb) shell of DAT KO, HET and WT rats, which underwent five copulatory tests, when put in the presence of an inaccessible sexually receptive female rat and when copulation was allowed. Markers of neurotropism (BDNF, trkB), neural activation (Δ-FosB), functional (Arc and PSA-NCAM) and structural synaptic plasticity (synaptophysin, syntaxin-3, PSD-95) were also measured in the ventral tegmental area (VTA), Acb (shell and core) and medial prefrontal cortex (mPFC) by Western Blot assays. The results indicate that the sexual behavior of DAT KO vs. HET and WT rats shows peculiar differences, mainly due to a more rapid acquisition of stable sexual activity levels and to higher levels of sexual motivation and activity. These differences occurred with differential changes in dopamine and glutamic acid concentrations in Acb dialysates during sexual behavior, with lower increases of dopamine and glutamic acid in DAT KO vs. WT and HET rats, and a lower expression of the markers investigated, mainly in the mPFC, in DAT KO vs. WT rats. Together these findings confirm a key role of dopamine in sexual behavior and provide evidence that the permanently high levels of dopamine triggered by DAT gene silencing cause alterations in both the frontocortical glutamatergic neurons projecting to the Acb and VTA and in the mesolimbic dopaminergic neurons, leading to specific brain regional changes in trophic support and neuroplastic processes, which may have a role in the sexual behavior differences found among the three rat genotypes.
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Affiliation(s)
- Fabrizio Sanna
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, Cagliari, Italy
| | - Jessica Bratzu
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, Cagliari, Italy
| | - Maria Pina Serra
- Department of Biomedical Sciences, Section of Citomorphology, University of Cagliari, Cagliari, Italy
| | - Damiana Leo
- Department of Neurosciences, University of Mons, Mons, Belgium
| | - Marina Quartu
- Department of Biomedical Sciences, Section of Citomorphology, University of Cagliari, Cagliari, Italy
| | - Marianna Boi
- Department of Biomedical Sciences, Section of Citomorphology, University of Cagliari, Cagliari, Italy
| | - Stefano Espinoza
- Department of Neuroscience and Brain Technologies, Fondazione Istituto Italiano di Tecnologia, Genoa, Italy
| | - Raul R Gainetdinov
- Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| | - Maria Rosaria Melis
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, Cagliari, Italy
| | - Antonio Argiolas
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, Cagliari, Italy.,Institute of Neuroscience, National Research Council, Cagliari Section, Cagliari, Italy
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Rats selectively bred for showing divergent behavioral traits in response to stress or novelty or spontaneous yawning with a divergent frequency show similar changes in sexual behavior: the role of dopamine. Rev Neurosci 2018; 30:427-454. [DOI: 10.1515/revneuro-2018-0058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 07/26/2018] [Indexed: 02/07/2023]
Abstract
Abstract
Sexual behavior plays a fundamental role for reproduction in mammals and other animal species. It is characterized by an anticipatory and a consummatory phase, and several copulatory parameters have been identified in each phase, mainly in rats. Sexual behavior varies significantly across rats even when they are of the same strain and reared under identical conditions. This review shows that rats of the same strain selectively bred for showing a divergent behavioral trait when exposed to stress or novelty (i.e. Roman high and low avoidance rats, bred for their different avoidance response to the shuttle box, and high and low novelty exploration responders rats, bred for their different exploratory response to a novel environment) or a spontaneous behavior with divergent frequency (i.e. low and high yawning frequency rats, bred for their divergent yawning frequency) show similar differences in sexual behavior, mainly in copulatory pattern, but also in sexual motivation. As shown by behavioral pharmacology and intracerebral microdialysis experiments carried out mainly in Roman rats, these sexual differences may be due to a more robust dopaminergic tone present in the mesocorticolimbic dopaminergic system of one of the two sub-lines (e.g. high avoidance, high novelty exploration, and low yawning rat sub-lines). Thus, differences in genotype and/or in prenatal/postnatal environment lead not only to individual differences in temperament and environmental/emotional reactivity but also in sexual behavior. Because of the highly conserved mechanisms controlling reproduction in mammals, this may occur not only in rats but also in humans.
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Chen G, Chen J, Yang B, Yu W, Chen Y, Dai Y. Dopamine D2 receptors in the basolateral amygdala modulate erectile function in a rat model of nonorganic erectile dysfunction. Andrologia 2018; 51:e13160. [PMID: 30276840 DOI: 10.1111/and.13160] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/22/2018] [Accepted: 09/03/2018] [Indexed: 01/30/2023] Open
Abstract
Nonorganic erectile dysfunction is a problem with unknown central mechanisms. Changes in brain activity in the amygdala have been observed in human patients. This study aimed to investigate the dopamine system in the basolateral amygdala of male rats with nonorganic erectile dysfunction. We applied chronic mild stress to induce nonorganic erectile dysfunction. After exposure to chronic mild stress, the sucrose consumption test, sexual behaviour test and apomorphine test were used to select depression-like rats with erectile dysfunction as nonorganic erectile dysfunction model rats. The sexual behaviour of these rats after central infusion of a dopamine D1/D2 receptor agonist/antagonist was observed. The expression levels of dopamine D1/D2 receptors and tyrosine hydroxylase in the basolateral amygdala were also measured. The result of the sucrose consumption test, sexual behaviour test and apomorphine test indicated a successful nonorganic erectile dysfunction model. Central infusion of a dopamine D2 receptor agonist increased intromission ratio in model rats. Lower expression levels of tyrosine hydroxylase and the dopamine D2 receptor in the basolateral amygdala were observed in rats with nonorganic erectile dysfunction. These results suggest that impairment of the dopamine D2 receptor pathway in the basolateral amygdala may contribute to the development of nonorganic erectile dysfunction.
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Affiliation(s)
- Guotao Chen
- Department of Urology, The Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University, Wuxi, China.,Department of Andrology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Jianhuai Chen
- Department of Andrology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Baibing Yang
- Department of Andrology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Wen Yu
- Department of Andrology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Yun Chen
- Department of Andrology, Jiangsu Province Hospital of TCM, Affiliated Hospital of Nanjing University of TCM, Nanjing, China
| | - Yutian Dai
- Department of Andrology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China
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Seizert CA. The neurobiology of the male sexual refractory period. Neurosci Biobehav Rev 2018; 92:350-377. [DOI: 10.1016/j.neubiorev.2018.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 04/03/2018] [Accepted: 06/13/2018] [Indexed: 02/07/2023]
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12
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Gamal-Eltrabily M, Manzano-García A. Role of central oxytocin and dopamine systems in nociception and their possible interactions: suggested hypotheses. Rev Neurosci 2018; 29:377-386. [DOI: 10.1515/revneuro-2017-0068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 09/16/2017] [Indexed: 12/17/2022]
Abstract
AbstractCentral oxytocin and dopamine have an important role in the process of nociception at the spinal level as well as supraspinal structures, e.g. anterior cingulate cortex, insular cortex, amygdala, nucleus accumbens, and hypothalamus. Many studies have pointed out the importance of both systems in the pain descending modulatory system and in pain-related symptoms in some chronic disorders, e.g. Parkinson disease and fibromyalgia. The interaction between oxytocin and dopamine systems has been addressed in some motivational behaviors, e.g. maternal and sexual behaviors, pair bonding, and salience. In this aspect, we propose that an oxytocin-dopamine interaction could be present in nociception, and we also explain the possible hypotheses of such an interaction between these systems.
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Sanna F, Bratzu J, Argiolas A, Melis MR. Oxytocin induces penile erection and yawning when injected into the bed nucleus of the stria terminalis: Involvement of glutamic acid, dopamine, and nitric oxide. Horm Behav 2017; 96:52-61. [PMID: 28916137 DOI: 10.1016/j.yhbeh.2017.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 08/19/2017] [Accepted: 09/09/2017] [Indexed: 02/02/2023]
Abstract
Oxytocin (5-100ng), but not Arg8-vasopressin (100ng), injected unilaterally into the bed nucleus of the stria terminalis (BNST) induces penile erection and yawning in a dose-dependent manner in male rats. The minimal effective dose was 20ng for penile erection and 5ng for yawning. Oxytocin responses were abolished not only by the oxytocin receptor antagonist d(CH2)5Tyr(Me)2-Orn8-vasotocin (1μg), but also by (+) MK-801 (1μg), an excitatory amino acid receptor antagonist of the N-methyl-d-aspartic acid (NMDA) subtype, SCH 23390 (1μg), a D1 receptor antagonist, but not haloperidol (1μg), a D2 receptor antagonist, and SMTC (40μg), an inhibitor of neuronal nitric oxide synthase, injected into the BNST 15min before oxytocin. Oxytocin-induced penile erection, but not yawning, was also abolished by CNQX (1μg), an excitatory amino acid receptor antagonist of the AMPA subtype. In contrast, oxytocin responses were not reduced by bicuculline (20ng), a GABAA receptor antagonist, phaclofen (5μg), a GABAB receptor antagonist, CP 376395, a CRF receptor-1 antagonist (5μg), or astressin 2B, a CRF receptor-2 antagonist (150ng). Considering the ability of NMDA (100ng) to induce penile erection and yawning when injected into the BNST and the available evidence showing possible interaction among oxytocin, glutamic acid, and dopamine in the BNST, oxytocin possibly activates glutamatergic neurotransmission in the BNST. This in turn leads to the activation of neural pathways projecting back to the paraventricular nucleus, medial preoptic area, ventral tegmental area, and/or ventral subiculum/amygdala, thereby inducing penile erection and yawning.
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Affiliation(s)
- Fabrizio Sanna
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy.
| | - Jessica Bratzu
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy
| | - Antonio Argiolas
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy; Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy; Institute of Neuroscience, National Research Council, Cagliari Section, Cittadella Universitaria, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy
| | - Maria Rosaria Melis
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy; Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, SS 554, km 4,500, 09042 Monserrato, Cagliari, Italy
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14
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Simonsen U, Comerma-Steffensen S, Andersson KE. Modulation of Dopaminergic Pathways to Treat Erectile Dysfunction. Basic Clin Pharmacol Toxicol 2016; 119 Suppl 3:63-74. [DOI: 10.1111/bcpt.12653] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/16/2016] [Indexed: 12/14/2022]
Affiliation(s)
- Ulf Simonsen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology; Aarhus University; Aarhus C Denmark
| | - Simon Comerma-Steffensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology; Aarhus University; Aarhus C Denmark
- Department of Biomedical Science; Faculty of Veterinary Science; Central University of Venezuela; Maracay Bolivarian Republic of Venezuela
| | - Karl-Erik Andersson
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology; Aarhus University; Aarhus C Denmark
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15
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Shridharani AN, Brant WO. The treatment of erectile dysfunction in patients with neurogenic disease. Transl Androl Urol 2016; 5:88-101. [PMID: 26904415 PMCID: PMC4739980 DOI: 10.3978/j.issn.2223-4683.2016.01.07] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Erectile dysfunction (ED) related to compromise of the nervous system is an increasingly common occurrence. This may be due to the multifactorial nature of ED, the myriad of disorders affecting the neurotransmission of erectogenic signals, and improved awareness and diagnosis of ED. Nevertheless, neurogenic ED remains poorly understood and characterized. Disease related factors such as depression, decreased physical and mental function, the burden of chronic illness, and loss of independence may preclude sexual intimacy and lead to ED as well. The amount of data regarding treatment options in subpopulations of differing neurologic disorders remains scarce except for men with spinal cord injury. The treatment options including phosphodiesterase inhibitors, intracavernosal or intraurethral vasoactive agents, vacuum erection devices (VED) and penile prosthetic implantation remain constant. This review discusses the options in specific neurologic conditions, and briefly provides insight into new and future developments that may reshape the management of neurogenic ED.
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Affiliation(s)
- Anand N Shridharani
- 1 Department of Urology, University of Tennessee College of Medicine, Chattanooga, TN, USA ; 2 Division of Urology, University of Utah, Salt Lake City, Utah, USA
| | - William O Brant
- 1 Department of Urology, University of Tennessee College of Medicine, Chattanooga, TN, USA ; 2 Division of Urology, University of Utah, Salt Lake City, Utah, USA
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16
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Prabsattroo T, Wattanathorn J, Iamsaard S, Somsapt P, Sritragool O, Thukhummee W, Muchimapura S. Moringa oleifera extract enhances sexual performance in stressed rats. J Zhejiang Univ Sci B 2015; 16:179-90. [PMID: 25743119 DOI: 10.1631/jzus.b1400197] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Aphrodisiacs are required to improve male sexual function under stressful conditions. Due to the effects of oxidative stress and dopamine on male sexual function, we hypothesized that Moringa oleifera leaves might improve male sexual dysfunction induced by stress. Therefore, the effects on various factors playing important roles in male sexual behavior, such as antioxidant effects, the suppression of monoamine and phosphodiesterase type 5 (PDE-5) activities, serum testosterone and corticosterone levels, and histomorphological changes in the testes, of a hydroethanolic extract of M. oleifera leaves were investigated. Various doses of extract including 10, 50, and 250 mg/kg body weight (BW) were given orally to male Wistar rats before exposure to 12 h-immobilization stress for 7 d. The results demonstrated that the extract showed both antioxidant and monoamine oxidase type B (MAO-B) suppression activities. At 7 d of treatment, the low dose of extract improved sexual performance in stress-exposed rats by decreasing intromission latency and increasing intromission frequency. It also suppressed PDE-5 activity, decreased serum corticosterone level, but increased serum testosterone, numbers of interstitial cells of Leydig and spermatozoa. The increased numbers of interstitial cells of Leydig and spermatozoa might have been due to the antioxidant effect of the extract. The increased sexual performance during the intromission phase might have been due to the suppression of MAO-B and PDE-5 activities and increased testosterone. Therefore, M. oleifera is a potential aphrodisiac, but further research concerning the precise underlying mechanisms is still needed.
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Affiliation(s)
- Thawatchai Prabsattroo
- Graduate School and Department of Physiology (Neuroscience Program), Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Physiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Integrative Complementary and Alternative Medicine Research and Development Center, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
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17
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Sanna F, Contini A, Melis MR, Argiolas A. Role of dopamine D4 receptors in copulatory behavior: Studies with selective D4 agonists and antagonists in male rats. Pharmacol Biochem Behav 2015; 137:110-8. [DOI: 10.1016/j.pbb.2015.08.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 07/30/2015] [Accepted: 08/13/2015] [Indexed: 01/14/2023]
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18
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Serafine KM, Bentley TA, Kilborn DJ, Koek W, France CP. Drinking sucrose or saccharin enhances sensitivity of rats to quinpirole-induced yawning. Eur J Pharmacol 2015; 764:529-536. [PMID: 26189020 DOI: 10.1016/j.ejphar.2015.07.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 07/14/2015] [Accepted: 07/15/2015] [Indexed: 12/31/2022]
Abstract
Diet can impact sensitivity of rats to some of the behavioral effects of drugs acting on dopamine systems. The current study tested whether continuous access to sucrose is necessary to increase yawning induced by the dopamine receptor agonist quinpirole, or if intermittent access is sufficient. These studies also tested whether sensitivity to quinpirole-induced yawning increases in rats drinking the non-caloric sweetener saccharin. Dose-response curves (0.0032-0.32 mg/kg) for quinpirole-induced yawning were determined once weekly in rats with free access to standard chow and either continuous access to water, 10% sucrose solution, or 0.1% saccharin solution, or intermittent access to sucrose or saccharin (i.e., 2 days per week with access to water on other days). Cumulative doses of quinpirole increased then decreased yawning, resulting in an inverted U-shaped dose-response curve. Continuous or intermittent access to sucrose enhanced sensitivity to quinpirole-induced yawning. Continuous, but not intermittent, access to saccharin also enhanced sensitivity to quinpirole-induced yawning. In all groups, pretreatment with the selective D3 receptor antagonist PG01037 shifted the ascending limb of the quinpirole dose-response curve to the right, while pretreatment with the selective D2 receptor antagonist L-741,626 shifted the descending limb to the right. These results suggest that even intermittent consumption of diets containing highly palatable substances (e.g. sucrose) alters sensitivity to drugs acting on dopamine systems in a manner that could be important in vulnerability to abuse drugs.
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Affiliation(s)
- Katherine M Serafine
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA
| | - Todd A Bentley
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA
| | - Dylan J Kilborn
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA
| | - Wouter Koek
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA; Department of Psychiatry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA
| | - Charles P France
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA; Department of Psychiatry, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, Mail Code 7764, San Antonio, TX 78229, USA.
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19
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Sanna F, Piludu MA, Corda MG, Melis MR, Giorgi O, Argiolas A. Involvement of dopamine in the differences in sexual behaviour between Roman high and low avoidance rats: An intracerebral microdialysis study. Behav Brain Res 2015; 281:177-86. [DOI: 10.1016/j.bbr.2014.12.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Accepted: 12/02/2014] [Indexed: 12/15/2022]
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20
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Dopamine is involved in the different patterns of copulatory behaviour of Roman high and low avoidance rats: Studies with apomorphine and haloperidol. Pharmacol Biochem Behav 2014; 124:211-9. [DOI: 10.1016/j.pbb.2014.06.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/07/2014] [Accepted: 06/15/2014] [Indexed: 01/14/2023]
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21
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Lacivita E, De Giorgio P, Colabufo NA, Berardi F, Perrone R, Niso M, Leopoldo M. Design, synthesis, lipophilic properties, and binding affinities of potential ligands in positron emission tomography (PET) for visualization of brain dopamine D4 receptors. Chem Biodivers 2014; 11:299-310. [PMID: 24591318 DOI: 10.1002/cbdv.201300194] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Indexed: 11/11/2022]
Abstract
We report the synthesis of compounds structurally related to the high-affinity dopamine D4 receptor ligand N-{2-[4-(3-cyanopyridin-2-yl)piperazin-1-yl]ethyl}-3-methoxybenzamide (1e). All compounds were specifically designed as potential PET radioligands for brain D4 receptor visualization, having lipophilicity within a range for brain uptake and weak non-specific binding (0.75<cLogP<3.15) and bearing a substituent for easy access to labeling with the positron emitter isotope (11) C or (18) F. The best compound of the series, N-{2-[4-(4-chlorophenyl)piperazin-1-yl]ethyl}-6-fluoropyridine-3-carboxamide (7a), displayed excellent selectivity over D2 and D3 receptors (>100-fold), but its D4 receptor affinity was suboptimal for imaging of brain D4 receptors (Ki =30 nM).
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Affiliation(s)
- Enza Lacivita
- Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, via Orabona, 4, IT-70125, Bari, (phone +39 080 544 2798; fax +39 080 544 2231)
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22
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Dopamine agonist-induced penile erection and yawning: A comparative study in outbred Roman high- and low-avoidance rats. Pharmacol Biochem Behav 2013; 109:59-66. [DOI: 10.1016/j.pbb.2013.05.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 04/12/2013] [Accepted: 05/02/2013] [Indexed: 11/22/2022]
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23
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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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Kyratsas C, Dalla C, Anderzhanova E, Polissidis A, Kokras N, Konstantinides K, Papadopoulou‐Daifoti Z. Experimental Evidence for Sildenafil's Action in the Central Nervous System: Dopamine and Serotonin Changes in the Medial Preoptic Area and Nucleus Accumbens During Sexual Arousal. J Sex Med 2013; 10:719-29. [DOI: 10.1111/j.1743-6109.2012.03000.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Sanna F, Melis MR, Angioni L, Argiolas A. Clavulanic acid induces penile erection and yawning in male rats: comparison with apomorphine. Pharmacol Biochem Behav 2012; 103:750-5. [PMID: 23234836 DOI: 10.1016/j.pbb.2012.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Revised: 11/16/2012] [Accepted: 12/01/2012] [Indexed: 12/24/2022]
Abstract
The beta-lactamase inhibitor clavulanic acid induced penile erection and yawning in a dose dependent manner when given intraperitoneally (IP, 0.05-5mg/kg), perorally (OS, 0.1-5mg/kg) and intracereboventricularly (ICV, 0.01-5 μg/rat) to male rats. The effect resembles that of the dopamine receptor agonist apomorphine given subcutaneously (SC) (0.02-0.25mg/kg), although the responses of the latter followed a U inverted dose-response curve, disappearing at doses higher than 0.1mg/kg. Clavulanic acid responses were reduced by about 55% by haloperidol, a dopamine D2 receptor antagonist (0.1mg/kg IP), and by d(CH(2))(5)Tyr(Me)(2)-Orn(8)-vasotocin, an oxytocin receptor antagonist (2 μg/rat ICV), both given 15 min before clavulanic acid. A higher reduction of clavulanic acid responses (more than 80%) was also found with morphine, an opioid receptor agonist (5mg/kg IP), and with mianserin, a serotonin 5HT(2c) receptor antagonist (0.2mg/kg SC). In contrast, no reduction was found with naloxone, an opioid receptor antagonist (1mg/kg IP). The ability of haloperidol, d(CH(2))(5)Tyr(Me)(2)-Orn(8)-vasotocin and morphine to reduce clavulanic acid induced penile erection and yawning suggests that clavulanic acid induces these responses, at least in part, by increasing central dopaminergic neurotransmission. Dopamine in turn activates oxytocinergic neurotransmission and centrally released oxytocin induces penile erection and yawning. However, since both penile erection and yawning episodes were reduced not only by the blockade of central dopamine and oxytocin receptors and by the stimulation of opioid receptors, which inhibits oxytocinergic neurotransmission, but also by mianserin, an increase of central serotonin neurotransmission is also likely to participate in these clavulanic acid responses.
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Affiliation(s)
- Fabrizio Sanna
- Department of Biomedical Sciences, Neuroscience and Clinical Pharmacology Section, University of Cagliari, Italy
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26
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Löber S, Hübner H, Buschauer A, Sanna F, Argiolas A, Melis MR, Gmeiner P. Novel azulene derivatives for the treatment of erectile dysfunction. Bioorg Med Chem Lett 2012; 22:7151-4. [DOI: 10.1016/j.bmcl.2012.09.064] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 09/17/2012] [Accepted: 09/18/2012] [Indexed: 11/16/2022]
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27
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Sanna F, Argiolas A, Melis MR. Oxytocin-induced yawning: sites of action in the brain and interaction with mesolimbic/mesocortical and incertohypothalamic dopaminergic neurons in male rats. Horm Behav 2012; 62:505-14. [PMID: 22981942 DOI: 10.1016/j.yhbeh.2012.08.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 08/27/2012] [Accepted: 08/29/2012] [Indexed: 02/07/2023]
Abstract
Oxytocin (80 ng) induces yawning when injected into the caudal part of the ventral tegmental area, the hippocampal ventral subiculum and the posteromedial nucleus of the amygdala of male rats. The behavioural response occurred concomitantly with an increase in the concentration of extracellular dopamine and its main metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) in the dialysate obtained from the shell of the nucleus accumbens and of the prelimbic medial prefrontal cortex by means of intracerebral microdialysis. Both oxytocin responses were significantly reduced by d(CH₂)₅Tyr(Me)²-Orn⁸-vasotocin, a selective oxytocin receptor antagonist, injected in the above brain areas 15 min before oxytocin. Similar results were obtained by activating central oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to the ventral tegmental area, the hippocampus and the amygdala, with the dopamine agonist apomorphine given at a dose that induces yawning when injected into the paraventricular nucleus. Since oxytocin is considered a key regulator of emotional and social reward that enhances amygdala-dependent, socially reinforced learning and emotional empathy, mesolimbic and mesocortical dopamine neurons play a key role in motivation and reward, and yawning in mammals is considered a primitive, unconscious form of empathy, the present results support the hypothesis that oxytocinergic neurons originating in the paraventricular nucleus of the hypothalamus and projecting to the above brain areas and mesolimbic and mesocortical dopaminergic neurons participate in the complex neural circuits that play a role in the above mentioned functions.
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Affiliation(s)
- Fabrizio Sanna
- Department of Biomedical Sciences, Neuroscience Section, and Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, and Institute of Neuroscience, National Research Council, Cagliari Section, 09042 Monserrato Cagliari, Italy
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28
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Sanna F, Succu S, Melis MR, Argiolas A. Dopamine agonist-induced penile erection and yawning: Differential role of D2-like receptor subtypes and correlation with nitric oxide production in the paraventricular nucleus of the hypothalamus of male rats. Behav Brain Res 2012; 230:355-64. [DOI: 10.1016/j.bbr.2012.02.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 02/11/2012] [Accepted: 02/16/2012] [Indexed: 10/28/2022]
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