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Navarro-Dorado J, Climent B, López-Oliva ME, Pilar Martínez M, Hernández-Martín M, Agis-Torres Á, Recio P, Victoria Barahona M, Benedito S, Fernandes VS, Hernández M. The bitter taste receptor (TAS2R) agonist denatonium promotes a strong relaxation of rat corpus cavernosum. Biochem Pharmacol 2023; 215:115754. [PMID: 37597814 DOI: 10.1016/j.bcp.2023.115754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 08/21/2023]
Abstract
Bitter taste receptors (TAS2R) are found in numerous extra-oral tissues, including smooth muscle (SM) cells in both vascular and visceral tissues. Upon activation, TAS2R stimulate the relaxation of the SM. Nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway is involved in penile erection, and type 5 phosphodiesterase (PDE5) inhibitors, a cGMP-specific hydrolase are used as first-line treatments for erectile dysfunction (ED). Nevertheless, PDE5 inhibitors are ineffective in a considerable number of patients, prompting research into alternative pharmacological targets for ED. Since TAS2R agonists regulate SM contractility, this study investigates the role of TAS2Rs in rat corpus cavernosum (CC). We performed immunohistochemistry to detect TAS2R10, isometric force recordings for TAS2R agonists denatonium and chloroquine, the slow-release H2S donor GYY 4137, the NO donor SNAP, the β-adrenoceptor agonist isoproterenol and electrical field stimulation (EFS), as well as measurement of endogenous hydrogen sulfide (H2S) production. The immunofluorescence staining indicated that TAS2R10 was broadly expressed in the CC SM and to some extent in the nerve fibers. Denatonium, chloroquine, SNAP, and isoproterenol cause potent dose-dependent SM relaxations. H2S production was decreased by NO and H2S synthase inhibitors, while it was enhanced by denatonium. In addition, denatonium increased the relaxations induced by GYY 4137 and SNAP but failed to modify EFS- and isoproterenol-induced responses. These results suggest neuronal and SM TAS2R10 expression in the rat CC, where denatonium induces a strong SM relaxation per se and promotes the H2S- and NO-mediated inhibitory gaseous neurotransmission. Thus, TAS2R10 might represent a valuable therapeutic target in ED.
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Affiliation(s)
- Jorge Navarro-Dorado
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Belén Climent
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - María Elvira López-Oliva
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Embriología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Marina Hernández-Martín
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Ángel Agis-Torres
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - María Victoria Barahona
- Departamento de Farmacología y Toxicología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Sara Benedito
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Vítor S Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain.
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain.
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2
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Fernandes VS, López-Oliva ME, Martínez MP, Agis-Torres Á, Recio P, Navarro-Dorado J, Barahona MV, Benedito S, Prieto D, Climent B, Hernández M. In vitro inhibition of phosphodiesterase type 4 enhances rat corpus cavernosum nerve-mediated relaxation induced by gasotransmitters. Life Sci 2022; 296:120432. [PMID: 35219697 DOI: 10.1016/j.lfs.2022.120432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 11/15/2022]
Abstract
AIMS Nitric oxide (NO) and hydrogen sulfide (H2S) are involved in nerve-mediated corpus cavernosum (CC) relaxation. Expression of phosphodiesterase type 5 (PDE5) and type 4 (PDE4), cyclic guanosine monophosphate (cGMP)- and cyclic adenosine monophosphate (cAMP)-specific, respectively, has been described and PDE5- and PDE4-inhibitors induce cavernous smooth muscle relaxation. Whereas the NO/cGMP signaling pathway is well established in penile erection, the cAMP-mediated mechanism is not fully elucidated. The aim of this study is to investigate the localization and the functional significance of PDE4 in rat CC tone regulation. MAIN METHODS We performed immunohistochemistry for the detection of the PDE4A isoenzyme. Isometric tension recordings for roflumilast and tadalafil, PDE4 and PDE5 inhibitors, respectively, electrical field stimulation (EFS) and β-adrenoceptor agonist isoproterenol and endogenous H2S production measurement. KEY FINDINGS A marked PDE4A expression was detected mainly localized in the nerve cells of the cavernous smooth muscle. Furthermore, roflumilast and tadalafil exhibited strong corpus cavernous relaxations. Endogenous H2S production was decreased by NO and H2S synthase inhibitors and increased by roflumilast. Isoproterenol- and EFS-induced relaxations were increased by roflumilast. SIGNIFICANCE These results indicate that PDE4A is mainly expressed within the nerves cells of the rat CC, where roflumilast induces a potent corpus cavernous relaxation per se and potentiates the response induced by β-adrenoceptor activation. The fact that roflumilast enhances H2S production, as well as EFS-elicited responses suggests that PDE4 inhibitors modulate, in a positive feedback fashion, nerve-mediated relaxation induced by gasotransmitters, thus indicating a key role for neuronal PDE4 in penile erection.
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Affiliation(s)
- Vítor S Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Elvira López-Oliva
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Ángel Agis-Torres
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jorge Navarro-Dorado
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Victoria Barahona
- Departamento de Farmacología y Toxicología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Sara Benedito
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Belén Climent
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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3
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A Review on Phosphodiesterase-5 Inhibitors as a Topical Therapy for Erectile Dysfunction. Sex Med Rev 2022; 10:376-391. [DOI: 10.1016/j.sxmr.2022.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 02/12/2022] [Accepted: 02/15/2022] [Indexed: 11/18/2022]
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4
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Ajeigbe OF, Oboh G, Ademosun AO, Umar HI. Fig (Ficus exasperata and Ficus asperifolia)-Supplemented diet improves sexual function, endothelial nitric oxide synthase and suppresses tumour necrosis factor-alpha genes in hypertensive rats. Andrologia 2021; 54:e14289. [PMID: 34693556 DOI: 10.1111/and.14289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 10/13/2021] [Indexed: 11/28/2022] Open
Abstract
We measured the effect of varieties of Fig leaves, Ficus exasperata Vahl. (FE) and Ficus asperifolia Miq (FA), commonly found in Sub-sahara Africa for managing hypertension on sexual performance in hypertensive rats, which is unknown. Hypertensive rats experienced erectogenic damage after exposure to 40 mg kg-1 bw-1 , N(G)-nitro-l-arginine-methyl-ester (L-NAME). Experimental rats were grouped into eight groups (n = 6) namely: control rats, hypertensive rats, hypertensive treatment groups with atenolol (10 mg kg-1 day-1 ) and sildenafil (5.0 mg/kg), rats treated with FE- and FA-formulated biscuits at proportions of 2.5 g and 5.0 g respectively. Furthermore, we measured the level of sexual performance (Intromission number, latency, Mounting number, and latency), hormonal levels, phosphodiesterase-5 enzyme (PDE-5) activity and genes expressed using real-time quantitative polymerase chain reaction (RT-qPCR) in hypertensive rats. The result deduced revealed that treated hypertensive rats showed significantly reduced follicle-stimulating hormone, luteinising hormone levels, PDE-5 enzyme activity, tumour necrosis factor-alpha (TNF-α) expression while having a marked increase in testosterone level, sexual performance and endothelial nitric oxide synthase (eNOS) expression. Therefore, this study revealed the comparative dietary enhancing effect of FE- and FA-formulated biscuit on sexual behaviour activity, hormonal levels and the level of eNOS and TNF-α genes expressed in hypertensive rats.
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Affiliation(s)
- Olufunke Florence Ajeigbe
- Functional Foods and Nutraceutical Unit, Department of Biochemistry, Federal University of Technology Akure, Akure, Nigeria.,Department of Physical and Chemical Sciences, Biochemistry Programme, Elizade University, Akure, Nigeria
| | - Ganiyu Oboh
- Functional Foods and Nutraceutical Unit, Department of Biochemistry, Federal University of Technology Akure, Akure, Nigeria
| | - Ayokunle Olubode Ademosun
- Functional Foods and Nutraceutical Unit, Department of Biochemistry, Federal University of Technology Akure, Akure, Nigeria
| | - Haruna Isiyaku Umar
- Department of Biochemistry, Federal University of Technology Akure, Akure, Nigeria
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5
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Giatti S, Di Domizio A, Diviccaro S, Falvo E, Caruso D, Contini A, Melcangi RC. Three-Dimensional Proteome-Wide Scale Screening for the 5-Alpha Reductase Inhibitor Finasteride: Identification of a Novel Off-Target. J Med Chem 2021; 64:4553-4566. [PMID: 33843213 PMCID: PMC8154553 DOI: 10.1021/acs.jmedchem.0c02039] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Indexed: 12/15/2022]
Abstract
Finasteride, a 5-alpha reductase (5α-R) inhibitor, is a widely used drug for treating androgen-dependent conditions. However, its use is associated with sexual, psychological, and physical complaints, suggesting that other mechanisms, in addition to 5α-R inhibition, may be involved. Here, a multidisciplinary approach has been used to identify potential finasteride off-target proteins. SPILLO-PBSS software suggests an additional inhibitory activity of finasteride on phenylethanolamine N-methyltransferase (PNMT), the limiting enzyme in formation of the stress hormone epinephrine. The interaction of finasteride with PNMT was supported by docking and molecular dynamics analysis and by in vitro assay, confirming the inhibitory nature of the binding. Finally, this inhibition was also confirmed in an in vivo rat model. Literature data indicate that PNMT activity perturbation may be correlated with sexual and psychological side effects. Therefore, results here obtained suggest that the binding of finasteride to PNMT might have a role in producing the side effects exerted by finasteride treatment.
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Affiliation(s)
- Silvia Giatti
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milano, Italy
| | - Alessandro Di Domizio
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milano, Italy
- SPILLOproject, via Stradivari
17, Paderno Dugnano, 20037 Milano, Italy
| | - Silvia Diviccaro
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milano, Italy
| | - Eva Falvo
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milano, Italy
| | - Donatella Caruso
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milano, Italy
| | - Alessandro Contini
- Dipartimento
Di Scienze Farmaceutiche, Università
degli Studi di Milano, 20133 Milano, Italy
| | - Roberto Cosimo Melcangi
- Department
of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, via Balzaretti 9, 20133 Milano, Italy
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6
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Otasevic V, Stancic A, Korac A, Jankovic A, Korac B. Reactive oxygen, nitrogen, and sulfur species in human male fertility. A crossroad of cellular signaling and pathology. Biofactors 2020; 46:206-219. [PMID: 31185138 DOI: 10.1002/biof.1535] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 05/17/2019] [Indexed: 12/23/2022]
Abstract
Infertility is a significant global health problem that currently affects one of six couples in reproductive age. The quality of male reproductive cells dramatically decreased over the last years and almost every aspect of modern life additionally worsen sperm functional parameters that consequently markedly increase male infertility. This clearly points out the importance of finding a new approach to treat male infertility. Redox signaling mediated by reactive oxygen, nitrogen and sulfur species (ROS, RNS, and RSS respectively), has appeared important for sperm reproductive function. Present review summarizes the current knowledge of ROS, RNS, and RSS in male reproductive biology and identifies potential targets for development of novel pharmacological and therapeutic approaches for male infertility by targeted therapeutic modulation of redox signaling.
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Affiliation(s)
- Vesna Otasevic
- University of Belgrade, Institute for Biological Research "Sinisa Stankovic", Belgrade, Serbia
| | - Ana Stancic
- University of Belgrade, Institute for Biological Research "Sinisa Stankovic", Belgrade, Serbia
| | - Aleksandra Korac
- University of Belgrade, Faculty of Biology, Center for Electron Microscopy, Belgrade, Serbia
| | - Aleksandra Jankovic
- University of Belgrade, Institute for Biological Research "Sinisa Stankovic", Belgrade, Serbia
| | - Bato Korac
- University of Belgrade, Institute for Biological Research "Sinisa Stankovic", Belgrade, Serbia
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7
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Oboh G, Adebayo AA, Ademosun AO. Hunteria umbellata seed extract administration modulates activities of phosphodiesterase-5 and purinergic enzymes relevant to erection in normal male rats. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s13596-019-00368-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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8
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Jimoh TO, Ademiluyi AO, Oboh G, Boligon AA. Phenolic extracts and amino acids content from Cucumeropsis mannii naudin and Citrullus lanatus inhibit relevant enzymes of erectile dysfunction in rat's penile tissue. Biochem Biophys Rep 2017; 12:5-11. [PMID: 28955786 PMCID: PMC5613215 DOI: 10.1016/j.bbrep.2017.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 03/31/2017] [Accepted: 08/06/2017] [Indexed: 11/23/2022] Open
Abstract
•A focused on the erectogenic potentials of two tropical pumpkin seeds was established.•The antioxidant properties of these seed varieties were also discussed.•The inhibitory effects of the seeds on key enzymes relevant to ED were critically explored.•The potentials of the seeds to manage ED were recommended.
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Affiliation(s)
- Tajudeen O. Jimoh
- Department of Biochemistry, Federal University of Technology, PMB 704, Akure 340001, Nigeria
| | - Adedayo O. Ademiluyi
- Department of Biochemistry, Federal University of Technology, PMB 704, Akure 340001, Nigeria
| | - Ganiyu Oboh
- Department of Biochemistry, Federal University of Technology, PMB 704, Akure 340001, Nigeria
| | - Aline A. Boligon
- Phytochemical Research Laboratory, Department of Industrial Pharmacy, Federal University of Santa Maria, Building 26, Room 1115, 97105-900 Santa Maria, RS, Brazil
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9
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Ademiluyi AO, Ogunsuyi OB, Adebayo AA, Oboh G. Effect of fermented legume seeds on some key enzymes relevant to erectile dysfunction in vitro. J Food Biochem 2017. [DOI: 10.1111/jfbc.12437] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adedayo O. Ademiluyi
- Functional Foods and Nutraceutical Research Unit, Department of Biochemistry; Federal University of Technology; Akure Nigeria
| | - Opeyemi B. Ogunsuyi
- Functional Foods and Nutraceutical Research Unit, Department of Biochemistry; Federal University of Technology; Akure Nigeria
- Department of Biomedical Technology; Federal University of Technology; Akure Nigeria
| | - Adeniyi A. Adebayo
- Functional Foods and Nutraceutical Research Unit, Department of Biochemistry; Federal University of Technology; Akure Nigeria
| | - Ganiyu Oboh
- Functional Foods and Nutraceutical Research Unit, Department of Biochemistry; Federal University of Technology; Akure Nigeria
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10
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Shang HS, Wu YN, Liao CH, Chiueh TS, Lin YF, Chiang HS. Long-term administration of ketamine induces erectile dysfunction by decreasing neuronal nitric oxide synthase on cavernous nerve and increasing corporal smooth muscle cell apoptosis in rats. Oncotarget 2016; 8:73670-73683. [PMID: 29088735 PMCID: PMC5650290 DOI: 10.18632/oncotarget.10727] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 06/01/2016] [Indexed: 11/28/2022] Open
Abstract
We investigated and evaluated the mechanisms of erectile dysfunction (ED) in a rat model of long-term ketamine administration. Adult male Sprague-Dawley rats (n = 32) were divided into four groups: namely the control group receiving intraperitoneal injection of saline, 1-month, 2-month and 3-month groups receiving daily intraperitoneal injection of ketamine (100 mg/kg/day) for 1, 2, and 3 month respectively. After treatment, animals underwent an erectile response protocol to assess intracavernosal pressure (ICP). Smooth muscle content was evaluated. Neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) expression were assessed using immunostaining assay. Ketamine-induced apoptosis was analyzed using TUNEL assay. Long-term ketamine administration caused significantly decreased erectile responses as measured by ICP. Smooth muscle content was significantly decreased in the ketamine-treated rats for 3 months. In the erectile tissue, ketamine administration significantly reduced nNOS expression and increased iNOS content compared with controls, whereas eNOS expression was not altered. Ketamine induced apoptosis in corpus cavernosum. The present study demonstrates that long-term ketamine administration led to erectile dysfunction in rat. The molecular mechanisms of ketamine-induced ED involved the increased apoptosis and up-regulated iNOS expression incorporating with loss of corporal smooth muscle content and reduced nNOS expression in cavernous nerve.
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Affiliation(s)
- Hung-Sheng Shang
- Graduate Institute of Clinical of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Clinical Pathology, Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-No Wu
- Graduate Institute of Basic Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Chun-Hou Liao
- Division of Urology, Department of Surgery, Cardinal Tien Hospital, Taipei City, Taiwan.,College of Medicine, Fu Jen Catholic University, Taipei City, Taiwan
| | - Tzong-Shi Chiueh
- Division of Clinical Pathology, Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yuh-Feng Lin
- Graduate Institute of Clinical of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.,Division of Nephrology, Department of Medicine, Shuang Ho Hospital, School of Medicine, College of Medicine, Taipei Medical University, New Taipei City, Taiwan.,Division of Nephrology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Han-Sun Chiang
- Graduate Institute of Basic Medicine, Fu Jen Catholic University, New Taipei City, Taiwan.,Division of Urology, Department of Surgery, Cardinal Tien Hospital, Taipei City, Taiwan.,Department of Urology, Taipei Medical University Hospital, Taipei, Taiwan
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11
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Alkan E, Ugan RA, Basar MM, Halici Z, Karakus E, Balbay MD, Un H. Role of endothelin receptors and relationship with nitric oxide synthase in impaired erectile response in diabetic rats. Andrologia 2016; 49. [PMID: 27145076 DOI: 10.1111/and.12607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/11/2016] [Indexed: 12/16/2022] Open
Abstract
To evaluate the protective role of bosentan (BOS), an endothelin-1 (ET-1) receptor antagonist, and to show the changes in rats with experimentally induced diabetic erectile dysfunction (ED), a total of 24 albino Wistar rats were allocated into four groups. Group 1 was the healthy group and Group 2 had diabetes mellitus (DM) induced by intraperitoneal injection of 60 mg kg-1 streptozotocin (STZ). Following the establishment of DM, Group 3 and Group 4 were treated with oral BOS doses of 50 mg kg-1 and 100 mg kg-1 , respectively, for 60 days. At the end of the treatment, we evaluated yawning and erection response to apomorphine treatment and then the animals were sacrificed. ET-1, eNOS, iNOS, tumour necrosis factor (TNF)-α, ET-RA and ET-RB mRNA expressions were analysed in cavernosal tissue. It was observed that yawning and erection response decreased in the diabetic group; however, both of these improved with BOS treatment. While ET-1, TNF-α and iNOS gene expressions increased, eNOS, ET-RA and ET-RB gene expressions decreased in the DM group compared to the healthy group. DM has a negative impact on cavernosal tissue blood flow through activating vasoconstrictor mediators in cavernosal tissue. BOS regulates significantly eNOS, iNOS and TNF-α expressions in a dose-dependent manner.
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Affiliation(s)
- E Alkan
- Department of Urology, Memorial Sisli Hospital, Istanbul, Turkey
| | - R A Ugan
- Faculty of Medicine, Department of Pharmacology, Ataturk University, Erzurum, Turkey
| | - M M Basar
- Department of Urology, Memorial Sisli Hospital, Istanbul, Turkey
| | - Z Halici
- Faculty of Medicine, Department of Pharmacology, Ataturk University, Erzurum, Turkey
| | - E Karakus
- Faculty of Veterinary, Department of Pharmacology and Toxicology, Ataturk University, Erzurum, Turkey
| | - M D Balbay
- Department of Urology, Memorial Sisli Hospital, Istanbul, Turkey
| | - H Un
- Faculty of Pharmacy, Department of Biochemistry, Ibrahim Cecen University, Agri, Turkey
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12
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Kallakuri S, Kreipke CW, Rossi N, Rafols JA, Petrov T. Spatial alterations in endothelin receptor expression are temporally associated with the altered microcirculation after brain trauma. Neurol Res 2013; 29:362-8. [PMID: 17626731 DOI: 10.1179/016164107x204675] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES To study the cellular distribution of endothelin receptors A and B (ETrA and ETrB) in the post-traumatic sensorimotor cortex and hippocampus. MATERIALS AND METHODS We inflicted closed head trauma to male Sprague-Dawley rats and visualized ETrA and ETrB immunoreactivity with 3,3'-diaminobenzidine. RESULTS ETrA immunolabeling was the most prominent in pyramidal neurons 24 and 48 hours post-trauma, while it reached its peak in the microvasculature at hour 4. ETrB immunolabeling was observed in endothelial cells, perivascular neurons, smooth muscle cells (SM) and pericytes, the expression being the most pronounced 24 hours post-trauma. DISCUSSION The results suggest that the vasoconstrictor effect of endothelin-1 (ET-1) is mediated primarily by ETrA. The dual effects of ETrB are reflected in its vasoconstrictor role at the vascular bed and conversely, in the attenuation of ET-1 availability and synthesis. We conclude that both receptors play a role in the disturbed microvascular autoregulation and in the sustained reduction of blood flow following trauma to the brain.
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Affiliation(s)
- Srinivasu Kallakuri
- Department of Anatomy and Cell Biology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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13
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Kreipke CW, Schafer PC, Rossi NF, Rafols JA. Retracted Article: Differential effects of endothelin receptor A and B antagonism on cerebral hypoperfusion following traumatic brain injury. Neurol Res 2013; 32:209-14. [DOI: 10.1179/174313209x414515] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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14
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Krishna R, Wong P, Stevens C, De Lepeleire I, Van Dyck K, Rosen RC, Gendrano IN, Peeters M, Wagner JA, Herman GA. Lack of Erectogenic Activity of a Novel Selective Melanocortin-4 Receptor Agonist in a Clinical Experimental Model. J Clin Pharmacol 2013; 48:1237-41. [DOI: 10.1177/0091270008320925] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Bivalacqua TJ, Usta MF, Champion HC, Kadowitz PJ, Hellstrom WJG. Endothelial Dysfunction in Erectile Dysfunction: Role of the Endothelium in Erectile Physiology and Disease. ACTA ACUST UNITED AC 2013; 24:S17-37. [PMID: 14581492 DOI: 10.1002/j.1939-4640.2003.tb02743.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Trinity J Bivalacqua
- Department of Urology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA
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Bernardi MM, Kirsten TB, Lago JHG, Giovani TM, Massoco CDO. Nepeta cataria L. var. citriodora (Becker) increases penile erection in rats. JOURNAL OF ETHNOPHARMACOLOGY 2011; 137:1318-1322. [PMID: 21843621 DOI: 10.1016/j.jep.2011.07.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 07/26/2011] [Accepted: 07/29/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nepeta cataria (NC), catnip, induces pleasure in cats and humans. AIM OF THE STUDY Because sexual behavior is involved in pleasure, the effect of NC on sexual behavior and penile erection was evaluated in male rats that were acutely fed chow enriched with 10% NC leaves. Further, yawning was monitored because we previously demonstrated that NC modifies dopaminergic-related behaviors and that sexual behavior is closely linked with the dopaminergic system. The general activity and the motor coordination were examined to investigate the possible motor and emotional interferences of the sexual performance. MATERIAL AND METHODS Male rats of the NC group received for a 4h period the chow enriched with 10% NC leaves while the control groups received regular chow. Fifteen min after the end of the 4h period of NC feeding the sexual behavior, apomorphine-induced penile erection and motor coordination were observed; the general activity in the open field was assessed 0, 15, 30 and 60 min after treatment. RESULTS NC treatment increased male rat's penile erection. A slightly facilitation on male rat sexual behavior and a decreased in general activity of NC treated rats were observed. No effects on motor coordination and yawning episodes were detected by the NC treatment. CONCLUSIONS It was suggested that NC increases penile erection and slightly improves male rat sexual behavior by an action on dopaminergic systems.
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Hisasue SI. Advances in the study of the peripheral nervous system for erection in animals and humans. Reprod Med Biol 2011; 10:121-129. [PMID: 29699088 DOI: 10.1007/s12522-011-0081-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Accepted: 03/19/2011] [Indexed: 11/27/2022] Open
Abstract
Introduction Since Walsh first emphasized the importance of preserving the neurovascular bundle n to protect the cavernous nerve during pelvic surgery, patients' sexual life quality has dramatically improved. Today, nerve-sparing radical prostatectomy is the established gold standard for organ-confined prostate cancer patients. Recent technical advances in functional assessment such as intraoperative electrical stimulation have unveiled new anatomical features and physiological roles. Basic research has advanced understanding of cavernous nerve function, while molecular biology has uncovered the crucial role of neuronal nitric oxide in mediating erection, and has led to new treatments such as phosphodiesterase type-5 inhibitors. A recent focus in cavernous nerve research concerns the nerve distribution external to the neurovascular bundle. The cavernous nerves in humans appear to be distributed more widely beneath the lateral pelvic fascia than in other animals, and electrical stimulation studies suggest possible involvement of these nerves in erection. These findings have prompted new surgical techniques such as the "veil of Aphrodite", or "intrafascial nerve-sparing" procedures. Materials and Methods These recent anatomical and physiological studies in humans and animals and their impact are reviewed in this article. Conclusions Further investigation should stimulate future advances in strategies to preserve erectile function in RP patients.
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Affiliation(s)
- Shin-Ichi Hisasue
- Department of Urology, School of Medicine Sapporo Medical University S1-W16, Chuo-ku 060-8543 Sapporo Hokkaido Japan
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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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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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Single nucleotide polymorphism in the drug transporter gene ABCB1 in treatment-resistant depression: clinical practice. J Clin Psychopharmacol 2010; 30:209-11. [PMID: 20520302 DOI: 10.1097/jcp.0b013e3181d2ef5a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nangle MR, Proietto J, Keast JR. Impaired Cavernous Reinnervation after Penile Nerve Injury in Rats with Features of the Metabolic Syndrome. J Sex Med 2009; 6:3032-44. [DOI: 10.1111/j.1743-6109.2009.01415.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Briganti A, Salonia A, Gallina A, Saccà A, Montorsi P, Rigatti P, Montorsi F. Drug Insight: oral phosphodiesterase type 5 inhibitors for erectile dysfunction. ACTA ACUST UNITED AC 2006; 2:239-47. [PMID: 16474835 DOI: 10.1038/ncpuro0186] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2004] [Accepted: 04/18/2005] [Indexed: 12/13/2022]
Abstract
Erectile dysfunction (ED) is a common medical condition that affects the sexual life of millions of men. At present, first-line oral pharmacotherapy for most patients with ED is a phosphodiesterase type 5 (PDE-5) inhibitor, of which three are currently available worldwide. Sildenafil (Viagra, Pfizer) has a very satisfactory efficacy-safety profile in all patient categories. The first PDE-5 inhibitor to reach the market, it is now the most widely prescribed oral agent for ED. Tadalafil (Cialis, Lilly ICOS) and vardenafil (Levitra, Bayer/GlaxoSmithKline) were introduced to the European Union and the US in 2003 and 2004, respectively. These three PDE-5 inhibitors share many characteristics, but each has unique features. This review describes the chemical, pharmacologic and clinical features of sildenafil, vardenafil and tadalafil as oral first-line treatments for ED. First, we describe the physiology of penile erection and PDE-5 inhibitor pharmacology, including chemistry, PDE selectivity, pharmacokinetics, and possible drug interactions. We then summarize data on the efficacy and safety profiles of the three PDE-5 inhibitors for the treatment of ED in the general population, in patients with diabetes mellitus and in men that have undergone bilateral nerve-sparing retropubic radical prostatectomy.
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Affiliation(s)
- Alberto Briganti
- Department of Urology at Università Vita Salute San Raffaele, Milan, Italy
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Briganti A, Salonia A, Deho' F, Zanni G, Barbieri L, Rigatti P, Montorsi F. Clinical update on phosphodiesterase type-5 inhibitors for erectile dysfunction. World J Urol 2005; 23:374-84. [PMID: 16273417 DOI: 10.1007/s00345-005-0022-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 10/27/2005] [Indexed: 11/26/2022] Open
Abstract
Erectile dysfunction (ED) affects the sexual lives of millions of men. The first-line oral pharmacotherapy for most ED patients is phosphodiesterase type-5 (PDE-5) inhibitors, of which three are available. Sildenafil is the most widely prescribed oral agent for ED and has a very satisfactory efficacy-safety profile in all patient categories. Tadalafil and vardenafil were introduced in the European Union and in the United States in 2003 and 2004, respectively. The three PDE-5 inhibitors share many pharmacological and clinical characteristics, and each has unique features. This review, which is based on the contemporary literature on PDE-5 inhibitors, describes the chemical, pharmacological, and clinical features of sildenafil, vardenafil, and tadalafil. The first section reviews the pathophysiology of penile erection and PDE-5 inhibitor pharmacology. The second section summarizes data regarding efficacy and safety of the three drugs in treating ED in the general population as well as in selected patient categories.
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Affiliation(s)
- Alberto Briganti
- Department of Urology, Universitá Vita-Salute San Raffaele, Milan, Italy
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Kendirci M, Walls MM, Hellstrom WJG. Central Nervous System Agents in the Treatment of Erectile Dysfunction. Urol Clin North Am 2005; 32:487-501, vii. [PMID: 16291040 DOI: 10.1016/j.ucl.2005.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In the last two decades, a better understanding of the mechanisms governing erectile function and the pathophysiologies underlying erectile dysfunction (ED) have led re-searchers to investigate novel treatment concepts. Selective type-5 phosphodiesterase inhibitors are recommended as first-line therapy because of their high efficacy, but 30% to 40% of patients who have ED do not respond adequately to these agents and require alternative methods. The central nervous system plays a fundamental role in sexual behavior. Animal models have advanced our understanding of the neuroanatomic and neuropharmacologic basis of centrally induced penile erections. Clinical research with apomorphine has demonstrated efficacy in men who have a range of ED. Recent interest has focused on other centrally acting agents for ED treatment, including the melanocortin receptor agonists.
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Affiliation(s)
- Muammer Kendirci
- Department of Urology, Tulane University, Health Sciences Center, SL-42, New Orleans, LA 70112, USA
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Briganti A, Salonia A, Gallina A, Suardi N, Rigatti P, Montorsi F. Emerging oral drugs for erectile dysfunction. Expert Opin Emerg Drugs 2005. [DOI: 10.1517/14728214.9.1.179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Aversa A, Pili M, Fabbri A, Spera E, Spera G. Erectile dysfunction: expectations beyond phosphodiesterase type 5 inhibition. J Endocrinol Invest 2004; 27:192-206. [PMID: 15129818 DOI: 10.1007/bf03346268] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the last few years the pathophysiological mechanisms of erection have been partially clarified, and the molecular machinery of the cellular components of the corpus cavernosum (CC) has been widely investigated. Since erection is a vascular event and the penis is a vascular organ, there must be an intact endothelium for an erection to occur. The regulation of penile tumescence inside the CC involves a balance between contracting and relaxing factors which regulate the functional state of smooth muscle cells. Recent studies have highlighted the importance of new local factors (i.e. phosphodiesterases, rho-kinases and endothelins), and pharmacological agents are available in the armamentarium of the specialist which are targeted to modulate the function of those mediators of erection. It is now well understood that male erectile dysfunction (ED) is a symptom rather than a disease; for this reason in the near future both general practitioners and specialists in internal medicine would have to interplay with sexual medicine. This review is intended to give the clinician some basic concepts of the pathophysiology of erection with relevance to the clinical practice, and to discuss the newest therapeutic approaches for those patients who do not respond to the treatment with oral inhibitors of phosphodiesterase Type 5.
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Affiliation(s)
- A Aversa
- Department of Medical Phisiopathology, University La Sapienza, Rome, Italy.
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Caruso S, Intelisano G, Farina M, DiMari L, Agnello C, Giammusso B. Efficacy and safety of daily intake of apomorphine SL in men affected by erectile dysfunction and mild hyperprolactinemia: a prospective, open-label, pilot study. Urology 2003; 62:922-7. [PMID: 14624921 DOI: 10.1016/s0090-4295(03)00694-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVES To evaluate the efficacy of the "daily" use of apomorphine SL compared with the "on demand" administration of the drug in patients with mild to moderate erectile dysfunction (ED) and mild hyperprolactinemia who were nonresponders to apomorphine administered "on demand." METHODS In this open-label prospective study, 34 patients with mild-to-moderate ED and mild hyperprolactinemia were screened. The subjects answered the International Index of Erectile Function (IIEF) questionnaire and underwent follicle-stimulating hormone, luteinizing hormone, testosterone, free testosterone, and prolactin plasma testing, and Doppler sonography at the 2-week screening period to define the ED severity and etiology, at the end of a 4-week "as required" dose-escalation regimen of 2 mg/3 mg apomorphine SL, and at the end of a 4-week period of daily administration of the drug to assess the efficacy of each treatment modality. RESULTS Twenty patients (age range 27 to 46 years) were included in the study. Eighteen subjects completed the 4-week "as required" drug intake period, and three (16.7%) benefited from this modality of treatment (P <0.05). Fifteen nonresponder patients participated in the 4-week daily apomorphine SL use, and 13 (86%) reported satisfaction with the treatment (P <0.05). The 3-mg daily administration was more effective than the 2-mg daily administration for erectile function (P <0.02) but not for other sexual domains scored with IIEF. Adverse events were of mild or moderate severity, either during the "as required" drug intake (4 patients) or during daily use (3 subjects) and were mainly nausea, dizziness, or headache. CONCLUSIONS Data from the clinical evaluation of symptomatic apomorphine SL use have always shown a poor success rate, probably because it is used "as sildenafil." Using apomorphine SL as a treatment of ED, we observed a significant improvement in both subjective and objective aspects scored with the IIEF. The increase of prolactin could influence the erective mechanisms, and it cannot be excluded that a subgroup of men with ED may have an impairment of central dopaminergic function. Moreover, additional studies need to define the daily use of apomorphine SL in large subgroups of men on the basis of ED etiology and severity.
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Affiliation(s)
- Salvatore Caruso
- Department of Microbiological and Gynecological Sciences, University of Catania School of Medicine, Ospedale S. Bambino, Catania, Italy
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Salonia A, Briganti A, Dehò F, Naspro R, Scapaticci E, Scattoni V, Rigatti P, Montorsi F. Pathophysiology of erectile dysfunction. INTERNATIONAL JOURNAL OF ANDROLOGY 2003; 26:129-36. [PMID: 12755990 DOI: 10.1046/j.1365-2605.2003.00342.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Andrea Salonia
- Department of Urology, University Vita-Salute San Raffaele, Milan, Italy
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Abstract
Sildenafil citrate (Viagra) is a potent orally active cGMP-specific phosphodiesterase type 5 (PDE5) inhibitor that is effective as a peripheral conditioner in the treatment of male erectile dysfunction (ED) of organic, psychogenic or mixed aetiology. Sildenafil is the first effective oral agent in the management of ED that has had a revolutionary impact on management of ED. The present review has been subdivided into five major sections. Based on the most recent peer-reviewed publications, the first section is aimed at critically evaluating PDE5 selectivity as well as the pharmacokinetics and pharmacodynamics of the drug, mainly to assess the best doses for each group of patients (i.e. adult and elderly men). Effectiveness in a broad spectrum ED population is the subject of the second section of the review, principally reporting post-marketing company-independent results. Safety and tolerability are the key concerns of the third section, with a broad consideration of the most commonly reported adverse events. Special attention has been paid to the cardiovascular safety of the drug, chiefly outlining the positive and potentially protective cardiac effects of sildenafil. Moreover, the impact of sildenafil in special patient populations is considered, namely in men complaining of diabetes mellitus, depression, neurological disorders, renal failure and those who have undergone a radical prostatectomy. Sildenafil and the ageing male has been especially underlined. Finally, the review covers a few new potential applications of sildenafil in ED patients with regard to high-dose treatment and combination therapy. The review ends with several considerations regarding the direct and/or indirect impact of sildenafil over quality of life and quality of partnership.
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Affiliation(s)
- Andrea Salonia
- Department of Urology, University Vita-Salute San Raffaele, Milan, Italy
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Abstract
Recent studies have demonstrated that vasoconstriction in the erectile vasculature of the penis is mediated in part by RhoA/Rho-kinase signaling. However, this constrictor activity must be overcome to permit the vasodilation essential for erection. We hypothesize that the primary action of nitric oxide and other agents that cause penile erection is inhibition of the RhoA/Rho-kinase pathway, thereby allowing vasodilation and erection. This hypothesis, as well as experiments using hypogonadal and hypertensive animal models, are discussed in terms of the potential clinical value of Rho-kinase inhibitors for the treatment of erectile dysfunction.
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Affiliation(s)
- Thomas M Mills
- Department of Physiology, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912-3000, USA.
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Melman A, Christ GJ. The hemodynamics of erection and the pharmacotherapies of erectile dysfunction. HEART DISEASE (HAGERSTOWN, MD.) 2002; 4:252-64. [PMID: 12147185 DOI: 10.1097/00132580-200207000-00008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The past few years have been witness to a sea of change in understanding the diagnosis and treatment of erectile dysfunction. In the wake of Viagra, effective orally administered therapies are now the expected gold standard. Currently available therapies include both peripherally (at the level of the penis) and centrally (brain, e.g., hypothalamic nuclei) acting compounds. When all modes of pharmacotherapy are considered, ranging from oral, to topical, to intraurethral, to intracavernous injection, it is clear that the vast majority of men with mild to moderate erectile dysfunction can now be effectively treated. However, all forms of pharmacotherapy have the lowest efficacy and greatest side effect profiles (including cardiovascular events) in the patients that need the therapy most, that is, those with relatively severe and longstanding erectile dysfunction. The newer generation of pharmacotherapies, which will likely include gene therapy techniques as well, will therefore have to target this latter group. Improved mechanism-based, perhaps patient-specific therapies are foreseen that will dramatically increase the number of patients seeking treatment, as well as the quality of their lives.
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Affiliation(s)
- Arnold Melman
- Department of Urology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York, USA.
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Thomas JA. Pharmacological aspects of erectile dysfunction. JAPANESE JOURNAL OF PHARMACOLOGY 2002; 89:101-12. [PMID: 12120751 DOI: 10.1254/jjp.89.101] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Erectile dysfunction (ED) is a common problem with a prevalence of approximately 50% in men aged 40 to 70. There are several etiologies for ED including vasculogenic, neurogenic, hormonal and/or psychogenic factors; one-fourth of ED cases can be drug-related. Penile erection involves a complex interaction between the CNS and local factors. It is a neurovascular event modulated by psychological and hormonal factors. Pharmacologically, neural modulation and endocrine status are very important to attaining penile erection. There have been several significant advances for the pharmacologic treatment of ED. Treatments include agents that are not only orally effective, but possess either local or central acting mechanisms of action. Apomorphine, a centrally-acting agent, is effective in the treatment of ED. Sildenafil, another orally effective agent, acts by inhibiting cyclic GMP-specific phosphodiesterase Type V. Testosterone can be effective transdermally. Non-orally active agents include alprostadil and papaverine. Phentolamine and trazodone are effective in selected cases. Some agents can interact with other medications. Several pharmacological agents, some with central-acting mechanisms and some with Iocally-acting vascular effects, are therapeutically useful in the treatment of ED.
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Affiliation(s)
- John A Thomas
- Department of Pharmacology & Toxicology, University of Texas Health Science Center, San Antonio 78284, USA.
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Melis MR, Argiolas A. Reduction of drug-induced yawning and penile erection and of noncontact erections in male rats by the activation of GABAA receptors in the paraventricular nucleus: involvement of nitric oxide. Eur J Neurosci 2002; 15:852-60. [PMID: 11906527 DOI: 10.1046/j.1460-9568.2002.01922.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effect of muscimol, a GABAA receptor agonist, injected into the paraventricular nucleus (PVN) of the hypothalamus on drug-induced (apomorphine, oxytocin and NMDA) yawning and penile erection, and on the increase in the concentration of NO2- and NO3- occurring in the paraventricular dialysate in these experimental conditions, was studied in male rats. Muscimol (50, 100 and 200 ng) reduced, in a dose-dependent manner, penile erection and yawning induced by apomorphine (50 ng), oxytocin (30 ng) and NMDA (50 ng) delivered into the PVN. The reduction of penile erection and yawning was parallel to a reduction of the concomitant NO2- and NO3- increase that occurs in the paraventricular dialysate in this experimental condition. In contrast, baclofen (200 ng), a GABAB receptor agonist, was ineffective. The muscimol effects on drug-induced penile erection, yawning and NO2- increase were prevented by the prior administration of bicuculline (250 ng into the paraventricular nucleus). Muscimol (200 ng) but not baclofen (200 ng), injected into the PVN, reduced both noncontact erections in male rats placed in the presence of an inaccessible receptive female, and also the NO2- increase that occurs in the paraventricular dialysate in this experimental condition. As found with drug-induced penile erection, the muscimol reduction of noncontact erections and of NO2- increase was prevented by bicuculline. The present results show that the activation of GABAA receptors in the PVN reduces yawning and penile erection induced by drugs or physiological stimuli by reducing the increase in NO activity that occurs in this hypothalamic nucleus in these experimental conditions.
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Affiliation(s)
- Maria Rosaria Melis
- Bernard B. Brodie Department of Neuroscience, University of Cagliari, S.P. Monserrato-Sestu, Km 0.700, 09042 Monserrato (CA), Italy.
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