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Adeyemi D, Arokoyo D, Hamed M, Dare A, Oyedokun P, Akhigbe R. Cardiometabolic Disorder and Erectile Dysfunction. Cell Biochem Biophys 2024:10.1007/s12013-024-01361-2. [PMID: 38907942 DOI: 10.1007/s12013-024-01361-2] [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: 05/08/2024] [Accepted: 06/12/2024] [Indexed: 06/24/2024]
Abstract
Erectile dysfunction (ED), which is defined as the inability to attain and maintain a satisfactory penile erection to sufficiently permit sexual intercourse, is a consequence and also a cause of cardiometabolic disorders like diabetes mellitus, systemic hypertension, central obesity, and dyslipidemia. Although there are mounting and convincing pieces of evidence in the literature linking ED and cardiometabolic disorders, impairment of nitric oxide-dependent vasodilatation seems to be the primary signaling pathway. Studies have also implicated the suppression of circulating testosterone, increased endothelin-1, and hyperactivation of Ang II/ATIr in the pathogenesis of ED and cardiometabolic disorders. This study provides comprehensive details of the association between cardiometabolic disorders and ED and highlights the mechanisms involved. This would open areas to be explored as therapeutic targets in the management of ED and cardiometabolic disorders. It also provides sufficient evidence establishing the need for the management of cardiometabolic disorders as an adjunct therapy in the management of ED.
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Affiliation(s)
- Damilare Adeyemi
- Department of Physiology, Faculty of Basic Medical Sciences, College of Health Sciences, Osun State University, Osogbo, Osun State, Nigeria
| | - Dennis Arokoyo
- Department of Physiology, Federal University of Technology, Akure, Ondo State, Nigeria
| | - Moses Hamed
- Department of Medical Laboratory Sciences, Afe Babalola University, Ado Ekiti, Ekiti State, Nigeria
- The Brainwill Laboratories, Osogbo, Osun State, Nigeria
- Reproductive Biology and Toxicology Research Laboratory, Oasis of Grace Hospital, Osogbo, Osun State, Nigeria
| | - Ayobami Dare
- School of Medicine, University of Missouri, Columbia, MO, 65201, USA
| | - Precious Oyedokun
- Reproductive Biology and Toxicology Research Laboratory, Oasis of Grace Hospital, Osogbo, Osun State, Nigeria
- Department of Physiology, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria
| | - Roland Akhigbe
- Reproductive Biology and Toxicology Research Laboratory, Oasis of Grace Hospital, Osogbo, Osun State, Nigeria.
- Department of Physiology, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
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Frara N, Giaddui D, Braverman AS, Jawawdeh K, Wu C, Ruggieri, Sr MR, Barbe MF. Mechanisms involved in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox)-derived reactive oxygen species (ROS) modulation of muscle function in human and dog bladders. PLoS One 2023; 18:e0287212. [PMID: 37352265 PMCID: PMC10289437 DOI: 10.1371/journal.pone.0287212] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/01/2023] [Indexed: 06/25/2023] Open
Abstract
Roles of redox signaling in bladder function is still under investigation. We explored the physiological role of reactive oxygen species (ROS) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox) in regulating bladder function in humans and dogs. Mucosa-denuded bladder smooth muscle strips obtained from 7 human organ donors and 4 normal dogs were mounted in muscle baths, and trains of electrical field stimulation (EFS) applied for 20 minutes at 90-second intervals. Subsets of strips were incubated with hydrogen peroxide (H2O2), angiotensin II (Ang II; Nox activator), apocynin (inhibitor of Noxs and ROS scavenger), or ZD7155 (specific inhibitor of angiotensin type 1 (AT1) receptor) for 20 minutes in continued EFS trains. Subsets treated with inhibitors were then treated with H2O2 or Ang II. In human and dog bladders, the ROS, H2O2 (100μM), caused contractions and enhanced EFS-induced contractions. Apocynin (100μM) attenuated EFS-induced strip contractions in both species; subsequent treatment with H2O2 restored strip activity. In human bladders, Ang II (1μM) did not enhance EFS-induced contractions yet caused direct strip contractions. In dog bladders, Ang II enhanced both EFS-induced and direct contractions. Ang II also partially restored EFS-induced contractions attenuated by prior apocynin treatment. In both species, treatment with ZD7155 (10μM) inhibited EFS-induced activity; subsequent treatment with Ang II did not restore strip activity. Collectively, these data provide evidence that ROS can modulate bladder function without exogenous stimuli. Since inflammation is associated with oxidative damage, the effects of Ang II on bladder smooth muscle function may have pathologic implications.
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Affiliation(s)
- Nagat Frara
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Dania Giaddui
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Alan S. Braverman
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Kais Jawawdeh
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
| | - Changhao Wu
- Department of Biochemistry and Physiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Michael R. Ruggieri, Sr
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Mary F. Barbe
- Center for Translational Medicine at the Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States of America
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Cripps SM, Mattiske DM, Pask AJ. Erectile Dysfunction in Men on the Rise: Is There a Link with Endocrine Disrupting Chemicals? Sex Dev 2021; 15:187-212. [PMID: 34134123 DOI: 10.1159/000516600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/18/2021] [Indexed: 11/19/2022] Open
Abstract
Erectile dysfunction (ED) is one of the most prevalent chronic conditions affecting men. ED can arise from disruptions during development, affecting the patterning of erectile tissues in the penis and/or disruptions in adulthood that impact sexual stimuli, neural pathways, molecular changes, and endocrine signalling that are required to drive erection. Sexual stimulation activates the parasympathetic system which causes nerve terminals in the penis to release nitric oxide (NO). As a result, the penile blood vessels dilate, allowing the penis to engorge with blood. This expansion subsequently compresses the veins surrounding the erectile tissue, restricting venous outflow. As a result, the blood pressure localised in the penis increases dramatically to produce a rigid erection, a process known as tumescence. The sympathetic pathway releases noradrenaline (NA) which causes detumescence: the reversion of the penis to the flaccid state. Androgen signalling is critical for erectile function through its role in penis development and in regulating the physiological processes driving erection in the adult. Interestingly, estrogen signalling is also implicated in penis development and potentially in processes which regulate erectile function during adulthood. Given that endocrine signalling has a prominent role in erectile function, it is likely that exposure to endocrine disrupting chemicals (EDCs) is a risk factor for ED, although this is an under-researched field. Thus, our review provides a detailed description of the underlying biology of erectile function with a focus on the role of endocrine signalling, exploring the potential link between EDCs and ED based on animal and human studies.
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Affiliation(s)
- Samuel M Cripps
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Deidre M Mattiske
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew J Pask
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
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de Oliveira AA, Nunes KP. Hypertension and Erectile Dysfunction: Breaking Down the Challenges. Am J Hypertens 2021; 34:134-142. [PMID: 32866225 DOI: 10.1093/ajh/hpaa143] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/15/2020] [Accepted: 08/29/2020] [Indexed: 02/07/2023] Open
Abstract
A diagnostic of hypertension increases the risk of erectile dysfunction (ED); likewise, ED can be an early sign of hypertension. In both cases, there is evidence that endothelial dysfunction is a common link between the 2 conditions. During hypertension, the sustained and widespread release of procontractile factors (e.g., angiotensin II, endothelin 1, and aldosterone) impairs the balance between vasoconstrictors and vasodilators and, in turn, detrimentally impacts vascular and erectile structures. This prohypertensive state associates with an enhancement in the generation of reactive oxygen species, which is not compensated by internal antioxidant mechanisms. Recently, the innate immune system, mainly via Toll-like receptor 4, has also been shown to actively contribute to the pathophysiology of hypertension and ED not only by inducing oxidative stress but also by sustaining a low-grade inflammatory state. Furthermore, some drugs used to treat hypertension can cause ED and, consequently, reduce compliance with the prescribed pharmacotherapy. To break down these challenges, in this review, we focus on discussing the well-established as well as the emerging mechanisms linking hypertension and ED with an emphasis on the signaling network of the vasculature and corpora cavernosa, the vascular-like structure of the penis.
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Affiliation(s)
- Amanda Almeida de Oliveira
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, Florida, USA
| | - Kenia Pedrosa Nunes
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, Florida, USA
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ALTUNÖREN O, ERKEN E, GÜNGÖR Ö, YAVUZ YC. Hipertansiyon ve Erektil Disfonksiyon. KAHRAMANMARAŞ SÜTÇÜ İMAM ÜNIVERSITESI TIP FAKÜLTESI DERGISI 2019. [DOI: 10.17517/ksutfd.477511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Kucukdurmaz F, Efe E, Kurutas EB, Olmez C, Temizer M, Resim S. Losartan treatment significantly attenuates the fibrotic changes in the corpus cavernosum of castrated rats. Rev Int Androl 2018; 18:14-20. [PMID: 30245178 DOI: 10.1016/j.androl.2018.07.001] [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: 01/16/2018] [Revised: 06/22/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
Abstract
INTRODUCTION AND OBJECTIVES The aim of this study is to evaluate the effects of castration and subsequent losartan administration on the fibrosis-related parameters in the corpora cavernosa of castrated rats. MATERIAL AND METHODS Twenty-four male rats were divided into four equal groups. Group 1:sham surgery plus vehicle (0.9% NaCl) (control:con), group 2:sham surgery plus losartan (con+los), group 3: castration plus vehicle (castration:cast) and group 4:castration plus losartan (cast+los). After four weeks of oral losartan treatment, corporal levels of transforming growth factor-beta (TGF-β), thrombospondin-1 (TSP-1), alpha-actin, beta-actin and fibronectin were investigated by ELISA kits. Changes in the collagen and smooth muscle content were evaluated by histological analysis with Masson trichrome staining. RESULTS Initial and post-treatment body weights of rats were similar among groups. Castration significantly increased the expression of TGF-β, TSP-1 and fibronectin and resulted in a significant decrease in alpha-actin levels in the corpora cavernosa. Administration of losartan reduced the levels of TGF-β, TSP-1 and fibronectin in castrated rats. Alpha actin levels also increased after losartan treatment. Beta-actin levels were not significantly different among 4 groups. The levels of all markers were similar in group 1 and 2. Rate of fibrosis was significantly higher in castrated rats and treatment with losartan reduced this rate. CONCLUSION Castration increased the expression of fibrosis-related markers in the corpora cavernosa of rats. Administration of losartan significantly attenuated those changes and exerted an antifibrotic effect.
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Affiliation(s)
- Faruk Kucukdurmaz
- Sutcu Imam University, Department of Urology, Kahramanmaras, Turkey.
| | - Erkan Efe
- Sutcu Imam University, Department of Urology, Kahramanmaras, Turkey
| | | | - Caner Olmez
- Sutcu Imam University, Department of Urology, Kahramanmaras, Turkey
| | | | - Sefa Resim
- Sutcu Imam University, Department of Urology, Kahramanmaras, Turkey
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Akomolafe SA, Oyeleye SI, Olasehinde TA, Oboh G. Phenolic characterization, antioxidant activities, and inhibitory effects of Physalis angulata and Newbouldia laevis on enzymes linked to erectile dysfunction. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2018. [DOI: 10.1080/10942912.2018.1446149] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Seun A. Akomolafe
- Department of Biochemistry, Ekiti State University, Ado Ekiti, Nigeria
| | - Sunday I. Oyeleye
- Department of Biomedical Technology, Federal University of Technology Akure, Akure, Nigeria
- Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology, Akure, Nigeria
| | - Tosin A. Olasehinde
- Department of Biochemistry and Microbiology, University of Fort Hare, Eastern Cape, South Africa
- Nutrition and Toxicology Division, Food Technology Department, Federal Institute of Industrial Research, Oshodi Lagos, Nigeria
| | - Ganiyu Oboh
- Functional Foods and Nutraceuticals Unit, Department of Biochemistry, Federal University of Technology, Akure, Nigeria
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Zafirovic S, Sudar-Milovanovic E, Obradovic M, Djordjevic J, Jasnic N, Borovic ML, Isenovic ER. Involvement of PI3K, Akt and RhoA in Oestradiol Regulation of Cardiac iNOS Expression. Curr Vasc Pharmacol 2018; 17:307-318. [PMID: 29437011 DOI: 10.2174/1570161116666180212142414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 01/12/2023]
Abstract
BACKGROUND Oestradiol is an important regulatory factor with several positive effects on the cardiovascular (CV) system. We evaluated the molecular mechanism of the in vivo effects of oestradiol on the regulation of cardiac inducible nitric oxide (NO) synthase (iNOS) expression and activity. METHODS Male Wistar rats were treated with oestradiol (40 mg/kg, intraperitoneally) and after 24 h the animals were sacrificed. The concentrations of NO and L-Arginine (L-Arg) were determined spectrophotometrically. For protein expressions of iNOS, p65 subunit of nuclear factor-κB (NFκB-p65), Ras homolog gene family-member A (RhoA), angiotensin II receptor type 1 (AT1R), insulin receptor substrate 1 (IRS-1), p85, p110 and protein kinase B (Akt), Western blot method was used. Coimmunoprecipitation was used for measuring the association of IRS-1 with the p85 subunit of phosphatidylinositol- 3-kinase (PI3K). The expression of iNOS messenger ribonucleic acid (mRNA) was measured with the quantitative real-time polymerase chain reaction (qRT-PCR). Immunohistochemical analysis of the tissue was used to detect localization and expression of iNOS in heart tissue. RESULTS Oestradiol treatment reduced L-Arg concentration (p<0.01), iNOS mRNA (p<0.01) and protein (p<0.001) expression, level of RhoA (p<0.05) and AT1R (p<0.001) protein. In contrast, plasma NO (p<0.05), Akt phosphorylation at Thr308 (p<0.05) and protein level of p85 (p<0.001) increased after oestradiol treatment. CONCLUSION Our results suggest that oestradiol in vivo regulates cardiac iNOS expression via the PI3K/Akt signaling pathway, through attenuation of RhoA and AT1R.
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Affiliation(s)
- Sonja Zafirovic
- Institute of Nuclear Sciences "Vinca", Department of Radiobiology and Molecular Genetics, University of Belgrade, Belgrade, Serbia
| | - Emina Sudar-Milovanovic
- Institute of Nuclear Sciences "Vinca", Department of Radiobiology and Molecular Genetics, University of Belgrade, Belgrade, Serbia
| | - Milan Obradovic
- Institute of Nuclear Sciences "Vinca", Department of Radiobiology and Molecular Genetics, University of Belgrade, Belgrade, Serbia
| | - Jelena Djordjevic
- Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Nebojsa Jasnic
- Institute of Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Milica Labudovic Borovic
- Institute of Histology and Embryology "Aleksandar D. Kostic", Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Esma R Isenovic
- Institute of Nuclear Sciences "Vinca", Department of Radiobiology and Molecular Genetics, University of Belgrade, Belgrade, Serbia.,Faculty of Stomatology, Pancevo, University Business Academy, Novi Sad, Serbia
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Nunes KP, Bomfim GF, Toque HA, Szasz T, Clinton Webb R. Toll-like receptor 4 (TLR4) impairs nitric oxide contributing to Angiotensin II-induced cavernosal dysfunction. Life Sci 2017; 191:219-226. [DOI: 10.1016/j.lfs.2017.10.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/10/2017] [Accepted: 10/10/2017] [Indexed: 10/18/2022]
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Welter H, Huber A, Lauf S, Einwang D, Mayer C, Schwarzer JU, Köhn FM, Mayerhofer A. Angiotensin II regulates testicular peritubular cell function via AT1 receptor: a specific situation in male infertility. Mol Cell Endocrinol 2014; 393:171-8. [PMID: 24970685 DOI: 10.1016/j.mce.2014.06.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/28/2014] [Accepted: 06/16/2014] [Indexed: 10/25/2022]
Abstract
We observed that peritubular myoid cells in the human testis are immunoreactive for angiotensin II (AngII) receptors (AT1R) and explored AngII actions in cultured human testicular peritubular cells (HTPCs). In response to AngII they contracted within minutes. The AT1R-blocker losartan blocked contraction, implying involvement of AngII and AT1R in intratesticular sperm transport. AngII also significantly increased IL-6 mRNA levels and IL-6 secretion within hours and losartan again prevented this action. This suggests involvement in inflammatory processes, which may play a role in male infertility. AngII can be generated locally by mast cell (MC)-derived chymase (CHY), which cleaves AngI. In testicular biopsies from infertile men we found abundant MCs, which express CHY, within the wall of seminiferous tubules. In contrast, CHY-positive MCs are hardly found in normal human testis. Testicular inflammatory events may fuel processes resulting in impaired spermatogenesis. Therefore therapeutic interference with MCs, CHY or AT1R might be novel options in male infertility.
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Affiliation(s)
- H Welter
- Anatomy III - Cell Biology, Ludwig Maximilian University, Schillerstrasse 42, 80336 Munich, Germany.
| | - A Huber
- Anatomy III - Cell Biology, Ludwig Maximilian University, Schillerstrasse 42, 80336 Munich, Germany
| | - S Lauf
- Anatomy III - Cell Biology, Ludwig Maximilian University, Schillerstrasse 42, 80336 Munich, Germany
| | - D Einwang
- Anatomy III - Cell Biology, Ludwig Maximilian University, Schillerstrasse 42, 80336 Munich, Germany
| | - C Mayer
- Anatomy III - Cell Biology, Ludwig Maximilian University, Schillerstrasse 42, 80336 Munich, Germany
| | | | - F M Köhn
- Andrologicum, 80331 Munich, Germany
| | - A Mayerhofer
- Anatomy III - Cell Biology, Ludwig Maximilian University, Schillerstrasse 42, 80336 Munich, Germany.
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Ertemi H, Lau DH, Mikhailidis DP, Mumtaz FH, Thompson CS. Angiotensin II Increases Corpus Cavernosal Contractility and Oxidative Stress in Partial Bladder Outlet Obstructed Rabbits: Relevance to Erectile Dysfunction. J Sex Med 2013; 10:1251-8. [DOI: 10.1111/j.1743-6109.2012.02768.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Losartan improves erectile dysfunction in diabetic patients: a clinical trial. Int J Impot Res 2012; 24:217-20. [DOI: 10.1038/ijir.2012.4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lee JH, Chae MR, Park JK, Jeon JH, Lee SW. The effects of the combined use of a PDE5 inhibitor and medications for hypertension, lower urinary tract symptoms and dyslipidemia on corporal tissue tone. Int J Impot Res 2012; 24:221-7. [PMID: 22763627 DOI: 10.1038/ijir.2012.19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
ED is closely associated with its comorbidities (hypertension, dyslipidemia and lower urinary tract symptoms (LUTS)). Therefore, several drugs have been prescribed simultaneously with PDE5 inhibitors. If a specific medication for ED comorbidities has enhancing effects on PDE5 inhibitors, it offers alternative combination therapy in nonresponders to monotherapy with PDE5 inhibitors and allows clinicians to treat ED and its comorbidities simultaneously. To establish theoretical basis of choosing an appropriate medication for ED and concomitant disease, we examined the effects combining a PDE5 inhibitor with representative drugs for hypertension, dyslipidemia and LUTS on relaxing the corpus cavernosum of rabbits using the organ-bath technique. The effect of mirodenafil on relaxing phenylephrine-induced cavernosal contractions was significantly enhanced by the presence of 10(-4) M losartan, 10(-6) M nifedipine, 10(-6) M amlodipine, 10(-7) M doxazosin and 10(-9) M tamsulosin (P<0.05). The maximum relaxation effects were 47.2±3.8%, 57.6±2.6%, 64.0±3.7%, 76.1±5.7% and 71.7±5.4%, respectively. Enalapril and simvastatin had no enhancing effects. The relaxation induced by sodium nitroprusside alone (39.0±4.0%) was significantly enhanced in the presence of the 10(-4) M losartan (66.0±6.0%, P<0.05). Tetraethylammonium (1 mM) significantly inhibited the enhancement effects of tamsulosin and doxazosin on mirodenafil-induced relaxation (doxazosin: 76.1±5.7% vs 45.3±2.3%; tamsulosin: 71.7±5.4% vs 48.1±3.5%). On the basis of these findings, losartan seemed to induce synergistic effects through an interaction with nitric oxide. In addition, K(+) channel activation could be one of the mechanisms for the synergistic effect of combining mirodenafil with doxazosin or tamsulosin. We believe that the combination of a PDE5 inhibitor with losartan, nifedipine, amlodipine, doxazosin or tamsulosin could be a pharmacologic strategy for simultaneously treating ED and its comorbidities and increasing response rates to PDE5 inhibitors.
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Affiliation(s)
- J H Lee
- Genitourinary Disease Oriented Translational Research, Seoul, Korea
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Abstract
PURPOSE OF REVIEW Erectile dysfunction is recognized as a quality-of-life disorder that needs to be treated. Currently, it is estimated to affect as many as 30 million American men. Thirty percent of hypertensive patients complain of erectile dysfunction. The understanding of common mechanisms involved in the cause of erectile dysfunction associated with hypertension, and the investigation of antihypertensive drugs that impact erectile dysfunction, will provide important tools toward identifying new therapeutic targets that will improve the quality of life for patients in these conditions. RECENT FINDINGS Hypertension and erectile dysfunction are closely intertwined diseases, which have endothelial dysfunction as a common base. During hypertension and/or erectile dysfunction, disturbance of endothelium-derived factors can lead to an increase in vascular smooth muscle (VSM) contraction. Hypertension can lead to erectile dysfunction as a consequence of high blood pressure (BP) or due to antihypertensive treatment. However, growing evidence suggests erectile dysfunction is an early sign for hypertension. Also, some phosphodiesterase-5 inhibitors used to treat erectile dysfunction can improve BP, but the link between these conditions has not been totally understood. SUMMARY This review will discuss the interplay between hypertension and erectile dysfunction, exploring newest insights regarding hypertension-associated erectile dysfunction, as well as the effect of antihypertensive drugs in erectile dysfunction patients.
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