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Otunctemur A, Ozbek E, Sahin S, Ozcan L, Dursun M, Polat EC, Cekmen M, Ozsoy OD, Erkoc M, Danis E, Bozkurt M. Low serum insulin-like growth factor-1 in patients with erectile dysfunction. Basic Clin Androl 2016; 26:1. [PMID: 26823979 PMCID: PMC4730635 DOI: 10.1186/s12610-015-0028-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 12/18/2015] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVE Endothelial dysfunction and microvascular damage play a crurical role in the pathogenesis of erectile dysfunction (ED). Insulin-like growth factor-1 (IGF-1) is one of the growth factors that have a wide range of biologic effects. IGF-1 is an important mediator of cell growth, differentiation and transformation in various tissues. The purpose of the current study was to determine the association between IGF-1 levels and ED. MATERIALS AND METHODS All men were evaluated for ED and divided into two groups: 80 patients suffering from ED for > 1 year and 80 subjects without ED were enrolled as a control group in this study. Diagnosis of ED was based on the International Index of Erectile Function Score-5. IGF-1 levels were measured in serum by an automated chemiluminescence immunoassay. The relationship between IGF-1 levels and ED scores in patients was statistically evaluated. RESULTS The mean age of patients in ED group was 60.4 ± 11.3 years and 55.4 ± 9.6 in control group. The plasma IGF-1 levels were significantly lower in ED than in control group (96.5 ± 38.3 and 132.5 ± 53.3 ng/ mL, respectively, P < 0.001). The IGF-1 levels were positively correlated with ED score (r = 0.623, P < 0.01). CONCLUSION In this study serum IGF-1 levels were found to be associated with endothelial dysfunction that predicts ED. Serum IGF-1 level appears to be a specific predictor of ED, and it might be used in early prediction of ED in male population.
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Affiliation(s)
- Alper Otunctemur
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Emin Ozbek
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Suleyman Sahin
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Levent Ozcan
- Department of Urology, Derince Training and Research Hospital, Kocaeli, Turkey
| | - Murat Dursun
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Emre Can Polat
- Department of Urology, Istanbul Medipol University, School of Medicine, Istanbul, Turkey
| | - Mustafa Cekmen
- Department of Biochemistry, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Ozgur Doga Ozsoy
- Department of Biochemistry, Kocaeli University, School of Medicine, Kocaeli, Turkey
| | - Mustafa Erkoc
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Eyup Danis
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Muammer Bozkurt
- Department of Urology, Okmeydani Training and Research Hospital, Istanbul, Turkey
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Animal models of erectile dysfunction. J Pharmacol Toxicol Methods 2015; 76:43-54. [PMID: 26279495 DOI: 10.1016/j.vascn.2015.07.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 07/02/2015] [Accepted: 07/30/2015] [Indexed: 12/19/2022]
Abstract
Erectile dysfunction (ED) is a prevalent male sexual dysfunction with profound adverse effects on the physical and the psychosocial health of men and, subsequently, on their partners. The expanded use of various types of rodent models has produced some advances in the study of ED, and neurophysiological studies using various animal models have provided important insights into human sexual dysfunction. At present, animal models play a key role in exploring and screening novel drugs designed to treat ED.
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Nguyen HB, Lee SY, Park SH, Han JH, Lee MY, Myung SC. Nicotine in high concentration causes contraction of isolated strips of rabbit corpus cavernosum. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 19:257-62. [PMID: 25954131 PMCID: PMC4422966 DOI: 10.4196/kjpp.2015.19.3.257] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/13/2015] [Accepted: 04/08/2015] [Indexed: 11/26/2022]
Abstract
It is well known that cigarette smoke can cause erectile dysfunction by affecting the penile vascular system. However, the exact effects of nicotine on the corpus cavernosum remains poorly understood. Nicotine has been reported to cause relaxation of the corpus cavernosum; it has also been reported to cause both contraction and relaxation. Therefore, high concentrations of nicotine were studied in strips from the rabbit corpus cavernosum to better understand its effects. The proximal penile corpus cavernosal strips from male rabbits weighing approximately 4 kg were used in organ bath studies. Nicotine in high concentrations (10-5~10-4 M) produced dose-dependent contractions of the corpus cavernosal strips. The incubation with 10-5 M hexamethonium (nicotinic receptor antagonist) significantly inhibited the magnitude of the nicotine associated contractions. The nicotine-induced contractions were not only significantly inhibited by pretreatment with 10-5 M indomethacin (nonspecific cyclooxygenase inhibitor) and with 10-6 M NS-398 (selective cyclooxygenase inhibitor), but also with 10-6 M Y-27632 (Rho kinase inhibitor). Ozagrel (thromboxane A2 synthase inhibitor) and SQ-29548 (highly selective TP receptor antagonist) pretreatments significantly reduced the nicotine-induced contractile amplitude of the strips. High concentrations of nicotine caused contraction of isolated rabbit corpus cavernosal strips. This contraction appeared to be mediated by activation of nicotinic receptors. Rho-kinase and cyclooxygenase pathways, especially cyclooxygenase-2 and thromboxane A2, might play a pivotal role in the mechanism associated with nicotine-induced contraction of the rabbit corpus cavernosum.
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Affiliation(s)
- Hoai Bac Nguyen
- Advanced Urogenital Disease Research Center; Research Institute for Translational System Biomics; Department of Urology, Chung-Ang University Hospital, Seoul 156-755, Korea
| | - Shin Young Lee
- Department of Urology, Seoul Medical Center, Seoul 131-795, Korea
| | - Soo Hyun Park
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 156-756, Korea
| | - Jun Hyun Han
- Department of Urology, Hallym University Dongtan Sacred Heart Hospital, Hwaseong 445-170, Korea
| | - Moo Yeol Lee
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 156-756, Korea
| | - Soon Chul Myung
- Advanced Urogenital Disease Research Center; Research Institute for Translational System Biomics; Department of Urology, Chung-Ang University Hospital, Seoul 156-755, Korea
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Hoyos CM, Melehan KL, Phillips CL, Grunstein RR, Liu PY. To ED or not to ED – Is erectile dysfunction in obstructive sleep apnea related to endothelial dysfunction? Sleep Med Rev 2015; 20:5-14. [DOI: 10.1016/j.smrv.2014.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 01/23/2023]
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Chen YG, Lin TY, Lin CL, Dai MS, Ho CL, Kao CH. Risk of erectile dysfunction in transfusion-naive thalassemia men: a nationwide population-based retrospective cohort study. Medicine (Baltimore) 2015; 94:e700. [PMID: 25837766 PMCID: PMC4554026 DOI: 10.1097/md.0000000000000700] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Based on the mechanism of pathophysiology, thalassemia major or transfusion-dependent thalassemia patients may have an increased risk of developing organic erectile dysfunction resulting from hypogonadism. However, there have been few studies investigating the association between erectile dysfunction and transfusion-naive thalassemia populations. We constructed a population-based cohort study to elucidate the association between transfusion-naive thalassemia populations and organic erectile dysfunction. This nationwide population-based cohort study involved analyzing data from 1998 to 2010 obtained from the Taiwanese National Health Insurance Research Database, with a follow-up period extending to the end of 2011. We identified men with transfusion-naive thalassemia and selected a comparison cohort that was frequency-matched with these according to age, and year of diagnosis thalassemia at a ratio of 1 thalassemia man to 4 control men. We analyzed the risks for transfusion-naive thalassemia men and organic erectile dysfunction by using Cox proportional hazards regression models. In this study, 588 transfusion-naive thalassemia men and 2337 controls were included. Total 12 patients were identified within the thalassaemia group and 10 within the control group. The overall risks for developing organic erectile dysfunction were 4.56-fold in patients with transfusion-naive thalassemia men compared with the comparison cohort after we adjusted for age and comorbidities. Our long-term cohort study results showed that in transfusion-naive thalassemia men, there was a higher risk for the development of organic erectile dysfunction, particularly in those patients with comorbidities.
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Affiliation(s)
- Yu-Guang Chen
- From the Department of Internal Medicine, Division of Hematology/Oncology (Y-GC, M-SD, C-LH); Department of Internal Medicine, Division of Infectious Diseases and Tropical Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei (T-YL); Management Office for Health Data, China Medical University Hospital (C-LL); College of Medicine (C-LL); Graduate Institute of Clinical Medical Science and School of Medicine, College of Medicine (C-HK); Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan (C-HK)
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MG G. Intracavernous Administration of Adipose Stem Cells: A New Technique of Treating Erectile Dysfunction in Diabetic Patient, Preliminary Report of 6 Cases. ACTA ACUST UNITED AC 2015. [DOI: 10.15406/mojcsr.2015.02.00018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Corbin J. The Unexpected Evolution of Basic Science Studies about Cyclic Nucleotide Action into a Treatment for Erectile Dysfunction. J Biol Chem 2015; 290:1374-88. [DOI: 10.1074/jbc.x114.632174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Costa MR, Reis AMBB, Pereira BP, Ponciano VC, Oliveira ECD. Associated factors and prevalence of erectile dysfunction in hemodialysis patients. Int Braz J Urol 2014; 40:44-55. [PMID: 24642163 DOI: 10.1590/s1677-5538.ibju.2014.01.07] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 11/14/2013] [Indexed: 02/11/2023] Open
Abstract
PURPOSE The proposal of this study was to determine the prevalence and the associated factors of erectile dysfunction (ED) among hemodialysis (HD) patients. MATERIALS AND METHODS This was a cross-sectional study based on data collected from HD male patients. Clinical, demographic and laboratory data of all patients were collected in three HD clinics from December 2010 to June 2011. Patients answered questions of erectile function domain from International Index of Erectile Function. Data were evaluated by descriptive analysis and by univariate (ULRA) and multivariate logistic regression analysis (MLRA). RESULTS Three hundred and five patients participated of the study. The prevalence of ED was 68.19%. ED was associated with diabetes (DM), benign prostatic hyperplasia, glomerulonephritis as cause of chronic renal failure (CRF), smoking habits, lower creatinine levels (ULRA), use of calcium channel blocker (MLRA), aging, lower education level, alcohol consumption, DM (as cause of CRF) and coronary insufficiency (ULRA and MLRA). CONCLUSIONS ED was highly prevalent in the HD men. It was independently associated with aging, current use of alcohol, long alcohol use (even for those who do not drink more), lower education level, diabetes as cause of CRF, coronary insufficiency and use of channel blockers calcium.
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Affiliation(s)
- Márcio Rodrigues Costa
- Division of Urology, Department of Surgery, Hospital das Clinicas, Federal University of Goiás Medical School, Goiânia, Brazil
| | | | - Bruno Paiva Pereira
- Division of Urology, Department of Surgery, Hospital das Clinicas, Federal University of Goiás Medical School, Goiânia, Brazil
| | - Viviane Campos Ponciano
- Division of Urology, Department of Surgery, Hospital das Clinicas, Federal University of Goiás Medical School, Goiânia, Brazil
| | - Enio Chaves de Oliveira
- Division of Urology, Department of Surgery, Hospital das Clinicas, Federal University of Goiás Medical School, Goiânia, Brazil
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Cander S, Coban S, Altuner S, Oz Gul O, Yetgin ZA, Akkurt A, Ucar H, Tuncel E. Prevalence and Correlates of Erectile Dysfunction in Type 2 Diabetes Mellitus: A Cross-Sectional Single-Center Study Among Turkish Patients. Metab Syndr Relat Disord 2014; 12:324-9. [DOI: 10.1089/met.2013.0150] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Soner Cander
- Clinic of Endocrinology and Metabolism, Sevket Yilmaz Training and Research Hospital, Bursa, Turkey
| | - Soner Coban
- Clinic of Urology, Sevket Yilmaz Training and Research Hospital, Bursa, Turkey
| | - Sakir Altuner
- Clinic of Internal Medicine, Sevket Yilmaz Training and Research Hospital, Bursa, Turkey
| | - Ozen Oz Gul
- Clinic of Endocrinology and Metabolism, Sevket Yilmaz Training and Research Hospital, Bursa, Turkey
| | - Zeynel Abidin Yetgin
- Clinic of Cardiology, Sevket Yilmaz Training and Research Hospital, Bursa, Turkey
| | - Aysen Akkurt
- Department of Endocrinology and Metabolism, Uludag University Faculty of Medicine, Bursa, Turkey
| | - Hakan Ucar
- Clinic of Cardiology, Sevket Yilmaz Training and Research Hospital, Bursa, Turkey
| | - Ercan Tuncel
- Department of Endocrinology and Metabolism, Uludag University Faculty of Medicine, Bursa, Turkey
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Wang F, Guo X, Shen X, Kream RM, Mantione KJ, Stefano GB. Vascular dysfunction associated with type 2 diabetes and Alzheimer's disease: a potential etiological linkage. Med Sci Monit Basic Res 2014; 20:118-29. [PMID: 25082505 PMCID: PMC4138067 DOI: 10.12659/msmbr.891278] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The endothelium performs a crucial role in maintaining vascular integrity leading to whole organ metabolic homeostasis. Endothelial dysfunction represents a key etiological factor leading to moderate to severe vasculopathies observed in both Type 2 diabetic and Alzheimer’s Disease (AD) patients. Accordingly, evidence-based epidemiological factors support a compelling hypothesis stating that metabolic rundown encountered in Type 2 diabetes engenders severe cerebral vascular insufficiencies that are causally linked to long term neural degenerative processes in AD. Of mechanistic importance, Type 2 diabetes engenders an immunologically mediated chronic pro-inflammatory state involving interactive deleterious effects of leukocyte-derived cytokines and endothelial-derived chemotactic agents leading to vascular and whole organ dysfunction. The long term negative consequences of vascular pro-inflammatory processes on the integrity of CNS basal forebrain neuronal populations mediating complex cognitive functions establish a striking temporal comorbidity of AD with Type 2 diabetes. Extensive biomedical evidence supports the pivotal multi-functional role of constitutive nitric oxide (NO) production and release as a critical vasodilatory, anti-inflammatory, and anti-oxidant, mechanism within the vascular endothelium. Within this context, we currently review the functional contributions of dysregulated endothelial NO expression to the etiology and persistence of Type 2 diabetes-related and co morbid AD-related vasculopathies. Additionally, we provide up-to-date perspectives on critical areas of AD research with special reference to common NO-related etiological factors linking Type 2 diabetes to the pathogenesis of AD.
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Affiliation(s)
- Fuzhou Wang
- Department of Anesthesiology and Critical Care Medicine, Nanjing Maternit and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - Xirong Guo
- Institutes of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - Xiaofeng Shen
- Department of Anesthesiology and Critical Care Medicine, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - Richard M Kream
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, USA
| | - Kirk J Mantione
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, USA
| | - George B Stefano
- Neuroscience Research Institute, State University of New York - College at Old Westbury, Old Westbury, USA
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Singh N, Vasam G, Pawar R, Jarajapu YPR. Angiotensin-(1-7) reverses angiogenic dysfunction in corpus cavernosum by acting on the microvasculature and bone marrow-derived cells in diabetes. J Sex Med 2014; 11:2153-63. [PMID: 24953642 DOI: 10.1111/jsm.12620] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Angiotensin (Ang)-(1-7) is a recently identified vasoprotective heptapeptide, and it appears to activate the reparative functions of bone marrow-derived stem/progenitor cells (BMPCs). AIM This study evaluated the effect of Ang-(1-7) in the angiogenic function of cavernosum in type 1 diabetes (T1D) and delineated the role of BMPCs in this protective function. METHODS T1D was induced by streptozotocin in mice, and mice with 20-24 weeks of diabetes were used for the study. Ang-(1-7) was administered subcutaneously by using osmotic pumps. Cavernosa, and BMPCs from peripheral blood and bone marrow were evaluated in different assay systems. MAIN OUTCOME MEASURES Angiogenic function was determined by endothelial tube formation in matrigel assay. Circulating BMPCs were enumerated by flow cytometry and proliferation was determined by BrdU incorporation. Cell-free supernatant of BMPCs were collected and tested for paracrine angiogenic effect. Expression of angiogenic factors in BMPCs and cavernosa were determined by real-time polymerase chain reaction. RESULTS Ang-(1-7) (100 nM) stimulated angiogenesis in mouse cavernosum that was partially inhibited by Mas1 receptor antagonist, A779 (10 μM) (P < 0.05). In cavernosa of T1D, the angiogenic responses to Ang-(1-7) (P < 0.005) and VEGF (100 nM) (P < 0.03) were diminished. Ang-(1-7) treatment for 4 weeks reversed T1D-induced decrease in the VEGF-mediated angiogenesis. Ang-(1-7) treatment increased the circulating number of BMPCs and proliferation that were decreased in T1D (P < 0.02). Paracrine angiogenic function of BMPCs was reduced in diabetic BMPCs, which was reversed by Ang-(1-7). In diabetic BMPCs, SDF and angiopoietin-1 were upregulated by Ang-(1-7), and in cavernosum, VEGFR1, Tie-2, and SDF were upregulated and angiopoietin-2 was down-regulated. CONCLUSIONS Ang-(1-7) stimulates angiogenic function of cavernosum in diabetes via its stimulating effects on both cavernosal microvasculature and BMPCs.
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Affiliation(s)
- Neha Singh
- Department of Pharmaceutical Sciences, College of Pharmacy, Nursing, and Allied Sciences, North Dakota State University, Fargo, ND, USA
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Sánchez A, Contreras C, Martínez P, Muñoz M, Martínez AC, García-Sacristán A, Hernández M, Prieto D. Endothelin A (ETA) Receptors Are Involved in Augmented Adrenergic Vasoconstriction and Blunted Nitric Oxide-Mediated Relaxation of Penile Arteries from Insulin-Resistant Obese Zucker Rats. J Sex Med 2014; 11:1463-74. [DOI: 10.1111/jsm.12526] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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D'Amico AG, Scuderi S, Maugeri G, Cavallaro S, Drago F, D'Agata V. NAP reduces murine microvascular endothelial cells proliferation induced by hyperglycemia. J Mol Neurosci 2014; 54:405-13. [PMID: 24874579 DOI: 10.1007/s12031-014-0335-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/15/2014] [Indexed: 11/26/2022]
Abstract
Hyperglycemia has been identified as a risk factor responsible for micro- and macrovascular complications in diabetes. NAP (Davunetide) is a peptide whose neuroprotective actions are widely demonstrated, although its biological role on endothelial dysfunctions induced by hyperglycemia remains uninvestigated. In the present study we hypothesized that NAP could play a protective role on hyperglycemia-induced endothelial cell proliferation. To this end we investigated the effects of NAP on an in vitro model of murine microvascular endothelial cells grown in high glucose for 7 days. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and cyclin D1 protein expression analysis revealed that NAP treatment significantly reduces viability and proliferation of the cells. Hyperglycemia induced the activation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase and/or phosphatidylinositol-3 kinase/Akt pathways in a time-dependent manner. NAP treatment reduced the phosphorylation levels of ERK and AKT in cells grown in high glucose. These evidences suggest that NAP might be effective in the regulation of endothelial dysfunction induced by hyperglycemia.
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Affiliation(s)
- Agata Grazia D'Amico
- Department of Bio-Medical Sciences, Section of Anatomy and Histology, University of Catania, Via S. Sofia, 87, 95123, Catania, Italy
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Measurement of endothelial dysfunction via peripheral arterial tonometry predicts vasculogenic erectile dysfunction. Int J Impot Res 2014; 26:218-22. [PMID: 24784889 PMCID: PMC4216643 DOI: 10.1038/ijir.2014.14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 01/08/2014] [Accepted: 03/27/2014] [Indexed: 01/08/2023]
Abstract
Introduction Endothelial cell dysfunction is associated with cardiovascular disease and vasculogenic erectile dysfunction (ED). Measured via Peripheral Artery Tonometry (PAT), endothelial dysfunction in the penis is an independent predictor of future cardiovascular events. Aim Determine whether measurement of endothelial dysfunction differentiates men with vasculogenic ED identified by duplex ultrasound from those without. Methods A total of 142 men were retrospectively assessed using patient history, penile duplex ultrasonography (US) and PAT (EndoPAT 2000). ED was self reported and identified on history. Vasculogenic ED was identified in men who exhibited a peak systolic velocity (PSV) of ≤25 cm/s obtained 15 minutes following vasodilator injection. The reactive hyperemia index (RHI), a measurement of endothelial dysfunction in medium/small arteries and the Augmentation Index (AI), a measurement of arterial stiffness, were recorded via PAT. Results Penile duplex US separated men into those with ED (n=111) and without (n=31). The cohort with ED had a PSV of 21±1 cm/s (left cavernous artery) and 22±1 cm/s (Right). The control group without ED had values of 39±2 cm/s (Left) and 39±2 (Right). Given the potential for altered endothelial function in diabetes mellitus, we confirmed that hemoglobin A1c, urinary microalbumin, and vibration pulse threshold were not different in men with vasculogenic ED and those without. RHI in patients with ED (1.85±0.06) was significantly decreased compared to controls (2.15±0.2) (p<0.05). The AI was unchanged when examined in isolation, and when standardized to heart rate. Conclusions Measurement of endothelial function with EndoPAT differentiates men with vasculogenic ED from those without. RHI could be used as a non-invasive surrogate in the assessment of vasculogenic ED and to identify those patients with higher cardiovascular risk.
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Jiang H, Torregrossa AC, Potts A, Pierini D, Aranke M, Garg HK, Bryan NS. Dietary nitrite improves insulin signaling through GLUT4 translocation. Free Radic Biol Med 2014; 67:51-7. [PMID: 24157451 DOI: 10.1016/j.freeradbiomed.2013.10.809] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 10/14/2013] [Accepted: 10/15/2013] [Indexed: 01/31/2023]
Abstract
Diabetes mellitus type 2 is a syndrome of disordered metabolism with inappropriate hyperglycemia owing to a reduction in the biological effectiveness of insulin. Type 2 diabetes is associated with an impaired nitric oxide (NO) pathway that probably serves as the key link between metabolic disorders and cardiovascular disease. Insulin-mediated translocation of GLUT4 involves the PI3K/Akt kinase signal cascade that results in activation of endothelial NO synthase (eNOS). eNOS is dysfunctional during diabetes. We hypothesize that loss of eNOS-derived NO terminates the signaling cascade and therefore cannot activate GLUT4 translocation and that dietary nitrite may repair this pathway. In this study, we administered 50mg/L sodium nitrite to db/db diabetic mice for 4 weeks. After 4 weeks treatment, the db/db mice experienced less weight gain, improved fasting glucose levels, and reduced insulin levels. Cell culture experiments using CHO-HIRc-myc-GLUT4eGFP cell lines stably expressing insulin receptor and myc-GLUT4eGFP protein, as well as L6 skeletal muscle cells stably expressing rat GLUT4 with a Myc epitope (L6-GLUT4myc), showed that NO, nitrite, and GSNO stimulate GLUT4 translocation independent of insulin, which is inhibited by NEM. Collectively our data suggest that nitrite improves insulin signaling through restoration of NO-dependent nitrosation of GLUT4 signaling translocation. These data suggest that NO-mediated nitrosation of GLUT4 by nitrite or other nitrosating agents is necessary and sufficient for GLUT4 translocation in target tissue. Description of this pathway may justify a high-nitrate/nitrite diet along with the glycemic index to provide a safe and nutritional regimen for the management and treatment of diabetes.
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Affiliation(s)
- Hong Jiang
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, Health Science Center, Houston, TX 77030, USA
| | - Ashley C Torregrossa
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, Health Science Center, Houston, TX 77030, USA
| | - Amy Potts
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, Health Science Center, Houston, TX 77030, USA
| | - Dan Pierini
- California State University at Fullerton, Fullerton, CA 92831, USA
| | - Mayank Aranke
- The University of Texas at Austin, Austin, TX 78712, USA
| | - Harsha K Garg
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, Health Science Center, Houston, TX 77030, USA
| | - Nathan S Bryan
- Texas Therapeutics Institute, Brown Foundation Institute of Molecular Medicine, Health Science Center, Houston, TX 77030, USA; Graduate School of Biomedical Sciences, The University of Texas at Houston, Houston, TX 77030, USA.
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Yilmaz D, Bayatli N, Un O, Kadowitz PJ, Sikka SC, Gur S. The Effect of Intracavernosal Avanafil, a Newer Phosphodiesterase-5 Inhibitor, on Neonatal Type 2 Diabetic Rats With Erectile Dysfunction. Urology 2014; 83:508.e7-12. [DOI: 10.1016/j.urology.2013.10.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 10/05/2013] [Accepted: 10/08/2013] [Indexed: 11/30/2022]
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67
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McMahon CG. Erectile dysfunction. Intern Med J 2014; 44:18-26. [DOI: 10.1111/imj.12325] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/27/2013] [Indexed: 11/30/2022]
Affiliation(s)
- C. G. McMahon
- Australian Centre for Sexual Health; Sydney New South Wales Australia
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Abstract
We aimed to summarize the etiology, clinical characteristics, diagnosis, and possible treatment options of sexual dysfunction in diabetic patients of both sexes. Details of dysfunction in diabetic women are less conclusive than in men due to the lack of standardized evaluation of sexual function in women. Male sexual dysfunction is a common complication of diabetes, including abnormalities of orgasmic/ejaculatory function and desire/libido in addition to penile erection. The prevalence of erectile dysfunction (ED) among diabetic men varies from 35% to 75%. Diabetes-induced ED has a multifactorial etiology including metabolic, neurologic, vascular, hormonal, and psychological components. ED should be regarded as the first sign of cardiovascular disease because it can be present before development of symptomatic coronary artery disease, as larger coronary vessels better tolerate the same amount of plaque compared to smaller penile arteries. The diagnosis of ED is based on validated questionnaires and determination of functional and organic abnormalities. First-, second- and third-line therapy may be applied. Phosphodiesterase-5 (PDE-5) inhibitor treatment from the first-line options leads to smooth muscle relaxation in the corpus cavernosum and enhancement in blood flow, resulting in erection during sexual stimulus. The use of PDE-5 inhibitors in the presence of oral nitrates is strictly contraindicated in diabetic men, as in nondiabetic subjects. All PDE-5 inhibitors have been evaluated for ED in diabetic patients with convincing efficacy data. Second-line therapy includes intracavernosal, trans- or intraurethral administration of vasoactive drugs or application of a vacuum device. Third-line therapies are the implantation of penile prosthesis and penile revascularization.
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Affiliation(s)
- Várkonyi Tamás
- First Department of Internal Medicine, University of Szeged, Szeged, Hungary.
| | - Peter Kempler
- First Department of Internal Medicine, Semmelweis University, Budapest, Hungary
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69
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Walsh TJ, Hotaling JM, Smith A, Saigal C, Wessells H. Men with diabetes may require more aggressive treatment for erectile dysfunction. Int J Impot Res 2013; 26:112-5. [PMID: 24352244 DOI: 10.1038/ijir.2013.46] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 09/29/2013] [Accepted: 10/20/2013] [Indexed: 11/09/2022]
Abstract
Diabetes mellitus (DM) and erectile dysfunction (ED) are common health problems that markedly increase in prevalence and incidence with advancing age. DM is a known risk factor for developing ED; however, among men with ED it is unknown if DM alters the need for more invasive therapies. We sought to determine whether DM is associated with increased ED severity, reduced effectiveness of first-line (oral) therapies, and therefore higher utilization of second- and third-line therapies. The Inovus I3 database was queried to identify men with ED. Claims were followed for 48 months. Men with incomplete follow-up data and those diagnosed with DM after ED diagnosis were excluded from analysis. Rates of second-line (penile suppositories or injectables) and third-line (penile prostheses) ED therapies were compared between men with and without preexisting DM. Risk of progressing to second- and third-line therapies associated with DM was assessed with logistic regression and Kaplan-Meier analysis. From 1 January 2002 to 31 December 2006, 136 306 men were identified with prevalent and incident ED. Among this group, 19 236 men had DM that preceded their ED diagnosis. Men with DM were more than 50% more likely to be prescribed secondary ED treatments over the 2-year observation period, and more than twice as likely to undergo penile prosthesis surgery. Among a large population-based cohort of men with ED, those with DM are more likely to require more aggressive treatments. These data suggest that ED among men with diabetes may be less responsive to first-line treatments (oral agents), worsen more rapidly, or both.
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Affiliation(s)
- T J Walsh
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - J M Hotaling
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - A Smith
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - C Saigal
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
| | - H Wessells
- Department of Urology, University of Washington School of Medicine, Seattle, WA, USA
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70
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Nickmann M, Saemisch M, Wilbert-Lampen U, Nickel T, Edelman ER, Methe H. Cell matrix contact modifies endothelial major histocompatibility complex class II expression in high-glucose environment. Am J Physiol Heart Circ Physiol 2013; 305:H1592-9. [PMID: 24043258 DOI: 10.1152/ajpheart.00018.2013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Atherosclerosis is a chronic inflammatory disease. Cardiovascular risk factors such as hyperglycemia, hyperlipidemia, and arterial hypertension induce endothelial dysfunction with alterations in endothelial biosecretion and immune behavior. The aim of this study is to elucidate whether glucose-induced modifications of endothelial biosecretory and immune functions are regulated by interactions of endothelial cells (ECs) with their extracellular matrix [ECs plated on polystyrene-coated tissue culture plates (TC-EC) vs. ECs embedded within three-dimensional (3-D) collagen-based matrixes (3D-EC)]. In the absence of glucose, IFN-γ-induced phosphorylation of JAK and STAT proteins and human leukocyte antigen (HLA)-DR expression were lower in 3D-EC compared with TC-EC. Inversely, the expression of suppressor of cytokine signaling proteins (SOCS)-1 and -3 were significantly higher in naïve 3D-EC compared with naïve TC-EC. IFN-γ-induced upregulation of SOCS proteins was further amplified by the 3-D environment. Glucose significantly augmented IFN-γ-dependent signaling pathways in TC-EC. IFN-γ-induced phosphorylation of JAK and STAT proteins as well as HLA-DR expression by ECs in low- and high-glucose medium was significantly lower in 3-D than in two-dimensional environment. Glucose increased SOCS expression in TC-EC and 3D-EC to the same extent, such that expression levels in 3D-EC exceeded SOCS-1 and -3 expression in TC-EC by 1.6-2.5-fold. In conclusion, low- and high-glucose concentrations amplify IFN-γ-induced signaling pathways in TC-EC. Increased SOCS expression raises the threshold for IFN-γ to induce HLA-DR expression in a 3-D environment. This immunoprotective effect is maintained even in states of experimental hyperglycemia.
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Affiliation(s)
- Markus Nickmann
- Department of Internal Medicine/Cardiology, University Hospital Grosshadern, Ludwig-Maximilians University, Munich, Germany
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71
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Yoon BI, Hong C, Lee JH, Kim SJ, Kim HS, Ha US, Hwang SY, Kim SW. The effects of new herbal formula (KBMSI-2) on penile erection and expression of nitric oxide synthase isoforms in streptozotocin-induced diabetic rat model. Chin J Integr Med 2013. [PMID: 24242134 DOI: 10.1007/s11655-013-1546-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To investigate the effects of new herbal formula (KBMSI-2) on erectile dysfunction in streptozotocin (STZ)-induced diabetic rat model. METHODS Twenty four Sprague-Dawley male rats were randomly divided into three groups; control (n=8), diabetes model (n=8), diabetes + KBMSI-2 200 mg/kg treatment (n=8) groups. The diabetes induced groups received a single intraperitoneal injection of STZ. Distilled water was administered in the control and model groups. To investigate the penile erection, intracavernosal pressure (ICP) and intracavernosal pressure/mean arterial pressure (ICP/MAP) were recorded in all groups. Serial sections of the penis were used to perform Masson's trichrome stain. The expression of neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS) and cyclic guanosine monophosphate (cGMP) concentration in the isolated corpus cavernosum were analyzed by Western blotting. RESULTS Peak ICP/MAP ratio was increased in the KBMSI-2 treatment group compared with the model group (P<0.05). Masson's trichrome staining confirmed that the smooth muscle component was increased in the KBMSI-2 treatment group compared with the model group (P<0.05). The nNOS, eNOS and cGMP expression of KBMSI-2 200 mg/kg treatment group was increased compared with the model group (P<0.05). CONCLUSION This study showed that herbal formula of KBMSI-2 improved the erectile function by preserving the smooth muscle content and inhibiting the fibrosis of the corpus cavernosum in STZ-induced diabetic rat model.
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Affiliation(s)
- Byung Il Yoon
- Department of Urology, The Catholic University of Korea, College of Medicine, Seoul, 137-701, Korea
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72
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Hafez G, Gonulalan U, Kosan M, Arioglu E, Ozturk B, Cetinkaya M, Gur S. Acetylsalicylic acid protects erectile function in diabetic rats. Andrologia 2013; 46:997-1003. [PMID: 24428436 DOI: 10.1111/and.12187] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2013] [Indexed: 11/28/2022] Open
Abstract
We aimed to evaluate the effect of acetylsalicylic acid (ASA) treatment on diabetes-induced erectile dysfunction. Adult male Sprague-Dawley rats were divided into four groups as follows: (i) control (C), (ii) diabetic (D), (iii) ASA-treated control (C+ASA) and (iv) ASA-treated diabetic (D+ASA) groups. In groups 2 and 4, diabetes was induced by injection of 35 mg kg(-1) streptozotocin. ASA (100 mg kg(-1) day(-1) , orally) was administrated to rats in groups 3 and 4 for 8 weeks. Both intracavernosal pressure (ICP) and mean arterial blood pressure (MAP) were measured in in vivo studies. In organ bath, the relaxation responses to acetylcholine (ACh), electrical field stimulation (EFS) and sodium nitroprusside were tested in corpus cavernosum (CC) strips. The mRNA expression for neuronal nitric oxide synthase (nNOS) was calculated using reverse transcription polymerase chain reaction technique. In in vivo experiments, diabetic rats displayed reduced ICP/MAP values, which were normalised with ASA treatment. The relaxant response to high-dose ACh and EFS at low frequencies (1-8 Hz) in CC strips from the D+ASA group were significantly higher when compared to the D group. Treatment with ASA normalised the raised mRNA expressions of nNOS in diabetic penile tissues. ASA may be involved in mRNA of protein synthesis of NO released from nonadrenergic and noncholinergic cavernosal nerve in diabetes.
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Affiliation(s)
- G Hafez
- Faculty of Pharmacy, Department of Pharmacology, Ankara University, Ankara, Turkey
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73
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Kobat MA, Fırdolas F, Balin M, Çelik A, Bentli R, Baydas A. Circulating Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 Levels Are Associated With Erectile Dysfunction in Patients Without Known Coronary Artery Disease. J Sex Med 2013; 10:2782-9. [DOI: 10.1111/j.1743-6109.2012.02964.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Geetha P, Aravind BS, Pallavi G, Rajendra V, Rao R, Akhtar N. Sexual dysfunction (Kṛcchra Vyavāya) in obesity (Sthaulya): Validation by an observational study. Anc Sci Life 2013; 32:76-81. [PMID: 24167331 PMCID: PMC3807961 DOI: 10.4103/0257-7941.118535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Objective: The present study intends to evaluate the relationship between Sthaulya (obesity) and Kṛcchra Vyavāya (sexual dysfunction) with respect to different phases of sexual intercourse through a single-centered, observational study in male patients of obesity. Materials and Methods: The study involved 33 obese males from the outpatient department of the Institution whose sexual functioning was assessed using an International Index of Erectile Function questionnaire, which was meant to assess five specific areas of sexual functioning. Results: A varying degree of sexual dysfunction was observed in four out of five areas of sexual functioning viz. erectile function (P < 0.02), orgasmic function (P < 0.02), sexual desire (P < 0.08), and overall satisfaction (P < 0.000) in obese individuals. Statistically significant dysfunction was not observed in intercourse satisfaction. Conclusions: Varying degree of sexual dysfunction is present in obese males, suggesting that obesity has a possible role in reducing the quality of sexual functioning in males as indicated in the classical ayurvedic literature.
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Affiliation(s)
- Parampalli Geetha
- Department of Ayurveda Siddhanta, Government Ayurveda Medical College, Mysore, India
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75
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Dalaklioglu S, Kuscu N, Celik-Ozenci C, Bayram Z, Nacitarhan C, Ozdem SS. Chronic treatment with taurine ameliorates diabetes-induced dysfunction of nitric oxide-mediated neurogenic and endothelium-dependent corpus cavernosum relaxation in rats. Fundam Clin Pharmacol 2013; 28:394-404. [PMID: 23848484 DOI: 10.1111/fcp.12041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/02/2013] [Accepted: 06/07/2013] [Indexed: 12/18/2022]
Abstract
This study was aimed to examine the effect of chronic taurine treatment on corpus cavernosum dysfunction in diabetic rats and to investigate possible underlying mechanisms. Thirty male rats were randomized to three groups of 10 each, including control, diabetic, and taurine-treated diabetic. Diabetes was induced in rats by streptozotocin (STZ, single intraperitoneal dose of 50 mg/kg body weight). Taurine was administered orally for 12 weeks (1% w/v in drinking water) from the day on which STZ was injected. At the end of the 12th week, strips of corpus cavernosum were suspended in an organ bath system for functional studies. Nitric oxide (NO)-mediated endothelium-dependent and neurogenic corpus cavernosum relaxation were evaluated by acetylcholine (ACh, 0.1-100 μm) and electrical field stimulation (EFS, 30 V, 5 ms, 2-32 Hz), respectively. The expressions of endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (p-eNOS) (Ser-1177), neuronal nitric oxide synthase (nNOS), NADPH oxidase subunit gp91(phox) , Rho A, and Rho kinase in corpus cavernosum were semi-quantitatively assessed by immunohistochemistry. Induction of diabetes resulted in significant inhibition of NO-mediated endothelium-dependent and neurogenic corpus cavernosum relaxation. Furthermore, eNOS, p-eNOS, and nNOS expressions decreased significantly in diabetic rats compared to controls, while gp91(phox) , RhoA and Rho kinase expressions increased significantly. The diminished relaxation response to ACh and EFS as well as diabetes-related changes in expressions of these proteins in corpus cavernosum of diabetic rats was significantly improved by taurine. Taurine treatment improves NO-mediated relaxations of corpus cavernosum in diabetic rats probably by inhibiting NADPH oxidase/Rho kinase pathways.
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Affiliation(s)
- Selvinaz Dalaklioglu
- Department of Pharmacology, Medical Faculty, Akdeniz University, 07070, Antalya, Turkey
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76
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Chronic administration of imipramine but not agomelatine and moclobemide affects the nitrergic relaxation of rabbit corpus cavernosum smooth muscle. Eur J Pharmacol 2013; 714:442-7. [PMID: 23845214 DOI: 10.1016/j.ejphar.2013.07.003] [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: 01/09/2013] [Revised: 06/10/2013] [Accepted: 07/01/2013] [Indexed: 11/21/2022]
Abstract
Sexual dysfunction is a common and underestimated effect of antidepressants. However, the mechanism by which these drugs cause erectile dysfunction is unclear. We investigated the reactivity of the corpus cavernosum of rabbits that were treated with either chronic imipramine, which is a tricyclic agent; agomelatine, which is a melatonergic agonist and serotonin 5HT(2c) antagonist; or moclobemide, which is a reversible inhibitor of monoamine-oxidase A. Twenty rabbits were randomly divided into four groups: the control group (n=5), the imipramine-treated group (n=5), which received i.p. injections of 10 mg/kg/day of imipramine, the moclobemide-treated group (n=5), which received i.p. injections of 20 mg/kg/day of moclobemide, and the agomelatine-treated group (n=5), which was orally administered 10 mg/kg/day of agomelatine. The reactivities of corpus cavernosum tissue obtained from the antidepressant-treated and the control groups were studied in organ chambers after the animals were subjected to 21 days of drug administration. The acetylcholine-induced endothelium-dependent and the electrical field stimulation (EFS)-induced neurogenic relaxation of the corpus cavernosum of the imipramine-treated group was significantly decreased compared with the control group. However, neither the acetylcholine- nor EFS-induced relaxation was changed in the moclobemide- or agomelatine-treated groups. There were no change in the relaxant response to the nitric oxide (NO) donor sodium nitroprusside and contractile response to KCl between the groups. This study suggests that chronic imipramine treatment but not agomelatine and moclobemide treatments causes significant functional changes in the penile erectile tissue of rabbits and that these changes may contribute to the development of impotence.
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77
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Soni SD, Song W, West JL, Khera M. Nitric oxide-releasing polymeric microspheres improve diabetes-related erectile dysfunction. J Sex Med 2013; 10:1915-25. [PMID: 23751157 DOI: 10.1111/jsm.12216] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
INTRODUCTION We have used a long-acting nitric oxide (NO)-releasing polymer to develop injectable biodegradable microspheres capable of localized NO release over prolonged periods of time. AIM The aim of this study was to evaluate the therapeutic potential of these microspheres for diabetes-related erectile dysfunction (ED) in the rat model. METHODS NO-releasing microspheres were incubated in physiologic buffer, and in vitro NO release was measured using a Griess assay. To ensure no migration, microspheres were fluorescently tagged and injected into the corpus cavernosum of adult rats, and fluorescent imaging was performed weekly for 4 weeks, at which point rats were sacrificed. To assess physiologic efficacy, diabetes was induced in 40 rats using streptozotocin (STZ), whereas 10 rats were kept as age-matched controls. Diabetic rats were divided into four groups: no treatment, sildenafil, NO-releasing microspheres, and combination therapy. For each rat, the cavernosal nerve (CN) was stimulated at various voltages, and intracavernosal pressure (ICP) and mean arterial pressure (MAP) were measured via corpus cavernosum and carotid artery catheterization, respectively. Long-term efficacy was determined by injecting diabetic rats with microspheres and measuring erectile response at predetermined intervals for up to 5 weeks. MAIN OUTCOME MEASURES Erectile response was determined via calculation of mean peak ICP/MAP and area under curve (AUC) for each experimental group. RESULTS Under physiologic conditions in vitro, microspheres continued NO release for up to 4 weeks. Fluorescent imaging revealed no detectable signal in tissues besides cavernosal tissue at 4 weeks postinjection. Upon CN stimulation, peak ICP/MAP ratio and AUC of diabetic rats improved significantly (P < 0.05) in microsphere and combination therapy groups compared with no treatment and sildenafil groups. In long-term efficacy studies, microspheres augmented the effect of sildenafil for 3 weeks following injection (P < 0.05). CONCLUSIONS NO-releasing microspheres significantly improved erectile response in diabetic rats for 3 weeks and hence offer a promising approach to ED therapy, either as monotherapy or combination therapy.
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Affiliation(s)
- Samit D Soni
- Scott Department of Urology, Baylor College of Medicine, Houston, TX 77030, USA.
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78
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Hamidi Madani A, Asadolahzade A, Mokhtari G, Shahrokhi Damavand R, Farzan A, Esmaeili S. Assessment of the Efficacy of Combination Therapy with Folic Acid and Tadalafil for the Management of Erectile Dysfunction in Men with Type 2 Diabetes Mellitus. J Sex Med 2013; 10:1146-50. [DOI: 10.1111/jsm.12047] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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79
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Azadzoi KM, Master TA, Siroky MB. Effect of Chronic Ischemia on Constitutive and Inducible Nitric Oxide Synthase Expression in Erectile Tissue. ACTA ACUST UNITED AC 2013; 25:382-8. [PMID: 15064316 DOI: 10.1002/j.1939-4640.2004.tb02804.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Arterial occlusive disease is one of the leading causes of organic erectile dysfunction (ED). Recent studies have shown that the incidence of cardiovascular disease closely correlates with the prevalence of ED. Also, ED is thought to be an early signal of impending cardiovascular problems. We previously found that the atherosclerosis of iliohypogastric arteries in the rabbit causes ED, down-regulates cavernosal neuronal nitric oxide synthase (nNOS) gene expression, and impairs NO synthesis. The goal of this study was to determine the effect of atherosclerosis-induced ischemia on cavernosal nNOS, endothelial NOS (eNOS), and inducible NOS (iNOS) expression and NO-mediated smooth muscle relaxation in the rabbit. Our study showed that iliac artery blood flow, intracavernosal blood flow, and intracavernosal oxygen tension were unchanged 4 weeks after the induction of arterial atherosclerosis, whereas they were significantly diminished at weeks 8 and 16. Erectile responses to nerve stimulation and cavernosal smooth muscle relaxation were unchanged at week 4 and were significantly diminished at weeks 8 and 16 after the induction of atherosclerosis. Western blotting showed that cavernosal nNOS and eNOS protein levels were unaffected at week 4 but were significantly decreased at weeks 8 and 16 after the induction of atherosclerosis. iNOS protein, however, markedly increased during the course of the induced arterial disease. Immunohistochemical staining showed no change in cavernosal eNOS or nNOS expression at week 4. A dramatic decrease in both was evident at 8 and 16 weeks. iNOS expression progressively increased between 4 and 16 weeks of atherosclerosis. Down-regulation of nNOS and eNOS, along with up-regulation of iNOS, may explain ischemic cavernosal smooth muscle relaxation impairment in the rabbit. Ischemically altered NOS expression may be of great pathophysiologic importance in atherosclerosis-induced ED. These data may provide further insight into the mechanism of arteriogenic ED.
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Affiliation(s)
- Kazem M Azadzoi
- Boston University School of Medicine, Boston, Massachusetts, USA.
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80
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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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81
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Kim DK, Yin GN, Ryu JK, Suh JK. Differential expression of nerve injury-induced protein 1 (ninjurin 1) in in vivo and in vitro models for diabetic erectile dysfunction. Korean J Urol 2012; 53:636-42. [PMID: 23061002 PMCID: PMC3460007 DOI: 10.4111/kju.2012.53.9.636] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/08/2012] [Indexed: 12/13/2022] Open
Abstract
Purpose Endothelial dysfunction and peripheral neuropathy are important mechanisms responsible for diabetes-induced erectile dysfunction (ED). Nerve injury-induced protein 1 (Ninjurin 1) is known to be related to neuroinflammatory processes and is also reported to induce vascular regression during the developmental period. In the present study, we determined the differential expression of Ninjurin 1 in penile tissue of streptozotocin (STZ)-induced diabetic mice with ED. Materials and Methods Diabetes was induced in 8-week-old C57BL/6J mice by intraperitoneal injections of STZ (50 mg/kg for 5 days). Eight weeks later, erectile function was measured by electrical stimulation of the cavernous nerve (n=6 per group). The penis was then harvested for immunohistochemical analysis and Western blot analysis for Ninjurin 1 (n=4 per group). We also determined Ninjurin 1 expression in primary cultured mouse cavernous endothelial cells (MCECs) incubated under the following conditions: normal glucose condition (5 mM), high-glucose condition (30 mM), and high-glucose condition (30 mM)+insulin (1 nM). Results The expression of Ninjurin 1 protein was significantly higher in both cavernous endothelial cells and the dorsal nerve bundle of diabetic mice than in those of controls. In the in vitro study in MCECs, Ninjurin 1 expression was also significantly increased by the high-glucose condition and was returned to baseline levels by treatment with insulin. Conclusions Regarding the role of Ninjurin 1 in neuropathy and vascular regression, it would be interesting to examine the effects of inhibition of Ninjurin 1 on erectile function in animal models of ED with a vascular or neurogenic cause.
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Affiliation(s)
- Do Kyung Kim
- Department of Urology, National Research Center for Sexual Medicine, Inha University School of Medicine, Incheon, Korea
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Choi WS, Park K, Paick JS, Kim SW. Time-dependent changes of erectile function in diabetic rats: role of systemic endothelial dysfunction. World J Mens Health 2012; 30:114-22. [PMID: 23596598 PMCID: PMC3623519 DOI: 10.5534/wjmh.2012.30.2.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/15/2012] [Accepted: 08/16/2012] [Indexed: 02/04/2023] Open
Abstract
PURPOSE To understand the potential contribution of systemic endothelial dysfunction to diabetic erectile dysfunction, and the time course of erectile dysfunction in a streptozotocin (STZ)-induced diabetic rat model. MATERIALS AND METHODS Among 84, 12-week-old Sprague-Dawley rats, 48 rats received intraperitoneal STZ and were classified into six groups of diabetes by the period of observation (n=8). The remaining 36 rats were also grouped, similar to the diabetic groups, and served as normal controls. After 4, 6, 8, 10, 12, and 14 weeks of diabetes (serum glucose >250 mg%), all rats underwent cavernous nerve electrostimulation (3 V, 0.2 ms, 30 sec) with varying frequency (2.5~20 Hz). At the end of the study, 8 ml of blood was taken to measure the plasma markers of endothelial function and glycosylated hemoglobin. RESULTS Compared to the control, significant reduction of erectile response was not observed until eight weeks after diabetes induction. The diabetic rats had elevation of all plasma markers except for l-selectin. However, the correlation analysis revealed that no systemic marker of endothelial dysfunction was associated with change in erectile function. Only the level of hemoglobin A1c (HbA1c) showed a modest but significant correlation with the peak intracavernosal pressure, corrected by mean arterial pressure (ρ=-0.183), and the area under the curve of the cavernosometry (ρ=-0.207). CONCLUSIONS Significant reduction of erectile function was not observed until eight weeks after the induction of diabetes. Except for HbA1c, there was no systemic marker associated with endothelial activation and erectile function in the diabetic rats.
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Affiliation(s)
- Woo Suk Choi
- Department of Urology, Seoul National University College of Medicine, Seoul, Korea
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83
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Chung H, Jung SH, Ryu JK, Kim B, Kim HS, Yang SK. Isolation and characterization of smooth muscle cells from rat corpus cavernosum tissue for the study of erectile dysfunction. Korean J Urol 2012; 53:556-63. [PMID: 22950001 PMCID: PMC3427841 DOI: 10.4111/kju.2012.53.8.556] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 07/20/2012] [Indexed: 11/18/2022] Open
Abstract
Purpose Primary culture of the cavernous smooth muscle cells from corpus cavernous tissues is known to be difficult, mainly because of contamination with fibroblasts. We applied a new method for better isolation of rat penile smooth muscle cells (RPSMCs) from rat corpus cavernosum tissue for reliable ex vivo research on erectile dysfunction. Materials and Methods With the use of 8-week-old adult male Sprague-Dawley rats, ex vivo migrations of rat cavernous tissue were measured by penis and aortic ring assay by use of a Matrigel-based D-valine-modified culture method. The expression of α-smooth muscle actin (α-SMA) and platelet/endothelial cell adhesion molecule (PECAM)-1 in the RPSMCs was determined by standard immunofluorescent staining and immunoblotting. The expression patterns of phosphodiesterase (PDE) family mRNA in RPSMCs were compared with patterns in rat aortic smooth muscle cells (RASMCs) by use of quantitative real-time reverse transcription polymerase chain reaction. Results Immunocytochemical staining showed greater α-SMA-positive and PCAM-1-negative fluorescence. Moreover, whereas the expression of α-SMA was detected in the RPSMCs, that of PECAM-1 was not. The levels of PDE1A, PDE1B, PDE1C, PDE2A, PDE3A, PDE4A, PDE4B, PDE4C, PDE4D, and PDE5A mRNA in the RPSMCs were about 3.2-, 4.4-, 3.4-, 29.0-, 3.5-, 2.8-, 2.9-, 6.1-, 45.0-, and 6.0-fold the corresponding expression in RASMCs. Conclusions We developed a two-stage tissue culture method utilizing a Matrigel-based sprouting culture system to facilitate stromal cell sprouting and an adherent culture system using D-valine to eliminate the contamination of fibroblasts into the smooth muscle cells.
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Affiliation(s)
- Hong Chung
- Department of Urology, Konkuk University School of Medicine, Chungju, Korea
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84
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Abdel Aziz MT, Motawi T, Rezq A, Mostafa T, Fouad HH, Ahmed HH, Rashed L, Sabry D, Senbel A, Al-Malki A, El-Shafiey R. Effects of a water-soluble curcumin protein conjugate vs. pure curcumin in a diabetic model of erectile dysfunction. J Sex Med 2012; 9:1815-33. [PMID: 22548787 DOI: 10.1111/j.1743-6109.2012.02741.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Curcumin is involved in erectile signaling via elevation of cyclic guanosine monophosphate (cGMP). AIM Assessment of the effects of water-soluble curcumin in erectile dysfunction (ED). METHODS One hundred twenty male white albino rats were divided into: 1st and 2nd control groups with or without administration of Zinc protoporphyrin (ZnPP), 3rd and 4th diabetic groups with or without ZnPP, 5th diabetic group on single oral dose of pure curcumin, 6th diabetic group on pure curcumin administered daily for 12 weeks, 7th and 8th diabetic groups on single dose of water-soluble curcumin administered with or without ZnPP, 9th and 10th diabetic groups on water-soluble curcumin administered daily for 12 weeks with or without ZnPP. All curcumin dosage schedules were administered after induction of diabetes. MAIN OUTCOME MEASURES Quantitative gene expression of endothelial nitric oxide synthase (eNOS), neuronal NOS (nNOS), inducible NOS (iNOS), heme oxygenase-1 (HO-1), nuclear transcription factor-erythroid2 (Nrf2), NF-Кβ, and p38. Cavernous tissue levels of HO and NOS enzyme activities, cGMP and intracavernosal pressure (ICP). RESULTS Twelve weeks after induction of diabetes, ED was confirmed by the significant decrease in ICP. There was a significant decrease in cGMP, NOS, HO enzymes, a significant decrease in eNOS, nNOS, HO-1 genes and a significant elevation of NF-Кβ, p38, iNOS genes. Administration of pure curcumin or its water-soluble conjugate led to a significant elevation in ICP, cGMP levels, a significant increase in HO-1 and NOS enzymes, a significant increase in eNOS, nNOS, HO-1, and Nrf2 genes, and a significant decrease in NF-Кβ, p38, and iNOS genes. Water-soluble curcumin showed significant superiority and more prolonged duration of action. Repeated doses regimens were superior to single dose regimen. Administration of ZnPP significantly reduced HO enzyme, cGMP, ICP/ mean arterial pressure (MAP), HO-1 genes in diabetic groups. CONCLUSION Water-soluble curcumin could enhance erectile function with more effectiveness and with more prolonged duration of action.
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Affiliation(s)
- Mohamed Talaat Abdel Aziz
- Medical Biochemistry Department, Unit of Biochemistry and Molecular Biology, Faculty of Medicine, Cairo University, Cairo, Egypt
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85
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Long T, Liu G, Wang Y, Chen Y, Zhang Y, Qin D. TNF-α, erectile dysfunction, and NADPH oxidase-mediated ROS generation in corpus cavernosum in high-fat diet/streptozotocin-induced diabetic rats. J Sex Med 2012; 9:1801-14. [PMID: 22524530 DOI: 10.1111/j.1743-6109.2012.02739.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Patients with diabetes-associated erectile dysfunction (ED) are characterized by an increase in circulating tumor necrosis factor-alpha (TNF-α). However, no study has indicated whether and how TNF-α plays a role in the pathogenesis of ED associated with diabetes. AIM We examined the effects and potential mechanism of infliximab (INF), a chimeric monoclonal antibody to TNF-α, on reactive oxygen species (ROS) generation in corpus cavernosum and ED in diabetic rats. METHODS Four groups of male rats were used: age-matched normal controls; diabetic rats induced by a high-fat diet (HFD) combined with a single streptozotocin (STZ) injection (35 mg/kg body weight, intraperitoneal [i.p.]); nondiabetic rats receiving INF (5 mg/kg body weight/week, i.p.), and diabetic rats receiving INF. Erectile function was assessed with electrical stimulation of the cavernous nerve after 8 weeks. The blood and penile tissues were harvested for plasma biochemical determinations, serum TNF-α measurement, penile ROS detection, and molecular assays of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits, endothelial nitric oxide synthase (eNOS), phospho-eNOS, and neural nitric oxide synthase (nNOS) in the penis. MAIN OUTCOME MEASURES The effect of INF on HFD/STZ-induced diabetic ED and NADPH oxidase-mediated ROS generation was studied in diabetic corpus cavernosum. RESULTS Untreated diabetic rats displayed significantly decreased erectile parameters, and increased plasma TNF-α levels, penile ROS production, p47(phox) and gp91(phox) expression compared with nondiabetic controls. INF neutralized TNF-α and significantly reduced ED in diabetic rats, in which marked decreases in p47(phox) and gp91(phox) expression and ROS generation in corpus cavernosum were noted. The ratio of phospho-eNOS to eNOS and expression of nNOS in the penis were significantly increased in INF-treated vs. untreated diabetic rats. CONCLUSIONS Increased TNF-α expression associated with diabetes contributes to ED by promoting NAPDH oxidase-mediated ROS generation in corpus cavernosum. INF protects against diabetic ED by neutralizing TNF-α.
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Affiliation(s)
- Ting Long
- Department of Physiology, Shantou University Medical College, Shantou, China
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86
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Schjørring O, Kun A, Flyvbjerg A, Kirkeby HJ, Jensen JB, Simonsen U. Flow‐Evoked Vasodilation Is Blunted in Penile Arteries from Zucker Diabetic Fatty Rats. J Sex Med 2012; 9:1789-800. [DOI: 10.1111/j.1743-6109.2012.02743.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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87
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Effects of male silkworm pupa powder on the erectile dysfunction by chronic ethanol consumption in rats. Lab Anim Res 2012; 28:83-90. [PMID: 22787481 PMCID: PMC3389843 DOI: 10.5625/lar.2012.28.2.83] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 05/14/2012] [Accepted: 05/15/2012] [Indexed: 11/21/2022] Open
Abstract
Erectile dysfunction (ED) is a highly prevalent disorder that affects millions of men worldwide. ED is now considered an early manifestation of atherosclerosis, and consequently, a precursor of systemic vascular disease. This study was designed to investigate the effects of male silkworm pupa powder (SWP) on the levels of nitric oxide synthase (NOS) expression, nitrite, and glutathione (GSH); lipid peroxidation; libido; and erectile response of the corpus cavernosum of the rat penis. We induced ED in the study animals by oral administration of 20% ethanol over 8 weeks. The SWP-treated male rats were divided into 3 groups that were orally administered 200, 400, and 800 mg/kg. The libido of the SWP-administered male rats was higher than that of the ethanol control group. In addition, the erectile response of the corpus cavernosum was restored in males on SWP administration, to a level similar to that of the normal group without ED. The testosterone concentration did not increase significantly. The lipid peroxidation in the corpus cavernosum of the male rats administered SWP decreased significantly. In contrast, compared to the ethanol group, SWP-administered male rats showed increased GSH levels in the corpus cavernosum. The level of nitrite and NOS expression in the corpus cavernosum of SWP-administered male rats increased significantly. These results indicated that SWP effectively restored ethanol-induced ED in male rats.
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88
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Porst H, Hell-Momeni K, Büttner H. Chronic PDE-5 inhibition in patients with erectile dysfunction – a treatment approach using tadalafil once-daily. Expert Opin Pharmacother 2012; 13:1481-94. [DOI: 10.1517/14656566.2012.693162] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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89
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Sánchez A, Contreras C, Martínez MP, Climent B, Benedito S, García-Sacristán A, Hernández M, Prieto D. Role of neural NO synthase (nNOS) uncoupling in the dysfunctional nitrergic vasorelaxation of penile arteries from insulin-resistant obese Zucker rats. PLoS One 2012; 7:e36027. [PMID: 22540017 PMCID: PMC3335073 DOI: 10.1371/journal.pone.0036027] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 03/28/2012] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE Erectile dysfunction (ED) is considered as an early sign of vascular disease due to its high prevalence in patients with cardiovascular risk factors. Endothelial and neural dysfunction involving nitric oxide (NO) are usually implicated in the pathophysiology of the diabetic ED, but the underlying mechanisms are unclear. The present study assessed the role of oxidative stress in the dysfunctional neural vasodilator responses of penile arteries in the obese Zucker rat (OZR), an experimental model of metabolic syndrome/prediabetes. METHODS AND RESULTS Electrical field stimulation (EFS) under non-adrenergic non-cholinergic (NANC) conditions evoked relaxations that were significantly reduced in penile arteries of OZR compared with those of lean Zucker rats (LZR). Blockade of NO synthase (NOS) inhibited neural relaxations in both LZR and OZR, while saturating concentrations of the NOS substrate L-arginine reversed the inhibition and restored relaxations in OZR to levels in arteries from LZR. nNOS expression was unchanged in arteries from OZR compared to LZR and nNOS selective inhibition decreased the EFS relaxations in LZR but not in OZR, while endothelium removal did not alter these responses in either strain. Superoxide anion production and nitro-tyrosine immunostaining were elevated in the erectile tissue from OZR. Treatment with the NADPH oxidase inhibitor apocynin or acute incubation with the NOS cofactor tetrahydrobiopterin (BH4) restored neural relaxations in OZR to levels in control arteries, while inhibition of the enzyme of BH4 synthesis GTP-cyclohydrolase (GCH) reduced neural relaxations in arteries from LZR but not OZR. The NO donor SNAP induced decreases in intracellular calcium that were impaired in arteries from OZR compared to controls. CONCLUSIONS The present study demonstrates nitrergic dysfunction and impaired neural NO signalling due to oxidative stress and nNOS uncoupling in penile arteries under conditions of insulin resistance. This dysfunction likely contributes to the metabolic syndrome-associated ED, along with the endothelial dysfunction also involving altered NO signalling.
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Affiliation(s)
- Ana Sánchez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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90
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Ha US, Koh JS, Kim HS, Woo JC, Kim SJ, Jang H, Yoon BI, Hwang SY, Kim SW. Cyanidin-3-O-β- D-Glucopyranoside Concentrated Materials from Mulberry Fruit Have a Potency to Protect Erectile Function by Minimizing Oxidative Stress in a Rat Model of Diabetic Erectile Dysfunction. Urol Int 2012; 88:470-6. [DOI: 10.1159/000336136] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 12/23/2011] [Indexed: 12/23/2022]
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91
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Kolluru GK, Bir SC, Kevil CG. Endothelial dysfunction and diabetes: effects on angiogenesis, vascular remodeling, and wound healing. Int J Vasc Med 2012; 2012:918267. [PMID: 22611498 PMCID: PMC3348526 DOI: 10.1155/2012/918267] [Citation(s) in RCA: 302] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Accepted: 10/18/2011] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by inappropriate hyperglycemia due to lack of or resistance to insulin. Patients with DM are frequently afflicted with ischemic vascular disease or wound healing defect. It is well known that type 2 DM causes amplification of the atherosclerotic process, endothelial cell dysfunction, glycosylation of extracellular matrix proteins, and vascular denervation. These complications ultimately lead to impairment of neovascularization and diabetic wound healing. Therapeutic angiogenesis remains an attractive treatment modality for chronic ischemic disorders including PAD and/or diabetic wound healing. Many experimental studies have identified better approaches for diabetic cardiovascular complications, however, successful clinical translation has been limited possibly due to the narrow therapeutic targets of these agents or the lack of rigorous evaluation of pathology and therapeutic mechanisms in experimental models of disease. This paper discusses the current body of evidence identifying endothelial dysfunction and impaired angiogenesis during diabetes.
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Affiliation(s)
| | | | - Christopher G. Kevil
- Department of Pathology, LSU Health Sciences Center-Shreveport, 1501 Kings Highway, Shreveport, LA 71130, USA
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92
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Arafa M, Zohdy W, Aboulsoud S, Shamloul R. Prevalence of late-onset hypogonadism in men with type 2 diabetes mellitus. Andrologia 2011; 44 Suppl 1:756-63. [PMID: 22211848 DOI: 10.1111/j.1439-0272.2011.01262.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2011] [Indexed: 12/16/2022] Open
Abstract
Late-onset hypogonadism (LOH) or age-associated testosterone deficiency syndrome is defined as a clinical and biochemical syndrome associated with advancing age and characterised by symptoms and a deficiency in serum testosterone levels. This condition may result in significant detriment in the quality of life and adversely affect the function of multiple organ systems. It has been suggested that sex steroid hormones may play a causal role in the development of insulin resistance and type II diabetes. This comparative study was aimed at determining the prevalence of LOH in diabetic men with erectile dysfunction and investigating the effect of testosterone replacement therapy on erectile function and on glycaemic control.
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Affiliation(s)
- M Arafa
- Department of Andrology, Cairo University, Cairo, Egypt
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93
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Nunes KP, Toque HA, Caldwell RB, William Caldwell R, Clinton Webb R. Extracellular Signal‐Regulated Kinase (ERK) Inhibition Decreases Arginase Activity and Improves Corpora Cavernosal Relaxation in Streptozotocin (STZ)‐Induced Diabetic Mice. J Sex Med 2011; 8:3335-44. [DOI: 10.1111/j.1743-6109.2011.02499.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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94
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Chung E, De Young L, Brock GB. Investigative Models in Erectile Dysfunction: A State‐of‐the‐Art Review of Current Animal Models. J Sex Med 2011; 8:3291-305. [DOI: 10.1111/j.1743-6109.2011.02505.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Chronic administration of fluoxetine impairs neurogenic and endothelium-dependent relaxation of the rabbit corpus cavernosum smooth muscle. Eur J Pharmacol 2011; 670:224-8. [PMID: 21925166 DOI: 10.1016/j.ejphar.2011.08.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/07/2011] [Accepted: 08/27/2011] [Indexed: 11/20/2022]
Abstract
Antidepressants, including selective serotonin reuptake inhibitors (SSRIs), cause erectile dysfunction; however, the mechanism by which they cause erectile function is unclear. We investigated the reactivity of the corpus cavernosum after chronic fluoxetine treatment in rabbits. Twelve rabbits were randomly divided into two groups: control (n=6) or 20mg/kg/day of fluoxetine delivered i.p. (n=6). The reactivity of the corpus cavernosum tissue from the fluoxetine-treated and control groups was studied in organ chambers after 21 days of fluoxetine injection. In the fluoxetine-treated group, endothelium-dependent relaxation of the corpus cavernosum in response to acetylcholine was significantly decreased compared to the control group. However, the sensitivity (i.e., pD(2)) of the fluoxetine-treated cavernosal tissue strips to acetylcholine was not changed with respect to controls. Electrical field stimulation (EFS)-induced neurogenic relaxation was also significantly reduced in the fluoxetine-treated group. Relaxation in response to the nitric oxide (NO) donor sodium nitroprusside was similar between the cavernosal tissues from the two groups. There was also no change in agonist potency between the two groups. Additionally, chronic fluoxetine treatment had no effect on KCl-induced contractile responses. When tissue contraction was produced with phenylephrine to study relaxation in response to various stimuli, the tension induced was similar between the fluoxetine-treated and control groups. This study suggests that chronic fluoxetine treatment causes significant functional changes to the penile erectile tissue of rabbits, and these changes may contribute to the development of impotence.
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96
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Andersson KE. Mechanisms of penile erection and basis for pharmacological treatment of erectile dysfunction. Pharmacol Rev 2011; 63:811-59. [PMID: 21880989 DOI: 10.1124/pr.111.004515] [Citation(s) in RCA: 232] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Erection is basically a spinal reflex that can be initiated by recruitment of penile afferents, both autonomic and somatic, and supraspinal influences from visual, olfactory, and imaginary stimuli. Several central transmitters are involved in the erectile control. Dopamine, acetylcholine, nitric oxide (NO), and peptides, such as oxytocin and adrenocorticotropin/α-melanocyte-stimulating hormone, have a facilitatory role, whereas serotonin may be either facilitatory or inhibitory, and enkephalins are inhibitory. The balance between contractant and relaxant factors controls the degree of contraction of the smooth muscle of the corpora cavernosa (CC) and determines the functional state of the penis. Noradrenaline contracts both CC and penile vessels via stimulation of α₁-adrenoceptors. Neurogenic NO is considered the most important factor for relaxation of penile vessels and CC. The role of other mediators, released from nerves or endothelium, has not been definitely established. Erectile dysfunction (ED), defined as the "inability to achieve or maintain an erection adequate for sexual satisfaction," may have multiple causes and can be classified as psychogenic, vasculogenic or organic, neurologic, and endocrinologic. Many patients with ED respond well to the pharmacological treatments that are currently available, but there are still groups of patients in whom the response is unsatisfactory. The drugs used are able to substitute, partially or completely, the malfunctioning endogenous mechanisms that control penile erection. Most drugs have a direct action on penile tissue facilitating penile smooth muscle relaxation, including oral phosphodiesterase inhibitors and intracavernosal injections of prostaglandin E₁. Irrespective of the underlying cause, these drugs are effective in the majority of cases. Drugs with a central site of action have so far not been very successful. There is a need for therapeutic alternatives. This requires identification of new therapeutic targets and design of new approaches. Research in the field is expanding, and several promising new targets for future drugs have been identified.
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Affiliation(s)
- K-E Andersson
- Wake Forest Institute for Regenerative Medicine, Wake Forest University School of Medicine, Medical Center Boulevard, Winston Salem, NC 27157, USA.
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Fonteles MC, do Nascimento NRF. Guanylin peptide family: history, interactions with ANP, and new pharmacological perspectives. Can J Physiol Pharmacol 2011; 89:575-85. [PMID: 21815750 DOI: 10.1139/y11-050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The guanylin family of peptides has 3 subclasses of peptides containing either 3 intramolecular disulfide bonds found in bacterial heat-stable enterotoxins (ST), or 2 disulfides observed in guanylin and uroguanylin, or a single disulfide exemplified by lymphoguanylin. These peptides bind to and activate cell-surface receptors that have intrinsic guanylate cyclase (GC) activity. These hormones are synthesized in the intestine and released both luminally and into the circulation, and are also produced within the kidney. Stimulation of renal target cells by guanylin peptides in vivo or ex vivo elicits a long-lived diuresis, natriuresis, and kaliuresis by both cGMP-dependent and independent mechanisms. Uroguanylin may act as a hormone in a novel endocrine axis linking the digestive system and kidney as well as a paracrine system intrarenally to increase sodium excretion in the postprandial period. This highly integrated and redundant mechanism allows the organism to maintain sodium balance by eliminating excess sodium in the urine. In addition, small concentrations of the atrial natriuretic peptide (ANP) can synergize with low concentrations of both guanylin or uroguanylin, which do not induce natriuresis per se, to promote significant natriuresis. Interestingly, the activation of the particulate guanylate cyclase receptors by natriuretic peptides can promote relaxation of animal and human penile erectile tissue and increase intracavernosal pressure to induce penile erection. These peptides can be prototypes for new drugs to treat erectile dysfunction, especially in patients with endothelial and nitrergic dysfunction, such as in diabetes.
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Affiliation(s)
- Manassés Claudino Fonteles
- Instituto Superior de Ciências Biomédicas (ISCB), Laboratório de Farmacologia - Universidade Estadual do Ceará (UECE), Avenida Paranjana 1700, Campus do Itaperi, CEP 60740-000, Fortaleza-CE, Brazil.
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El-Sakka AI, Morsy AM, Fagih BI. Severity of erectile dysfunction could predict left ventricular diastolic dysfunction in patients without overt cardiac complaint. J Sex Med 2011; 8:2590-7. [PMID: 21679302 DOI: 10.1111/j.1743-6109.2011.02350.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION It has been repeatedly demonstrated that presence of erectile dysfunction (ED) may predate the occurrence of overt event of coronary artery disease. However, the association between severity of ED and left ventricular diastolic dysfunction (LVDD) was rarely reported. AIM The aim of this study was to assess the association between severity of ED and LVDD in patients without overt cardiac complaint. MAIN OUTCOME MEASURES The International Index of Erectile Function (IIEF) was used to assess erectile function. Diastolic Doppler parameters measurements and tissue Doppler imaging were used to assess left ventricular diastolic function. METHODS A total of 230 male ED patients without overt cardiac complaint were enrolled in this study. Erectile function was assessed using the IIEF. Patients were also screened for socio demographic data and medical comorbidities that included age, smoking, diabetes, hypertension, and dyslipidemia. All patients were referred to cardiologist for cardiac assessment. Left ventricular diastolic function that included diastolic Doppler parameters measurements and tissue Doppler imaging were also assessed. RESULTS Mean age±standard deviation was 57.5±5.6 (range of 42-81). There were significant associations between the following risk factors: age, obesity, smoking, hypertension, dyslipidemia, and increased severity of ED (P<0.05 for each). Of the patients, 77.4%, 74.8%, 80%, and 66.1% had abnormal transmitral E/A (E/A) ratio, deceleration time (DT), isovolumic relaxation time (IVRT), mitral E velocity/tissue Doppler imaging E velocity (E/Em) ratio, respectively. Only the means of IVRT and (E/Em) ratio had significant associations with increased severity of ED (P<0.001 for each). There were significant associations between increased severity of ED and the following categorical echo parameters: grades 1 and 2 of E/A ratio, DT, IVRT, and grades 1, 2, and 3 of (E/Em) ratio (P<0.05 for each). CONCLUSIONS The current study clearly demonstrated that LVDD is prevalent among patients with ED-associated medical comorbidities without overt cardiac complaint. There were significant associations between increased severity of ED and presence of LVDD in those patients.
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Wan ZH, Li WZ, Li YZ, Chen L, Li GH, Hu WF, Peng S, Yu JJ, Guo F. Poly(ADP‐Ribose) Polymerase Inhibition Improves Erectile Function in Diabetic Rats. J Sex Med 2011; 8:1002-14. [DOI: 10.1111/j.1743-6109.2010.01963.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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100
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Luscher TF. Functional Abnormalities of the Vascular Endothelium in Hypertension and Atherosclerosis. Scandinavian Journal of Clinical and Laboratory Investigation 2011. [DOI: 10.1080/00365519009090539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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