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Giuliano F, Joussain C, Denys P, Laurin M, Behr-Roussel D, Assaly R. Intracavernosal OnabotulinumtoxinA Exerts a Synergistic Pro-Erectile Effect When Combined With Sildenafil in Spontaneously Hypertensive Rats. J Sex Med 2022; 19:899-906. [PMID: 35365400 DOI: 10.1016/j.jsxm.2022.03.213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 02/12/2022] [Accepted: 03/02/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND Botulinum toxin A (BTX-A) has a variety of uses in medicine. Some evidence suggests that intracavernosal (ic) BTX-A injection administered in addition to phosphodiesterase type 5 inhibitors (PDE5-Is) could effectively treat erectile dysfunction (ED) in insufficient responders to PDE5-Is. AIM To provide experimental pharmacological evidence for the use of onabotulinumtoxinA ic alone or in combination with PDE5-Is for difficult-to-treat ED. We thus compared the effects of BTX-A ic alone and BTX-A ic combined with PDE5-I iv, and a placebo treatment ic or iv. METHODS Erectile function was evaluated following cavernous nerve electrical stimulation (6 V, 1-millisecond pulse, 45-second duration) at different frequencies (0, 2, 3, 4, 5, 7.5, and 10 Hz) in 4 groups (n = 8 / group) of anesthetized, spontaneously hypertensive rats, a robust animal model of ED of vascular origin. Rats were treated by onabotulinumtoxinA 10U or saline ic 1 week prior to erectile function testing and sildenafil (0.3 mg/kg) or saline iv 4 minutes prior to testing. Frequency-response curves were compared with a 2 way ANOVA. OUTCOMES Both onabotulinumtoxinA ic, and sildenafil iv significantly improved erectile responses in spontaneously hypertensive rats, however the effect was greatly amplified when the treatments were combined. RESULTS Intracavernosal pressure and/or mean arterial pressure ratios were significantly increased by sildenafil and onabotulinumtoxinA ic versus the control condition. OnabotulinumtoxinA 10U ic combined with sildenafil iv significantly potentiated erectile responses. Area under the curve and/or mean arterial pressure ratio increased by 19% with sildenafil iv, by 15% with onabotulinumtoxinA ic and by 58% with the combined treatment following cavernous nerve electrical stimulation at 6V, 1 ms, 10 Hz: these stimulation parameters elicited the maximal erectile response. CLINICAL TRANSLATION These data provide a pharmacological rationale for the combined administration of onabotulinumtoxinA ic and sildenafil iv since the effects of both treatments were potentiated when their administration was combined. STRENGTHS & LIMITATIONS First evidence of a synergistic pro-erectile effect of BTX-A combined with PDE5-I, however the mechanism behind the pro-erectile effect of BTX-A ic remains hypothetical. CONCLUSIONS These results support further studies into the mechanisms behind the pro-erectile effect of BTX-A ic, as well as multicenter randomized control trials to evaluate the safety and efficacy of BTX-A ic combined with sildenafil for difficult-to-treat ED. Giuliano F., Joussain C., Denys P., et al. Intracavernosal OnabotulinumtoxinA Exerts a Synergistic Pro-Erectile Effect When Combined With Sildenafil in Spontaneously Hypertensive Rats. J Sex Med 2022;19:899-906.
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Affiliation(s)
- Francois Giuliano
- Neuro-Uro-Andrology Department, Raymond Poincare University Hospital, Garches, France; Faculty of Medicine, Versailles Saint Quentin University, Montigny le Bretonneux, Paris Saclay, France.
| | - Charles Joussain
- Neuro-Uro-Andrology Department, Raymond Poincare University Hospital, Garches, France; Faculty of Medicine, Versailles Saint Quentin University, Montigny le Bretonneux, Paris Saclay, France
| | - Pierre Denys
- Neuro-Uro-Andrology Department, Raymond Poincare University Hospital, Garches, France; Faculty of Medicine, Versailles Saint Quentin University, Montigny le Bretonneux, Paris Saclay, France
| | | | | | - Rana Assaly
- Pelvipharm SAS, Montigny le Bretonneux, France
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Cripps SM, Mattiske DM, Pask AJ. Erectile Dysfunction in Men on the Rise: Is There a Link with Endocrine Disrupting Chemicals? Sex Dev 2021; 15:187-212. [PMID: 34134123 DOI: 10.1159/000516600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/18/2021] [Indexed: 11/19/2022] Open
Abstract
Erectile dysfunction (ED) is one of the most prevalent chronic conditions affecting men. ED can arise from disruptions during development, affecting the patterning of erectile tissues in the penis and/or disruptions in adulthood that impact sexual stimuli, neural pathways, molecular changes, and endocrine signalling that are required to drive erection. Sexual stimulation activates the parasympathetic system which causes nerve terminals in the penis to release nitric oxide (NO). As a result, the penile blood vessels dilate, allowing the penis to engorge with blood. This expansion subsequently compresses the veins surrounding the erectile tissue, restricting venous outflow. As a result, the blood pressure localised in the penis increases dramatically to produce a rigid erection, a process known as tumescence. The sympathetic pathway releases noradrenaline (NA) which causes detumescence: the reversion of the penis to the flaccid state. Androgen signalling is critical for erectile function through its role in penis development and in regulating the physiological processes driving erection in the adult. Interestingly, estrogen signalling is also implicated in penis development and potentially in processes which regulate erectile function during adulthood. Given that endocrine signalling has a prominent role in erectile function, it is likely that exposure to endocrine disrupting chemicals (EDCs) is a risk factor for ED, although this is an under-researched field. Thus, our review provides a detailed description of the underlying biology of erectile function with a focus on the role of endocrine signalling, exploring the potential link between EDCs and ED based on animal and human studies.
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Affiliation(s)
- Samuel M Cripps
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Deidre M Mattiske
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew J Pask
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, Australia
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3
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de Oliveira AA, Nunes KP. Hypertension and Erectile Dysfunction: Breaking Down the Challenges. Am J Hypertens 2021; 34:134-142. [PMID: 32866225 DOI: 10.1093/ajh/hpaa143] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/15/2020] [Accepted: 08/29/2020] [Indexed: 02/07/2023] Open
Abstract
A diagnostic of hypertension increases the risk of erectile dysfunction (ED); likewise, ED can be an early sign of hypertension. In both cases, there is evidence that endothelial dysfunction is a common link between the 2 conditions. During hypertension, the sustained and widespread release of procontractile factors (e.g., angiotensin II, endothelin 1, and aldosterone) impairs the balance between vasoconstrictors and vasodilators and, in turn, detrimentally impacts vascular and erectile structures. This prohypertensive state associates with an enhancement in the generation of reactive oxygen species, which is not compensated by internal antioxidant mechanisms. Recently, the innate immune system, mainly via Toll-like receptor 4, has also been shown to actively contribute to the pathophysiology of hypertension and ED not only by inducing oxidative stress but also by sustaining a low-grade inflammatory state. Furthermore, some drugs used to treat hypertension can cause ED and, consequently, reduce compliance with the prescribed pharmacotherapy. To break down these challenges, in this review, we focus on discussing the well-established as well as the emerging mechanisms linking hypertension and ED with an emphasis on the signaling network of the vasculature and corpora cavernosa, the vascular-like structure of the penis.
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Affiliation(s)
- Amanda Almeida de Oliveira
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, Florida, USA
| | - Kenia Pedrosa Nunes
- Laboratory of Vascular Physiology, Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, Florida, USA
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4
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ALTUNÖREN O, ERKEN E, GÜNGÖR Ö, YAVUZ YC. Hipertansiyon ve Erektil Disfonksiyon. KAHRAMANMARAŞ SÜTÇÜ İMAM ÜNIVERSITESI TIP FAKÜLTESI DERGISI 2019. [DOI: 10.17517/ksutfd.477511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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5
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Palacios-Ramírez R, Hernanz R, Martín A, Pérez-Girón JV, Barrús MT, González-Carnicero Z, Aguado A, Jaisser F, Briones AM, Salaices M, Alonso MJ. Pioglitazone Modulates the Vascular Contractility in Hypertension by Interference with ET-1 Pathway. Sci Rep 2019; 9:16461. [PMID: 31712626 PMCID: PMC6848177 DOI: 10.1038/s41598-019-52839-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 09/11/2019] [Indexed: 02/07/2023] Open
Abstract
Endothelin-1 (ET-1) is an important modulator of the vascular tone and a proinflammatory molecule that contributes to the vascular damage observed in hypertension. Peroxisome-proliferator activated receptors-γ (PPARγ) agonists show cardioprotective properties by decreasing inflammatory molecules such as COX-2 and reactive oxygen species (ROS), among others. We investigated the possible modulatory effect of PPARγ activation on the vascular effects of ET-1 in hypertension. In spontaneously hypertensive rats (SHR), but not in normotensive rats, ET-1 enhanced phenylephrine-induced contraction through ETA by a mechanism dependent on activation of TP receptors by COX-2-derived prostacyclin and reduction in NO bioavailability due to enhanced ROS production. In SHR, the PPARγ agonist pioglitazone (2.5 mg/Kg·day, 28 days) reduced the increased ETA levels and increased those of ETB. After pioglitazone treatment of SHR, ET-1 through ETB decreased ROS levels that resulted in increased NO bioavailability and diminished phenylephrine contraction. In vascular smooth muscle cells from SHR, ET-1 increased ROS production through AP-1 and NFκB activation, leading to enhanced COX-2 expression. These effects were blocked by pioglitazone. In summary, in hypertension, pioglitazone shifts the vascular ETA/ETB ratio, reduces ROS/COX-2 activation and increases NO availability; these changes explain the effect of ET-1 decreasing phenylephrine-induced contraction.
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Affiliation(s)
- Roberto Palacios-Ramírez
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain.,Institut National de la Santé et de la Recherche Médicale Inserm U1138, Cordeliers Institute, Paris VI-University, Paris, France
| | - Raquel Hernanz
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - Angela Martín
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - José V Pérez-Girón
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain
| | - María T Barrús
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - Zoe González-Carnicero
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain
| | - Andrea Aguado
- Depto. de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPaz), Madrid, Spain
| | - Frederic Jaisser
- Institut National de la Santé et de la Recherche Médicale Inserm U1138, Cordeliers Institute, Paris VI-University, Paris, France
| | - Ana M Briones
- CIBER de Enfermedades Cardiovasculares, Madrid, Spain.,Depto. de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPaz), Madrid, Spain
| | - Mercedes Salaices
- CIBER de Enfermedades Cardiovasculares, Madrid, Spain.,Depto. de Farmacología, Facultad de Medicina, Universidad Autónoma de Madrid, Instituto de Investigación Hospital La Paz (IdiPaz), Madrid, Spain
| | - María J Alonso
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain. .,CIBER de Enfermedades Cardiovasculares, Madrid, Spain.
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Abstract
Endothelial nitric oxide (NO) synthase (eNOS) has an indispensable role in the erectile response. In the penis, eNOS activity and endothelial NO bioavailability are regulated by multiple post-translatlonal molecular mechanisms, such as eNOS phosphorylation, eNOS interaction with regulatory proteins and contractile pathways, and actions of reactive oxygen species (ROS). These mechanisms regulate eNOS-mediated responses under physiologic circumstances and provide various mechanisms whereby endothelial NO availability may be altered in states of vasculogenlc erectile dysfunction (ED), in view of the recent advances in the field of eNOS function in the penis and its role in penile erection, the emphasis in this review is placed on the mechanisms regulating eNOS activity and its interaction with the RhoA/Rho-kinase pathway in the physiology of penile erection and the pathophysiology of ED.
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Affiliation(s)
- Biljana Musicki
- Johns Hopkins Hospital, Department of Urology, 600 North Wolfe Street, Baltimore, MD 21287, USA
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Defeudis G, Gianfrilli D, Di Emidio C, Pofi R, Tuccinardi D, Palermo A, Lenzi A, Pozzilli P. Erectile dysfunction and its management in patients with diabetes mellitus. Rev Endocr Metab Disord 2015; 16:10.1007/s11154-015-9321-4. [PMID: 26497842 DOI: 10.1007/s11154-015-9321-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Diabetes can be described as a syndrome of multiple closely related conditions induced by a chronic state of hyperglycaemia resulting from defective insulin secretion, insulin action or both. Chronic complications associated with diabetes (including neuropathy, vascular disease, nephropathy and retinopathy) are common, and of these, erectile dysfunction (ED) deserves special attention. ED and its correlation with cardiovascular disease require careful evaluation and appropriate treatment. PDE5 inhibitors (PDE5is) are an important tool for the treatment of ED, with new drugs coming onto the market since the late 90s. This review offers an overview of PDE5is and their use in treating ED in diabetes. We underline the differences between different types of PDE5i, focusing on available doses, duration of action, T ½, side effects and selectivity profiles in relation to patients with diabetes. We also discuss the link between diabetes and ED in presence of various associated cofactors (obesity, hypertension and its pharmacological treatments, atherosclerosis, hyperhomocysteinaemia, neuropathy, nephropathy, hypogonadism and depression). Finally a number of past and ongoing clinical trials on the use of PDE5is in patients with diabetes are presented to offer an overview of the appropriate treatment of ED in this condition.
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Affiliation(s)
- Giuseppe Defeudis
- Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 21, Rome, Italy
- Department of Experimental Medicine, Sapienza University of Rome, Viale del Policlinico 155, Rome, Italy
| | - Daniele Gianfrilli
- Department of Experimental Medicine, Sapienza University of Rome, Viale del Policlinico 155, Rome, Italy
| | - Chiara Di Emidio
- Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 21, Rome, Italy
| | - Riccardo Pofi
- Department of Experimental Medicine, Sapienza University of Rome, Viale del Policlinico 155, Rome, Italy
| | - Dario Tuccinardi
- Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 21, Rome, Italy
| | - Andrea Palermo
- Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 21, Rome, Italy
| | - Andrea Lenzi
- Department of Experimental Medicine, Sapienza University of Rome, Viale del Policlinico 155, Rome, Italy
| | - Paolo Pozzilli
- Department of Endocrinology and Diabetes, University Campus Bio-Medico of Rome, Via Alvaro del Portillo 21, Rome, Italy.
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8
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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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9
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Abolyosr A, Elsagheer GA, Abdel-Kader MS, Hassan AM, Abou-Zeid AMM. Evaluation of the effect of sildenafil and/or doxazosin on Benign prostatic hyperplasia-related lower urinary tract symptoms and erectile dysfunction. Urol Ann 2013; 5:237-40. [PMID: 24311901 PMCID: PMC3835979 DOI: 10.4103/0974-7796.120293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2012] [Accepted: 09/08/2012] [Indexed: 11/04/2022] Open
Abstract
PURPOSE To verify the association between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) and evaluate the influence of sildenafil and doxazosin either as single agents or combined on both symptoms. MATERIAL AND METHODS A prospective randomized study including 150 patients presented with LUTS caused by BPH in association with clinically diagnosed ED, with age equal or more than 45 years from April 2010 to April 20011. They were categorized into three comparative groups each one containing 50 patients. These groups were comparable regarding pretreatment international prostate symptoms score (IPSS) and international index of erectile function (IIEF). The patients of the first group were given sildenafil 50 mg as monotherapy, those of the second group were given doxazosin 2 mg and those of the third group were given combination of both drugs for 4 months for each group. The main post-treatment parameters for assessment and comparison include assessment of patient's symptoms by repeated IPS Sand IIEF, uroflowmetry and assessment of PVR. The statistics was done by use of the Qui--square test. RESULTS Pre-treatment parameters were assessed and compared between the three groups. After 4 months of treatment, the comparative parameters were applied to all groups and the differences were measured post-treatment regarding IPSS, erectile function score, uroflowmetry, and post-void residual (PVR) urine. Sildenafil alone caused mild improvement in IPSS, more improvement in IIEF score, and little effect on flow rate and PVR urine. Doxazosin alone caused more improvement in IPSS, flow rate and PVR urine and less improvement in IIEF score. A combination of both sildenafil and doxazosin caused more improvement in all of the comparative parameters than when each drug was given alone. CONCLUSIONS There is a strong relationship between LUTS and ED. Doxazosin or sidenafil as a single drug could be used in treating mild or mild to moderate symptoms but more severe symptoms may usually need a combination of both drugs.
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Affiliation(s)
- Ahmed Abolyosr
- Urology Department, Qena Faculty of Medicine, South valley University, Egypt
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10
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Abstract
PURPOSE OF REVIEW Erectile dysfunction is recognized as a quality-of-life disorder that needs to be treated. Currently, it is estimated to affect as many as 30 million American men. Thirty percent of hypertensive patients complain of erectile dysfunction. The understanding of common mechanisms involved in the cause of erectile dysfunction associated with hypertension, and the investigation of antihypertensive drugs that impact erectile dysfunction, will provide important tools toward identifying new therapeutic targets that will improve the quality of life for patients in these conditions. RECENT FINDINGS Hypertension and erectile dysfunction are closely intertwined diseases, which have endothelial dysfunction as a common base. During hypertension and/or erectile dysfunction, disturbance of endothelium-derived factors can lead to an increase in vascular smooth muscle (VSM) contraction. Hypertension can lead to erectile dysfunction as a consequence of high blood pressure (BP) or due to antihypertensive treatment. However, growing evidence suggests erectile dysfunction is an early sign for hypertension. Also, some phosphodiesterase-5 inhibitors used to treat erectile dysfunction can improve BP, but the link between these conditions has not been totally understood. SUMMARY This review will discuss the interplay between hypertension and erectile dysfunction, exploring newest insights regarding hypertension-associated erectile dysfunction, as well as the effect of antihypertensive drugs in erectile dysfunction patients.
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11
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Hao YC, Yu LP, Li Q, Zhang XW, Zhao YP, He PY, Xu T, Wang XF. Effects of integrin-linked kinase on human corpus cavernosum smooth muscle cell cytoskeletal organisation. Andrologia 2012; 45:78-85. [PMID: 22616551 DOI: 10.1111/j.1439-0272.2012.01313.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2012] [Indexed: 11/26/2022] Open
Abstract
We investigated the effects of integrin-linked kinase (ILK) on the in vitro attachment, spreading, migration and microfilament dynamics of human corpus cavernosum smooth muscle cells. ILK small interfering RNA (siRNA) was used to transfect human corpus cavernosum smooth muscle cells; and cell attachment, spreading and migration were assessed. Additionally, microfilament dynamics were evaluated using Alexa Fluor 488 and phalloidin staining. We found that ILK gene knock-down significantly inhibited human corpus cavernosum smooth muscle cell attachment, spreading and migration. Moreover, blocking the expression of ILK disturbed actin cytoskeleton reorganisation and morphology in human corpus cavernosum smooth muscle cells. These results show that the targeting of ILK with siRNA significantly inhibited cell attachment, spreading, migration and microfilament dynamics in human corpus cavernosum smooth muscle cells. These findings indicate that ILK might be a potential therapeutic molecular target for the treatment of erectile dysfunction.
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Affiliation(s)
- Y-C Hao
- Urology Department, Peking University People's Hospital, Beijing, China
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12
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Bivalacqua TJ, Musicki B, Kutlu O, Burnett AL. New Insights into the Pathophysiology of Sickle Cell Disease‐Associated Priapism. J Sex Med 2012; 9:79-87. [DOI: 10.1111/j.1743-6109.2011.02288.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Liao CH, Chiang HS, Hsiao PJ. Lower urinary tract symptoms and erectile dysfunction. UROLOGICAL SCIENCE 2011. [DOI: 10.1016/j.urols.2011.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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14
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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: 234] [Impact Index Per Article: 18.0] [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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15
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Wu XJ, Song B, Zhang JH, Zhou ZS, Li LK, Li XM. Effect of exogenous l-arginine and ageing on NO and ET-1 in penile tissue of rat. Andrologia 2011; 43:303-6. [PMID: 21793865 DOI: 10.1111/j.1439-0272.2010.01064.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The aim of this study was to investigate the effect and significance of l-arginine and ageing on nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway and ET-1 in penile tissue of rats. The different months old rats were divided into control group and experiment group randomly, the content of NO, cGMP, the changes of activity of Nitrous Oxide Systems (NOS) and the content of endothelin-1(ET-1) in penile tissue were determined. Along with ageing, NO and the activity of NOS in penile tissue increased at first and then decreased (P < 0.001). The content of cGMP reduced obviously (P < 0.001), the content of ET-1 had a tendency to increase, and the ratio of ET-1/NO increased significantly (P < 0.001 or P < 0.01). After feeding rats with l-arginine for some time, both the activity of NOS and the content of cGMP increased significantly in penile tissue (P < 0.001), while there was no obvious change in the content of ET-1. Our study shows that whether the smooth muscle cells relax or contract might be decided by the content of cGMP and value of ET-1/NO in penile tissue. l-arginine had significant effect on increasing the activity of NOS and the content of NO and cGMP, indicating that l-arginine has potential clinical value to be used in treating ED.
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Affiliation(s)
- X-J Wu
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
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Allahdadi KJ, Hannan JL, Ergul A, Tostes RC, Webb RC. Internal pudendal artery from type 2 diabetic female rats demonstrate elevated endothelin-1-mediated constriction. J Sex Med 2011; 8:2472-83. [PMID: 21718448 DOI: 10.1111/j.1743-6109.2011.02375.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Diabetes is a risk factor for female sexual dysfunction (FSD). FSD has several etiologies, including a vasculogenic component that could be exacerbated in diabetes. The internal pudendal artery supplies blood to the vagina and clitoris and diabetes-associated functional abnormalities in this vascular bed may contribute to FSD. AIM The Goto-Kakizaki (GK) rat is a non-obese model of type 2 diabetes with elevated endothelin-1 (ET-1) activity. We hypothesize that female GK rats have diminished sexual responses and that the internal pudendal arteries demonstrate increased ET-1 constrictor sensitivity. METHODS Female Wistar and GK rats were used. Apomorphine (APO)-mediated genital vasocongestive arousal (GVA) was measured. Functional contraction (ET-1 and phenylephrine) and relaxation (acetylcholine, ACh) in the presence or absence of the ETA receptor antagonist (ETA R; atrasentan) or Rho-kinase inhibitor (Y-27632) were assessed in the internal pudendal and mesenteric arteries. Protein expression of ET-1 and RhoA/Rho-kinase signaling pathway was determined in the internal pudendal and mesenteric arteries. MAIN OUTCOME MEASURE APO-mediated GVAs; contraction and relaxation of internal pudendal and mesenteric arteries; ET-1/RhoA/Rho-kinase protein expression. RESULTS GK rats demonstrated no APO-induced GVAs. Internal pudendal arteries, but not mesenteric arteries, from GK rats exhibited greater contractile sensitivity to ET-1 compared with Wistar arteries. ETA R blockade reduced ET-1-mediated constriction in GK internal pudendal and mesenteric arteries. Rho-kinase inhibition reduced ET-1-mediated constriction of GK internal pudendal but not mesenteric arteries; however, it had no effect on arteries from Wistar rats. RhoA protein expression was elevated in GK internal pudendal arteries. At the highest concentrations, ACh-mediated relaxation was greater in the GK internal pudendal artery; however, no difference was observed in the mesenteric artery. CONCLUSIONS Female GK rats demonstrate decreased sexual responses that may be because of increased constrictor sensitivity to the ET-1/RhoA/Rho-kinase signaling in the internal pudendal artery.
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Affiliation(s)
- Kyan J Allahdadi
- Department of Physiology, Georgia Health Sciences University, Augusta, GA 30912, USA.
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Villalba N, Contreras C, Hernández M, García-Sacristán A, Prieto D. Impaired Ca2+ handling in penile arteries from prediabetic Zucker rats: involvement of Rho kinase. Am J Physiol Heart Circ Physiol 2011; 300:H2044-53. [DOI: 10.1152/ajpheart.01204.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Diabetes is associated with an increased vascular tone usually involved in the pathogenesis of diabetic cardiovascular complications such as hypertension, stroke, coronary artery disease, or erectile dysfunction (ED). Enhanced contractility of penile erectile tissue has been associated with augmented activity of the RhoA/Rho kinase (RhoK) pathway in models of diabetes-associated ED. The present study assessed whether abnormal vasoconstriction in penile arteries from prediabetic obese Zucker rats (OZRs) is due to changes in the intracellular Ca2+ concentration ([Ca2+]i) and/or in myofilament Ca2+ sensitivity. Penile arteries from OZRs and lean Zucker rats (LZRs) were mounted on microvascular myographs for simultaneous measurements of [Ca2+]i and tension. The relationships between [Ca2+]i and contraction for the α1-adrenergic vasoconstrictor phenylephrine (PE) were left shifted and steeper in OZRs compared with LZRs, although the magnitude of the contraction was similar in both groups. In contrast, the vasoconstriction induced by the thromboxane A2 receptor agonist U-46619 was augmented in arteries from OZRs, and this increase was associated with an increase in both the sensitivity and maximum responses to Ca2+. The RhoK inhibitor Y-27632 (10 μM) reduced the vasoconstriction induced by PE to a greater extent in OZRs than in LZRs, without altering Ca2+. Y-27632 inhibited with a greater potency the contraction elicited by high KCl in arteries from OZRs compared with LZRs without changing [Ca2+]i. RhoK-II expression was augmented in arteries from OZRs. These results suggest receptor-specific changes in the Ca2+ handling of penile arteries under conditions of metabolic syndrome. Whereas augmented vasoconstriction upon activation of the thromboxane A2 receptor is coupled to enhanced Ca2+ entry, a RhoK-mediated enhancement of myofilament Ca2+ sensitivity is coupled with the α1-adrenergic vasoconstriction in penile arteries from OZRs.
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Affiliation(s)
- Nuria Villalba
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
| | - Cristina Contreras
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
| | | | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
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18
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Endothelins & erectile dysfunction. Pharmacol Res 2011; 63:496-501. [DOI: 10.1016/j.phrs.2010.12.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 12/16/2010] [Accepted: 12/17/2010] [Indexed: 11/23/2022]
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Abstract
This review addresses the roles of Rho/Rho-kinase (ROCK) pathway in the pathogenesis of diabetes complications. Diabetes can cause many serious complications and can result in physical disability or even increased mortality. However, there are not many effective ways to treat these complications. The small guanosine-5'-triphosphate-binding protein Rho and its downstream target Rho-kinase mediate important cellular functions, such as cell morphology, motility, secretion, proliferation, and gene expression. Recently, the Rho/Rho-kinase pathway has attracted a great deal of attention in diabetes-related research. These studies have provided evidence that the activity and gene expression of Rho-kinase are upregulated in some tissues in animal models of type 1 or type 2 diabetes and in cell lines cultured with high concentrations of glucose. Inhibitors of Rho-kinase could prevent or ameliorate the pathological changes in diabetic complications. The inhibitory effects of statins on the Rho/Rho-kinase signalling pathway may also play a role in the prevention of diabetic complications. However, the precise molecular mechanism by which the Rho/Roh-kinase pathway participates in the development or progression of diabetic complications has not been extensively investigated. This article evaluates the relationship between Rho/Roh-kinase activation and diabetic complications, as well as the roles of Roh-kinase inhibitors and statins in the complications of diabetes, with the objective of providing a novel target for the treatment of long-term diabetic complications.
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Affiliation(s)
- Hong Zhou
- Department of Endocrinology, The Second Hospital of He Bei Medical University, Shijiazhuang, China
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Gur S, Kadowitz PJ, Hellstrom WJ. RhoA/Rho‐Kinase as a Therapeutic Target for the Male Urogenital Tract. J Sex Med 2011; 8:675-87. [DOI: 10.1111/j.1743-6109.2010.02084.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Chiba Y, Matsusue K, Misawa M. RhoA, a possible target for treatment of airway hyperresponsiveness in bronchial asthma. J Pharmacol Sci 2010; 114:239-47. [PMID: 20948164 DOI: 10.1254/jphs.10r03cr] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Airway hyperresponsiveness to nonspecific stimuli is one of the characteristic features of allergic bronchial asthma. An elevated contractility of bronchial smooth muscle has been considered as one of the causes of the airway hyperresponsiveness. The contraction of smooth muscles including airway smooth muscles is mediated by both Ca²+-dependent and Ca²+-independent pathways. The latter Ca²+-independent pathway, termed Ca²+ sensitization, is mainly regulated by a monomeric GTP-binding protein, RhoA, and its downstream target Rho-kinase. In animal models of allergic bronchial asthma, an augmented agonist-induced, RhoA-mediated contraction of bronchial smooth muscle has been suggested. The RhoA/Rho-kinase signaling is now proposed as a novel target for the treatment of airway hyperresponsiveness in asthma. Herein, we will discuss the mechanism of development of bronchial smooth muscle hyperresponsiveness, one of the causes of the airway hyperresponsiveness, based on the recent studies using animal models of allergic bronchial asthma and/or cultured airway smooth muscle cells. The possibility of RhoA as a therapeutic target in asthma, especially airway hyperresponsiveness, will also be described.
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Affiliation(s)
- Yoshihiko Chiba
- Department of Pharmacology, School of Pharmacy, Hoshi University, Japan.
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Carneiro FS, Nunes KP, Giachini FR, Lima VV, Carneiro ZN, Nogueira EF, Leite R, Ergul A, Rainey WE, Clinton Webb R, Tostes RC. Activation of the ET‐1/ETA Pathway Contributes to Erectile Dysfunction Associated with Mineralocorticoid Hypertension. J Sex Med 2008; 5:2793-807. [DOI: 10.1111/j.1743-6109.2008.01009.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Carneiro FS, Carneiro ZN, Giachini FRC, Lima VV, Nogueira E, Rainey WE, Tostes RC, Webb RC. Murine and rat cavernosal responses to endothelin-1 and urotensin-II Vasoactive Peptide Symposium. ACTA ACUST UNITED AC 2008; 2:439-447. [PMID: 19884966 DOI: 10.1016/j.jash.2008.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND: Endothelin-1 (ET-1) and urotensin-II (U-II) are the most potent constrictors of human vessels. Although the cavernosal tissue is higly responsive to ET-1, no information exists on the effects of U-II on cavernosal function. The aim of this study was to characterize ET-1 and U-II responses in corpora cavernosa from rats and mice. METHODS AND RESULTS: Male Wistar rats and C57/BL6 mice were used at 13 weeks. Cumulative concentration-response curves to ET-1, U-II and IRL-1620, an ET(B) agonist, were performed. ET-1 increased force generation in cavernosal strips from mice and rats, but no response to U-II was observed in the presence or absence of L-NAME, or in strips pre-stimulated with 20mM KCl. IRL-1620 did not induce cavernosal contraction even in presence of L-NAME, but induced a cavernosal relaxation which was greater in rats than mice. No relaxation responses to U-II were observed in cavernosal strips pre-contracted with phenylephrine. mRNA expression of ET-1, ET(A), ET(B) and U-II receptors, but not U-II was observed in cavernosal strips. CONCLUSION: ET-1, via ET(A) receptors activation, causes contractile responses in cavernosal strips from rats and mice whereas ET(B) receptor activation produces relaxation. Although the cavernosal tissue expresses U-II receptors, U-II does not induce contractile responses in corpora cavernosa from mice or rats.
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Carneiro FS, Giachini FRC, Lima VV, Carneiro ZN, Nunes KP, Ergul A, Leite R, Tostes RC, Webb RC. DOCA-salt treatment enhances responses to endothelin-1 in murine corpus cavernosum. Can J Physiol Pharmacol 2008; 86:320-8. [PMID: 18516094 DOI: 10.1139/y08-031] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The penis is kept in the flaccid state mainly via a tonic activity of norepinephrine and endothelins (ETs). ET-1 is important in salt-sensitive forms of hypertension. We hypothesized that cavernosal responses to ET-1 are enhanced in deoxycorticosterone acetate (DOCA)-salt mice and that blockade of ETA receptors prevents abnormal responses of the corpus cavernosum in DOCA-salt hypertension. Male C57BL/6 mice were unilaterally nephrectomized and treated for 5 weeks with both DOCA and water containing 1% NaCl and 0.2% KCl. Control mice were uninephrectomized and received tap water with no added salt. Animals received either the ETA antagonist atrasentan (5 mg x day(-1) x kg(-1) body weight) or vehicle. DOCA-salt mice displayed increased systolic blood pressure (SBP), and treatment with atrasentan decreased SBP in DOCA-salt mice. Contractile responses in cavernosal strips from DOCA-salt mice were enhanced by ET-1, phenylephrine, and electrical field stimulation (EFS) of adrenergic nerves, whereas relaxations were not altered by IRL-1620 (an ETB agonist), acetylcholine, sodium nitroprusside, and EFS of nonadrenergic noncholinergic nerves. PD59089 (an ERK1/2 inhibitor), but not Y-27632 (a Rho-kinase inhibitor), abolished enhanced contractions to ET-1 in cavernosum from DOCA-salt mice. Treatment of DOCA-salt mice with atrasentan did not normalize cavernosal responses. In summary, DOCA-salt treatment in mice enhances cavernosal reactivity to contractile, but not to relaxant, stimuli, via ET-1/ETA receptor-independent mechanisms.
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Affiliation(s)
- Fernando S Carneiro
- Medical College of Georgia, Department of Physiology, 1120 Fifteenth Street, CA-3141, Augusta, GA 30912-3000, USA.
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Köhler TS, McVary KT. The relationship between erectile dysfunction and lower urinary tract symptoms and the role of phosphodiesterase type 5 inhibitors. Eur Urol 2008; 55:38-48. [PMID: 18783872 DOI: 10.1016/j.eururo.2008.08.062] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 08/26/2008] [Indexed: 01/25/2023]
Abstract
CONTEXT The relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) and the potential interplay of phosphodiesterase type 5 inhibitors (PDE5-I) have clinical implications for both patient screening and treatment. OBJECTIVE To describe the current literature assessing the LUTS-ED relationship and the role of PDE5-I from both a basic science and clinical intervention perspective. EVIDENCE ACQUISITION We focused on data recently published (1990-2008) describing epidemiologic and mechanistic manuscripts of the LUTS-ED relationship with emphasis on papers involving PDE5-I-particularly those using level 1 evidence clinical trials. Base key words used included BPH, LUTS, ED, and phosphodiesterase inhibitors in combination with such secondary key words as nitric oxide, autonomic hyperactivity, Rho-kinase, atherosclerosis, and mechanism. We abstracted >200 articles and reviewed >100. EVIDENCE SYNTHESIS The large overlap of elderly men with both LUTS and ED likely stems from a cause-and-effect relationship. Thus far, four proposed mechanisms attempt to explain the relationship between LUTS and ED. Multiple studies showing that PDE5-I improved LUTS have been performed. Understanding the role of PDE5-I in the LUTS and ED relationship affects patient screening and treatment but also raises further research questions. CONCLUSIONS The future use of phosphodiesterase inhibitors as either prophylaxis or as a primary treatment for LUTS looms as a possibility and may not be limited to men.
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Affiliation(s)
- Tobias S Köhler
- Division of Urology, Southern Illinois University School of Medicine, Springfield, Illinois, USA
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Myung SC, Lee MY, Lee SY, Yum SH, Park SH, Kim SC. Contractile changes of the clitoral cavernous smooth muscle in female rabbits with experimentally induced overactive bladder. J Sex Med 2008; 5:1088-1096. [PMID: 18331275 DOI: 10.1111/j.1743-6109.2008.00777.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Recently, growing clinical evidence has suggested that sexual dysfunction is more prevalent in women with overactive bladder (OAB). Aims. However, there has been no basic research to clarify the relationship between OAB and female sexual dysfunction. Therefore, we investigated this issue using a rabbit model of OAB. METHODS Twenty-seven New Zealand white female rabbits were randomly divided into the OAB and control groups. MAIN OUTCOME MEASURES The contractile responses of clitoral cavernous strips to K(+), phenylephrine (PE), Bay K 8644, and endothelin (ET)-1, and the relaxation responses of acetylcholine (ACh), sodium nitroprusside (SNP), and Y-27632 to PE-induced contraction by measuring isometric tension. Results. The contractile responses to K(+), PE, Bay K 8644, and ET-1 were significantly more increased in the OAB group in a dose-dependant manner than in the control group (P < 0.05), and the responses to ET-1 were more prominent than those to the remaining substances (P < 0.01). The increased contractile responses to ET-1 were blocked by BQ123 (ET(A) receptor antagonist) but not by BQ788 (ET(B) receptor antagonist). Clitoral cavernosal strips from the OAB group were more difficult to relax than those from the control group in terms of ACh- and SNP-induced relaxation (P < 0.05). The Y-27632-induced relaxant responses to PE- and ET-1-induced contraction were less prominent in the OAB group than in the control group. CONCLUSIONS; The results of this study provide evidence that female OAB may deteriorate clitoral engorgement, which is associated with a greater force generation by increased calcium sensitization and subsequently decreased of relaxation. The activation of ET and Rho-kinase system may be crucial to negatively effect the clitoral smooth muscle relaxation in experimentally induced OAB animal model. But whether these vasomotor effects are revived in human clitoris is still debatable.
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Affiliation(s)
- Soon-Chul Myung
- Research Institute for Translational System Biomics, Chung-Ang University, College of Medicine, Seoul, South Korea
| | - Moo-Yeol Lee
- Department of Physiology, Chung-Ang University, College of Medicine, Seoul, South Korea
| | - Shin-Young Lee
- Research Institute for Translational System Biomics, Chung-Ang University, College of Medicine, Seoul, South Korea
| | - Seung-Hee Yum
- Department of Urology, Chung-Ang University, College of Medicine, Seoul, South Korea
| | - Soo-Hyun Park
- Research Institute for Translational System Biomics, Chung-Ang University, College of Medicine, Seoul, South Korea
| | - Sae-Chul Kim
- Research Institute for Translational System Biomics, Chung-Ang University, College of Medicine, Seoul, South Korea;.
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Gur S, Kadowitz PJ, Hellstrom WJG. Guide to Drug Therapy for Lower Urinary Tract Symptoms in Patients with Benign Prostatic Obstruction. Drugs 2008; 68:209-29. [DOI: 10.2165/00003495-200868020-00005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Imamura M, Waseda Y, Marinova GV, Ishibashi T, Obayashi S, Sasaki A, Nagai A, Azuma H. Alterations of NOS, arginase, and DDAH protein expression in rabbit cavernous tissue after administration of cigarette smoke extract. Am J Physiol Regul Integr Comp Physiol 2007; 293:R2081-9. [PMID: 17881617 DOI: 10.1152/ajpregu.00406.2007] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Cigarette smoking is an independent risk factor for vasculogenic erectile dysfunction (ED). Nitric oxide (NO) has been demonstrated to be the principal mediator of cavernous smooth muscle relaxation and penile erection. Therefore, we examined whether or not enzyme activities and factors involved in the NO generation pathway are affected in rabbit corpus cavernosum after administration of nicotine- and tar-free cigarette smoke extract (CSE). CSE was prepared by bubbling a stream of cigarette smoke into phosphate-buffered saline. CSE was injected subcutaneously into adult male rabbits once a day for 5 wk. In the CSE group, significantly decreased cyclic GMP production as a marker of NO generation was associated with attenuated overall nitric oxide synthase (NOS) activity, enhanced arginase activity, accumulation of endogenous NOS inhibitors such as monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA), and decreased dimethylarginine dimethylaminohydrolase (DDAH) activity as an metabolizing enzyme of endogenous NOS inhibitors. Neuronal NOS (nNOS) and DDAH I protein expression were decreased without altering endothelial NOS expression, while arginase I expression was upregulated. These results suggest that impaired NO production would result from blunted NOS activity, which is possibly brought about by the downregulation of nNOS protein, accumulation of endogenous NOS inhibitors, and enhanced arginase activity together with upregulation of arginase I protein in cavernous tissue. The impaired DDAH activity due to decreased expression of DDAH I protein would result in an accumulation of endogenous NOS inhibitors with CSE. These alterations may be relevant to induction of the erectile dysfunction following CSE.
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Affiliation(s)
- Masatoshi Imamura
- Dept. of Biosystem Regulation, Tokyo Medical and Dental University, 2-3-10 Surugadai, Kanda, Chiyoda-ku, Tokyo 101-0062, Japan.
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da Costa Gonçalves AC, Leite R, Fraga-Silva RA, Pinheiro SV, Reis AB, Reis FM, Touyz RM, Webb RC, Alenina N, Bader M, Santos RAS. Evidence that the vasodilator angiotensin-(1-7)-Mas axis plays an important role in erectile function. Am J Physiol Heart Circ Physiol 2007; 293:H2588-96. [PMID: 17616753 DOI: 10.1152/ajpheart.00173.2007] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The vasodilator/antiproliferative peptide angiotensin-(1-7) [ANG-(1-7)] is released into the corpus cavernosum sinuses, but its role in erectile function has yet to be defined. In this study, we sought to determine whether ANG-(1-7) and its receptor Mas play a role in erectile function. The ANG-(1-7) receptor Mas was immunolocalized in rat corpus cavernosum by confocal microscopy. Infusion of ANG-(1-7) into corpus cavernosum at a rate of 15.5 pmol x kg(-1) x min(-1) potentiated the elevation of the corpus cavernosum pressure induced by electrical stimulation of the major pelvic ganglion (MPG) in rats. The facilitatory effect of ANG-(1-7) was completely blunted by the specific ANG-(1-7) receptor blocker A-779 and N(omega)-nitro-L-arginine methyl ester. Nitric oxide (NO) release in the corpus cavernosum was evaluated with the fluorescent dye 4-amino-5 methylamino-2',7'-difluorofluorescein diacetate. Electrical stimulated-release of NO in rat corpus cavernosum was potentiated by ANG-(1-7). Furthermore, incubation of rat and mouse corpus cavernosum strips with ANG-(1-7) at 10 nmol/l resulted in an increase of NO release. This effect was completely abolished in mas-deficient mice. More importantly, genetic deletion of Mas resulted in compromised erectile function as demonstrated by penile fibrosis and severely depressed response to electrical stimulation of the MPG. Furthermore, the attenuated erectile function of DOCA-salt hypertensive rats was fully restored by ANG-(1-7) administration. Together these data provide strong evidence for a key role of the ANG-(1-7)-Mas axis in erectile function.
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McVary KT, Monnig W, Camps JL, Young JM, Tseng LJ, van den Ende G. Sildenafil citrate improves erectile function and urinary symptoms in men with erectile dysfunction and lower urinary tract symptoms associated with benign prostatic hyperplasia: a randomized, double-blind trial. J Urol 2007; 177:1071-7. [PMID: 17296414 DOI: 10.1016/j.juro.2006.10.055] [Citation(s) in RCA: 254] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Indexed: 01/23/2023]
Abstract
PURPOSE We evaluated sildenafil for erectile dysfunction and lower urinary tract symptoms in men with the 2 conditions. MATERIALS AND METHODS This was a 12-week, double-blind, placebo controlled study of sildenafil in men 45 years or older who scored 25 or less on the erectile function domain of the International Index of Erectile Function and 12 or greater on the International Prostate Symptom Score. Men with confirmed or suspected prostate malignancy, or prostate specific antigen 10 ng/ml or more were excluded. End points were changes in International Index of Erectile Function domain scores, International Prostate Symptom Score (irritative, obstructive and quality of life), the Benign Prostatic Hyperplasia Impact Index, the Self-Esteem And Relationship questionnaire and Erectile Dysfunction Inventory of Treatment Satisfaction Index Score. RESULTS The 189 men receiving sildenafil had significant improvements in erectile function domain score vs the 180 on placebo (9.17 vs 1.86, p<0.0001) and on all other International Index of Erectile Function domains. In men on sildenafil vs placebo significant improvements were observed in International Prostate Symptom Score (-6.32 vs -1.93, p<0.0001), Benign Prostatic Hyperplasia Impact Index (-2.0 vs -0.9, p<0.0001), mean International Prostate Symptom Score quality of life score (-0.97 vs -0.29, p<0.0001) and total Self-Esteem And Relationship questionnaire scores (24.6 vs 4.3, p<0.0001). There was no difference in urinary flow between the groups (p=0.08). Significantly more sildenafil vs placebo treated patients were satisfied with treatment (71.2 vs 41.7, p<0.0001). Sildenafil was well tolerated. CONCLUSIONS Improved erectile dysfunction and lower urinary tract symptoms with sildenafil in men with the 2 conditions were associated with improved quality of life and treatment satisfaction. Daily dosing with sildenafil may improve lower urinary tract symptoms. However, the lack of effect on urinary flow rates may mean that a new basic pathophysiology paradigm is needed to explain the etiology of lower urinary tract symptoms.
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Affiliation(s)
- Kevin T McVary
- Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611-3008, USA.
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Christ GJ, Hodges S. Molecular mechanisms of detrusor and corporal myocyte contraction: identifying targets for pharmacotherapy of bladder and erectile dysfunction. Br J Pharmacol 2006; 147 Suppl 2:S41-55. [PMID: 16465183 PMCID: PMC1751499 DOI: 10.1038/sj.bjp.0706627] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Post-Genomic age presents many new challenges and opportunities for the improved understanding, diagnosis and treatment of human disease. The long-term goal is to identify molecular correlates of disease processes, and use this information to develop novel and more effective therapeutics. A major hurdle in this regard is ensuring that the molecular targets of interest are indeed relevant to the physiology and/or pathophysiology of the processes being studied, and, moreover, to determine if they are specific to the tissue/organ being investigated. As a first step in this direction, we have reviewed the literature pertaining to bladder and erectile physiology/pharmacology and dysfunction and attempted to summarize some of the critical molecular mechanisms regulating detrusor and corporal myocyte tone. Because of the vast amount of published data, we have limited the scope of this review to consideration of the calcium-mobilizing and calcium-sensitizing pathways in these cells. Despite obvious differences in phenotypic characteristics of the detrusor and corporal myocyte, there are some common molecular changes that may contribute to, for example, the increased myocyte contractility characteristic of bladder and erectile dysfunction (i.e. increased Rho kinase activity and decreased K(+) channel function). Of course, there are also some important distinctions in the pathways that modulate contractility in these two cell types (i.e. the contribution of ryanodine-sensitive calcium stores and the nitric oxide/cGMP pathways). This report highlights some of these similarities and distinctions in the hope that it will encourage scientific discourse and research activity in this area, eventually leading to an improved quality of life for those millions of individuals that are afflicted with bladder and erectile dysfunction.
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MESH Headings
- Animals
- Erectile Dysfunction/drug therapy
- Erectile Dysfunction/metabolism
- Erectile Dysfunction/physiopathology
- Humans
- Male
- Muscle Contraction
- Muscle, Smooth/innervation
- Muscle, Smooth/metabolism
- Muscle, Smooth, Vascular/innervation
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- Penile Erection
- Penis/blood supply
- Penis/metabolism
- Signal Transduction
- Urinary Bladder/innervation
- Urinary Bladder/metabolism
- Urinary Bladder, Overactive/drug therapy
- Urinary Bladder, Overactive/metabolism
- Urinary Bladder, Overactive/physiopathology
- Urination
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Affiliation(s)
- George J Christ
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Baptist Medical Center, Winston-Salem, NC 27157, USA.
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Abstract
Erectile dysfunction (ED) is highly prevalent in diabetes mellitus. Pathophysiological mechanisms underlying diabetes-associated ED are in large part due to endothelial dysfunction, which functionally refers to the inability of the endothelium to produce vasorelaxing messengers and to maintain vasodilation and vascular homeostasis. The precise mechanisms leading to endothelial dysfunction in the diabetic vasculature, including the penis, are not yet fully understood. Hyperglycemia affects endothelial nitric oxide synthase activity and nitric oxide production/bioavailability, nitric oxide-independent relaxing factors, oxidative stress, production and/or action of hormones, growth factors and/or cytokines, and generation and activity of opposing vasoconstrictors. Considering recent advances in the field of vascular biology and diabetes, the emphasis in this review is placed on the mechanisms of hyperglycemia-induced endothelial dysfunction in the pathophysiology of diabetes-associated ED.
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Affiliation(s)
- B Musicki
- Department of Urology, Johns Hopkins University, SOM, Baltimore, MD 21287, USA.
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Jin L, Burnett AL. RhoA/Rho-kinase in erectile tissue: mechanisms of disease and therapeutic insights. Clin Sci (Lond) 2006; 110:153-65. [PMID: 16411892 DOI: 10.1042/cs20050255] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Penile erection is a complicated event involving the regulation of corpus cavernosal smooth muscle tone. Recently, the small monomeric G-protein RhoA and its downstream effector Rho-kinase have been proposed to be important players for mediating vasoconstriction in the penis. RhoA/Rho-kinase increases MLC (myosin light chain) phosphorylation through inhibition of MLCP (MLC phosphatase) thereby increasing Ca2+ sensitivity. This review will outline the RhoA/Rho-kinase signalling pathway, including the upstream regulators, guanine nucleotide exchange factors, GDP dissociation inhibitors and GTPase-activating proteins. We also summarize the current knowledge about the physiological roles of RhoA/Rho-kinase in both male and female erectile tissues and its aberrations contributing to erectile dysfunction in several disease states. Understanding the RhoA/Rho-kinase signalling pathway in the regulation of erection is important for the development of therapeutic interventions for erectile dysfunction.
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Affiliation(s)
- Liming Jin
- Department of Urology, Johns Hopkins University, Baltimore, MD 21287, USA.
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Jin L, Liu T, Lagoda GA, Champion HC, Bivalacqua TJ, Burnett AL. Elevated RhoA/Rho-kinase activity in the aged rat penis: mechanism for age-associated erectile dysfunction. FASEB J 2006; 20:536-8. [PMID: 16396994 DOI: 10.1096/fj.05-4232fje] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Epidemiologic studies have shown that aging accounts significantly for the prevalence of erectile dysfunction (ED). The pathophysiology of ED during aging and its underlying molecular mechanisms are largely unknown. We hypothesized that increased RhoA/Rho-kinase signaling is a major factor in the pathogenesis of age-associated ED and the mechanism involves increased penile smooth muscle contractility through inhibition of myosin light chain phosphatase. Male Fischer 344 young (4 month old) and aged (20-22 month old) rats underwent erectile function testing in vivo by measuring intracavernosal pressure (ICP) and mean arterial blood pressure (MAP) upon electrical stimulation of the cavernous nerve. The data demonstrated that erectile function was significantly lower in aged rats than that in young rats at all voltages tested (P<0.05). Western blot analysis results showed that there were no significant changes in protein expressions of RhoA, Rho-kinase-alpha and -beta isoforms, and myosin light chain phosphatase target subunit (MYPT1); however, membrane-bound RhoA and phosphorylated MYPT1 were increased in aged rat penes by 95 +/- 15 and 56 +/- 8% (P<0.05), respectively, indicating enhanced RhoA and Rho-kinase activity. Inhibition of Rho-kinase with Y27632 maximally increased ICP/MAP to 0.72 +/- 0.05 in aged rats vs. 0.47 +/- 0.06 in young rats (P<0.05). Gene transfer of adeno-associated virus (AAV) encoding dominant negative RhoA (T19NRhoA) to penes of aged and young rats for 7 days markedly improved erectile function in aged rats when compared with that in young rats (P<0.05). These observations were also supported by Rho-kinase activity assay results showing that basal Rho-kinase activity in aged rat penes receiving AAV vehicle treatment was twofold greater than that in young rat penes receiving AAV vehicle treatment, while it was reduced to a level similar to that in young rat penes after gene therapy of T19NRhoA (P<0.05). Taken together, these data suggest that impaired erectile function during the aging process involves increased RhoA/Rho-kinase signaling, and this pathway may be exploited for the treatment of age-associated ED.
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Affiliation(s)
- Liming Jin
- Department of Urology, Johns Hopkins University, Baltimore, Maryland 21287, USA
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Matsumoto K, Yoshida M, Andersson KE, Hedlund P. Effects in vitro and in vivo by apomorphine in the rat corpus cavernosum. Br J Pharmacol 2005; 146:259-67. [PMID: 16025145 PMCID: PMC1576267 DOI: 10.1038/sj.bjp.0706317] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Revised: 05/03/2005] [Accepted: 05/24/2005] [Indexed: 11/10/2022] Open
Abstract
The study was performed to clarify if apomorphine at the level of the rat corpus cavernosum can produce erectile responses or interfere with nerve-induced penile erection. Apomorphine (10(-9)-10(-4) M) exhibited a 10-fold higher potency to relax phenylephrine (Phe)- than endothelin-1 (ET-1)-induced contractions. Relaxant effects of apomorphine in Phe-activated corpus cavernosum did not change tissue levels of cyclic nucleotides, and were unaffected by inhibition of the synthesis of nitric oxide, or by inhibition of the soluble guanylate cyclase. Relaxations by apomorphine of ET-1-contracted rat corpus cavernosum were not influenced by alpha2-adrenoceptor blockade (yohimbine, 10(-7) M), or by the dopamine D1-like receptor antagonist SCH 23390 (10(-6) M). Clozapine (10(-6) M), a proposed dopamine D2-like receptor antagonist, partly reduced apomorphine-induced relaxations, and significantly altered the -log IC50 value for apomorphine. Nerve-induced contractions of the rat corpus cavernosum were attenuated by apomorphine in a concentration-dependent and biphasic manner. Yohimbine (10(-7) M) abolished the biphasic concentration-response pattern. SCH 23390 (10(-6) M) attenuated the inhibitory effects of apomorphine on contractions, and significantly altered the -log IC50 value for the compound. In anesthetized rats (50 mg kg(-1) pentobarbital sodium, 10 mg kg(-1) ketamine), intracavernous apomorphine (100, 300, or 1000 nmol) did not have effects on basal cavernous pressure under resting conditions, and did not affect filling or emptying rates, or peak pressures of the rat corpus cavernosum during submaximal activation of the cavernous nerve. In awake rats, apomorphine produced a maximal number of erections at 300 nmol kg(-1). In the rat isolated corpus cavernosum, pre- and postjunctional effects of apomorphine appear to involve dopamine D1- and D2-like receptors, as well as alpha-adrenoceptors. At relevant systemic doses of apomorphine, peripheral effects of the compound are unlikely to contribute to its proerectile effects in rats.
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Affiliation(s)
- Kenshi Matsumoto
- Department of Clinical and Experimental Pharmacology, Lund University Hospital, Lund S-221 85, Sweden
- Department of Urology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Masaki Yoshida
- Department of Urology, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Karl-Erik Andersson
- Department of Clinical and Experimental Pharmacology, Lund University Hospital, Lund S-221 85, Sweden
| | - Petter Hedlund
- Department of Clinical and Experimental Pharmacology, Lund University Hospital, Lund S-221 85, Sweden
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Rosano GMC, Aversa A, Vitale C, Fabbri A, Fini M, Spera G. Chronic Treatment with Tadalafil Improves Endothelial Function in Men with Increased Cardiovascular Risk. Eur Urol 2005; 47:214-20; discussion 220-2. [PMID: 15661417 DOI: 10.1016/j.eururo.2004.10.002] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/04/2004] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Erectile dysfunction (ED) is often associated with a cluster of risk factors for coronary artery disease and reduced endothelial function. Acute and chronic administration of oral sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, improves endothelial function in patients with ED. Tadalafil (TAD) is a new PDE5 inhibitor with a long half life that allows alternate day administration. Aim of the study was to evaluate whether chronic therapy (4 weeks) with TAD improves endothelial function in patients with increased cardiovascular risk and whether this effect is sustained after discontinuation of therapy. METHODS We randomized 32 patients with increased cardiovascular risk to receive either TAD 20 mg on alternate days or matching placebo (PLB) for 4 weeks. Patients underwent evaluation of brachial artery flow-mediated dilation (FMD), nitrite/nitrate and endothelin-1 plasma levels at baseline, at the end of treatment period and after two-weeks follow-up. RESULTS At 4 weeks, FMD was significantly improved by TAD (from 4.2+/-3.2 to 9.3+/-3.7%, p<0.01 vs. baseline), but was not modified by PLB (from 4.1+/-2.8 to 4.0+/-3.4%, p=NS). At 6 weeks the benefit in FMD was sustained in patients that received TAD (9.1+/-3.9% vs. 4.2+/-3.2%, p=0.01 vs. baseline; 9.1+/-3.9% vs. 9.3+/-3.7%, vs. 4 weeks, p=NS) while no changes in FMD were observed in patients randomized to PLB. Also, compared to baseline, a net increase in nitrite/nitrate levels (38.2+/-12.3 vs. 52.6+/-11.7 and 51.1+/-3.1, p<0.05) and a decrease in endothelin-1 levels (3.3+/-0.9 vs. 2.9.+/-0.7 and 2.9+/-0.9, p<0.05) was found both at four and six-weeks after TAD; these changes were inversely correlated as shown by regression analysis (adjusted R2=0.81, p<0.0001). CONCLUSIONS Chronic therapy with TAD improves endothelial function in patients with increased cardiovascular risk regardless their degree of ED. The benefit of this therapy is sustained for at least two weeks after the discontinuation of therapy. Larger studies are needed in order to assess the possible clinical implications of chronic therapy with TAD.
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Affiliation(s)
- Giuseppe M C Rosano
- Cardiovascular Research Unit, Department of Medical Sciences, San Raffaele--Roma, TOSINVEST SANITA', Rome, Italy
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Brown JS, Wessells H, Chancellor MB, Howards SS, Stamm WE, Stapleton AE, Steers WD, Van Den Eeden SK, McVary KT. Urologic complications of diabetes. Diabetes Care 2005; 28:177-85. [PMID: 15616253 DOI: 10.2337/diacare.28.1.177] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Jeanette S Brown
- University of California, San Francisco, San Francisco, California 94115, USA.
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Behr-Roussel D, Gorny D, Mevel K, Compagnie S, Kern P, Sivan V, Bernabé J, Bedigian MP, Alexandre L, Giuliano F. Erectile dysfunction: an early marker for hypertension? A longitudinal study in spontaneously hypertensive rats. Am J Physiol Regul Integr Comp Physiol 2004; 288:R276-83. [PMID: 15297263 DOI: 10.1152/ajpregu.00040.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Erectile dysfunction (ED) is another manifestation of vascular disease. We evaluated the natural history of ED in the spontaneously hypertensive rat (SHR) and the respective participation of associated pathophysiological modifications, i.e., endothelial dysfunction and tissue remodeling. SHR and their normotensive counterparts [Wistar-Kyoto rats (WKY)] of 6, 12, and 24 wk of age (n = 12) were used to evaluate erectile function, erectile and aortic tissue reactivity, and remodeling. Erectile responses in SHR are reduced at all ages (P < 0.001). In both aortic and erectile tissues of SHR and WKY, relaxations to ACh are altered progressively with age, although more markedly in SHR. They are decreased at 12 wk of age in erectile tissue of SHR compared with WKY (maximal relaxation: -19.2 +/- 2.8% vs. -28.3 +/- 3.9%, P < 0.001) but only at 24 wk of age in aortas (-47.9 +/- 6.4% vs. -90.5 +/- 2.9%, P < 0.001). Relaxations to sodium nitroprusside are unaltered in aortic rings of both strains but enhanced in erectile tissue of SHR at 12 wk of age. Major modifications in the distribution of collagen I, III, and V in SHR occur in both types of tissue and are detectable sooner in erectile tissue compared with aortic tissue. The onset of ED is detectable before the onset of hypertension in the SHR. Structural and functional alterations, while similar, occur earlier in erectile compared with vascular tissue. If confirmed in humans, ED could be an early warning sign for hypertension, and common therapeutic strategies targeting both ED and hypertension could be investigated.
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Affiliation(s)
- Delphine Behr-Roussel
- Pelvipharm, Domaine CNRS, 1 Avenue de la terrasse, BAtiment 5, 91190 Gif sur Yvette, France
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