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Liu S, Li J, Wang W, Zhang Y, Li S, Li T, Jiang J, Zhao F. Prenatal exposure to dibutyl phthalate contributes to erectile dysfunction in offspring male rats by activating the RhoA/ROCK signalling pathway. Toxicology 2024; 508:153925. [PMID: 39151608 DOI: 10.1016/j.tox.2024.153925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 08/01/2024] [Accepted: 08/12/2024] [Indexed: 08/19/2024]
Abstract
Prenatal exposure to dibutyl phthalate (DBP) has been reported to cause erectile dysfunction (ED) in adult offspring rats. However, its underlying mechanisms are not fully understood. Previously, we found that DBP activates the RhoA/ROCK pathway in the male reproductive system. This study investigated how prenatal exposure to DBP activates the RhoA/ROCK signalling pathway, leading to ED in male rat offspring. Pregnant rats were stratified into DBP-exposed and NC groups, with the exposed group receiving 750 milligrams per kilogram per day (mg/kg/day) of DBP through gavage from days 14-18 of gestation. DBP exposure activated the RhoA/ROCK pathway in the penile corpus cavernosum (CC) of descendants, causing smooth muscle cell contraction, fibrosis, and apoptosis, all of which contribute to ED. In vitro experiments confirmed that DBP induces apoptosis and RhoA/ROCK pathway activation in CC smooth muscle cells. Treatment of DBP-exposed offspring with the ROCK inhibitor Y-27632 for 8 weeks significantly improved smooth muscle cell condition, erectile function, and reduced fibrosis. Thus, prenatal DBP exposure induces ED in offspring through RhoA/ROCK pathway activation, and the ROCK inhibitor Y-27632 shows potential as an effective treatment for DBP-induced ED.
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Affiliation(s)
- Siyu Liu
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; Department of Andrology, Center for Men's Health, Urologic Medical Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Jianying Li
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; Department of Andrology, Center for Men's Health, Urologic Medical Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Wenhao Wang
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Yijun Zhang
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; Department of Andrology, Center for Men's Health, Urologic Medical Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Shufeng Li
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; Department of Andrology, Center for Men's Health, Urologic Medical Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Tiewen Li
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Juntao Jiang
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
| | - Fujun Zhao
- Department of Urology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China; Department of Andrology, Center for Men's Health, Urologic Medical Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.
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Hypertension and reproductive dysfunction: a possible role of inflammation and inflammation-associated lymphangiogenesis in gonads. Clin Sci (Lond) 2021; 134:3237-3257. [PMID: 33346358 DOI: 10.1042/cs20201023] [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: 08/04/2020] [Revised: 10/29/2020] [Accepted: 12/01/2020] [Indexed: 01/12/2023]
Abstract
Hypertension is one of the most prevalent diseases that leads to end organ damage especially affecting the heart, kidney, brain, and eyes. Numerous studies have evaluated the association between hypertension and impaired sexual health, in both men and women. The detrimental effects of hypertension in men includes erectile dysfunction, decrease in semen volume, sperm count and motility, and abnormal sperm morphology. Similarly, hypertensive females exhibit decreased vaginal lubrication, reduced orgasm, and several complications in pregnancy leading to fetal and maternal morbidity and mortality. The adverse effect of hypertension on male and female fertility is attributed to hormonal imbalance and changes in the gonadal vasculature. However, mechanistic studies investigating the impact of hypertension on gonads in more detail on a molecular basis remain scarce. Hence, the aim of the current review is to address and summarize the effects of hypertension on reproductive health, and highlight the importance of research on the effects of hypertension on gonadal inflammation and lymphatics.
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Abstract
PURPOSE OF REVIEW Tissue engineering and regenerative medicine has emerged as a new scientific interdisciplinary field focusing on developing new strategies to repair or recreate tissues and organs. This review gathers findings on erectile dysfunction and, Peyronie's disease from recent preclinical and clinical studies under heading of stem-cell regenerative medicine. RECENT FINDINGS Over the last 2 years, preclinical studies on rat models demonstrated the tangible beneficial role of stem cells and stromal vascular fraction in the context of preventing fibrosis and restoring erectile function in different animal models of Erectile dysfunction and Peyronie's disease. There are not solid evidences in the clinical settings. SUMMARY Large randomized, double blind clinical trials are needed to prove the efficacy of stem-cell therapy on human patients. Owing to the lack of solid evidences, the stem-cell therapy should be only administrated in a clinical research setting.
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Milenkovic U, Albersen M, Castiglione F. The mechanisms and potential of stem cell therapy for penile fibrosis. Nat Rev Urol 2018; 16:79-97. [DOI: 10.1038/s41585-018-0109-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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De Nunzio C, Roehrborn CG, Andersson KE, McVary KT. Erectile Dysfunction and Lower Urinary Tract Symptoms. Eur Urol Focus 2017; 3:352-363. [PMID: 29191671 DOI: 10.1016/j.euf.2017.11.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/12/2017] [Accepted: 11/13/2017] [Indexed: 01/10/2023]
Abstract
CONTEXT Lower urinary tract symptoms (LUTSs) and erectile dysfunction (ED) are substantial health concerns with a significant impact on the overall male quality of life. OBJECTIVE To evaluate the available evidence of the association between LUTSs and ED in patients with benign prostatic hyperplasia (BPH), and discuss possible clinical implications for the management of LUTS/BPH. EVIDENCE ACQUISITION A systematic review of the existing literature published between 1997 and June 2017 and available in the Medline, Scopus, and Web of Science databases was conducted using both the Medical Subject Heading (MeSH) and free-text protocols. The MeSH search was conducted by combining the following terms: "lower urinary tract symptoms," "LUTS," "benign prostatic hyperplasia," "BPH," "erectile dysfunction," "sexual dysfunction," "BPE," and "benign prostatic enlargement." The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed. EVIDENCE SYNTHESIS Several community-based studies in different geographical areas have provided strong evidence of an age-independent association between LUTSs and ED. Several biological mechanisms have been proposed to explain this association, but further research is required to better understand the molecular pathways involved. It is necessary to evaluate the possible impact of the metabolic syndrome treatment on LUTS/ED management. Considering the possible relationship between LUTSs and ED, their impact on the quality of life, and the possible adverse effects associated with LUTS medical treatment, clinicians should always evaluate ED in patients with LUTSs and take the opportunity to evaluate patients reporting ED for LUTSs. CONCLUSIONS Data from the peer-reviewed literature suggest the existence of an association between LUTS/BPH and ED, although their casual relationship has not been established yet. Emerging data also suggest that pathophysiological mechanisms involved in the metabolic syndrome are key factors in both disorders. Considering the association, it is also recommended that men presenting with LUTSs or ED should be evaluated for both disorders. A better understanding of the molecular pathways behind this association may also help identify new possible targets and develop novel therapeutic approaches to manage LUTSs and ED. PATIENT SUMMARY In this manuscript, we report on all the available evidence linking erectile dysfunction and lower urinary tract symptoms. Our findings suggest the existence of a strong relationship between these two conditions. On the basis of these findings, we recommend that clinicians always explore both conditions in male patients presenting with either of symptoms.
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Affiliation(s)
- Cosimo De Nunzio
- Department of Urology, Sant'Andrea Hospital, "La Sapienza" University, Roma, Italy.
| | - Claus G Roehrborn
- Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | - Kevin T McVary
- Southern Illinois University School of Medicine, Springfield, IL, USA
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Echeverri Tirado LC, Ferrer JE, Herrera AM. Aging and Erectile Dysfunction. Sex Med Rev 2016; 4:63-73. [DOI: 10.1016/j.sxmr.2015.10.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/22/2015] [Indexed: 01/23/2023]
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Toque HA, Caldwell RW. New approaches to the design and discovery of therapies to prevent erectile dysfunction. Expert Opin Drug Discov 2014; 9:1447-69. [DOI: 10.1517/17460441.2014.949234] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Choi YS, Lee SK, Bae WJ, Kim SJ, Cho HJ, Hong SH, Lee JY, Hwang TK, Kim SW. Bariatric surgery improves the cavernosal neuronal, vasorelaxation, and contraction mechanisms for erectile dysfunction as result of amelioration of glucose homeostasis in a diabetic rat model. PLoS One 2014; 9:e104042. [PMID: 25137300 PMCID: PMC4138031 DOI: 10.1371/journal.pone.0104042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 07/09/2014] [Indexed: 01/14/2023] Open
Abstract
Background Bariatric surgery is an effective treatment option for both obesity and obesity-related type 2 diabetes mellitus (T2DM). However, little is known regarding the effects of bariatric surgery on erectile dysfunction among patients with T2DM. Therefore, we investigated whether bariatric surgery would lead to structural and biochemical changes in the corpus cavernosum. Material and Method Twenty-five male Otsuka Long-Evans Tokushima Fatty rats were assigned to either a control group (sham operation, n = 10) or a bariatric surgery group (gastric bypass surgery, n = 15). Four weeks after the operation, each group of rats was evaluated with an oral glucose tolerance test (OGTT). The penile intracavernous pressure was measured for erectile functional analysis. Histologic evaluation of the tissue was performed with Masson's trichrome staining. Endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), Rho kinase, and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels in the corpus cavernosum were assayed by using western blot and ELISA. Results The mean body weight of the bariatric surgery group was lower than the control group (p = 0.002). The postoperative OGTT result was lower in the bariatric surgery group than in the control group (p = 0.014), and this was lower than the preoperative value (p = 0.037). The intracavernous pressure/mean arterial pressure ratio was higher in the bariatric surgery group compared to the control group (p = 0.021), and a higher cavernosum smooth muscle/collagen ratio was observed in the bariatric surgery group compared to the control group (p = 0.025). Likewise, the expression of eNOS and nNOS was higher in bariatric surgery group than in the control group (p = 0.027 and p = 0.008, respectively). Decreased expression of Rho kinase and levels of 8-OHdG were observed in the bariatric surgery group (p = 0.032). Conclusion In this animal model, bariatric surgery appears to ameliorate T2DM-related metabolic dysfunction leading to structural and biochemical changes in the corpus cavernosum, and thus, results in improvement of erectile dysfunction associated with T2DM.
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Affiliation(s)
- Yong Sun Choi
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sang Kuon Lee
- Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Woong Jin Bae
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Su Jin Kim
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Hyuk Jin Cho
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sung-Hoo Hong
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Ji Youl Lee
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Tae-Kon Hwang
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Sae Woong Kim
- Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea
- * E-mail:
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Sezen SF, Lagoda G, Musicki B, Burnett AL. Hydroxyl fasudil, an inhibitor of Rho signaling, improves erectile function in diabetic rats: a role for neuronal ROCK. J Sex Med 2014; 11:2164-71. [PMID: 24919622 DOI: 10.1111/jsm.12613] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
INTRODUCTION The pathogenesis of diabetic erectile dysfunction (ED) includes neuropathy, but the molecular basis for neurogenic ED is incompletely understood. The RhoA/ROCK pathway has been implicated in diabetic neuropathy and in ED, but its role in diabetic neurogenic ED is not known. AIMS The aim of this study was to determine whether hydroxyl fasudil, a ROCK inhibitor, affects diabetic neuropathy-related ED. METHODS Type 1 diabetes mellitus was induced in male rats by streptozotocin (75 mg/kg, intraperitoneally). After 8 weeks, diabetic rats were administered hydroxyl fasudil, a selective ROCK inhibitor (10 mg/kg/day, intraperitoneally) or vehicle, for 4 weeks. Age-matched control, nondiabetic, rats were treated intraperitoneally for 4 weeks with saline. At week 12, after a 2 day washout, neuro-stimulated erectile function was evaluated. Major pelvic ganglia (MPG) were collected for Western blot analysis of RhoA, ROCK-1, ROCK-2, phospho (P)-AKT (Ser(473) ), and P-phosphatase and tensin homolog (P-PTEN) (Ser(380) /Thr(382/383) ). MAIN OUTCOME MEASURES Effect of ROCK inhibitor hydroxyl fasudil on erectile function and ROCK/P-AKT/P-PTEN pathway in the MPG of diabetic rats. RESULTS Erectile response was significantly (P < 0.05) reduced in diabetic rats compared with nondiabetic rats and was preserved (P < 0.05) in diabetic rats treated with hydroxyl fasudil. In diabetic rats, RhoA and ROCK-2 protein expressions in MPG were increased (P < 0.05) and remained increased in hydroxyl fasudil-treated rats. P-AKT (Ser(473) ) expression was decreased (P < 0.05), whereas P-PTEN (Ser(380) /Thr(382/383) ) expression was increased (P < 0.05) in MPG of diabetic rats compared with nondiabetic rats, and both were reversed (P < 0.05) in diabetic rats treated with hydroxyl fasudil. CONCLUSION Improved erectile function and restored P-AKT and P-PTEN in the MPG with hydroxyl fasudil treatment suggest the role of Rho signaling via PTEN/AKT pathway in neurogenic diabetic ED.
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Affiliation(s)
- Sena F Sezen
- The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, MD, USA
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Hadeed NNF, Thanoon IAJ, Al-Mukhtar SB. Total testosterone levels and the effect of sildenafil on type 2 diabetics with erectile dysfunction. Oman Med J 2014; 29:46-50. [PMID: 24498482 DOI: 10.5001/omj.2014.10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/12/2013] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES Hypotestosteronemia has been reported in approximately half of type 2 diabetic men in general. This study aims to assess serum total testosterone levels in type 2 diabetics with erectile dysfunction and to correlate the degree of improvement between sildenafil citrate and testosterone levels. METHODS A cross sectional and prospective comparative interventional study was conducted at the Diabetic Clinic of Assalam Teaching Hospital in Mosul, during the period from January 1, 2009 through to December 31, 2011. The study enrolled 120 type 2 diabetic males with erectile dysfunction who were analyzed with regard to age, duration of diabetes, duration and severity of erectile dysfunction, serum total testosteron levels and the degree of response to sildenafil citrate in terms of testosterone levels. The data were statistically analyzed using the independent two-sample Student t test, χ (2) test and Pearson correlation test. A p-value of <0.05 was considered statistically significant. RESULTS Thirty six percent of type 2 diabetic males with erectile dysfunction were found to have low serum testosterone levels. The hypotestosteronemic and normotestosteronemic subgroups were not significantly different in terms of mean age, duration of diabetes, reduction of libido, and reduction in erectile function. The rate and the degree of improvement of erection by sildenafil in the normo-and-hypotestosteronemic respondents were not significantly different, but the degree of improvement by sildenafil was significantly correlated to testosterone levels among the hypotestosteronemic group. CONCLUSION Hypotestosteronemia was found in 36% of type 2 diabetic males with erectile dysfunction. The degree of improvement of erectile dysfunction by sildenafil was directly proportional to the serum testosterone levels among the hypotestosteronemic group. Therapeutic supplement with testosterone preparation in the hypotestosteronemic diabetics with erectile dysfunction may improve their response to sildenafil.
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Lasker GF, Pankey EA, Kadowitz PJ. Modulation of soluble guanylate cyclase for the treatment of erectile dysfunction. Physiology (Bethesda) 2013; 28:262-9. [PMID: 23817801 DOI: 10.1152/physiol.00001.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Nitric oxide (NO) is the principal mediator of penile erection, and PDE-5 inhibitors are the first-line agents used to treat erectile dysfunction (ED). When NO formation or bioavailability is decreased by oxidative stress and PDE-5 inhibitors are no longer effective, a new class of agents called soluble guanylate cyclase (sGC) stimulators like BAY 41-8543 will induce erection. sGC stimulators bind to the normally reduced, NO-sensitive form of sGC to increase cGMP formation and promote erection. The sGC stimulators produce normal erectile responses when NO formation is inhibited and the nerves innervating the corpora cavernosa are damaged. However, with severe oxidative stress, the heme iron on sGC can be oxidized, rendering the enzyme unresponsive to NO or sGC stimulators. In this pathophysiological situation, another newly developed class of agents called sGC activators can increase the catalytic activity of the oxidized enzyme, increase cGMP formation, and promote erection. The use of newer agents that stimulate or activate sGC to promote erection and treat ED is discussed in this brief review article.
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Affiliation(s)
- George F Lasker
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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Fraga-Silva RA, Montecucco F, Mach F, Santos RAS, Stergiopulos N. Pathophysiological role of the renin-angiotensin system on erectile dysfunction. Eur J Clin Invest 2013; 43:978-85. [PMID: 23909886 DOI: 10.1111/eci.12117] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 05/15/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND The renin-angiotensin system (RAS) has been shown to play an active role within the erectile tissues. The aim of this narrative review is to summarize the literature addressing the pathophysiological role of RAS on erectile function. Additionally, we update evidence on recent findings on the role of the Ang-(1-7) and Mas receptor on the erectile function and its therapeutic potential for treating erectile dysfunction (ED). MATERIALS AND METHODS This narrative review is based on the material searched and obtained via MEDLINE and PubMed up to November 2012. The search terms we used are 'angiotensin, erectile dysfunction, renin, Mas receptor' in combination with 'pathophysiology, fibrosis, pathways'. RESULTS The levels of angiotensin (Ang) II, the main component of this system, are increased in the corpus cavernosum as compared to those found in the systemic circulation. Moreover, emerging evidence indicates that an increased activity of Ang II via AT1 receptor might contribute to the development of ED, whereas the pharmacological blockage of Ang II/AT1 actions has beneficial effects on the erection. On the other hand, the heptapeptide Ang-(1-7), known as a major endogenous counter-regulator of Ang II actions, favours penile erection via the activation of Mas receptor. CONCLUSIONS Ang-(1-7) and Mas receptor pathway might be considered as a promising therapeutic target for the treatment of ED.
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Marx JO, Basha ME, Mohanan S, Hypolite JA, Chang S, Wein AJ, Zderic SA, Laping NJ, Chacko S. Effects of Rho-kinase inhibition on myosin light chain phosphorylation and obstruction-induced detrusor overactivity. Int J Urol 2013; 21:319-24. [PMID: 24033563 DOI: 10.1111/iju.12247] [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: 12/12/2012] [Accepted: 07/09/2013] [Indexed: 12/30/2022]
Abstract
OBJECTIVES To study the relationship between myosin light chain phosphorylation of the detrusor muscle and spontaneous smooth muscle contractions in a rabbit model of partial outlet obstruction. METHODS New Zealand white rabbit urinary bladders were partially obstructed for 2 weeks. Rabbits were euthanized, detrusor muscle strips were hung on a force transducer and spontaneous activity was measured at varying concentrations (0-0.03 μM/L) of the Rho-kinase inhibitors GSK 576371 or 0.01 μM/L Y27632. Basal myosin light chain phosphorylation was measured by 2-D gel electrophoresis in control and GSK 576371-treated strips. RESULTS Both drugs suppressed the force of spontaneous contractions, whereas GSK 576371 had a more profound effect on the frequency of the contractions. The IC₅₀ values for the inhibition of frequency and force of spontaneous contractions were 0.17 μM/L and 0.023 μM/L for GSK 576371, respectively. The compound significantly decreased the basal myosin light chain phosphorylation from 28.0 ± 3.9% to 13.5 ± 1.9% (P < 0.05). At 0.01 μM/L, GSK 576371 inhibited spontaneous bladder overactivity by 50%, but inhibited carbachol-elicited contractions force by just 25%. CONCLUSIONS These data suggest that Rho-kinase regulation of myosin light chain phosphorylation contributes to the spontaneous detrusor activity induced by obstruction. This finding could have therapeutic implications by providing another therapeutic option for myogenic, overactive bladder.
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Affiliation(s)
- James O Marx
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, USA
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The promise of inhibition of smooth muscle tone as a treatment for erectile dysfunction: where are we now? Int J Impot Res 2011; 24:49-60. [PMID: 21975566 DOI: 10.1038/ijir.2011.49] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ten years ago, the inhibition of Rho kinase by intracavernosal injection of Y-27632 was found to induce an erectile response. This effect did not require activation of nitric oxide-mediated signaling, introducing a novel target pathway for the treatment of erectile dysfunction (ED), with potential added benefit in cases where nitric oxide bioavailability is attenuated (and thus phosphodiesterase type 5 (PDE5) inhibitors are less efficacious). Rho-kinase antagonists are currently being developed and tested for a wide range of potential uses. The inhibition of this calcium-sensitizing pathway results in blood vessel relaxation. It is also possible that blockade of additional smooth muscle contractile signaling mechanisms may have the same effect. In this review, we conducted an extensive search of pertinent literature using PUBMED. We have outlined the various pathways involved in the maintenance of penile smooth muscle tone and discussed the current potential benefit for the pharmacological inhibition of these targets for the treatment of ED.
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Ückert S, Waldkirch ES, Kauffels W, Kuczyk MA, Hedlund P. Rho Kinase‐related Proteins in Human Vaginal Arteries: An Immunohistochemical and Functional Study. J Sex Med 2011; 8:2739-45. [DOI: 10.1111/j.1743-6109.2011.02390.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Abstract
Erectile dysfunction (ED) affects up to 50% of men between the ages of 40 and 70. Treatment with PDE-5 inhibitors is effective in the majority of men with ED. However, PDE-5 inhibitors are not effective when levels of nitric oxide (NO), the principle mediator of erection, are low. The pharmacologic actions of three new potential treatments for ED are discussed in this paper: (1) sGC stimulators/activators, (2) Rho-kinase inhibitors, and (3) sodium nitrite.
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Chitaley K. Type 1 and Type 2 diabetic-erectile dysfunction: same diagnosis (ICD-9), different disease? J Sex Med 2009; 6 Suppl 3:262-8. [PMID: 19267848 DOI: 10.1111/j.1743-6109.2008.01183.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Although hyperglycemia is a common defining feature of both type 1 and type 2 diabetes, many unique characteristics distinguish these diseases, including insulin and lipid levels, obesity status, and inflammatory agent profiles. In the laboratory, the presence of erectile dysfunction (ED) has been established in animal models of both type 1 and type 2 diabetes. AIM The purpose of this study was to determine whether unique mechanisms underlie ED in type 1 vs. type 2 diabetic animal models. MAIN OUTCOME MEASURES Many mechanisms can underlie ED, including impaired dilatory signaling, heightened contractile sensitivity, and veno-occlusive disorder. METHODS Using PubMed, the literature was mined to evaluate what is known about which mechanism underlie ED in type 1 vs. type 2 diabetic animal models. RESULTS Impaired cavernosal vasodilation has been established in type 1 diabetic rodents. This dysfunction appears to be mediated by a severe defect in non-adrenergic-non-cholinergic nerve signaling, as well as impairment in penile endothelial function. In contrast, type 2 diabetic animals appear to have minimal impairment in parasympathetic-mediated dilatory function, but do have evidence of endothelial dysfunction. Type 2 diabetic models also exhibit a significant and striking increase in cavernosal contractile sensitivity, and a significant veno-occlusive disorder, neither of which is consistently reported in type 1 diabetic animals. CONCLUSIONS With the distinct mechanisms underlying the ED phenotype in animal models of type 1 and type 2 diabetes, tailoring therapeutic treatments for diabetic-ED to the specific mechanisms underlying this disease complication may be warranted. Further examination of mechanisms underlying ED in diabetic human patients may thus lead to significant changes in the way urologists diagnose, code, and treat diabetic-ED.
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Affiliation(s)
- Kanchan Chitaley
- University of Washington, Department of Urology, Seattle, WA 98109, USA.
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Neurophysiology of the Genitourinary Organs. Neuromodulation 2009. [DOI: 10.1016/b978-0-12-374248-3.00077-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hidalgo-Tamola J, Chitaley K. Review type 2 diabetes mellitus and erectile dysfunction. J Sex Med 2008; 6:916-926. [PMID: 19067787 DOI: 10.1111/j.1743-6109.2008.01116.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Diabetes mellitus (DM) is a major risk factor for the development of erectile dysfunction (ED). Although most diabetic ED cases are in patients with type 2 diabetes (T2DM), the majority of basic science studies examining mechanisms of diabetic ED have been conducted in animal models of type 1 diabetes. AIM Recently, however, clinical and laboratory-based studies have uncovered some key underlying factors of T2DM-associated ED, which we have compiled in this review of T2DM ED. MAIN OUTCOME MEASURES The outcomes discussed in this review include major mechanisms underlying T2DM, discussing both clinical and basic science studies. METHODS We conducted an extensive search of pertinent clinical and basic science literature using PUBMED. RESULTS Mechanisms causing ED in T2DM are multifactorial and often lead to resistance to current therapy. Systemic effects of hyperglycemia and hypogonadism contribute to the development of impaired vasodilatory signaling, smooth muscle cell hypercontractility, and veno-occlusive disorder in T2DM ED. CONCLUSIONS Understanding the different causes for ED in T2DM patients may allow targeted therapy for improved erectile function.
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Affiliation(s)
| | - Kanchan Chitaley
- University of Washington-Department of Urology, Seattle, Washington, WA, USA.
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Lin CS, Xin ZC, Wang Z, Lin G, Lue TF. Molecular Yin and Yang of erectile function and dysfunction. Asian J Androl 2008; 10:433-40. [PMID: 18385905 DOI: 10.1111/j.1745-7262.2008.00396.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: 11/28/2022] Open
Abstract
In regard to erectile function, Yin is flaccidity and Yang erection. In the past decade, research has mostly focused on the Yang aspect of erectile function. However, in recent years, the Yin side is attracting increasingly greater attention. This is due to the realization that penile flaccidity is no less important than penile erection and is actively maintained by mechanisms that play critical roles in certain types of erectile dysfunction (ED); for example, in diabetic patients. In addition, there is evidence that the Yin and Yang signaling pathways interact with each other during the transition from flaccidity to erection, and vice versa. As such, it is important that we view erectile function from not only the Yang but also the Yin side. The purpose of this article is to review recent advances in the understanding of the molecular mechanisms that regulate the Yin and Yang of the penis. Emphasis is given to the Rho kinase signaling pathway that regulates the Yin, and to the cyclic nucleotide signaling pathway that regulates the Yang. Discussion is organized in such a way so as to follow the signaling cascade, that is, beginning with the extracellular signaling molecules (e.g., norepinephrin and nitric oxide) and their receptors, converging onto the intracellular effectors (e.g., Rho kinase and protein kinase G), branching into secondary effectors, and finishing with contractile molecules and phosphodiesterases. Interactions between the Yin and Yang signaling pathways are discussed as well.
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Affiliation(s)
- Ching-Shwun Lin
- Knuppe Molecular Urology Laboratory, University of California, San Francisco, CA 94143, USA.
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Abstract
Important roles for reactive oxygen species (ROS) in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular functions. However, enhanced ROS production as a result of the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contributes significantly to the pathogeneses of vascular diseases. Although it has become evident that increased ROS is associated with erectile dysfunction (ED), the sources of ROS in the penis remain largely unknown. In recent years, emergent evidence suggests the possible role of NADPH oxidase in inducing ED. In this review, we examine the relationship between ROS and ED in different disease models and discuss the current evidence basis for NADPH oxidase-derived ROS in ED.
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Affiliation(s)
- Liming Jin
- Department of Internal Medicine, University of California, Davis, CA 95616, USA.
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Uckert S, Mayer ME, Stief CG, Jonas U. The future of the oral pharmacotherapy of male erectile dysfunction: things to come. Expert Opin Emerg Drugs 2007; 12:219-28. [PMID: 17604498 DOI: 10.1517/14728214.12.2.219] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The convincing clinical data on the use of the orally active phosphodiesterase inhibitors sildenafil, vardenafil and tadalafil for the treatment of male erectile dysfunction have boosted research activities on the physiology of the male erectile mechanism. This included both peripheral intracellular signal transduction in the corpus cavernosum as well as central brain and spinal cord pathways controlling penile erection. This work provided the basis for the development and introduction of several new therapeutic modalities into the management of erectile dysfunction, some of which are already offered to the patients. As the concept of 'taking a pill' as a cure for an illness or the relief of symptoms of a disease has become widely accepted by the consumers, the pharmacologic treatment of erectile dysfunction has primarily focussed on selective, orally available drugs acting by influencing intracellular or central regulatory mechanisms, combining a high response rate and the advantage of an on-demand intake. These agents are regarded as more efficacious, and have a faster onset of drug action in the target tissue and an improved effect to side-effect ratio. The purpose of this review is to describe the major novel and evolving pharmacologic advances in the field of oral pharmacotherapy for the treatment of male erectile dysfunction.
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Affiliation(s)
- Stefan Uckert
- Hannover Medical School, Department of Urology, 30625 Hannover, Germany.
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25
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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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Schwarz ER, Rastogi S, Kapur V, Sulemanjee N, Rodriguez JJ. Erectile Dysfunction in Heart Failure Patients. J Am Coll Cardiol 2006; 48:1111-9. [PMID: 16978992 DOI: 10.1016/j.jacc.2006.05.052] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 04/26/2006] [Accepted: 05/01/2006] [Indexed: 11/17/2022]
Abstract
Chronic heart failure (HF) and erectile dysfunction (ED) are 2 highly prevalent disorders that frequently occur concomitantly. Coronary artery disease, HF, and ED share several common risk factors, including diabetes mellitus, hypertension, smoking, and dyslipidemia. Additionally, the distinct physiologic sequelae of HF create unique organic and psychologic factors contributing to ED in this patient population. Standard HF therapy with beta-receptor blockers, digoxin and thiazide diuretics may worsen sexual dysfunction owing to medication side effects. This may, in turn, lead to noncompliance in misguided efforts to retain satisfactory sexual activity, with secondary worsening of cardiac capacity. This review describes the unique aspects of ED in the HF population.
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Affiliation(s)
- Ernst R Schwarz
- Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
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Rastogi S, Rodriguez JJ, Kapur V, Schwarz ER. Why do patients with heart failure suffer from erectile dysfunction? A critical review and suggestions on how to approach this problem. Int J Impot Res 2006; 17 Suppl 1:S25-36. [PMID: 16391540 DOI: 10.1038/sj.ijir.3901426] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic heart failure (HF) is an increasingly common cardiovascular disorder. The goal of health-care providers is to optimize quality of life in this population, including sexual health. Up to 75% of patients with HF report erectile dysfunction (ED). As HF is a condition with distinct physiologic sequelae, some unique organic and psychological factors contributing to ED in this patient population have been identified, along with risk factors common to the development of coronary artery disease, HF and ED. This review describes contributing factors to ED in the setting of HF and highlights treatment considerations for this distinct patient population.
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Affiliation(s)
- S Rastogi
- Department of Internal Medicine, Division of Cardiology, The University of Texas Medical Branch (UTMB), Galveston, 77555, USA
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28
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Tamura M, Nakao H, Yoshizaki H, Shiratsuchi M, Shigyo H, Yamada H, Ozawa T, Totsuka J, Hidaka H. Development of specific Rho-kinase inhibitors and their clinical application. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1754:245-52. [PMID: 16213195 DOI: 10.1016/j.bbapap.2005.06.015] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2005] [Revised: 06/17/2005] [Accepted: 06/20/2005] [Indexed: 11/29/2022]
Abstract
Hexahydro-1-(isoquinoline-5-sulfonyl)-1H-1,4-diazepine, HA-1077, is a known selective inhibitor of Rho-kinase. Although its IC(50) value against Rho-kinase is more than 10 times lower than those for kinases such as PKA, PKB, PKC, PKG, MLCK, CaMKII and others, the molecule still retains relative potent inhibition activities against these kinases. In order to produce highly specific Rho-kinase inhibitors, several HA-1077 analogs were synthesized and their kinase inhibition properties evaluated. (S)-Hexahydro-1-(4-ethenylisoquinoline-5-sulfonyl)-2-methyl-1H-1,4-diazepine was found to be a potent Rho-kinase inhibitor. The IC50 value against Rho-kinase was 6 nM, while those against other kinases remained at almost the same level as that of HA-1077. Furthermore, we designed HA-1077 analogs on the basis of the complex structure of PKA and HA-1077. Amongst these, (S)-hexahydro-4-glycyl-2-methyl-1-(4-methylisoquinoline-5-sulfonyl)-1H-1,4-diazepine and other glycine derivatives were found to be highly specific Rho-kinase inhibitors. These Rho-kinase specific inhibitors were applied to rabbit ocular hypertensive models and were shown to reduce intraocular pressure. These results demonstrate that the new 5-isoquinolinesulfonylamides are not only potent ROCK selective compounds, but are also useful compounds for clinical applications.
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Affiliation(s)
- Masahiro Tamura
- Tokyo New Drug Research Laboratories II, Kowa Company Ltd., Noguchi-cho, Higashimurayama, Tokyo 189-0022, Japan
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Abstract
PURPOSE OF REVIEW The existence of three phosphodiesterase 5 inhibitors has resulted in an increase in the marketing of the drugs. This has led to a shift in focus from scientifically rigorous endpoints such as efficacy and adverse event profiles to patient preference. RECENT FINDINGS Although no consensus currently exists as to the correct methodology for preference studies, some basic guidelines should be adhered to, including: (1) the double-blinding of drug administration; (2) non-biased drug administration instructions; (3) an adequately conducted crossover study; (4) comparison of equivalent doses; (5) standardized preference assessment; (6) declaration of patient demographics; and (7) rigorous statistical analysis. These factors are discussed in the light of the three published preference studies. SUMMARY In the final analysis, it is unclear to this author how preference studies impact upon clinician decision-making when confronted by a patient with erectile dysfunction.
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Affiliation(s)
- John P Mulhall
- Department of Urology, Weill Medical College of Cornell University, New York Presbyterian Hospital, 525 East 68th Street, New York, NY 10021, USA.
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Andersson KE. Erectile physiological and pathophysiological pathways involved in erectile dysfunction. J Urol 2003; 170:S6-13; discussion S13-4. [PMID: 12853766 DOI: 10.1097/01.ju.0000075362.08363.a4] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
PURPOSE The importance of signaling pathways in penile smooth muscles involved in normal erection and erectile dysfunction (ED) is discussed based on a review of the literature. MATERIALS AND METHODS Erection is basically a spinal reflex that can be initiated by recruitment of penile afferents but also by visual, olfactory and imaginary stimuli. The generated nervous signals will influence the balance between the contractant and relaxant factors, which control the degree of contraction of penile smooth muscles and, thus, determine the functional state of the penis. The different steps involved in neurotransmission, impulse propagation and intracellular transduction of neural signals may be changed in different types of erectile dysfunction. RESULTS Recent findings have suggested an important role for RhoA/Rho kinase in the regulation of cavernosal smooth muscle tone and that changes in this pathway may contribute to ED in various patient subgroups, eg diabetes and vascular disease. Neurogenic nitric oxide is still considered the most important factor for immediate relaxation of penile vessels and corpus cavernosum. However, endothelially generated nitric oxide seems essential for maintaining erection. Endothelial dysfunction can contribute to ED in several patient subgroups. In addition, in conditions associated with reduced function of nerves and endothelium, such as aging, hypertension, smoking, hypercholesterolemia and diabetes, circulatory and structural changes in the penile tissues can result in arterial insufficiency and defect muscle relaxation. CONCLUSIONS Different types of ED often have overlapping pathophysiologies but may also have common pathways contributing to ED. Such pathways may be potential treatment targets.
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Nehra A, Steers WD, Althof SE, Andersson KE, Burnett AL, Costabile RA, Goldstein I, Kloner RA, Lue TF, Morales A, Rosen RC, Shabsigh R, Siroky MB, King L. Third International Conference on the Management of Erectile Dysfunction: Linking Pathophysiology and Therapeutic Response. J Urol 2003; 170:S3-5. [PMID: 12853765 DOI: 10.1097/01.ju.0000075566.73330.90] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
PURPOSE While a modest amount of medical literature has been written on the topic of priapism, reports heretofore have focused predominantly on diagnostic and management related aspects of the disorder, providing meager information in regard to its pathophysiology. Accordingly the intent of this review was to explore the etiological and pathogenic factors involved in priapism. MATERIALS AND METHODS The review entailed an overview of traditional and modern concepts that have been applied to the pathophysiology of priapism and an evaluation of assorted observational and experimental data relating to this field of study. The basic exercise consisted of a literature search using the National Library of Medicine PubMed Services, index referencing provided through the Historical Collection of the Institute of Medicine of The Johns Hopkins University and a survey of abstract proceedings from national meetings relevant to priapism. RESULTS Insight into the pathophysiology of priapism was derived from a synthesis of evolutionary clinical experiences, mythical beliefs, clinical variants and scientific advances associated with the field of priapism. The results can be summarized. 1) Clinicopathological manifestations of priapism support its basic classification into low flow (ischemic) and high flow (nonischemic) hemodynamic categories, commonly attributed to venous outflow occlusion and unregulated arterial overflow of the penis, respectively. 2) Factual information is insufficient to substantiate etiological roles for urethral infection, bladder distention, failed ejaculation, satyriasis and sleep apnea in priapism. 3) Features of the variant forms of priapism invoke changes in nervous system control of erection and penile vascular homeostasis as having pathogenic roles in the disorder. 4) Clinical therapeutic and basic science investigative studies have revealed various effector mechanisms of the erectile tissue response that may act in dysregulated fashion to subserve priapism. CONCLUSIONS This exercise suggested that, while priapism is commonly defined in terms of adverse mechanical contexts affecting penile circulation, it may also be viewed at least in some situations as an unbalanced erectile response involving derangements in possibly diverse systems of regulatory control. An integrative scientific approach that encompasses tissular, cellular and molecular levels of investigation may allow further understanding of the pathophysiology of the disorder. Ongoing elucidation of this pathophysiology can be expected to promote the development of new priapism therapies.
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Affiliation(s)
- Arthur L Burnett
- Department of Urology, James Buchanan Brady Urological Institute, The Johns Hopkins Hospital, 600 North Wolfe Street, Marburg 407, Baltimore, MD 21287-2411, USA
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Abstract
Recent studies have demonstrated that vasoconstriction in the erectile vasculature of the penis is mediated in part by RhoA/Rho-kinase signaling. However, this constrictor activity must be overcome to permit the vasodilation essential for erection. We hypothesize that the primary action of nitric oxide and other agents that cause penile erection is inhibition of the RhoA/Rho-kinase pathway, thereby allowing vasodilation and erection. This hypothesis, as well as experiments using hypogonadal and hypertensive animal models, are discussed in terms of the potential clinical value of Rho-kinase inhibitors for the treatment of erectile dysfunction.
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Affiliation(s)
- Thomas M Mills
- Department of Physiology, Medical College of Georgia, 1120 15th Street, Augusta, GA 30912-3000, USA.
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Wang H, Eto M, Steers WD, Somlyo AP, Somlyo AV. RhoA-mediated Ca2+ sensitization in erectile function. J Biol Chem 2002; 277:30614-21. [PMID: 12060659 DOI: 10.1074/jbc.m204262200] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A Rho-kinase inhibitor increases corpus cavernosum (CC) pressure in an in vivo rat model (Chitaley, K., Wingard, C. J., Webb, R. C., Branam, H., Stopper, V. S., Lewis, R. W., and Mills, T. M. (2001) Nat. Med. 7, 119-122) suggesting that Rho-mediated Ca(2+) sensitization of CC smooth muscle maintains the flaccid (contracted) state. We directly demonstrate Ca(2+) sensitization of permeabilized rabbit and human CC and identify a highly expressed molecular component of this pathway. Ca(2+) sensitization of force induced by endothelin or GTPgammaS was significantly greater in CC than in rabbit ileum smooth muscle and was accompanied by a 17-fold higher RhoA content. Pull-down assays with the RhoA binding domain of mDia showed the high RhoA content of CC to be available for activation by GTPgammaS. Ca(2+) sensitization induced by endothelin, phenylephrine, or GTPgammaS was completely relaxed by the Rho kinase inhibitor Y-27632. Human and rabbit CC both express the phosphatase inhibitor CPI-17, the myosin phosphatase regulatory (MYPT-1) and catalytic (PP1delta) subunits, and two isoforms of Rho kinase. We suggest that high expression of RhoA contributes, through RhoA-mediated Ca(2+) sensitization, to the flaccid state of CC that can be reversed by a water-soluble, orally active Rho kinase inhibitor suitable for therapy of erectile dysfunction.
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Affiliation(s)
- Hua Wang
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908-0736, USA
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SPEKTOR MARIYA, RODRIGUEZ RAMON, ROSENBAUM RAYMONDS, WANG HONGZANG, MELMAN ARNOLD, CHRIST GEORGEJ. Potassium Channels and Human Corporeal Smooth Muscle Cell Tone: Further Evidence of the Physiological Relevance of the Maxi-K Channel Subtype to the Regulation of Human Corporeal Smooth Muscle Tone In Vitro. J Urol 2002. [DOI: 10.1016/s0022-5347(05)65049-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- MARIYA SPEKTOR
- From the Departments of Urology and Physiology and Biophysics, Institute for Smooth Muscle Biology, Albert Einstein College of Medicine, Bronx, New York
| | - RAMON RODRIGUEZ
- From the Departments of Urology and Physiology and Biophysics, Institute for Smooth Muscle Biology, Albert Einstein College of Medicine, Bronx, New York
| | - RAYMOND S. ROSENBAUM
- From the Departments of Urology and Physiology and Biophysics, Institute for Smooth Muscle Biology, Albert Einstein College of Medicine, Bronx, New York
| | - HONG-ZANG WANG
- From the Departments of Urology and Physiology and Biophysics, Institute for Smooth Muscle Biology, Albert Einstein College of Medicine, Bronx, New York
| | - ARNOLD MELMAN
- From the Departments of Urology and Physiology and Biophysics, Institute for Smooth Muscle Biology, Albert Einstein College of Medicine, Bronx, New York
| | - GEORGE J. CHRIST
- From the Departments of Urology and Physiology and Biophysics, Institute for Smooth Muscle Biology, Albert Einstein College of Medicine, Bronx, New York
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36
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Potassium Channels and Human Corporeal Smooth Muscle Cell Tone: Further Evidence of the Physiological Relevance of the Maxi-K Channel Subtype to the Regulation of Human Corporeal Smooth Muscle Tone In Vitro. J Urol 2002. [DOI: 10.1097/00005392-200206000-00070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Mills TM, Chitaley K, Lewis RW, Webb RC. Nitric oxide inhibits RhoA/Rho-kinase signaling to cause penile erection. Eur J Pharmacol 2002; 439:173-4. [PMID: 11937108 DOI: 10.1016/s0014-2999(02)01408-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The RhoA/Rho-kinase pathway mediates vasoconstriction in the cavernosal circulation. Inhibition of this pathway leads to penile erection in the in vivo rat model. These studies examined the hypothesis that nitric oxide (NO) inhibits RhoA/Rho-kinase signaling as part of normal erection. The results show that NO causes increased intracavernosal pressure and that this response is potentiated by prior treatment with a threshold dose of the Rho-kinase inhibitor, (+)-(R)-trans-4-(1-Aminoethyl)-N-(4-pyridyl) cyclohexanecarboxamide dihydrochloride, monohydrate (Y-27632). These results support the hypothesis that NO inhibits Rho-kinase-induced cavernosal vasoconstriction during erection.
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Affiliation(s)
- Thomas M Mills
- Department of Physiology, Medical College of Georgia, Augusta, GA, USA.
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Montorsi F, Salonia A, Zanoni M, Colombo R, Pompa P, Rigatti P. Counselling the patient with prostate cancer about treatment-related erectile dysfunction. Curr Opin Urol 2001; 11:611-7. [PMID: 11734698 DOI: 10.1097/00042307-200111000-00009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
At present, a significant proportion of patients with prostate cancer are diagnosed at an early stage and may receive treatments able to bring about the long-term control of the disease. Thus, the impact of available treatments on the patient's quality of life has been gaining increasing importance; for patients with prostate cancer, counselling on the treatment-related effects on sexual function has become mandatory. Radical prostatectomy is very frequently performed in patients with clinically localized prostate cancer. Postoperative erectile function has been reported as being satisfactory in the majority of the patients operated on in centers of excellence for this procedure. However, overall, the results for postoperative potency are disappointing in view of the large amounts of data available from community practices. Attempts to improve postoperative potency include the intraoperative use of cavernous nerve stimulation and grafting of peripheral nerves to restore the innervation of the corpora cavernosa. Erectile dysfunction has also been associated with prostate radiotherapy. It has been shown that both ultrasound-guided brachytherapy and three-dimensional conformal radiation therapy cause an impairment of erectile function that is usually seen some time after the completion of therapy. Treatment with sildenafil citrate remains a viable option both for patients treated with radical prostatectomy (in whom the cavernous nerve function is at least partially present) and in patients treated with radiotherapy.
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Affiliation(s)
- F Montorsi
- Department of Urology, 'Vita e Salute' University--San Raffaele, Milan, Italy.
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39
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Mills TM, Chitaley K, Wingard CJ, Lewis RW, Webb RC. Effect of Rho-kinase inhibition on vasoconstriction in the penile circulation. J Appl Physiol (1985) 2001; 91:1269-73. [PMID: 11509525 DOI: 10.1152/jappl.2001.91.3.1269] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A recent report from this laboratory (Chitaley K, Wingard C, Webb R, Branam H, Stopper V, Lewis R, and Mills T. Nature Medicine 7: 119-122, 2001) showed that inhibition of Rho-kinase increased the erectile response (intracavernosal pressure and mean arterial pressure) by a process that does not require nitric oxide or cGMP. The present study investigated whether vasoconstrictor agents, which are active in the penis, act via the Rho-kinase pathway. Western analysis revealed RhoA and Rho-kinase protein in the penis. Treatment with the selective Rho-kinase inhibitor Y-27632 significantly increased the magnitude of the erectile response. Intracavernous administration of endothelin-1 (ET-1; 50 pmol) or methoxamine (10 microg/kg) reduced the erectile response to autonomic stimulation. If Y-27632 was given before ET-1 or methoxamine, the vasoconstrictor effect was reduced, and intracavernosal pressure and mean arterial pressure remained elevated. However, when given after methoxamine, Y-27632 had a reduced vasodilatory effect, and Y-27632 had no vasodilatory effect when given after ET-1. These findings suggest that ET-1 and methoxamine increase Rho-kinase activity in the cavernous circulation and support the hypothesis that the vasoconstriction that maintains the penis in the nonerect state is mediated, in part, by the Rho-kinase pathway.
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Affiliation(s)
- T M Mills
- Department of Physiology, Medical College of Georgia, Augusta, Georgia 30912-3000, USA.
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