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Argiolas A, Argiolas FM, Argiolas G, Melis MR. Erectile Dysfunction: Treatments, Advances and New Therapeutic Strategies. Brain Sci 2023; 13:802. [PMID: 37239274 PMCID: PMC10216368 DOI: 10.3390/brainsci13050802] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/08/2023] [Accepted: 05/11/2023] [Indexed: 05/28/2023] Open
Abstract
Erectile dysfunction (ED) is the inability to get and maintain an adequate penile erection for satisfactory sexual intercourse. Due to its negative impacts on men's life quality and increase during aging (40% of men between 40 and 70 years), ED has always attracted researchers of different disciplines, from urology, andrology and neuropharmacology to regenerative medicine, and vascular and prosthesis implant surgery. Locally and/or centrally acting drugs are used to treat ED, e.g., phosphodiesterase 5 inhibitors (first in the list) given orally, and phentolamine, prostaglandin E1 and papaverine injected intracavernously. Preclinical data also show that dopamine D4 receptor agonists, oxytocin and α-MSH analogues may have a role in ED treatment. However, since pro-erectile drugs are given on demand and are not always efficacious, new strategies are being tested for long lasting cures of ED. These include regenerative therapies, e.g., stem cells, plasma-enriched platelets and extracorporeal shock wave treatments to cure damaged erectile tissues. Although fascinating, these therapies are laborious, expensive and not easily reproducible. This leaves old vacuum erection devices and penile prostheses as the only way to get an artificial erection and sexual intercourse with intractable ED, with penile prosthesis used only by accurately selected patients.
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Affiliation(s)
- Antonio Argiolas
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Monserrato, Italy; (F.M.A.); (M.R.M.)
| | - Francesco Mario Argiolas
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Monserrato, Italy; (F.M.A.); (M.R.M.)
| | - Giacomo Argiolas
- General Medicine Unit, Hospital San Michele, ARNAS“G. Brotzu”, Piazzale Ricchi 1, 09100 Cagliari, Italy;
| | - Maria Rosaria Melis
- Department of Biomedical Sciences, Section of Neuroscience and Clinical Pharmacology, University of Cagliari, 09042 Monserrato, Italy; (F.M.A.); (M.R.M.)
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Lee SH, Ok SH, Subbarao RB, Kim JY, Bae SI, Hwang Y, Tak S, Sohn JT. Nitric oxide-mediated inhibition of phenylephrine-induced contraction in response to hypothermia is partially modulated by endothelial Rho-kinase. Int J Med Sci 2020; 17:21-32. [PMID: 31929735 PMCID: PMC6945562 DOI: 10.7150/ijms.39074] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/07/2019] [Indexed: 12/17/2022] Open
Abstract
This study examined the possible upstream cellular signaling pathway associated with nitric oxide (NO)-mediated inhibition of phenylephrine-induced contraction in isolated rat aortae in response to mild hypothermia, with a particular focus on endothelial Rho-kinase. We examined the effects of mild hypothermia (33°C), wortmannin, Nω-nitro-L-arginine methyl ester (L-NAME), Y-27632, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) and methylene blue, alone and combined, on phenylephrine-induced contraction in isolated rat aortae. Finally, we examined the effects of mild hypothermia, wortmannin, Y-27632 and L-NAME, alone and combined, on endothelial nitric oxide synthase (eNOS) and endothelial Rho-kinase membrane translocation induced by phenylephrine. Mild hypothermia attenuated phenylephrine-induced contraction only in endothelium-intact aortae. L-NAME, wortmannin, ODQ and methylene blue increased phenylephrine-induced contraction of endothelium-intact aortae pretreated at 33°C. Wortmannin did not significantly alter the L-NAME-induced enhancement of phenylephrine-induced maximal contraction of endothelium-intact aortae pretreated at 33°C. Wortmannin abolished the ability of Y-27632 to magnify the hypothermic inhibition of maximal phenylephrine-induced contraction. Wortmannin and L-NAME inhibited the enhancing effect of mild hypothermia on phenylephrine-induced eNOS phosphorylation. Y-27632 and L-NAME attenuated the enhancing effect of hypothermia on phenylephrine-induced endothelial Rho-kinase membrane translocation. The results suggest that hypothermia-induced, NO-dependent inhibition of phenylephrine-induced contraction is mediated by phosphoinositide 3-kinase and inhibited by endothelial Rho-kinase activation.
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Affiliation(s)
- Soo Hee Lee
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University College of Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea
| | - Seong-Ho Ok
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Changwon Hospital, Changwon, 51427, Republic of Korea
| | - Raghavendra Baregundi Subbarao
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University College of Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea
| | - Ji-Yoon Kim
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea
| | - Sung Il Bae
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea
| | - Yeran Hwang
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea
| | - Seongyeong Tak
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea
| | - Ju-Tae Sohn
- Department of Anesthesiology and Pain Medicine, Gyeongsang National University College of Medicine, Gyeongsang National University Hospital, 15 Jinju-daero 816 beon-gil, Jinju-si, Gyeongsangnam-do, 52727, Republic of Korea.,Institute of Health Sciences, Gyeongsang National University, Jinju-si, 52727, Republic of Korea
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Brunová A, Bencze M, Behuliak M, Zicha J. Acute and chronic role of nitric oxide, renin-angiotensin system and sympathetic nervous system in the modulation of calcium sensitization in Wistar rats. Physiol Res 2016; 64:447-57. [PMID: 26291725 DOI: 10.33549/physiolres.933094] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Principal vasoactive systems - renin-angiotensin system (RAS), sympathetic nervous system (SNS), nitric oxide (NO) and prostanoids - exert their vascular effects through the changes in calcium levels and/or calcium sensitization. To estimate a possible modulation of calcium sensitization by the above vasoactive systems, we studied the influence of acute and chronic blockade of particular vasoactive systems on blood pressure (BP) changes elicited in conscious normotensive rats by acute dose-dependent administration of Rho-kinase inhibitor fasudil. Adult male chronically cannulated Wistar rats were used throughout this study. The acute inhibition of NO synthase (NOS) by L-NAME enhanced BP response to fasudil, the effect being considerably augmented in rats deprived of endogenous SNS. The acute inhibition of prostanoid synthesis by indomethacin modified BP response to fasudil less than the acute NOS inhibition. The chronic NOS inhibition caused moderate BP elevation and a more pronounced augmentation of fasudil-induced BP changes compared to the effect of acute NOS inhibition. This indicates both short-term and long-term NO-dependent attenuation of calcium sensitization. Long-term inhibition of RAS by captopril caused a significant attenuation of BP changes elicited by fasudil. In contrast, a long-term attenuation of SNS by chronic guanethidine treatment (in youth or adulthood) had no effect on BP response to fasudil, suggesting the absence of SNS does not affect calcium sensitization in vascular smooth muscle of normotensive rats. In conclusion, renin-angiotensin system contributes to the long-term increase of calcium sensitization and its effect is counterbalanced by nitric oxide which decreases calcium sensitization in Wistar rats.
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Affiliation(s)
- A Brunová
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.
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Anwar MA, Ford WR, Herbert AA, Broadley KJ. Signal transduction and modulating pathways in tryptamine-evoked vasopressor responses of the rat isolated perfused mesenteric bed. Vascul Pharmacol 2012; 58:140-9. [PMID: 23117109 PMCID: PMC3884126 DOI: 10.1016/j.vph.2012.10.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 10/10/2012] [Accepted: 10/24/2012] [Indexed: 12/31/2022]
Abstract
Tryptamine is an endogenous and dietary indoleamine-based trace amine implicated in cardiovascular pathologies, including hypertension, migraine and myocardial infarction. This study aimed at identifying the signalling pathways for the vasoconstrictor response to tryptamine in rat isolated perfused mesenteric arterial beds and co-released vasodilator modulators of tryptamine-mediated vasoconstriction. Tryptamine caused concentration-dependent vasoconstriction of the mesenteric bed, measured as increases in perfusion pressure. These were inhibited by the 5-HT2A receptor antagonist, ritanserin, indicating mediation via 5-HT2A receptors. The response was inhibited by the phospholipase C (PLC) and phospholipase A2 (iPLA2) inhibitors, U-73122 and PACOCF3, suggesting involvement of phospholipase pathways. Activation of these pathways by tryptamine releases cyclooxygenase (COX) products since indomethacin (non-selective inhibitor of COX-1/2) and nimesulide (selective COX-2 inhibitor) reduced the vasoconstriction. The most likely COX vasoconstrictor product was prostaglandin PGE2 since the responses to tryptamine were reduced by AH-6809, a non-selective EP1 receptor antagonist. Involvement of the Rho-kinase pathway in the tryptamine-evoked vasoconstriction was also indicated by its reduction by the Rho-kinase inhibitors, Y-27,632 and fasudil. The tryptamine vasoconstriction is modulated by the co-released endothelial vasodilator, nitric oxide. Thus, circulating tryptamine can regulate mesenteric blood flow through a cascade of signalling pathways secondary to stimulation of 5-HT2A receptors.
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Affiliation(s)
- M Akhtar Anwar
- Division of Pharmacology, Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, Cathays Park, Cardiff CF10 3NB, UK
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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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Priviero FBM, Jin LM, Ying Z, Teixeira CE, Webb RC. Up-regulation of the RhoA/Rho-kinase signaling pathway in corpus cavernosum from endothelial nitric-oxide synthase (NOS), but not neuronal NOS, null mice. J Pharmacol Exp Ther 2010; 333:184-92. [PMID: 20093396 DOI: 10.1124/jpet.109.160606] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We tested the hypothesis that the basal release of nitric oxide (NO) from endothelial cells modulates contractile activity in the corpus cavernosum (CC) via inhibition of the RhoA/Rho-kinase signaling pathway. Cavernosal strips from wild-type (WT), endothelial nitric-oxide synthase knockout [eNOS(-/-)], and neuronal nitric-oxide synthase knockout [nNOS(-/-)] mice were mounted in myographs, and isometric force was recorded. mRNA and protein expression of key molecules in the RhoA/Rho-kinase pathway were analyzed by real-time polymerase chain reaction and Western blot, respectively. The cGMP levels were determined. The Rho-kinase inhibitors (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) and (S)-(+)-2-methyl-1-[(4-methyl-5-isoquinolinyl)sulfonyl] homopiperazine (H-1152) reduced cavernosal contractions evoked by phenylephrine or electrical field stimulation (EFS) in a concentration-dependent manner, although this inhibition was less effective in tissues from eNOS(-/-) mice. Y-27632 enhanced relaxations induced by sodium nitroprusside, EFS, and NO (administered as acidified NaNO2) without affecting the cGMP content of the cavernosal strips. This enhancement was less prominent in CC from eNOS(-/-). The protein expression of RhoA, Rho-guanine dissociation inhibitor, and Rho-kinase beta did not differ among the strains. However, in eNOS(-/-) CC, the protein expression of Rho-kinase alpha and both mRNA and protein expression of p115-Rho-associated guanine exchange factor (RhoGEF), PDZ-RhoGEF, and leukemia-associated RhoGEF were up-regulated. Phosphorylation of MYPT1 at Thr696 was higher in tissues from eNOS(-/-) mice. A high concentration of Y-27632 significantly enhanced NO release in CC stimulated by EFS. These results suggest a basal release of NO from endothelial cells, which inhibits contractions mediated by the RhoA/Rho-kinase pathway and modulates the expression of proteins related to this pathway in mouse CC. It indicates that endothelial integrity is essential to the maintenance of erectile function.
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Linder AE, Dorrance AM, Mills TM, Webb RC, Leite R. Erectile function in two-kidney, one-clip hypertensive rats is maintained by a potential increase in nitric oxide production. J Sex Med 2009; 6 Suppl 3:279-85. [PMID: 19267850 DOI: 10.1111/j.1743-6109.2008.01185.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Hypertension is closely associated with erectile dysfunction (ED) as it has been observed in many experimental models of hypertension. Additionally, epidemiological studies show that approximately a third of hypertensive patients have ED. AIM To test the hypothesis that the two-kidney, one-clip (2K-1C) rat model of hypertension displays normal erectile function due to increased nitric oxide (NO) production in the penis. METHODS Ganglionic-induced increase in intracavernosal pressure (ICP)/mean arterial pressure (MAP) ratio was used as an index of erectile function in 2K-1C and in normotensive sham-operated (SHAM) anesthetized rats. Cavernosal strips from hypertensive and normotensive rats were used for isometric tension measurement. The contraction induced by alpha-adrenergic agonist phenylephrine and the relaxation induced by the NO donor sodium nitroprusside (SNP) and by the Rho-kinase inhibitor Y-27632 were performed in the absence and in the presence of the NO synthase inhibitor N(omega)-nitro-L-arginine (L-NNA). RESULTS Changes in ICP/MAP induced by ganglionic stimulation were not different between 2K-1C and SHAM rats. The contractile response induced by phenylephrine as well as the relaxation induced by SNP or the Y-27632 were similar in cavernosal strips from both groups. However, in the presence of L-NNA, the relaxation induced by Y-27632 was significantly impaired in 2K-1C compared to SHAM. CONCLUSIONS These data suggest that hypertension and ED could be dissociated from high levels of blood pressure in some animal models of hypertension. Erectile function in 2K-1C hypertensive rats is maintained in spite of the increased Rho-kinase activity by increased NO signaling.
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Affiliation(s)
- A Elizabeth Linder
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
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Büssemaker E, Herbrig K, Pistrosch F, Palm C, Passauer J. Role of rho-kinase in the regulation of vascular tone in hypertensive renal transplant recipients. Atherosclerosis 2009; 207:567-72. [PMID: 19717154 DOI: 10.1016/j.atherosclerosis.2009.05.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 05/18/2009] [Accepted: 05/19/2009] [Indexed: 11/18/2022]
Abstract
Activation of rho-kinase (ROK) is involved in the development of hypertension as it is a potent regulator of vascular smooth muscle cell (VSMC) contractility. Here we evaluated whether activation of ROK is present in hypertensive kidney transplant recipients (NTX). We tested the effect of the ROK-inhibitor fasudil on the regulation of forearm blood flow (FBF) in NTX and in healthy control subjects (CTL). In addition potential modulating effects of ROK-inhibition on local vascular nitric oxide (NO) release were studied. The effect of intra-arterial infusion of fasudil on FBF was studied by venous-occlusion plethysmography in NTX and CTL. To unmask the role of NO fasudil was infused with/without clamping of vascular NO in NTX and CTL. To unravel the basal NO-mediated tone the NO-synthase inhibitor l-NMMA was infused. Fasudil markedly but comparably increased FBF in NTX and CTL. The vascular response to fasudil was blunted during NO-clamp in CTL (104+/-18% vs. 244+/-48% for NO-clamp+fasudil vs. fasudil alone; baseline=0%, P<0.05) but not in NTX. The l-NMMA-induced vasoconstriction was impaired in NTX compared to CTL. In NTX and CTL basal vascular tone equally depends on ROK. Fasudil-induced vasodilatation is partly mediated by vascular NO in CTL but not in NTX. The greater NO-insensitive fasudil-induced increase in FBF in NTX suggests an increased ROK-mediated VSMC constrictor tone in these patients. Basal NO-mediated tone is attenuated in hypertensive NTX.
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Affiliation(s)
- E Büssemaker
- Medizinische Klinik und Poliklinik D, Universitätsklinikum Münster, Münster, Germany.
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The Rho-A/Rho-kinase pathway is up-regulated but remains inhibited by cyclic guanosine monophosphate-dependent mechanisms during endotoxemia in small mesenteric arteries. Crit Care Med 2009; 37:1716-23. [PMID: 19325475 DOI: 10.1097/ccm.0b013e31819efb43] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE We investigated whether a reduced activity in the Rho-A/Rho-kinase pathway could be involved in the impaired vascular reactivity observed in septic shock. DESIGN Ex vivo animal study. SETTING University research laboratory. SUBJECTS Male Wistar rats. INTERVENTIONS Rats received an intraperitoneal injection of lipopolysaccharide (LPS, 10 mg/kg) either 6 or 24 hours before the onset of our experiments. The effects of Y-27632 (a Rho-kinase inhibitor) were assessed in first-order mesenteric rings taken from these animals using wire myograph. The expression of Rho-A, Rho-kinases I and II, and the total and phosphorylated myosin phosphatase targeting subunit 1 (MYPT1) were assessed by Western blotting. MEASUREMENTS AND MAIN RESULTS The EC50 to Y-27632 was reduced from 2.10 microM (1.22-3.66 microM) (control) to 0.21 microM (0.09-0.44 microM), and 9.54 (0.82-110.30) nM in LPS-treated groups 6 and 24 hours, respectively. The increased potency of Y-27632 was partially reversed by endothelium removal at both 6 and 24 hours. Incubation of Nomega-nitro-l-arginine methyl ester hydrochloride or 1400W (a nonselective and an inducible nitric oxide synthase inhibitor, respectively) normalized the responses to Y-27632 seen 6 hours after LPS. However, 1400W had no effect, whereas Nomega-nitro-l-arginine methyl ester hydrochloride caused a partial reduction in the enhanced potency of Y-27632 found 24 hours after LPS. The soluble guanylate cyclase inhibitor oxadiazolo[4,3-alpha]quinoxalin-1-one was able to bring the Y-27632 response back to normal both 6 and 24 hours after LPS. Rho-A, Rho-kinase I, Rho-kinase II, and MYPT1 were increased in mesenteric arteries from endotoxemic rats, but the phosphorylated MYPT1 was significantly reduced. However, incubation with oxadiazolo[4,3-alpha]quinoxalin-1-one circumvented the inhibition of MYPT1 phosphorylation found in preparations from LPS-treated animals. CONCLUSIONS Our findings revealed an impaired Rho-A/Rho-kinase-mediated phosphorylation of MYPT1 in vessels from endotoxemic animals in a cyclic guanosine monophosphate-dependent manner, suggesting that changes in mechanisms involved in calcium sensitization play a pivotal role in cardiovascular changes observed in septic shock.
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Teixeira CE, Priviero FBM, Webb RC. Effects of 5-Cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]pyrimidin-4-ylamine (BAY 41-2272) on Smooth Muscle Tone, Soluble Guanylyl Cyclase Activity, and NADPH Oxidase Activity/Expression in Corpus Cavernosum from Wild-Type, Neuronal, and Endothelial Nitric-Oxide Synthase Null Mice. J Pharmacol Exp Ther 2007; 322:1093-102. [PMID: 17596536 DOI: 10.1124/jpet.107.124594] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We aimed to characterize the relaxation induced by the soluble guanylyl cyclase (sGC) stimulator 5-cyclopropyl-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]pyrimidin-4-ylamine (BAY 41-2272) and its pharmacological interactions with nitric oxide (NO) in the corpus cavernosum (CC) from wild-type (WT), endothelial nitric-oxide synthase (eNOS)(-/-), and neuronal (n)NOS(-/-) mice. The effect of BAY 41-2272 on superoxide formation and NADPH oxidase expression was also investigated. Tissues were mounted in myographs for isometric force recording. Enzyme immunoassay kits were used for cGMP determination. sGC activity was determined in the supernatant fractions of the cavernosal samples by the conversion of GTP to cGMP. Superoxide formation and expression of NADPH oxidase subunits were studied using the reduction of ferricytochrome c and Western blot analysis, respectively. BAY 41-2272 (0.01-10 microM) relaxed CC with pEC(50) values of 6.36 +/- 0.07 (WT), 6.27 +/- 0.06 (nNOS(-/-)), and 5.88 +/- 0.07 (eNOS(-/-)). The relaxations were accompanied by increases in cGMP levels. N(omega)-Nitro-L-arginine methyl ester inhibited BAY 41-2272-evoked responses in CC from WT and nNOS(-/-), but not eNOS(-/-).1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one reduced and sildenafil potentiated the relaxations induced by BAY 41-2272 in all groups. BAY 41-2272 enhanced NO (endogenous and exogenous)-induced relaxations in a concentration-dependent manner. Expression and activity of sGC was similar among the different groups. Superoxide formation was reduced by BAY 41-2272 (0.1-1 microM). The compound also inhibited p22(phox) and gp91(phox) expression induced by 9,11-dideoxy-11 alpha,9 alpha-epoxymethanoprostaglandin F(2 alpha (U46619). Our results demonstrated that sGC activation in the penis by BAY 41-2272 directly or via enhancement of NO effects may provide a novel treatment for erectile dysfunction, particularly in the event of an increased intrapenile oxidative stress.
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Affiliation(s)
- Cleber E Teixeira
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, São Paulo, Brazil
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Jeon SB, Jin F, Kim JI, Kim SH, Suk K, Chae SC, Jun JE, Park WH, Kim IK. A role for Rho kinase in vascular contraction evoked by sodium fluoride. Biochem Biophys Res Commun 2006; 343:27-33. [PMID: 16527249 DOI: 10.1016/j.bbrc.2006.02.120] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2006] [Accepted: 02/21/2006] [Indexed: 11/22/2022]
Abstract
Agonist and depolarization-induced vascular smooth muscle contractions involve the activation of Rho-kinase pathway. However, there are no reports addressing the question whether this pathway is involved in NaF-induced vascular contractions. We hypothesized that Rho-kinase plays a role in vascular contraction evoked by sodium fluoride in rat aortae. In both physiological salt solution and calcium-free solution with 2 mM EGTA, cumulative addition of NaF increased vascular tension in concentration-dependent manners. Effects of Rho-kinase inhibitor (Y27632) on phosphorylation of myosin light chain (MLC20) and myosin targeting subunit (MYPT1(Thr696)) of myosin light chain phosphatase as well as NaF-induced contractions were determined using isolated tissue and the Western blot experiments. Y27632 inhibited NaF-induced contractions in a concentration-dependent manner. NaF increased phosphorylation of MLC20 and MYPT1(Thr696), which were also inhibited by Y27632. However, MLCK inhibitor (ML-7) or PKC inhibitor (Ro31-8220) did not inhibit the NaF-induced contraction. These results indicate that activation of Rho-kinase and the subsequent phosphorylation of MYPT1(Thr696) play important roles in NaF-induced contraction of rat aortae.
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Affiliation(s)
- Su Bun Jeon
- Department of Pharmacology, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
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