1
|
Navarro-Dorado J, Climent B, López-Oliva ME, Pilar Martínez M, Hernández-Martín M, Agis-Torres Á, Recio P, Victoria Barahona M, Benedito S, Fernandes VS, Hernández M. The bitter taste receptor (TAS2R) agonist denatonium promotes a strong relaxation of rat corpus cavernosum. Biochem Pharmacol 2023; 215:115754. [PMID: 37597814 DOI: 10.1016/j.bcp.2023.115754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 08/21/2023]
Abstract
Bitter taste receptors (TAS2R) are found in numerous extra-oral tissues, including smooth muscle (SM) cells in both vascular and visceral tissues. Upon activation, TAS2R stimulate the relaxation of the SM. Nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling pathway is involved in penile erection, and type 5 phosphodiesterase (PDE5) inhibitors, a cGMP-specific hydrolase are used as first-line treatments for erectile dysfunction (ED). Nevertheless, PDE5 inhibitors are ineffective in a considerable number of patients, prompting research into alternative pharmacological targets for ED. Since TAS2R agonists regulate SM contractility, this study investigates the role of TAS2Rs in rat corpus cavernosum (CC). We performed immunohistochemistry to detect TAS2R10, isometric force recordings for TAS2R agonists denatonium and chloroquine, the slow-release H2S donor GYY 4137, the NO donor SNAP, the β-adrenoceptor agonist isoproterenol and electrical field stimulation (EFS), as well as measurement of endogenous hydrogen sulfide (H2S) production. The immunofluorescence staining indicated that TAS2R10 was broadly expressed in the CC SM and to some extent in the nerve fibers. Denatonium, chloroquine, SNAP, and isoproterenol cause potent dose-dependent SM relaxations. H2S production was decreased by NO and H2S synthase inhibitors, while it was enhanced by denatonium. In addition, denatonium increased the relaxations induced by GYY 4137 and SNAP but failed to modify EFS- and isoproterenol-induced responses. These results suggest neuronal and SM TAS2R10 expression in the rat CC, where denatonium induces a strong SM relaxation per se and promotes the H2S- and NO-mediated inhibitory gaseous neurotransmission. Thus, TAS2R10 might represent a valuable therapeutic target in ED.
Collapse
Affiliation(s)
- Jorge Navarro-Dorado
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Belén Climent
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - María Elvira López-Oliva
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Embriología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Marina Hernández-Martín
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Ángel Agis-Torres
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - María Victoria Barahona
- Departamento de Farmacología y Toxicología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Sara Benedito
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain
| | - Vítor S Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain.
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040-Madrid, Spain.
| |
Collapse
|
2
|
Fernandes VS, López-Oliva ME, Martínez MP, Agis-Torres Á, Recio P, Navarro-Dorado J, Barahona MV, Benedito S, Prieto D, Climent B, Hernández M. In vitro inhibition of phosphodiesterase type 4 enhances rat corpus cavernosum nerve-mediated relaxation induced by gasotransmitters. Life Sci 2022; 296:120432. [PMID: 35219697 DOI: 10.1016/j.lfs.2022.120432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 11/15/2022]
Abstract
AIMS Nitric oxide (NO) and hydrogen sulfide (H2S) are involved in nerve-mediated corpus cavernosum (CC) relaxation. Expression of phosphodiesterase type 5 (PDE5) and type 4 (PDE4), cyclic guanosine monophosphate (cGMP)- and cyclic adenosine monophosphate (cAMP)-specific, respectively, has been described and PDE5- and PDE4-inhibitors induce cavernous smooth muscle relaxation. Whereas the NO/cGMP signaling pathway is well established in penile erection, the cAMP-mediated mechanism is not fully elucidated. The aim of this study is to investigate the localization and the functional significance of PDE4 in rat CC tone regulation. MAIN METHODS We performed immunohistochemistry for the detection of the PDE4A isoenzyme. Isometric tension recordings for roflumilast and tadalafil, PDE4 and PDE5 inhibitors, respectively, electrical field stimulation (EFS) and β-adrenoceptor agonist isoproterenol and endogenous H2S production measurement. KEY FINDINGS A marked PDE4A expression was detected mainly localized in the nerve cells of the cavernous smooth muscle. Furthermore, roflumilast and tadalafil exhibited strong corpus cavernous relaxations. Endogenous H2S production was decreased by NO and H2S synthase inhibitors and increased by roflumilast. Isoproterenol- and EFS-induced relaxations were increased by roflumilast. SIGNIFICANCE These results indicate that PDE4A is mainly expressed within the nerves cells of the rat CC, where roflumilast induces a potent corpus cavernous relaxation per se and potentiates the response induced by β-adrenoceptor activation. The fact that roflumilast enhances H2S production, as well as EFS-elicited responses suggests that PDE4 inhibitors modulate, in a positive feedback fashion, nerve-mediated relaxation induced by gasotransmitters, thus indicating a key role for neuronal PDE4 in penile erection.
Collapse
Affiliation(s)
- Vítor S Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Elvira López-Oliva
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Ángel Agis-Torres
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jorge Navarro-Dorado
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - María Victoria Barahona
- Departamento de Farmacología y Toxicología, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Sara Benedito
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Belén Climent
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| |
Collapse
|
3
|
Kayode OT, Yakubu MT. Parquetina nigrescens leaves: chemical profile and influence on the physical and biochemical indices of sexual activity of male Wistar rats. JOURNAL OF INTEGRATIVE MEDICINE-JIM 2018; 15:64-76. [PMID: 28088261 DOI: 10.1016/s2095-4964(17)60318-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE The leaves of Parquetina nigrescens have been claimed in folk medicine to be useful for managing sexual dysfunction, but there is inadequate scientific evidence for this claim. This investigation was conducted to assess the effects of aqueous leaf extract of Parquetina nigrescens (AEPN) in rats induced with sexual dysfunction. METHODS Male rats were allocated into various groups after being induced into sexual dysfunction with paroxetine hydrochloride. The groups were treated with distilled water, PowMaxM (reference drug), and the AEPN at 20, 40 and 80 mg/kg body weight (BW) respectively for 7 d. Frequencies of mount (MF), intromission (IF), ejaculation (EF), as well as latencies of mount (ML), intromission (IL) and post-ejaculatory interval (PEI) were progressively monitored with receptive female rats on days 1, 3 and 7. The precentage of mounted, intromitted, and ejaculated rats, intromission ratio (IR), copulatory efficiency (CE) and intercopulatory interval (ICI) were also computed. Standard methods were employed to determine the levels of serum luteinizing and follicle stimulating hormones (LH and FSH), testosterone, nitric oxide (NO) and the activity of phosphodiesterase V (PDE5). RESULTS The plant contained alkaloids, saponins, flavonoids, cardiac glycosides, steroids, tannins, phlobatannins, cardenolides, phenolics, anthraquinones and triterpenes with alkaloids (2.32 mg/g) occurring in greatest quantity while flavonoids, anthraquinones and cardenolides (0.01 mg/g, each) were the least. All the 20 standard amino acids were detected in the plant leaf, with the lowest concentration being 0.30 mg/g for methionine and the highest being 2.12 mg/g for cysteine. Furthermore, P. nigrescens leaves contained Na, K, Fe, Mg, Zn, Ca, Cu, Mn, P, Pb, Cd, Ni, Cr, and Co, with Fe present in the highest and Co the lowest concentrations. Paroxetine significantly (P<0.05) reduced MF, IF, EF, percentage mounted , intromitted, ejaculated, IR, CE, serum testosterone, LH, FSH and NO, while ML, IL, PEI, IF and PDE5 were significantly (P<0.05) increased and/or prolonged. The AEPN significantly reversed these paroxetine-treatment-related alterations with most profound activity at the highest dose of 80 mg/kg BW, similar to that of the PowMaxM-treated animals. CONCLUSION The AEPN restored both the physical and biochemical indices of male sexual activity/competence via changes in reproductive hormones, NO and PDE5 activity. The pro-sexual activity, attributed to a myriad of mineral, amino acid and secondary metabolite constituents, was best at 80 mg/kg BW of AEPN.
Collapse
Affiliation(s)
- Omowumi Titilola Kayode
- Phytomedicine, Toxicology and Reproductive Biochemistry Research Laboratory, Department of Biochemistry, University of Ilorin, Ilorin, Nigeria.,Department of Chemical Sciences, Bells University of Technology, Ota, Ogun State, Nigeria
| | - Musa Toyin Yakubu
- Phytomedicine, Toxicology and Reproductive Biochemistry Research Laboratory, Department of Biochemistry, University of Ilorin, Ilorin, Nigeria
| |
Collapse
|
4
|
Meng XL, Arning E, Wight-Carter M, Day TS, Jabbarzadeh-Tabrizi S, Chen S, Ziegler RJ, Bottiglieri T, Schneider JW, Cheng SH, Schiffmann R, Shen JS. Priapism in a Fabry disease mouse model is associated with upregulated penile nNOS and eNOS expression. J Inherit Metab Dis 2018; 41:231-238. [PMID: 29110178 DOI: 10.1007/s10545-017-0107-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/09/2017] [Accepted: 10/18/2017] [Indexed: 12/31/2022]
Abstract
Fabry disease is a glycosphingolipidosis caused by deficient activity of α-galactosidase A; it is one of a few diseases that are associated with priapism, an abnormal prolonged erection of the penis. The goal of this study was to investigate the pathogenesis of Fabry disease-associated priapism in a mouse model of the disease. We found that Fabry mice develop late-onset priapism. Neuronal nitric oxide synthase (nNOS), which was predominantly present as the 120-kDa N-terminus-truncated form, was significantly upregulated in the penis of 18-month-old Fabry mice compared to wild type controls (~fivefold). Endothelial NOS (eNOS) was also upregulated (~twofold). NO level in penile tissues of Fabry mice was significantly higher than wild type controls at 18 months. Gene transfer-mediated enzyme replacement therapy reversed abnormal nNOS expression in the Fabry mouse penis. The penile nNOS level was restored by antiandrogen treatment, suggesting that hyperactive androgen receptor signaling in Fabry mice may contribute to nNOS upregulation. However, the phosphodiesterase-5A expression level and the adenosine content in the penis, which are known to play roles in the development of priapism in other etiologies, were unchanged in Fabry mice. In conclusion, these data suggested that increased nNOS (and probably eNOS) content and the consequential elevated NO production and high arterial blood flow in the penis may be the underlying mechanism of priapism in Fabry mice. Furthermore, in combination with previous findings, this study suggested that regulation of NOS expression is susceptible to α-galactosidase A deficiency, and this may represent a general pathogenic mechanism of Fabry vasculopathy.
Collapse
Affiliation(s)
- Xing-Li Meng
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, 75226, USA
| | - Erland Arning
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, 75226, USA
| | - Mary Wight-Carter
- Animal Resources Center Diagnostic Laboratory, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Taniqua S Day
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, 75226, USA
| | | | - Shuyuan Chen
- Baylor Research Institute, Dallas, TX, 75226, USA
| | | | - Teodoro Bottiglieri
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, 75226, USA
| | - Jay W Schneider
- Department of Internal Medicine, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75390, USA
| | - Seng H Cheng
- Sanofi, 49 New York Avenue, Framingham, MA, 01701, USA
| | - Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, 75226, USA
| | - Jin-Song Shen
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, 75226, USA.
| |
Collapse
|
5
|
Salil G, Nevin KG, Rajamohan T. Arginine-rich coconut kernel diet influences nitric oxide synthase activity in alloxandiabetic rats. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2012; 92:1903-1908. [PMID: 22231513 DOI: 10.1002/jsfa.5558] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 08/29/2011] [Accepted: 11/16/2011] [Indexed: 05/31/2023]
Abstract
BACKGROUND Coconut kernel protein (CKP) has been reported to contain significant amounts of L-arginine. Its potential effect on glucose homeostasis, possibly through the nitric oxide synthase (NO) pathway, was therefore investigated in alloxan-induced diabetic rats. Diabetes was induced by a single intraperitoneal dose of alloxan (150 mg kg⁻¹ body weight). Experimental rats were grouped as follows: Group I, normal control; Group II, diabetic control; Group III, diabetic + CKP; Group IV, diabetic + L-arginine; Group V, diabetic + L-arginine + L-N(G)-Nitroarginine methyl ester (L-NAME). Purified CKP isolated from dried coconut kernel and L-arginine was administered to rats along with a semi-synthetic diet for 45 days. L-NAME (0.5 mg kg⁻¹ body weight) was given to Group V animals. After the experimental period, serum glucose, insulin, activities of liver nitric oxide synthase and arginase, liver glycogen levels and histopathology of the pancreas were evaluated. RESULTS Serum glucose, insulin and antioxidant enzyme activities and liver glycogen levels were found to be restored to basal levels in CKP-fed rats. Decreased arginase and increased nitric oxide synthase (NOS) activities were found in CKP- and arginine-fed rats. L-NAME treatment showed a partial effect on these parameters. Histopathology revealed that CKP and L-arginine feeding reduced the diabetes-related pancreatic damage in treated rats compared to the diabetic control. CONCLUSION The results observed in this study indicate that the potential antidiabetic activity of CKP may be through an arginine-NO pathway leading to pancreatic beta cell regeneration.
Collapse
Affiliation(s)
- Gopalakrishnan Salil
- Department of Biochemistry, University of Kerala, Kariavattom Campus, Thiruvananthapuram, Kerala 695581, India
| | | | | |
Collapse
|
6
|
Yeh KY, Wu CH, Tsai YF. Ginkgo biloba treatment increases copulation but not nNOS activity in the medial preoptic area in male rats. Neurosci Lett 2011; 500:182-6. [PMID: 21723370 DOI: 10.1016/j.neulet.2011.06.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 05/28/2011] [Accepted: 06/15/2011] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) is an important messenger in the central nervous system to mediate male copulatory behavior. EGb 761, a standardized extract of Gingko biloba, has been reported to facilitate male copulation in rats. The present study is to determine the effects of neuronal nitric oxide synthase (nNOS) in the medial preoptic area (MPOA) on copulation in male rats following EGb 761 treatment. Adult male rats were treated with 50mg/kg of EGb 761 or distilled water by oral gavage for 14 consecutive days. The animals were sacrificed approximately 14h after the last behavioral test and MPOA brain tissues were collected for nNOS immunohistochemistry. EGb 761 treatment for 14 days significantly increased the intromission frequency compared to the vehicle-treated controls on day 14. An increase in ejaculation frequency was also seen in the EGb 761-treated group compared to the vehicle-treated controls on day 14 and to the same group on day 0. However, EGb 761 treatment did not influence the number of nNOS-immunoreactive cells in the MPOA. These results suggest that enhanced male copulatory performance in sexually experienced rats administered EGb 761 may not be related to central nNOS activity in the MPOA.
Collapse
Affiliation(s)
- Kuei-Ying Yeh
- Department of Physical Therapy, HungKuang University, No. 34 Chung-Chie Road, Sha Lu, Taichung 443, Taiwan, ROC.
| | | | | |
Collapse
|
7
|
Ohmasa F, Saito M, Tsounapi P, Dimitriadis F, Inoue S, Shomori K, Shimizu S, Kinoshita Y, Satoh K. Edaravone ameliorates diabetes-induced dysfunction of NO-induced relaxation in corpus cavernosum smooth muscle in the rat. J Sex Med 2011; 8:1638-49. [PMID: 21477013 DOI: 10.1111/j.1743-6109.2011.02238.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Diabetes mellitus (DM) represents a major risk factor for erectile dysfunction (ED). Although the etiology of diabetes-induced ED is multifactorial and still unknown, reactive oxygen species are thought to be one of the key factors. AIM The aim of this article is to investigate whether administration of edaravone, a free radical scavenger, could prevent type 1 diabetes-induced dysfunction of nitric oxide (NO)-induced relaxation in corpus cavernosum smooth muscle in the rat. METHODS Six-week-old male Wistar rats were randomly divided into three groups. One group was treated with citrate-phosphate buffer plus normal saline (group Cont), whereas in the other two groups, diabetes was induced by streptozotocin (50 mg/kg intraperitoneally [i.p.]). Subsequently, the diabetic rats were treated for 4 weeks either with edaravone (10 mg/kg/day, i.p.; group DM + E) or with normal saline (group DM). MAIN OUTCOME MEASURES Serum glucose and malondialdehyde levels as well as penile cyclic guanosine monophosphate (cGMP) concentrations were determined, and penile function was estimated by organ bath studies with norepinephrine-mediated contractions and acetylcholine-mediated relaxations. The participation mRNA levels of muscarinic M(3) receptors, neuronal nitrous oxide synthase (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS), and participation protein levels of nNOS, eNOS, phosphorylated nNOS, and phosphorylated eNOS were investigated by quantitative real-time polymerase chain reaction (PCR) and immunoblot analysis, respectively. RESULTS Treatment with edaravone prevented partially but significantly the decreased body and penile weight induced by diabetes. Treatment with edaravone significantly improved the increased diabetes-induced malondialdehyde levels, the decreased penile cGMP concentrations, the increased diabetes-induced norepinephrine-mediated contractions, and the decreased acetylcholine-mediated relaxation. Although there were no significant differences in expression levels of mRNAs in nNOS, diabetes-induced upregulation of muscarinic M(3) receptor and iNOS mRNAs as well as diabetes-induced downregulations of eNOS, phosphorylated nNOS, and phosphorylated eNOS were significantly prevented by edaravone. CONCLUSIONS Edaravone decreases the oxidative insult in the penile corpus cavernosum by ameliorating the NO-NOS system and thus preventing partially the developing ED in DM in the rat.
Collapse
Affiliation(s)
- Fumiya Ohmasa
- Division of Molecular Pharmacology, Tottori University School of Medicine, Yonago, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Increased expression of the nitric oxide synthase gene and protein in corpus cavernosum by repeated dosing of udenafil in a rat model of chemical diabetogenesis. Asian J Androl 2009; 11:435-42. [PMID: 19465935 DOI: 10.1038/aja.2009.27] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Erectile dysfunction (ED) is a major complication of diabetes mellitus (DM). This study investigates the relationship between ED and the downregulation of constitutive nitric oxide synthase (cNOS) in the corpus cavernosum (CC) of diabetic rats. It also examines the effects of udenafil, a phosphodiesterase type 5 (PDE5) inhibitor, on ED and cNOS expression levels. After 16 weeks of daily oral treatment with udenafil in diabetic rats, the intracavernous pressure/mean arterial pressure (ICP/MAP) ratio was recorded to measure erectile function, and cNOS expression was measured using reverse transcriptase (RT)-PCR and immunoblots. Although the ICP/MAP ratio and the expression levels of endothelial NOS (eNOS) and neuronal NOS (nNOS) in the CC were markedly decreased in diabetic rats, long-term udenafil treatment improved the erectile function and increased cNOS expression compared with diabetic controls. These findings suggest that ED in DM is closely related to decreased cNOS expression in the CC and that udenafil has the ability to compensate for this pathological change by modulating cNOS expression. Udenafil also has an inhibitory role in cGMP (cyclic guanosine monophosphate) degradation.
Collapse
|
9
|
Applications for regulatory region of nitric oxide synthase isoforms. Expert Opin Ther Pat 2005. [DOI: 10.1517/13543776.8.11.1525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
10
|
Grant MKO, El-Fakahany EE. Therapeutic interventions targeting the nitric oxide system: current and potential uses in obstetrics, bone disease and erectile dysfunction. Life Sci 2004; 74:1701-21. [PMID: 14741730 DOI: 10.1016/j.lfs.2003.08.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Nitric oxide is involved in a countless number of physiological processes and is known to have cytoprotective as well as cytotoxic effects. Increased knowledge about the multifaceted role of nitric oxide in a variety of disease states has led to the design of multiple treatment strategies involving the nitric oxide system. The current review focuses on recent research advances in the fields of obstetrics, bone disease and erectile dysfunction that have led to current or potential future therapies involving nitric oxide.
Collapse
Affiliation(s)
- Marianne K O Grant
- Neuroscience Research in Psychiatry, University of Minnesota Medical School, Mayo Mail Code 392, 420 Delaware Street S.E., Minneapolis, MN 55455, USA
| | | |
Collapse
|
11
|
Different distribution of nitric oxide synthase and soluble guanylyl cyclase activities in the detrusor and proximal urethra of the rabbit. J Urol 2002; 168:2286-90. [PMID: 12394776 DOI: 10.1016/s0022-5347(05)64372-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
PURPOSE We investigated the different distributions of nitric oxide synthase (NOS) and soluble guanylate cyclase activities in the detrusor and proximal urethra in the rabbit. MATERIALS AND METHODS The detrusor and proximal urethra were excised, the mucosa and muscularis were separated and each layer was homogenized to measure the activities of NOS as well as baseline and sodium nitroprusside (SNP) activated soluble guanylate cyclase. Isometric tension experiments were performed in detrusor and urethral strips with and without mucosa. RESULTS In the detrusor NOS and sodium nitroprusside activated soluble guanylate cyclase activities in the mucosa were much higher than in the muscularis. While in the proximal urethra NOS activity in the 2 layers was similar, SNP activated soluble guanylate cyclase activity in the muscularis was 2.8 times higher than in the mucosa. Removing the mucosa reduced nitric oxide (NO) mediated neurogenic relaxation in the proximal urethra, while no relaxation responses could be elicited by electrical field stimulation with or without mucosa in the detrusor. On the other hand, removing the mucosa did not affect SNP or 8-bromo-cyclic guanosine monophosphate induced relaxation in the detrusor and proximal urethra. CONCLUSIONS In the detrusor NOS and soluble guanylate cyclase activities were mainly detected in the mucosa, while in the urethra these activities were distributed throughout the mucosa and muscularis. Also, the mucosa in the urethra but not in the detrusor contributed to electrical field stimulation induced, NO mediated relaxation. These findings confirm previous studies demonstrating that NO has a different role in the detrusor than in the proximal urethra.
Collapse
|
12
|
Different Distribution of Nitric Oxide Synthase and Soluble Guanylyl Cyclase Activities in the Detrusor and Proximal Urethra of the Rabbit. J Urol 2002. [DOI: 10.1097/00005392-200211000-00115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
13
|
Ito TY, Trant AS, Polan ML. A double-blind placebo-controlled study of ArginMax, a nutritional supplement for enhancement of female sexual function. JOURNAL OF SEX & MARITAL THERAPY 2001; 27:541-549. [PMID: 11554217 DOI: 10.1080/713846828] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study was open to women over the age of 21 years with an interest in improving their sexual function. Of the 77 participants, 34 received ArginMax and 43 received a placebo. ArginMax for Women is a proprietary nutritional supplement consisting of extracts of ginseng, ginkgo, and damiana, L-arginine, multivitamins, and minerals. After 4 weeks, 73.5% of the ArginMax group improved in satisfaction with their overall sex life, compared with 37.2% of the placebo group (p < 0.01). Notable improvements were also observed in sexual desire, reduction of vaginal dryness, frequency of sexual intercourse and orgasm, and clitoral sensation. No significant side effects were noted.
Collapse
Affiliation(s)
- T Y Ito
- University of Hawaii, School of Medicine, Honolulu, Hawaii, USA
| | | | | |
Collapse
|
14
|
Shen ZJ, Lu YL, Chen ZD, Chen F, Chen Z. Effects of androgen and ageing on gene expression of vasoactive intestinal polypeptide in rat corpus cavernosum. BJU Int 2000; 86:133-7. [PMID: 10886097 DOI: 10.1046/j.1464-410x.2000.00721.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To clarify the effects of androgens (testosterone and dihydrotestosterone, DHT) and ageing on gene expression of vasoactive intestinal polypeptide (VIP), assessed as the expression of VIP mRNA, in rat corpus cavernosum. Materials and methods The study comprised 160 male Sprague Dawley rats divided into group A (56 rats, 5 weeks old), group B (50 rats, 10 weeks old) and group C (54 rats, 58 weeks old). Groups A-C were subdivided, respectively, into subgroups 1 (intact controls), 2 (castrated), 3 (castrated but given testosterone undecanoate 25 mg/kg per month by intramuscular injection), 4 (castrated with testosterone undecanoate 50 mg/kg per month) and 5 (treated with finasteride 4.5 mg/kg per day, orally). At 4 and 10 weeks after these treatments half the rats were killed. Serum samples were taken for the measurement of total and free testosterone and DHT, using a radioimmunoassay. Penile samples (corpus cavernosum) were frozen in liquid nitrogen and stored at -80 degrees C. VIP mRNA was estimated using a semi-quantitative reverse-transcription polymerase chain reaction. RESULTS There was no significant difference in VIP mRNA in rat corpus cavernosum between intact control and castrated subgroups, or subgroups treated with finasteride, in groups A-C, including both the 4- and 10-week old animals (P > 0.05). Penile VIP mRNA was unchanged at any dose of testosterone in the castrated subgroups in all groups (P > 0.05). There was no significant relationship between penile VIP mRNA and ageing (P > 0.05). CONCLUSIONS The gene expression of VIP in rat corpus cavernosum is independent of androgens (testosterone and DHT) and ageing. Androgens probably induce penile erection by pathways other than VIP; ageing may have little effect on penile VIP mRNA.
Collapse
Affiliation(s)
- Z J Shen
- Department of Urology, Sir Run Run Shao Hospital, Medical School of Zhejiang University, Hangzhou, P. R. China
| | | | | | | | | |
Collapse
|
15
|
Lane P, Gross SS. The autoinhibitory control element and calmodulin conspire to provide physiological modulation of endothelial and neuronal nitric oxide synthase activity. ACTA PHYSIOLOGICA SCANDINAVICA 2000; 168:53-63. [PMID: 10691780 DOI: 10.1046/j.1365-201x.2000.00654.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
NO production by the endothelial and neuronal isoforms of nitric oxide synthase (cNOS) is regulated on a moment-to-moment basis by calmodulin binding, triggered by transient elevations in intracellular-free calcium levels. Nonetheless, additional modes of cNOS regulation are implicit in the discoveries of stimuli that elicit a sustained increase in cNOS activity despite undetectable or transient increases in intracellular Ca2+ in endothelial cells; such stimuli include shear-stress, oestrogen, insulin or insulin-like growth factor treatment of endothelial cells. Recently, we identified a peptide insertion within the FMN-binding domain of mammalian NOSs that is unique to calcium-dependent isoforms, and not shared with inducible NOS or ancestral flavoproteins. Evidence suggests that this insertion serves as a fundamental control element, analogous to intrinsic autoinhibitory peptides that have been demonstrated to regulate activity of other calmodulin-dependent enzymes. Thus, the peptide insertion of cNOSs appears to function as structural element that is displaced upon calmodulin binding, resulting in dysinhibition of NO synthesis. Once displaced, the peptide may also be subject to transient chemical modifications and protein-protein interactions that modulate autoinhibitory function. Herein we summarize our present knowledge and speculate on mechanisms by which calmodulin and the autoinhibitory peptide conspire to regulate cNOS activity.
Collapse
Affiliation(s)
- P Lane
- Department of Pharmacology, Cornell University Medical College, New York, NY 10021, USA
| | | |
Collapse
|
16
|
DUKE JAMESA. Is There an Herbal Viagra? J Med Food 1998. [DOI: 10.1089/jmf.1998.1.227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|