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Akintunde J, Olayinka M, Ugbaja V, Akinfenwa C, Akintola T, Akamo A, Bello I. Downregulation of inflammatory erectile dysfunction by Mantisa religiosa egg-cake through NO-cGMP-PKG dependent NF-kB signaling cascade activated by mixture of salt intake. Toxicol Rep 2023; 10:633-646. [PMID: 37250529 PMCID: PMC10220466 DOI: 10.1016/j.toxrep.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/06/2023] [Accepted: 05/13/2023] [Indexed: 05/31/2023] Open
Abstract
We hypothesized whether 10% praying-mantis-egg-cake (10% PMEC) can be applied against inflammatory-erectile-dysfunction and whether it could be linked to NO-cGMP-dependent PKG signaling cascade. Ninety male albino-rats were randomly distributed into nine (n = 10) groups. Group I was given distilled water. Group II and III were pre-treated with 80 mg/kg NaCl and 75 mg/kg MSG, respectively. Group IV was pre-treated with 80 mg/kg NaCl + 75 mg/kg MSG. Group V was administered with 80 mg/kg NaCl+ 3 mg/kg Amylopidin. Group VI was given 80 mg/kg NaCl + 10% PMEC. Group VII was treated with 75 mg/kg MSG + 10% PMEC. Group VIII was treated with 80 mg/kg NaCl+ 75 mg/kg MSG + 10% PMEC. Group IX was post-treated with 10% PMEC for 14 days. Penile PDE-51, arginase, ATP hydrolytic, cholinergic, dopaminergic (MAO-A) and adenosinergic (ADA) enzymes were hyperactive on intoxication with NaCl and MSG. The erectile dysfunction caused by inflammation was linked to alteration of NO-cGMP-dependent PKG signaling cascade via up-regulation of key cytokines and chemokine (MCP-1). These lesions were prohibited by protein-rich-cake (10% PMEC). Thus, protein-rich-cake (10% PMEC) by a factor of 4 (25%) inhibited penile cytokines/MCP-1 on exposure to mixture of salt-intake through NO-cGMP-PKG dependent-NF-KB signaling cascade in rats.
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Affiliation(s)
- J.K. Akintunde
- Molecular Toxicology and Biomedical, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - M.C. Olayinka
- Molecular Toxicology and Biomedical, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - V.C. Ugbaja
- Molecular Toxicology and Biomedical, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - C.A. Akinfenwa
- Molecular Toxicology and Biomedical, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - T.E. Akintola
- Molecular Toxicology and Biomedical, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - A.J. Akamo
- Molecular Toxicology and Biomedical, Department of Biochemistry, College of Biosciences, Federal University of Agriculture, Abeokuta, Nigeria
| | - I.J. Bello
- School of Applied Sciences, Adeyemi Federal University of Education, Ondo, Nigeria
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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.
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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.
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Senthilkumaran S, Williams HF, Patel K, Trim SA, Thirumalaikolundusubramanian P, Vaiyapuri S. Priapism following a juvenile Russell's viper bite: An unusual case report. PLoS Negl Trop Dis 2021; 15:e0009242. [PMID: 33764978 PMCID: PMC7993604 DOI: 10.1371/journal.pntd.0009242] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Following a bite from a juvenile Russell's viper (Daboia russelii), a priapism (painful erection) developed rapidly in a 16-year-old male and only subsided after administration of antivenom 3 hours later. Potential mechanisms for this snakebite-induced priapism are unclear but likely due to venom toxins causing nitric oxide (NO) release and subsequent vasodilation of endothelium in the corpus cavernosum, although the possible involvement of other mechanisms cannot be ruled out. We strongly believe that this unusual case report may lead to further scientific research in order to improve the clinical understanding of the pathophysiology of envenomation due to Russell's viper bites. Although it is too early to speculate, further research may also discover the possibilities of developing venom-based candidate molecules to treat sexual dysfunction in males and females.
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Affiliation(s)
| | | | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading, United Kingdom
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Sen S, Thomas A, Das S, Dey JK, Peedicayil A, Thomas V, Peedicayil J. Inhibition by tadalafil of contractility of isolated nonpregnant human myometrium. J Pharmacol Pharmacother 2017; 7:177-181. [PMID: 28163539 PMCID: PMC5242031 DOI: 10.4103/0976-500x.195902] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Objective: To investigate the inhibitory effect of tadalafil on the contractility of isolated nonpregnant human myometrium. Materials and Methods: The ability of tadalafil (25, 40, and 63 μM) to inhibit 55 mM KCl-induced contractility of isolated nonpregnant human myometrium was studied. The ability of the ATP-sensitive potassium channel blocker glibenclamide (10 μM) and the calcium-sensitive potassium channel (BKCa) blocker iberiotoxin (100 nM) to reverse the inhibitory effect of 40 μM tadalafil on 55 mM KCl-induced myometrial contractility was also studied. Results: Tadalafil produced a concentration-dependent inhibition of myometrial contractility that was statistically significant at 40 and 63 μM concentrations of tadalafil. The inhibition by tadalafil of myometrial contractility was statistically significantly reversed by the concurrent administration of glibenclamide and iberiotoxin. Conclusions: These results suggest that tadalafil inhibits human myometrial contractility by opening ATP-sensitive potassium channels and BKCa channels. The opening of these channels could have been due to the action of raised intracellular levels of cGMP due to inhibition of PDE-5 by tadalafil. The results suggest that tadalafil could be investigated for use in clinical conditions requiring relaxation of the myometrium.
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Affiliation(s)
- Sumalya Sen
- Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Anitha Thomas
- Division of Obstetrics and Gynaecology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Saibal Das
- Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Jayanta Kumar Dey
- Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Abraham Peedicayil
- Division of Obstetrics and Gynaecology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Vinotha Thomas
- Division of Obstetrics and Gynaecology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Jacob Peedicayil
- Department of Pharmacology and Clinical Pharmacology, Christian Medical College, Vellore, Tamil Nadu, India
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Guan NN, Thor A, Hallén K, Wiklund NP, Gustafsson LE. Cascade bioassay evidence for the existence of urothelium-derived inhibitory factor in Guinea pig urinary bladder. PLoS One 2014; 9:e103932. [PMID: 25084114 PMCID: PMC4118989 DOI: 10.1371/journal.pone.0103932] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 07/08/2014] [Indexed: 11/20/2022] Open
Abstract
Our aim was to investigate whether guinea pig urothelium-derived bioactivities compatible with the existence of urothelium-derived inhibitory factor could be demonstrated by in vitro serial bioassay and whether purinergic P1 receptor agonists, nitric oxide, nitrite or prostaglandins might explain observed activities. In a cascade superfusion system, urothelium-denuded guinea pig ureters were used as bioassay tissues, recording their spontaneous rhythmic contractions in presence of scopolamine. Urothelium-intact or -denuded guinea pig urinary bladders were used as donor tissues, stimulated by intermittent application of carbachol before or during the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), the adenosine/P1 nucleoside receptor antagonist 8-(p-sulfophenyl)theophylline (8-PST) or the cyclo-oxygenase inhibitor diclofenac infused to bath donor and bioassay tissues. The spontaneous contractions of bioassay ureters were unaltered by application of carbachol 1-5 µM in the presence of scopolamine 5-30 µM. When carbachol was applied over the urothelium-denuded bladder, the assay ureter contraction rate was unaltered. Introducing carbachol over the everted urothelium-intact bladder significantly inhibited the contraction frequency of the assay ureter, suggesting the transfer of an inhibitory activity from the bladder to the assay ureter. The transmissible inhibitory activity was not markedly antagonized by L-NAME, 8-PST or diclofenac, while L-NAME nearly abolished nitrite release from the urothelium-intact bladder preparations. We suggest that urothelium-derived inhibitory factor is a transmissible entity over a significant distance as demonstrated in this novel cascade superfusion assay and seems less likely to be nitric oxide, nitrite, an adenosine receptor agonist or subject to inhibition by administration of a cyclo-oxygenase inhibitor.
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Affiliation(s)
- Na N. Guan
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Anna Thor
- Section of Urology, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Katarina Hallén
- Section of Urology, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - N. Peter Wiklund
- Section of Urology, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Lars E. Gustafsson
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Senbel AM, Hashad A, Sharabi FM, Daabees TT. Activation of muscarinic receptors inhibits neurogenic nitric oxide in the corpus cavernosum. Pharmacol Res 2011; 65:303-11. [PMID: 22178337 DOI: 10.1016/j.phrs.2011.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/23/2011] [Accepted: 12/05/2011] [Indexed: 12/19/2022]
Abstract
The functional role of cholinergic transmission in erection is still far from being fully elucidated. This work aims to further elucidate the modulatory role of neostigmine on NO in the corpus cavernosum and to highlight whether cholinergic transmission in the penis modulates sildenafil action. The isolated rabbit corpus cavernosum and measurement of intracavernosal pressure in the anesthetized rat model were used. Neostigmine (0.02 mg/kg) reduced increase of intracavernosal pressure/mean arterial pressure (ICP/MAP) next to cavernous nerve stimulation. Higher doses (0.06 and 0.4 mg/kg) potentiated ICP/MAP rise and atropine (1.5 and 10 mg/kg) did the opposite. In vitro, neostigmine (10⁻⁵ and 10⁻⁴ M) potentiated neurogenic relaxations and this effect was significantly inhibited by hexamethonium (10⁻⁴ M) or N(ω)-propyl-L-arginine (3 × 10⁻⁵ M) and partially but significantly reduced in the presence of atropine. Lower dose neostigmine (10⁻⁷ M), inhibited electrically induced relaxation over the range of 1-4 Hz, atropine (10⁻⁶ M) almost abolished this inhibitory effect as well as N(G)-nitro-L-arginine (10⁻⁵ M). It was also significantly reduced by selective nNOS inhibitor N(ω)-propyl-L-arginine (3 × 10⁻⁵ M). Nicotine (10⁻⁴ M) significantly potentiated electrically induced relaxations amounting to 84.625 ± 8.06% at 1 Hz and potentiated the effect of sildenafil synergistically. Hexamthonium did the opposite. The potentiatory effect of sildenafil on neurogenic erection was significantly reduced by low dose neostigmine both in vitro and in vivo. This study provides evidence that muscarinic receptors may modulate NO synthesis in nitrergic nerves by inhibiting nNOS and high level of cholinergic stimulation may activate nicotinic receptors to promote erection probably by potentiating NO synthesis in nitrergic nerves.
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Affiliation(s)
- A M Senbel
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Alexandria University, Egypt.
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Relaxant effect and possible mechanism of 17-nor-subincanadine E in rabbit corpora cavernosa. Asian J Androl 2011; 13:747-53. [PMID: 21765439 DOI: 10.1038/aja.2011.41] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Compounds with dual action on cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) may be a treatment option for erectile dysfunction, as they not only promote penile erection but also prevent the upregulation of phosphodiesterase-5. In this study, we examined the possible relaxant effect and mechanism of 17-nor-subincanadine E (SEC, 0.2-200 µmol l⁻¹), a plant-derived alkaloid, in rabbit corpus cavernosum (RbCC) strips that had been precontracted by exposure to phenylephrine (10 µmol l⁻¹) or a high concentration of K(+) (60 mmol l⁻¹) in vitro. In addition to SEC's effect on cAMP and cGMP levels, electrical field stimulation (EFS) in phenylephrine-precontracted RbCC and calcium chloride (1-100 mmol l⁻¹) evoked responses in depolarized RbCC were analysed. SEC relaxed the phenylephrine-precontracted RbCCs in a concentration-dependent manner. Atropine, guanethidine and N-ω-nitro-l-arginine methyl ester (L-NAME) did not have any effect on the relaxation of RBCCs. When 1H-(1, 2, 4)oxadiazole[4,3-a] quinoxalin-1-one (ODQ) was added, it effectively blocked the relaxant response of SEC. Although SEC enhanced the maximal relaxation produced by sodium nitroprusside (SNP) and forskolin in phenylephrine-precontracted cavernosal smooth muscle, it caused a decrease in the maximal contractile response induced by calcium chloride in depolarized RbCCs. The relaxant effect of SEC was paralleled by an increase in the tissue levels of the cyclic nucleotides cAMP and cGMP. We conclude that SEC promotes the relaxation of RbCC, possibly favouring cAMP and cGMP accumulation and calcium blockade. This novel mechanism could be useful for patients who do not benefit from phosphodiesterase inhibitors and for those with endothelial and nitrergic dysfunction, such as patients with diabetes, hypertension and dyslipidaemias.
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Zhao C, Cho KW, Park JK. Three phases of corporal tracing elicited by electrical field stimulation on rabbit corpus cavernosum smooth muscle in penile perfusion model. J Sex Med 2011; 8:1039-47. [PMID: 21235727 DOI: 10.1111/j.1743-6109.2010.02178.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Nitric oxide (NO) has been shown to mediate electrical field stimulation (EFS)-caused smooth muscle relaxation. It is known that the neural control of penile erection involves adrenergic, cholinergic, and non-adrenergic-non-cholinergic (NANC) neuro-effector systems; however, the effects of EFS on adrenergic and cholinergic nerves are not clear. AIMS To elucidate EFS-induced signal transductions involved in adrenergic, cholinergic, and NANC neuro-effector systems by using an in vitro penile perfusion model. METHODS EFS was performed on penile corpus cavernosum smooth muscle from male New Zealand White rabbits, which was pre-contracted with L-phenylephrine (10 µM). We investigated the penile tracing elicited by EFS on tissues pre-incubated with guanethidine (Guan, 50 µM), tetrodotoxin (TTX, 10 µM), Nω nitro-L-arginine-methyl ester (L-NAME, 1 mM), atropine (50 µM), or eserine (10 µM). MAIN OUTCOME MEASURES The time-to-peak of each phase, the percentage of relaxation, and the area under the curve (AUC). RESULTS We discovered an extraordinary phenomenon: three distinct phases elicited by EFS. Phase I was abolished by L-NAME. Phase II was decreased by eserine and Guan, but increased by L-NAME. Phase III was abolished by atropine, but enhanced by eserine and Guan. TTX diminished all three phases. The time to reach the top of phase I was delayed by TTX. The time to attain the peak of phase II was shortened by L-NAME, but delayed by TTX and atropine. The time to reach the top of phase III was shortened by L-NAME, eserine, and Guan. AUC was significantly decreased by L-NAME and TTX. CONCLUSIONS EFS stimulated adrenergic, cholinergic, and NANC neuro-effector systems simultaneously. Phase I was related to the NO pathway. Phase II was multiply affected by self-recovery properties, and adrenergic and cholinergic nerves. Phase III was related to cholinergic nerves. The corporal tracing elicited by EFS was the balanced result of multiple factors.
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Affiliation(s)
- Chen Zhao
- Department of Urology, Medical School, and Institute for Medical Sciences, Chonbuk National University, and Research Institute and CTC for Medical Device of Chonbuk National University Hospital, Jeonju, Korea
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Zhao C, Chae HJ, Kim SH, Cui WS, Lee SW, Jeon JH, Park JK. A new perfusion model for studying erectile function. J Sex Med 2010; 7:1419-28. [PMID: 20059654 DOI: 10.1111/j.1743-6109.2009.01652.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
INTRODUCTION The present study introduces a newly devised in vitro penile perfusion model, which allows the measurement of changes in intracavernosum pressure (ICP), tension, and cyclic nucleotides in penile tissue in a one-step procedure. AIMS We compared the penile perfusion model with the classical penile strip chamber model to develop the new model. METHODS We investigated the role of nitric oxide-cyclic guanosine monophosphate pathway in both systems activated by acetylcholine or electrical field stimulation (EFS). We measured cGMP (cyclic guanosine monophosphate) in the penile corpus cavernosum smooth muscle in both systems and perfusates in the penile perfusion model. We determined ICP, tension, and cGMP simultaneously in penile perfusion model during the experiments. MAIN OUTCOME MEASURES Changes of tension and cGMP in both models, and of cGMP in perfusates and of ICP in penile perfusion model. RESULTS In both systems, acetylcholine relaxed the phenylephrine-precontracted penile corpus cavernosum smooth muscle in a concentration-dependent manner. EFS decreased the tension in both models and ICP in the penile perfusion model in a frequency-dependent manner. Pretreatment with atropine, Nomega nitro-L-arginine-methyl ester (L-NAME), and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) blocked the acetylcholine-induced decrease in the tension in both models and ICP in penile perfusion model. Acetylcholine increased cGMP levels in the perfusate of penile perfusion model and the changes were attenuated by tetrodotoxin (TTX), atropine, L-NAME and ODQ. EFS increased cGMP levels of the penile corpus cavernosum smooth muscle of both models and the changes were attenuated by TTX, atropine, L-NAME, and ODQ. CONCLUSION The results indicated that the responses of penile strip and perfused penile tissue to acetylcholine and EFS were very similar in both models in terms of tension and cGMP levels. Furthermore, the new model has more advantages over the classical penile strip chamber model in measuring intracavernosum metabolic changes and ICP without interruption of the procedure.
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Affiliation(s)
- Chen Zhao
- Department of Urology, Medical School, and Institute for Medical Sciences, Chonbuk National University, and Research Institute of Clinical Medicine and CTC for Medical Device of Chonbuk National University Hospital, Jeonju 561-712, Korea
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Chuanxiongzine relaxes isolated corpus cavernosum strips and raises intracavernous pressure in rabbits. Int J Impot Res 2009; 22:120-6. [PMID: 19940852 PMCID: PMC2834341 DOI: 10.1038/ijir.2009.53] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been shown that there are many Chinese traditional herbals that can enhance sexual activity. Chuanxiongzine is a vasoactive ingredient that has been isolated and purified from Ligusticum chuanxiong Hort. In previous studies, it has been found that chuanxiongzine was effective in relaxing rabbit corpus cavernosum smooth muscle. We determined the effects of chuanxiongzine on relaxation of isolated corpus cavernosum strips in vitro and on increase of intracavernous pressure (ICP) in vivo in rabbits. Chuanxiongzine caused a concentration-dependent relaxation of phenylephrine precontracted isolated corpus cavernosum strips (EC50 1.58 × 10−4 mol l−1), which were endothelium independent and NO independent. However, the guanylyl cyclase inhibitor 1-H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one significantly shifted the chuanxiongzine concentration–response relationship to the right. Although there was no significant difference in the level of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) in isolated corpus cavernosum strips treated with chuanxiongzine or vehicle, chuanxiongzine caused a significant rise in the level of cGMP and cAMP in isolated corpus cavernosum strips pretreated with the activator of adenylyl cyclase forskolin and the source of NO sodium nitroprusside. In an in vivo study, chuanxiongzine dose-dependently raised ICP after the intracavernous injection of its cumulative doses (0.5, 1, 2 and 5 mg kg−1). The ICP increased from baseline to 19.1±3.7, 24.8±2.1, 30.2±4.8 and 39.7±6.1 mm Hg, respectively, and the duration of tumescence ranged from 8.5±2.8 to 22.9±7.3 min. Our results show that chuanxiongzine can relax isolated corpus cavernosum strips of rabbits in vitro and increase ICP of rabbits in vivo, which is neither endothelium dependent nor NO dependent, but may be partly mediated by the inhibition of cAMP phosphodiesterase or cGMP phosphodiesterase.
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Comparative Relaxing Effects of Sildenafil, Vardenafil, and Tadalafil in Human Corpus Cavernosum: Contribution of Endogenous Nitric Oxide Release. Urology 2009; 74:216-21. [DOI: 10.1016/j.urology.2008.12.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Revised: 11/26/2008] [Accepted: 12/24/2008] [Indexed: 11/20/2022]
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Oger S, Behr-Roussel D, Gorny D, Charles Tremeaux J, Combes M, Alexandre L, Giuliano F. Combination of alfuzosin and tadalafil exerts in vitro an additive relaxant effect on human corpus cavernosum. J Sex Med 2008; 5:935-945. [PMID: 18221277 DOI: 10.1111/j.1743-6109.2007.00754.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
INTRODUCTION Phosphodiesterase type 5 (PDE5) inhibitors, such as tadalafil, are a first-line treatment for erectile dysfunction (ED). Nevertheless, some patients do not respond to this treatment. Clinical data suggest that the addition of alpha1-adrenoceptor blocker, such as alfuzosin, commonly prescribed for lower urinary tract symptoms suggestive of benign prostatic hyperplasia, may be of benefit. Aim. Evaluation of the effect of alfuzosin, tadalafil or the combination of both on human corpus cavernosum. METHODS Human cavernosal tissues were obtained from 10 patients undergoing penile surgery. Strips contractility was studied in organ baths. Concentration-response curves to tadalafil were generated on norepinephrine (NE, 1-10 microM)-precontracted strips in the presence of alfuzosin or vehicle. Frequency-response curves (FRC) to electrical field stimulation (EFS, 0-64 Hz, 3 ms, 10 seconds, 300 mA) were generated in the presence of vehicle, alfuzosin, tadalafil, or both drugs combined. EFS (20 Hz, 1 ms, 10 seconds, 300 mM)-induced nitrergic relaxation on NE-precontracted strips was studied in the presence of vehicle, alfuzosin, tadalafil, or both drugs combined. MAIN OUTCOME MEASURES Functional measurement of cavernosal smooth muscle relaxation in the presence of tadalafil and alfuzosin. RESULTS The relaxation induced by tadalafil (10(-10) to 10(-5) M) on precontracted strips was enhanced by alfuzosin at both 10(-8) and 10(-7) M. The combination of alfuzosin (3.10(-8) M) and tadalafil (10(-7) M) was more efficient to inhibit FRC-induced contractions than each compound alone. The combination of tadalafil (10(-6) M) and alfuzosin (10(-8) M) increased the relaxation induced by EFS and its effect was greater than tadalafil alone. In addition, the combination of tadalafil (10(-6) M) and alfuzosin (10(-7) M) prolonged EFS-induced relaxation to a greater extent than each compound alone. CONCLUSIONS In vitro, the combination of alfuzosin and tadalafil is more efficient than each compound alone to relax adrenergic tone or to enhance nitrergic relaxation of the human corpus cavernosum. Such a combination deserves further investigation in placebo-controlled studies to evaluate its benefit in ED patients who are not sufficiently improved by PDE5 inhibitors.
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Affiliation(s)
| | | | | | | | | | | | - François Giuliano
- Raymond Poincaré Hospital-Department of Physical Medicine and Rehabilitation, Garches, France.
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Reffelmann T, Kloner RA. Vardenafil: a selective inhibitor of phosphodiesterase-5 for the treatment of erectile dysfunction. Expert Opin Pharmacother 2007; 8:965-74. [PMID: 17472542 DOI: 10.1517/14656566.8.7.965] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Vardenafil is a selective phosphodiesterase-5 inhibitor approved for the treatment of erectile dysfunction. It was found to be effective in a high percentage of patients and a broad spectrum of underlying conditions. It potentiates the increase in intracellular cGMP in the corpora cavernosa in response to sexual stimuli, resulting in enhanced and prolonged erections. The overall tolerability and safety profile is acceptable, with headache, flushing, rhinitis and dyspepsia being the major reported side effects. Importantly, tolerability and safety in cardiovascular patients seems to be good with no significant increase in cardiovascular events that could be directly attributed to the pharmacologic agent. Only mild blood-pressure lowering effects were observed in healthy individuals, as well as hypertensive patients on multiple antihypertensive agents. However, special caution is mandatory if vardenafil is administered in combination with alpha-blockers, as significant hypotension might occur. Importantly, any drug serving as a nitric oxide donor is contraindicated in combination with vardenafil.
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Affiliation(s)
- Thorsten Reffelmann
- Klinik und Poliklinik für Innere Medizin B Ernst-Moritz-Arndt-Universität Greifswald, Greifswald, Germany.
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