1
|
Leukes VN, Malherbe ST, Hiemstra A, Kotze LA, Roos K, Keyser A, De Swardt D, Gutschmidt A, Walzl G, du Plessis N. Sildenafil, a Type-5 Phosphodiesterase Inhibitor, Fails to Reverse Myeloid-Derived Suppressor Cell-Mediated T Cell Suppression in Cells Isolated From Tuberculosis Patients. Front Immunol 2022; 13:883886. [PMID: 35935981 PMCID: PMC9353143 DOI: 10.3389/fimmu.2022.883886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 06/24/2022] [Indexed: 11/13/2022] Open
Abstract
Successful TB treatment is hampered by increasing resistance to the two most effective first-line anti-TB drugs, namely isoniazid and rifampicin, thus innovative therapies focused on host processes, termed host-directed therapies (HDTs), are promising novel approaches for increasing treatment efficacy without inducing drug resistance. We assessed the ability of Sildenafil, a type-5 phosphodiesterase inhibitor, as a repurposed compound, to serve as HDT target, by counteracting the suppressive effects of myeloid-derived suppressor cells (MDSC) obtained from active TB cases on T-cell responsiveness. We confirm that MDSC suppress non-specific T-cell activation. We also show that Sildenafil treatment fails to reverse the MDSC-mediated suppression of T-cell functions measured here, namely activation and proliferation. The impact of Sildenafil treatment on improved immunity, using the concentration tested here, is likely to be minimal, but further identification and development of MDSC-targeting TB host-directed therapies are warranted.
Collapse
Affiliation(s)
- Vinzeigh N. Leukes
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Stephanus T. Malherbe
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Andriette Hiemstra
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Leigh A. Kotze
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Kelly Roos
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Alana Keyser
- Division of Medical Virology, Department of Pathology, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Dalene De Swardt
- Central Analytical Facility, Stellenbosch University, Cape Town, South Africa
| | - Andrea Gutschmidt
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Gerhard Walzl
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Nelita du Plessis
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medical and Health Sciences, Stellenbosch University, Cape Town, South Africa
- *Correspondence: Nelita du Plessis,
| |
Collapse
|
2
|
Mohamed YT, Naguib IA, Abo-Saif AA, Elkomy MH, Alghamdi BS, Mohamed WR. Role of ADMA/DDAH-1 and iNOS/eNOS signaling in the gastroprotective effect of tadalafil against indomethacin-induced gastric injury. Biomed Pharmacother 2022; 150:113026. [PMID: 35658250 DOI: 10.1016/j.biopha.2022.113026] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/16/2022] [Accepted: 04/20/2022] [Indexed: 11/02/2022] Open
Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs)-induced gastric ulcers represent a significant clinical concern and adversely affect the quality of life. Inducible nitric oxide synthase/endothelial nitric oxide synthase (iNOS/eNOS) and asymmetric dimethylarginine/ dimethylarginine dimethylaminohydrolase-1 (ADMA/DDAH-1) signaling are key players in gastric ulcer pathogenesis. This work was planned to explore the role of iNOS/eNOS and ADMA/DDAH-1 signaling in rats with indomethacin-induced gastric ulcer, as potential pathways for the gastro-protective effect of tadalafil. Split into 5 separate groups, rats were assigned to control, tadalafil (10 mg/kg, p.o), indomethacin (single oral dose of 60 mg/kg), indomethacin + pantoprazole (40 mg/kg, p.o), and indomethacin + tadalafil (10 mg/kg, p.o). The results indicated that pretreatment with tadalafil significantly reduced ulcer index (UI), increased preventive index (PI), and counteracted indomethacin-induced histopathological aberrations. Tadalafil significantly reduced the gastric content of NO while it significantly elevated that of GSH and enhanced SOD activity. It significantly reduced the gastric expression of TNF-α and ADMA while it significantly elevated that of COX-2, PGE-2, and DDAH-1. Western blot analysis revealed that pretreatment with tadalafil significantly reduced iNOS protein expression while it significantly elevated that of eNOS. Collectively, these data suggest that tadalafil exerts potential protective effect against indomethacin-induced ulcer through suppression of inflammation, attenuation of oxidative stress, and boosting of antioxidants. Moreover, tadalafil protective effects are mediated via upregulation of PGE-2 with modulating the signaling pathways of ADMA/DDAH-1, and iNOS/eNOS. As a result, the current evidence corroborates the use of tadalafil in controlling gastric ulcers and preventing NSAID gastric side effects.
Collapse
Affiliation(s)
- Yasmin T Mohamed
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Nahda University, Beni-Suef 62514, Egypt.
| | - Ibrahim A Naguib
- Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
| | - Ali A Abo-Saif
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Nahda University, Beni-Suef 62514, Egypt.
| | - Mohammed H Elkomy
- Department of Pharmaceutics, College of Pharmacy, Jouf University, Sakaka 72341, Saudi Arabia.
| | - Badrah S Alghamdi
- Department of Physiology, Neuroscience Unit, Faculty of Medicine, King Abdulaziz University, Jeddah 22252, Saudi Arabia; Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
| | - Wafaa R Mohamed
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514, Egypt.
| |
Collapse
|
3
|
Cyperus esculentus L. and Tetracarpidium conophorum Müll. Arg. Supplemented Diet Improved Testosterone Levels, Modulated Ectonucleotidases and Adenosine Deaminase Activities in Platelets from L-NAME-Stressed Rats. Nutrients 2021; 13:nu13103529. [PMID: 34684530 PMCID: PMC8541559 DOI: 10.3390/nu13103529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 02/07/2023] Open
Abstract
In hypertensive individuals, platelet morphology and function have been discovered to be altered, and this has been linked to the development of vascular disease, including erectile dysfunction (ED). The impact of nutritional supplementation with Cyperus esculentus (tiger nut, TN) and Tetracarpidium conophorum (walnut, WN) on androgen levels, ectonucleotidases, and adenosine deaminase (ADA) activities in platelets from L-NAME (Nω-nitro-L-arginine methyl ester hydrochloride) challenged rats were investigated. We hypothesized that these nuts may show a protective effect on platelets aggregation and possibly enhance the sex hormones, thereby reverting vasoconstriction. Wistar rats (male; 250-300 g; n = 10) were grouped into seven groups as follows: basal diet control group (I); basal diet/L-NAME/Viagra (5 mg/kg/day) as positive control group (II); ED-induced group (basal diet/L-NAME) (III); diet supplemented processed TN (20%)/L-NAME (IV); diet supplemented raw TN (20%)/L-NAME (V); diet supplemented processed WN (20%)/L-NAME (VI); and diet supplemented raw WN (20%)/L-NAME (VII). The rats were given their regular diet for 2 weeks prior to actually receiving L-NAME (40 mg/kg/day) for ten days to induce hypertension. Platelet androgen levels, ectonucleotidases, and ADA were all measured. L-NAME considerably lowers testosterone levels (54.5 ± 2.2; p < 0.05). Supplementing the TN and WN diets revealed improved testosterone levels as compared to the control (306.7 ± 5.7), but luteinizing hormone levels remained unchanged. Compared to control groups, the L-NAME-treated group showed a rise in ATP (127.5%) hydrolysis and ADA (116.7%) activity, and also a decrease in ADP (76%) and AMP (45%) hydrolysis. Both TN and WN supplemented diets resulted in substantial (p < 0.05) reversal effects. Enhanced testosterone levels and modulation of the purinergic system in platelets by TN and WN could be one of the mechanisms by which they aid in vasoconstriction control.
Collapse
|
4
|
AboYoussef AM, Khalaf MM, Malak MN, Hamzawy MA. Repurposing of sildenafil as antitumour; induction of cyclic guanosine monophosphate/protein kinase G pathway, caspase-dependent apoptosis and pivotal reduction of Nuclear factor kappa light chain enhancer of activated B cells in lung cancer. J Pharm Pharmacol 2021; 73:1080-1091. [PMID: 33856030 DOI: 10.1093/jpp/rgab049] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/23/2021] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Lung cancer is one of the most frequent types of cancers that lead to death. Sildenafil is a potent inhibitor of phosphodiesterase-5 and showed potential anticancer effects, which has not yet been fully evaluated. Thus, this study aims to investigate the potential anticancer effect of sildenafil in urethane-induced lung cancer in BALB/c mice. METHODS Five-week-old male BALB/c mice were treated with either (i) normal saline only, (ii) sildenafil only 50 mg kg-1/ P.O every other day for the last four successive weeks, (iii) urethane 1.5 gm kg-1 i.p (at day 1 and day 60), (iv) carboplatin after urethane induction, or (v) sildenafil after urethane induction. KEY FINDINGS It was shown that sildenafil significantly increased the levels of cGMP and Caspase-3 with a reduction of NF-κB, Bcl-2, Cyclin D1, intercellular adhesion molecule 1, matrix metalloproteinase-2 levels and normalisation of Nrf2 along with pronounced improvement in the histological patterns. CONCLUSIONS These results indicated that sildenafil markedly induces cell cycle arrest, apoptosis and inhibits the metastatic activity through activation of cyclic guanosine monophosphate/protein kinase G pathway and down-regulation of cyclin D1 and nuclear factor kappa light chain enhancer of activated B cells with downstream anti-apoptotic gene Bcl-2, which underscores the critical importance of future using sildenafil in the treatment of lung cancer.
Collapse
Affiliation(s)
- Amira M AboYoussef
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Marwa M Khalaf
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Marina N Malak
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Mohamed A Hamzawy
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Fayoum University, Fayoum, Egypt
| |
Collapse
|
5
|
Hypertension and reproductive dysfunction: a possible role of inflammation and inflammation-associated lymphangiogenesis in gonads. Clin Sci (Lond) 2021; 134:3237-3257. [PMID: 33346358 DOI: 10.1042/cs20201023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/29/2020] [Accepted: 12/01/2020] [Indexed: 01/12/2023]
Abstract
Hypertension is one of the most prevalent diseases that leads to end organ damage especially affecting the heart, kidney, brain, and eyes. Numerous studies have evaluated the association between hypertension and impaired sexual health, in both men and women. The detrimental effects of hypertension in men includes erectile dysfunction, decrease in semen volume, sperm count and motility, and abnormal sperm morphology. Similarly, hypertensive females exhibit decreased vaginal lubrication, reduced orgasm, and several complications in pregnancy leading to fetal and maternal morbidity and mortality. The adverse effect of hypertension on male and female fertility is attributed to hormonal imbalance and changes in the gonadal vasculature. However, mechanistic studies investigating the impact of hypertension on gonads in more detail on a molecular basis remain scarce. Hence, the aim of the current review is to address and summarize the effects of hypertension on reproductive health, and highlight the importance of research on the effects of hypertension on gonadal inflammation and lymphatics.
Collapse
|
6
|
Wang Y, Wondisford FE, Song C, Zhang T, Su X. Metabolic Flux Analysis-Linking Isotope Labeling and Metabolic Fluxes. Metabolites 2020; 10:metabo10110447. [PMID: 33172051 PMCID: PMC7694648 DOI: 10.3390/metabo10110447] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/03/2020] [Accepted: 11/04/2020] [Indexed: 01/02/2023] Open
Abstract
Metabolic flux analysis (MFA) is an increasingly important tool to study metabolism quantitatively. Unlike the concentrations of metabolites, the fluxes, which are the rates at which intracellular metabolites interconvert, are not directly measurable. MFA uses stable isotope labeled tracers to reveal information related to the fluxes. The conceptual idea of MFA is that in tracer experiments the isotope labeling patterns of intracellular metabolites are determined by the fluxes, therefore by measuring the labeling patterns we can infer the fluxes in the network. In this review, we will discuss the basic concept of MFA using a simplified upper glycolysis network as an example. We will show how the fluxes are reflected in the isotope labeling patterns. The central idea we wish to deliver is that under metabolic and isotopic steady-state the labeling pattern of a metabolite is the flux-weighted average of the substrates’ labeling patterns. As a result, MFA can tell the relative contributions of converging metabolic pathways only when these pathways make substrates in different labeling patterns for the shared product. This is the fundamental principle guiding the design of isotope labeling experiment for MFA including tracer selection. In addition, we will also discuss the basic biochemical assumptions of MFA, and we will show the flux-solving procedure and result evaluation. Finally, we will highlight the link between isotopically stationary and nonstationary flux analysis.
Collapse
Affiliation(s)
- Yujue Wang
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA; (Y.W.); (F.E.W.)
- Metabolomics Shared Resource, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
| | - Fredric E. Wondisford
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA; (Y.W.); (F.E.W.)
| | - Chi Song
- Division of Biostatistics, College of Public Health, The Ohio State University, Columbus, OH 43210, USA;
| | - Teng Zhang
- Department of Mathematics, University of Central Florida, Orlando, FL 32816, USA;
| | - Xiaoyang Su
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ 08901, USA; (Y.W.); (F.E.W.)
- Metabolomics Shared Resource, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08903, USA
- Correspondence: ; Tel.: +1-732-235-5447
| |
Collapse
|
7
|
Leukes V, Walzl G, du Plessis N. Myeloid-Derived Suppressor Cells as Target of Phosphodiesterase-5 Inhibitors in Host-Directed Therapeutics for Tuberculosis. Front Immunol 2020; 11:451. [PMID: 32269568 PMCID: PMC7109258 DOI: 10.3389/fimmu.2020.00451] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/27/2020] [Indexed: 01/11/2023] Open
Abstract
Resistance toward current and new classes of anti-tuberculosis (anti-TB) antibiotics are rapidly emerging; thus, innovative therapies focused on host processes, termed host-directed therapies (HDTs), are promising novel approaches for shortening therapy regimens without inducing drug resistance. Development of new TB drugs is lengthy and expensive, and success is not guaranteed; thus, alternatives are needed. Repurposed drugs have already passed Food and Drug Administration (FDA) as well as European Medicines Agency (EMA) safety requirements and may only need to prove efficacy against Mycobacterium tuberculosis (M.tb). Phosphodiesterases (PDEs) hydrolyze the catalytic breakdown of both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) to their inactive mononucleotides. Advances in molecular pharmacology have identified 11 PDE families; and the success of sildenafil, a PDE-5 selective inhibitor (PDE-5i), in treating pulmonary hypertension and erectile dysfunction has invigorated research into the therapeutic potential of selective PDE inhibitors in other conditions. Myeloid-derived suppressor cells (MDSCs) suppress anti-TB T-cell responses, likely contributing to TB disease progression. PDE-5i increases cGMP within MDSC resulting in the downregulation of arginase-1 (ARG1) and nitric oxide synthase 2 (NOS2), reducing MDSC's suppressive potential. The effect of this reduction decreases MDSC-induced T-cell-suppressive mechanisms. This review highlights the possibility of HDT targeting of MDSC, using a PDE-5i in combination with the current TB regimen, resulting in improved TB treatment efficacy.
Collapse
Affiliation(s)
- Vinzeigh Leukes
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
| | - Gerhard Walzl
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
| | - Nelita du Plessis
- Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, DST-NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council for Tuberculosis Research, Stellenbosch University, Cape Town, South Africa
| |
Collapse
|
8
|
El‐Wakeel LM, Fouad FA, Saleem MD, Saber‐Khalaf M. Efficacy and tolerability of sildenafil/
l
‐arginine combination relative to sildenafil alone in patients with organic erectile dysfunction. Andrology 2019; 8:143-147. [DOI: 10.1111/andr.12671] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 03/26/2019] [Accepted: 05/28/2019] [Indexed: 11/26/2022]
Affiliation(s)
| | - F. A. Fouad
- Faculty of Pharmacy Ain Shams University Cairo Egypt
| | - M. D. Saleem
- Department of Urology Sohag University Hospital Sohag University Sohag Egypt
| | - M. Saber‐Khalaf
- Department of Urology Sohag University Hospital Sohag University Sohag Egypt
| |
Collapse
|
9
|
Huo C, Wu H, Xiao J, Meng D, Zou S, Wang M, Qi P, Tian H, Hu Y. Genomic and Bioinformatic Characterization of Mouse Mast Cells (P815) Upon Different Influenza A Virus (H1N1, H5N1, and H7N2) Infections. Front Genet 2019; 10:595. [PMID: 31281330 PMCID: PMC6598080 DOI: 10.3389/fgene.2019.00595] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/05/2019] [Indexed: 12/14/2022] Open
Abstract
Influenza A virus (IAV) is a segmented negative-stranded RNA virus that brings a potentially serious threat to public health and animal husbandry. Mast cells play an important role in both the inherent and adaptive immune response. Previous studies have indicated that mast cells support the productive replication of H1N1, H5N1, and H7N2. To date, the distinct molecular mechanism behind the pathogenesis in mast cells among the three different viruses has been poorly understood. In this study, we investigated the genomic profiles in detail and the dynamic change of genomes regulated by different subtypes of IAV in mouse mast cells using microassays. Compared with any two of the three IAV-infected groups, many more differentially expressed genes (DEGs), cellular functions, and signaling pathways were confirmed in H1N1 or H7N2 group, with the H7N2 group showing the highest levels. However, few DEGs were detected and various cellular functions and signaling pathways were dramatically suppressed in the H5N1 group. With an in-depth study on the H1N1 and H7N2 groups, we demonstrated the essential role of the 5-HT signaling pathway and the cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG) signaling pathway, which were preferentially activated in P815 cells infected by H1N1, and the crucial role of the HIF-1 signaling pathway that was preferentially activated in P815 cells infected by the H7N2 virus. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) results showed significantly increased mRNA levels of 5-HT and PKG in H1N1-infected P815 cells and increased HIF-1 in H7N2-infected P815 cells. In addition, exosomes were preferentially secreted from H1N1-infected or H7N2-infected P815 cells and are potentially pivotal in innate immunity to fight IAV infection. This study provides novel information and insight into the distinct molecular mechanism of H1N1, H5N1, and H7N2 viruses in mast cells from the perspective of genomic profiles.
Collapse
Affiliation(s)
- Caiyun Huo
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hongping Wu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jin Xiao
- Key Laboratory of Veterinary Bioproduction and Chemical Medicine of the Ministry of Agriculture, Zhongmu Institutes of China Animal Husbandry Industry Co., Ltd, Beijing, China
| | - Di Meng
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Shumei Zou
- Key Laboratory for Medical Virology, National Health and Family Planning Commission, Collaboration Innovation Center for Diagnosis and Treatment of Infectious Diseases, Chinese Center for Disease Control and Prevention, National Institute for Viral Disease Control and Prevention, Beijing, China
| | - Ming Wang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Veterinary Bioproduction and Chemical Medicine of the Ministry of Agriculture, Zhongmu Institutes of China Animal Husbandry Industry Co., Ltd, Beijing, China
| | - Peng Qi
- Key Laboratory of Veterinary Bioproduction and Chemical Medicine of the Ministry of Agriculture, Zhongmu Institutes of China Animal Husbandry Industry Co., Ltd, Beijing, China
| | - Haiyan Tian
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yanxin Hu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| |
Collapse
|
10
|
Zainol M, Sidi H, Kumar J, Das S, Ismail SB, Hatta MH, Baharuddin N, Ravindran A. Co-Morbid Erectile Dysfunction (ED) and Antidepressant Treatment in a Patient – A Management Challenge? Curr Drug Targets 2018; 20:182-191. [DOI: 10.2174/1389450118666170315110902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 01/06/2017] [Accepted: 01/18/2017] [Indexed: 11/22/2022]
Abstract
Throughout the world, antidepressants (AD) and phosphodiesterase-5 inhibitors (PDE-5i) are the commonly prescribed psychopharmacological agents for treating patients with co-morbid mental health problem and sexual dysfunction (SD). The serotonergic and noradrenergic ADs, although effective, are not without any SD adverse-effects, especially erectile dysfunction (ED). ED is a failure to obtain a satisfactory erection for rewarding sexual coitus during the phases of male’s sexual arousal. It is recognized as an important reason why non-adherence to treatment was observed in patients who were on AD. AD intervention caused remission to some of the pre- treatment psychopathology of ED. However, in many patients, AD potentially magnified the unwanted sexual sideeffects. This made the situation challenging for the mental health professional. These challenges are based on the complexity of ED, its etiology and the associated risk factors, which further add to its AD side-effect. The neuro-psychopharmacological basis for AD treatment selection was deliberated. Bio-psycho-social interventions are recommended at two pivotal stages. Firstly, a step should be taken for proper assessment (e.g. detailed history, psychosocial and laboratory investigations); and identify few modifiable risk factors for ED and associated mental health issues. Secondly, with guidance of an algorithm pathway, a practical intervention should include strategies such as dose reduction, augmentation or changing to an AD with lesser or no sexual adverse-effects. It is recommended that bupropion and mirtazepine to be prescribed when patients develop adverse sexual effects with serotonin selective reuptake inhibitor (SSRI), serotonin norepinephrine reuptake inhibitor (SNRI) and tricyclic antidepressant (TCA). Few suggestions which may be borne in mind are revising sexual scripts and improving sexual techniques, life-style modifications, psychotherapy and other nonpharmacological approaches which may be beneficial to both patients and their partners.
Collapse
Affiliation(s)
- Maszaidi Zainol
- Department of Psychiatry, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Hatta Sidi
- Department of Psychiatry, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Srijit Das
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Shaiful Bahari Ismail
- Department of Family Medicine, School of Medicine, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | | | - Najwa Baharuddin
- Department of Psychiatry, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, 56000 Cheras, Kuala Lumpur, Malaysia
| | - Arun Ravindran
- Department of Psychiatry, University of Toronto, Ontario, Canada
| |
Collapse
|
11
|
Brennan LJ, Goulopoulou S, Bourque SL. Prenatal therapeutics and programming of cardiovascular function. Pharmacol Res 2018; 139:261-272. [PMID: 30458216 DOI: 10.1016/j.phrs.2018.11.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 01/08/2023]
Abstract
Cardiovascular diseases (CVD) are a leading cause of mortality worldwide. Despite recognizing the importance of risk factors in dictating CVD susceptibility and onset, patient treatment remains a challenging endeavor. Increasingly, the benefits of prevention and mitigation of risk factors earlier in life are being acknowledged. The developmental origins of health and disease posits that insults during specific periods of development can influence long-term health outcomes; this occurs because the developing organism is highly plastic, and hence vulnerable to environmental perturbations. By extension, targeted therapeutics instituted during critical periods of development may confer long-term protection, and thus reduce the risk of CVD in later life. This review provides a brief overview of models of developmental programming, and then discusses the impact of perinatal therapeutic interventions on long-term cardiovascular function in the offspring. The discussion focuses on bioactive food components, as well as pharmacological agents currently approved for use in pregnancy; in short, those agents most likely to be used in pregnancy and early childhood.
Collapse
Affiliation(s)
- Lesley J Brennan
- Department of Anesthesiology & Pain Medicine, Pharmacology, and Pediatrics, Women and Children's Health Research Institute, University of Alberta, Canada.
| | - Styliani Goulopoulou
- Department of Physiology and Anatomy, University of North Texas Health Science Center, United States.
| | - Stephane L Bourque
- Department of Anesthesiology & Pain Medicine, Pharmacology, and Pediatrics, Women and Children's Health Research Institute, University of Alberta, Canada.
| |
Collapse
|
12
|
Ibrahim A, Ali M, Kiernan TJ, Stack AG. Erectile Dysfunction and Ischaemic Heart Disease. Eur Cardiol 2018; 13:98-103. [PMID: 30697353 DOI: 10.15420/ecr.2017.21.3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Erectile dysfunction (ED) is a common disorder that affects the quality of life of many patients. It is prevalent in more than half of males aged over 60 years. Increasing evidence suggests that ED is predominantly a vascular disorder. Endothelial dysfunction seems to be the common pathological process causing ED. Many common risk factors for atherosclerosis such as diabetes, hypertension, smoking, obesity and hyperlipidaemia are prevalent in patients with ED and so management of these common cardiovascular risk factors can potentially prevent ED. Phosphodiesterase type 5 inhibitors provide short-term change of haemodynamic factors to help initiate and maintain penile erection. They have been shown to be an effective and safe treatment strategy for ED in patients with heart disease, including those with ischaemic heart disease and hypertension.
Collapse
Affiliation(s)
- Abdalla Ibrahim
- Cardiology Department, University Hospital Limerick Limerick, Ireland
| | - Mohamed Ali
- Cardiology Department, St James's Hospital Dublin, Ireland
| | - Thomas J Kiernan
- Cardiology Department, University Hospital Limerick Limerick, Ireland
| | - Austin G Stack
- Division of Nephrology, University Hospital Limerick Limerick, Ireland
| |
Collapse
|
13
|
El-Sisi AE, Sokar SS, Abu-Risha SE, Ibrahim HA. Combination of tadalafil and diltiazem attenuates renal ischemia reperfusion-induced acute renal failure in rats. Biomed Pharmacother 2016; 84:861-869. [DOI: 10.1016/j.biopha.2016.10.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/27/2016] [Accepted: 10/03/2016] [Indexed: 12/24/2022] Open
|
14
|
Sikandaner HE, Park SY, Kim MJ, Park SN, Yang DW. Neuroprotective effects of sildenafil against oxidative stress and memory dysfunction in mice exposed to noise stress. Behav Brain Res 2016; 319:37-47. [PMID: 27836585 DOI: 10.1016/j.bbr.2016.10.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/27/2016] [Accepted: 10/28/2016] [Indexed: 12/13/2022]
Abstract
Noise exposure has been well characterized as an environmental stressor, and is known to have auditory and non-auditory effects. Phosphodiesterase 5 (PDE5) inhibitors affect memory and hippocampus plasticity through various signaling cascades which are regulated by cGMP. In this study, we investigated the effects of sildenafil on memory deficiency, neuroprotection and oxidative stress in mice caused by chronic noise exposure. Mice were exposed to noise for 4h every day up to 14days at 110dB SPL of noise level. Sildenafil (15mg/kg) was orally administered 30min before noise exposure for 14days. Behavioral assessments were performed using novel object recognition (NOR) test and radial arm maze (RAM) test. Higher levels of memory dysfunction and oxidative stress were observed in noise alone-induced mice compared to control group. Interestingly, sildenafil administration increased memory performance, decreased oxidative stress, and increased neuroprotection in the hippocampus region of noise alone-induced mice likely through affecting memory related pathways such as cGMP/PKG/CREB and p25/CDK5, and induction of free radical scavengers such as SOD1, SOD2, SOD3, Prdx5, and catalase in the brain of stressed mice.
Collapse
Affiliation(s)
- Hu Erxidan Sikandaner
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - So Young Park
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Min Jung Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Shi Nae Park
- Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| | - Dong Won Yang
- Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| |
Collapse
|
15
|
Xuan XJ, Bai G, Zhang CX, Xu C, Lu FD, Peng Y, Ma G, Han CH, Chen J. The application of color Doppler flow imaging in the diagnosis and therapeutic effect evaluation of erectile dysfunction. Asian J Androl 2016; 18:118-22. [PMID: 25994651 PMCID: PMC4736339 DOI: 10.4103/1008-682x.155533] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
We aim to investigate the correlations between hemodynamic parameters, penile rigidity grading, and the therapeutic effects of phosphodiesterase type 5 inhibitors using color Doppler flow imaging after intracavernosal injection in patients with erectile dysfunction. This study involved 164 patients. After intracavernosal injection with a mixture of papaverine (60 mg), prostaglandin E 1 (10 mg), and lidocaine (2%, 0.5-1 ml), the penile vessels were assessed using color Doppler flow imaging. Penile rigidity was classified based on the Erection Hardness Score system as Grades 4, 3, 2 or 1 (corresponding to Schramek Grades V to II). Then, the patients were given oral sildenafil (50-100 mg) and scored according to the International Index of Erectile Function (IIEF-5) questionnaire. The number of patients with penile rigidities of Schramek Grades II to V was 14, 18, 21, and 111, respectively. The IIEF-5 score was positively correlated with the refilling index of the penile cavernosal artery (r = 0.79, P< 0.05), the peak systolic velocity (r = 0.45, P< 0.05), and penile rigidity (r = 0.75, P< 0.05), and was negatively correlated with the end diastolic velocity (r = -0.74, P< 0.05). For patients with erectile dysfunction, both the IIEF-5 score after sildenafil administration, which is correlated with penile rigidity, and the hemodynamic parameters detected using color Doppler flow imaging may predict the effects of phosphodiesterase type 5 inhibitor treatment and could provide a reasonable model for the targeted-treatment of erectile dysfunction.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Cong-Hui Han
- Department of Urology, The Affiliated School of Clinical Medicine, Xuzhou Medical College, Xuzhou, China
| | - Jun Chen
- Department of Infertility and Sexual Medicine, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
| |
Collapse
|
16
|
El-Mahdy NA, El-Sayad MES, El-Kadem AH. Combination of telmisartan with sildenafil ameliorate progression of diabetic nephropathy in streptozotocin-induced diabetic model. Biomed Pharmacother 2016; 81:136-144. [DOI: 10.1016/j.biopha.2016.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 03/31/2016] [Accepted: 04/01/2016] [Indexed: 02/07/2023] Open
|
17
|
Smith-Harrison LI, Patel A, Smith RP. The devil is in the details: an analysis of the subtleties between phosphodiesterase inhibitors for erectile dysfunction. Transl Androl Urol 2016; 5:181-6. [PMID: 27141444 PMCID: PMC4837309 DOI: 10.21037/tau.2016.03.01] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Erectile dysfunction (ED) is a common sexual disorder with numerous etiologies involving multiple organ systems that leads to significant distress and decreased quality of life for the affected men. Fortunately, there are several modalities and interventions for treating ED. Oral medications, intra-urethral compounds, intracorporeal injections, vacuum-assist devices and surgically implanted prostheses are all part of the treatment algorithm. One of the first-lines and certainly the most widely used options for treating ED is the family of oral phosphodiesterase type 5 inhibitors (PDE5I). The introduction of these medications in the late 1990s revolutionized the field of sexual medicine. Currently there are no guidelines and minimal literature to help providers choose among drugs in this class. This review will address differences in efficacy and side effects between various members of the oral selective phosphodiesterase-5 inhibitor class of drugs.
Collapse
Affiliation(s)
- L I Smith-Harrison
- Department of Urology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Abhishek Patel
- Department of Urology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Ryan P Smith
- Department of Urology, University of Virginia Health System, Charlottesville, VA 22908, USA
| |
Collapse
|
18
|
Kakigano A, Tomimatsu T, Mimura K, Kanayama T, Fujita S, Minato K, Kumasawa K, Taniguchi Y, Kanagawa T, Endo M, Ishihara T, Namba T, Mizushima T, Kimura T. Drug Repositioning for Preeclampsia Therapeutics by In Vitro Screening: Phosphodiesterase-5 Inhibitor Vardenafil Restores Endothelial Dysfunction via Induction of Placental Growth Factor. Reprod Sci 2015; 22:1272-80. [PMID: 25736325 DOI: 10.1177/1933719115574340] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We screened a library of 528 approved drugs to identify candidate compounds with therapeutic potential as preeclampsia treatments via their proangiogenic properties. Using human umbilical vein endothelial cells (HUVECs), we assessed whether the screened drugs induced placental growth factor (PIGF) and restored damaged endothelial cell function. Enzyme-linked immunosorbent assays (ELISAs) were carried out to measure levels of PlGF in conditioned media treated with each drug (100 µmol/L) in the drug library. Tube formation assays were performed using HUVECs to evaluate the angiogenic effects of drugs that induced PlGF. We also performed ELISA, quantitative reverse transcription polymerase chain reaction, and tube formation assays after treatment with a range of concentrations of the candidate drug. Of the drugs that induced PlGF, vardenafil was the only compound that significantly facilitated tube formation in comparison with the control cells (P < .01). Treatment with vardenafil at concentrations of 50, 100, and 250 µmol/L increased expression of PlGF in a dose-dependent manner. Vardenafil (250 µmol/L) significantly improved tube formation which was inhibited in the presence of soluble fms-like tyrosine kinase 1 (100 ng/mL) and/or soluble endoglin (100 ng/mL). Production of PlGF from HUVECs in the presence of sera derived from patients with preeclampsia was significantly elevated by administration of vardenafil (250 µmol/L). By assessing drug repositioning through screening a library of approved drugs, we identified vardenafil as a potential protective agent against preeclampsia. The therapeutic mechanism of vardenafil may involve inhibition of the systemic maternal antiangiogenic state that leads to preeclampsia, in addition to its vasodilating effect. As concentrations used are high and unlikely to be useful clinically, further work is needed before testing it in humans.
Collapse
Affiliation(s)
- Aiko Kakigano
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Takuji Tomimatsu
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kazuya Mimura
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tomoko Kanayama
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Satoko Fujita
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Kenji Minato
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Keiichi Kumasawa
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Yukiko Taniguchi
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Takeshi Kanagawa
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Masayuki Endo
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | | | - Takushi Namba
- Science Research Center, Kochi University, Kochi, Japan
| | | | - Tadashi Kimura
- Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| |
Collapse
|
19
|
Senturk S, Gurcay AG, Bozkurt I, Gurcan O, Eroglu H, Turkoglu OF, Bodur E, Bavbek M. Effects of tadalafil-Type-V phosphodiesterase enzyme inhibitor-On rats with spinal trauma. Br J Neurosurg 2014; 29:254-9. [PMID: 25380483 DOI: 10.3109/02688697.2014.976174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In this research, the effect of tadalafil, a selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5, on rats with spinal trauma was evaluated. The evaluation consisted of neurological examination and biochemical parameters. Twenty healthy male Wistar albino rats were used in this study. They were separated into three groups: tadalafil-receiving (TD) group (n=7), laminectomy and trauma (LT) group (n=7), and just laminectomy group (n=6). The TD group received daily dose of tadalafil (10 mg/kg) for a week along with bait and water. Each rat's spinal cord was dissected with utter caution. The spinal cord was traumatized by Allen's weight-drop method. Using a standard apparatus, 5 g of weight was dropped from a height of 10 cm on the spinal cords of the TD and LT (laminectomy+trauma) group. No extra maneuvers were conducted on the laminectomy group. A day later, the rat's functional neurological status was examined followed by re-exploration of the spinal cord for sampling 1 cm of tissue. The Tarlov scale was used to evaluate the functional neurological status. The modified Tarlov scale was rated to be significantly higher in the TD group than that in the LT group. For the biochemical parameters, malondialdehyde (MDA) and cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) involved in the inflammatory process were examined. MDA--an indicator of lipid peroxidation--was found to be significantly lower in the TD group compared with that in the LT group. TNF-α and IL-6 levels were also found to be lower in the TD group compared with those in the LT group. Shortly, this research showed that the use of TD group in spinal trauma resulted in better neurological outcome and significant improvement in biochemical parameters.
Collapse
Affiliation(s)
- Salim Senturk
- Department of Neurosurgery, Hitit University Corum Training and Research Hospital , Corum , Turkey
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Butrous G. The role of phosphodiesterase inhibitors in the management of pulmonary vascular diseases. Glob Cardiol Sci Pract 2014; 2014:257-90. [PMID: 25780785 PMCID: PMC4352681 DOI: 10.5339/gcsp.2014.42] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 09/11/2014] [Indexed: 01/07/2023] Open
Abstract
Phosphodiesterase inhibitors (PDE) can be used as therapeutic agents for various diseases such as dementia, depression, schizophrenia and erectile dysfunction in men, as well as congestive heart failure, chronic obstructive pulmonary disease, rheumatoid arthritis, other inflammatory diseases, diabetes and various other conditions. In this review we will concentrate on one type of PDE, mainly PDE5 and its role in pulmonary vascular diseases.
Collapse
|
21
|
Effects of tadalafil on ischemia/reperfusion injury in rat brain. Acta Neurol Belg 2014; 114:33-40. [PMID: 23918637 DOI: 10.1007/s13760-013-0234-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 07/17/2013] [Indexed: 10/26/2022]
Abstract
Cerebral ischemia-reperfusion (I/R) injury is caused by lack of blood supply to the brain. The accumulation of toxic products such as reactive oxygen species (ROS) occurs on reperfusion, when the occlusion is removed. The resulting oxidative stress results in the initiation of pathways leading to necrotic and apoptotic cell death. Tadalafil (TAD) prevents the accumulation of ROS and increases antioxidant cellular protective mechanisms. The aim of this study was to investigate the effect of TAD treatment against short-term global brain I/R injury in rats. The study was carried out on 30 Wistar-albino rats, which were divided into three groups including a control group (n = 10), an I/R group (n = 10) and an I/R + TAD group (n = 10) (2 mg/kg/day for 4 days before ischemia). At the end of the experiment, tissue samples were collected for both biochemical and histopathological analyses. Malondialdehyde was significantly lower in the TAD-administered group (9.06 ± 0.15) than in the I/R group (p < 0.05). However, no significant difference was observed in nitric oxide levels in the TAD-administered group compared to the I/R group. The mean superoxide dismutase level was significantly higher in the I/R-TAD group than the I/R group. There was no statistically significant difference in glutathione peroxidase levels in I/R + TAD group compared to I/R group. Histopathologically, TAD-administered group provided significant morphological improvement compared to the I/R group. We concluded that TAD prevented I/R-induced neurotoxicity as shown by obtained biochemical and histopathological findings.
Collapse
|
22
|
Lasker GF, Pankey EA, Kadowitz PJ. Modulation of soluble guanylate cyclase for the treatment of erectile dysfunction. Physiology (Bethesda) 2013; 28:262-9. [PMID: 23817801 DOI: 10.1152/physiol.00001.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Nitric oxide (NO) is the principal mediator of penile erection, and PDE-5 inhibitors are the first-line agents used to treat erectile dysfunction (ED). When NO formation or bioavailability is decreased by oxidative stress and PDE-5 inhibitors are no longer effective, a new class of agents called soluble guanylate cyclase (sGC) stimulators like BAY 41-8543 will induce erection. sGC stimulators bind to the normally reduced, NO-sensitive form of sGC to increase cGMP formation and promote erection. The sGC stimulators produce normal erectile responses when NO formation is inhibited and the nerves innervating the corpora cavernosa are damaged. However, with severe oxidative stress, the heme iron on sGC can be oxidized, rendering the enzyme unresponsive to NO or sGC stimulators. In this pathophysiological situation, another newly developed class of agents called sGC activators can increase the catalytic activity of the oxidized enzyme, increase cGMP formation, and promote erection. The use of newer agents that stimulate or activate sGC to promote erection and treat ED is discussed in this brief review article.
Collapse
Affiliation(s)
- George F Lasker
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | | | | |
Collapse
|
23
|
Erectile dysfunction medication induced-changes in plasma levels of homocysteine and antioxidant enzyme activities as risk factors for cardiovascular disease. J Taibah Univ Med Sci 2013. [DOI: 10.1016/j.jtumed.2013.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
24
|
Treatments for fibrosis of the corpora cavernosa. Arab J Urol 2013; 11:294-8. [PMID: 26558095 PMCID: PMC4443017 DOI: 10.1016/j.aju.2013.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Revised: 05/28/2013] [Accepted: 05/30/2013] [Indexed: 01/22/2023] Open
Abstract
Introduction Corporal fibrosis usually occurs after explantation of an infected penile prosthesis, severe penile trauma, refractory low-flow priapism, Peyronie’s disease, or the chronic intracavernous injection of vasoactive drugs. Methods We analysed current treatmentss for penile fibrosis. We searched PubMed using the keywords ’penile corporal fibrosis’, ’treatment’ and ’penile fibrosis’, resulting in 63 matches, of which 19 articles met the inclusion criteria. Results and conclusions This review covers conservative medical therapy for corporal fibrosis and surgical therapeutic methods. The roles of phosphodiesterase- 5 inhibitors and pentoxifylline are analysed. Surgical therapy includes implantation of a penile prosthesis and corporal reconstruction, and these are reviewed. Corporal fibrosis is a major problem for patients, and is associated with severe erectile dysfunction. Conservative treatment options can be applicable in the early phase, but simultaneous corporal reconstruction procedures with concomitant implantation of a penile prosthesis should be attempted in severe cases of corporal fibrosis.
Collapse
|
25
|
Lasker GF, Pankey EA, Allain AV, Murthy SN, Stasch JP, Kadowitz PJ. The selective Rho-kinase inhibitor azaindole-1 has long-lasting erectile activity in the rat. Urology 2013; 81:465.e7-14. [PMID: 23374844 DOI: 10.1016/j.urology.2012.10.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/11/2012] [Accepted: 10/24/2012] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To investigate the effects of the selective Rho-associated protein kinase (ROCK) inhibitor azaindole-1 on erectile function under physiologic and pathophysiologic conditions in the rat. METHODS The effect of intracavernosal (i.c.) injections of azaindole-1 on change in intracavernous pressure (ICP), ICP/mean arterial pressure (MAP), area under the curve (AUC), and response duration were investigated in the anesthetized rat under control conditions and when nonadrenergic noncholinergic neurotransmission and cholinergic function or soluble guanylyl cyclase (sGC) were inhibited or after cavernosal nerve crush injury. RESULTS The i.c. injections of azaindole-1 produced dose-related increases in ICP/MAP and AUC that were long-lasting at the highest doses studied compared with the prototypical ROCK inhibitor fasudil. Erectile responses were not altered by 7-nitroindazole and atropine in doses that reduced the response to cavernosal nerve stimulation by 86%, indicating that they were independent of NO release by cavernosal nerves or activation of muscarinic receptors in the corpora cavernosa. Erectile responses to azaindole-1 were not altered by the sGC inhibitor ODQ in a dose that attenuated responses to the NO donor sodium nitroprusside, indicating that they were independent of an action on sGC. The erectile response to i.c. injections of azaindole-1 or Y-27632, which was reported to be NO/cyclic guanosine monophosphate-dependent, was not attenuated after cavernosal nerve crush injury. CONCLUSION The present studies indicate that azaindole-1 has long-lasting erectile activity that is independent of NO release, muscarinic receptor, or sGC activation or the integrity of the cavernosal nerves.
Collapse
Affiliation(s)
- George F Lasker
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana 70112-2699, USA
| | | | | | | | | | | |
Collapse
|
26
|
Potential effects of yohimbine and sildenafil on erectile dysfunction in rats. Eur J Pharmacol 2013; 700:127-33. [DOI: 10.1016/j.ejphar.2012.12.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 12/14/2012] [Accepted: 12/19/2012] [Indexed: 11/21/2022]
|
27
|
Cyclic AMP-dependent phosphorylation of neuronal nitric oxide synthase mediates penile erection. Proc Natl Acad Sci U S A 2012; 109:16624-9. [PMID: 23012472 DOI: 10.1073/pnas.1213790109] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Nitric oxide (NO) generated by neuronal NO synthase (nNOS) initiates penile erection, but has not been thought to participate in the sustained erection required for normal sexual performance. We now show that cAMP-dependent phosphorylation of nNOS mediates erectile physiology, including sustained erection. nNOS is phosphorylated by cAMP-dependent protein kinase (PKA) at serine(S)1412. Electrical stimulation of the penile innervation increases S1412 phosphorylation that is blocked by PKA inhibitors but not by PI3-kinase/Akt inhibitors. Stimulation of cAMP formation by forskolin also activates nNOS phosphorylation. Sustained penile erection elicited by either intracavernous forskolin injection, or augmented by forskolin during cavernous nerve electrical stimulation, is prevented by the NOS inhibitor L-NAME or in nNOS-deleted mice. Thus, nNOS mediates both initiation and maintenance of penile erection, implying unique approaches for treating erectile dysfunction.
Collapse
|
28
|
Stanley JL, Andersson IJ, Poudel R, Rueda-Clausen CF, Sibley CP, Davidge ST, Baker PN. Sildenafil citrate rescues fetal growth in the catechol-O-methyl transferase knockout mouse model. Hypertension 2012; 59:1021-8. [PMID: 22392899 DOI: 10.1161/hypertensionaha.111.186270] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Preeclampsia and fetal growth restriction are responsible for the majority of maternal and perinatal morbidity and mortality associated with complicated pregnancies. Although their etiologies are complex and multifactorial, both are associated with increased uterine artery resistance. Sildenafil citrate is able to rescue the dysfunction observed ex vivo in uterine arteries of women with preeclampsia. The ability of sildenafil citrate to increase uterine artery vasodilation, thereby decreasing uterine artery resistance and, hence, ameliorated preeclampsia and fetal growth restriction, was tested in a mouse model of preeclampsia, the catechol-O-methyl transferase knockout mouse (COMT(-/-)). COMT(-/-) and C57BL/6J mice were treated (0.2 mg/mL in drinking water, n=6-12) from gestational day 12.5 to 18.5. Measures of pup growth, including body weight, crown/rump length, and abdominal circumference, were reduced in COMT(-/-) mice; this was normalized after treatment with Sildenafil. COMT(-/-) mice also demonstrated abnormal umbilical Doppler waveforms, including reverse arterial blood flow velocity. This was normalized after treatment with Sildenafil. Abnormal uterine artery Doppler waveforms were not demonstrated in COMT(-/-) mice, although ex vivo responses of uterine arteries to phenylephrine were increased; moreover, treatment with Sildenafil did improve ex vivo sensitivity to an endothelium-dependent vasodilator. The data presented here demonstrate that Sildenafil can rescue pup growth and improve abnormal umbilical Doppler waveforms, providing support for a potential new therapeutic strategy targeting fetal growth restriction.
Collapse
Affiliation(s)
- Joanna L Stanley
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada.
| | | | | | | | | | | | | |
Collapse
|
29
|
Kuno Y, Iyoda M, Shibata T, Hirai Y, Akizawa T. Sildenafil, a phosphodiesterase type 5 inhibitor, attenuates diabetic nephropathy in non-insulin-dependent Otsuka Long-Evans Tokushima Fatty rats. Br J Pharmacol 2011; 162:1389-400. [PMID: 21133896 DOI: 10.1111/j.1476-5381.2010.01149.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND It is well established that the pathogenesis of diabetic nephropathy is associated with abnormalities of renal nitric oxide (NO) generation. Many of the biological actions of NO are mediated by cGMP, which is rapidly degraded by phosphodiesterases. In this study, we evaluated the renoprotective effects of sildenafil (SIL), an inhibitor of phosphodiesterase-5, in type 2 diabetic rats. METHODS Male Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a non-insulin-dependent diabetes model, and Long-Evans Tokushima Otsuka rats, a non-diabetic control, were treated with either SIL (2.5 mg·kg(-1) in drinking water) or undosed water for 28 weeks, starting at 30 weeks of age. RESULTS Sildenafil treatment significantly decreased albuminuria, attenuated glomerular hyperfiltration and resulted in a decrease in glomerular hypertrophy, in addition to a reduced glomerulosclerosis score and a dramatic decrease in the number of glomerular and tubulointerstitial proliferating cell nuclear antigen-positive cells in OLETF rats. This was accompanied by a significant reduction in renal cortical mRNA levels of collagen types I and III. The increased mRNA levels of matrix metalloproteinase (MMP)-2, MMP-9, tissue inhibitors of MMPs (TIMP)-1 and TIMP-2 in the OLETF rats were significantly or partially attenuated by SIL treatment. CONCLUSIONS This study suggests that SIL attenuated diabetic nephropathy due to its potent antiproliferative effects and its regulatory effects on extracellular matrix. This latter effect is thought to be a result of its ability to affect the balance between MMPs and their inhibitors.
Collapse
Affiliation(s)
- Yoshihiro Kuno
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan
| | | | | | | | | |
Collapse
|
30
|
Hotston M, Jeremy JY, Persad R, Bloor J, Shukla N. 8-isoprostane F2α up-regulates the expression of type 5 phosphodiesterase in cavernosal vascular smooth muscle cells: inhibition with sildenafil, iloprost, nitric oxide and picotamide. BJU Int 2011; 106:1794-8. [PMID: 20500512 DOI: 10.1111/j.1464-410x.2010.09270.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To explore the possible role of of 8-isoprostane F(2α) (8-IPF(2α) ) in the aetiology of erectile dysfunction (ED), as the over-production of superoxide (O(2)(-)) derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase results in the formation of 8-IPF(2α) in vascular tissue, which has similar properties to thromboxane A(2) (TXA(2) ). TXA(2) is vasoconstrictor and up-regulates the expression of NADPH oxidase and phosphodiesterase type 5 (PDE5). MATERIALS AND METHODS Cavernosal vascular smooth muscle cells (CVSMCs) were incubated with 8-IPF(2α) or the TXA(2) analogue, U46619, ±sildenafil, iloprost (a stable prostacyclin [PGI(2) ] analogue) or the nitric oxide (NO) donor NONOate for 16 h. The formation of O(2)(-) was then measured, PDE5 expression assessed using Western blotting and PGI(2) and 8-IPF(2α) formation measured using enzyme-linked immunoassays. RESULTS 8-IPF(2α) promoted the formation of O(2)(-) , an effect inhibited by apocynin (an NADPH oxidase inhibitor) and up-regulated the expression of PDE5. Under identical incubation conditions, 8-IPF(2α) induced an increase in the formation of 8-IPF(2α) but reduced the formation of PGI(2) . All, these effects were reversed by sildenafil, iloprost, NONOate and picotamide. CONCLUSIONS These data show that O(2) (-) derived from NADPH oxidase influences the relative balance of PGI(2) and 8-IPF(2α) in CVSMCs, which in turn alters the degree of PDE5 expression. This is a novel pathogenic mechanism underlying ED and a novel mechanism of action of sildenafil.
Collapse
Affiliation(s)
- Matthew Hotston
- Department of Urology and Bristol Heart Institute, University of Bristol, Bristol, UK
| | | | | | | | | |
Collapse
|
31
|
Francis SH, Busch JL, Corbin JD, Sibley D. cGMP-dependent protein kinases and cGMP phosphodiesterases in nitric oxide and cGMP action. Pharmacol Rev 2010; 62:525-63. [PMID: 20716671 DOI: 10.1124/pr.110.002907] [Citation(s) in RCA: 687] [Impact Index Per Article: 49.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To date, studies suggest that biological signaling by nitric oxide (NO) is primarily mediated by cGMP, which is synthesized by NO-activated guanylyl cyclases and broken down by cyclic nucleotide phosphodiesterases (PDEs). Effects of cGMP occur through three main groups of cellular targets: cGMP-dependent protein kinases (PKGs), cGMP-gated cation channels, and PDEs. cGMP binding activates PKG, which phosphorylates serines and threonines on many cellular proteins, frequently resulting in changes in activity or function, subcellular localization, or regulatory features. The proteins that are so modified by PKG commonly regulate calcium homeostasis, calcium sensitivity of cellular proteins, platelet activation and adhesion, smooth muscle contraction, cardiac function, gene expression, feedback of the NO-signaling pathway, and other processes. Current therapies that have successfully targeted the NO-signaling pathway include nitrovasodilators (nitroglycerin), PDE5 inhibitors [sildenafil (Viagra and Revatio), vardenafil (Levitra), and tadalafil (Cialis and Adcirca)] for treatment of a number of vascular diseases including angina pectoris, erectile dysfunction, and pulmonary hypertension; the PDE3 inhibitors [cilostazol (Pletal) and milrinone (Primacor)] are used for treatment of intermittent claudication and acute heart failure, respectively. Potential for use of these medications in the treatment of other maladies continues to emerge.
Collapse
Affiliation(s)
- Sharron H Francis
- Department of Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, 2215 Garland Avenue, Nashville, TN 37232-0615, USA.
| | | | | | | |
Collapse
|
32
|
Arikan DC, Bakan V, Kurutas EB, Sayar H, Coskun A. Protective effect of tadalafil on ischemia/reperfusion injury of rat ovary. J Pediatr Surg 2010; 45:2203-9. [PMID: 21034945 DOI: 10.1016/j.jpedsurg.2010.07.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Revised: 07/07/2010] [Accepted: 07/07/2010] [Indexed: 12/17/2022]
Abstract
BACKGROUND/PURPOSE The aim of the study was to evaluate the effects of tadalafil (TDF) on ischemia/reperfusion (I/R) injury in rat ovaries. METHODS Thirty-five female Sprague-Dawley rats were randomly divided into 5 groups (n = 7): sham (S), I/R1, I/R2, TDF1, and TDF2. In the I/R1 and TDF1 groups, 3-hour ischemia was followed by 12-hour reperfusion; and in the I/R2 and TDF2 groups, 3-hour ischemia was followed by 24-hour reperfusion. In the TDF groups, 30 minutes before reperfusion, a single dose of 5 mg/kg TDF was administered intraperitoneally. The ovarian tissue levels of malondialdehyde and nitric oxide (NO), and the activities of superoxide dismutase and catalase were measured biochemically. Tissue damage to ovarian tissue was scored by histopathologic examination. RESULTS The tissue malondialdehyde levels were significantly higher and the catalase and superoxide dismutase activities were significantly lower in the I/R groups compared with the S and TDF groups (P < .05). The NO levels were significantly higher in the TDF1 group than the S and I/R1 groups (P < .05). Although the NO levels were increased in the TDF2 group compared with the I/R2 group, the difference was not significant. Ovarian tissue damage scores of the I/R groups were significantly higher than those of the S group (P < .05). Treatment with TDF significantly decreased the ovarian tissue damage scores in the TDF groups compared with the I/R groups (P < .05). CONCLUSIONS Tadalafil is effective in preventing tissue damage induced by I/R in rat ovaries.
Collapse
Affiliation(s)
- Deniz Cemgil Arikan
- Medical Faculty, Department of Obstetrics and Gynecology, Kahramanmaras Sutcuimam University, Kahramanmaras, Turkey.
| | | | | | | | | |
Collapse
|
33
|
Eardley I, Donatucci C, Corbin J, El-Meliegy A, Hatzimouratidis K, McVary K, Munarriz R, Lee SW. Pharmacotherapy for Erectile Dysfunction. J Sex Med 2010; 7:524-40. [DOI: 10.1111/j.1743-6109.2009.01627.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
34
|
Shukla N, Rossoni G, Hotston M, Sparatore A, Del Soldato P, Tazzari V, Persad R, Angelini GD, Jeremy JY. Effect of hydrogen sulphide-donating sildenafil (ACS6) on erectile function and oxidative stress in rabbit isolated corpus cavernosum and in hypertensive rats. BJU Int 2009; 103:1522-9. [PMID: 19245441 DOI: 10.1111/j.1464-410x.2009.08415.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To study the effect of the H(2)S-donating derivative of sildenafil (ACS6) compared to sildenafil citrate and sodium hydrosulphide (NaHS) on relaxation, superoxide formation and NADPH oxidase and type 5 phosphodiesterase (PDE5) expression in isolated rabbit cavernosal tissue and smooth muscle cells (CSMCs), and in vivo on indices of oxidative stress induced with buthionine sulphoximine (BSO). MATERIALS AND METHODS Relaxation was studied in an organ bath in response to carbachol and after incubation with interleukin-1beta for 12 h. CSMCs were incubated with tumour-necrosis factor-alpha or the thromboxane A(2) (TXA(2)) analogue, U46619, with or with no sildenafil citrate, ACS6 or NaHS for 16 h. Superoxide formation and the expression of p47(phox) (an active subunit of the NADPH oxidase complex) and PDE5 protein was then assessed using Western blotting. Rats were also treated with BSO (with or with no sildenafil citrate or ACS6) for 7 days; cavernosal cGMP, cAMP, glutathionine and plasma TXA(2) and 8-isoprostane F(2alpha) was measured by enzyme-linked immunosorbent assay. RESULTS ACS6 and sildenafil citrate relaxed cavernosal smooth muscle equipotently; NaHS alone had little effect at up to 100 microm. The formation of superoxide and expression of p47(phox) and PDE5 was reduced by ACS6, sildenafil citrate and NaHS (order of potency: ACS6 > sildenafil citrate > NaHS). The effects of ACS6 were blocked by inhibitors of protein kinase A (PKA) and PKG. In rats treated with BSO, both ASC6 and sildenafil citrate reduced the increased plasma levels of TXA(2) and 8-isoprostane F(2alpha) but increased cGMP, cAMP and glutathionine levels in corpus cavernosum. CONCLUSIONS By virtue of a dual action on PKA and PKG activation, ACS6 not only promotes erection, acutely, but might also have a long-term beneficial effect through inhibition of oxidative stress and downregulation of PDE5.
Collapse
|
35
|
Perk H, Armagan A, Naziroğlu M, Soyupek S, Hoscan MB, Sütcü R, Ozorak A, Delibas N. Sildenafil citrate as a phosphodiesterase inhibitor has an antioxidant effect in the blood of men. J Clin Pharm Ther 2009; 33:635-40. [PMID: 19138241 DOI: 10.1111/j.1365-2710.2008.00962.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND AND OBJECTIVE Sildenafil citrate enhances the action of nitric oxide by preventing the hydrolysis of cGMP, and is widely used to treat erectile dysfunction. We investigated the effects of sildenafil citrate administration on lipid peroxidation and antioxidant redox enzymes in blood of healthy men. METHOD Thirty healthy male subjects were divided equally into two groups. The first group was used as the control. A single dose of sildenafil citrate was administrated orally to subjects constituting the second group. Blood samples were obtained at 0, 2, 6 and 24 h after intake of the single dose of 100 mg sildenafil citrate or placebo. RESULTS AND DISCUSSION The dose of sildenafil citrate resulted in significant increase in the erythrocyte superoxide dismutase and catalase activities at 6 and 24 h. Plasma lipid peroxidation levels decreased slightly. There was no statistical difference in erythrocyte glutathione peroxidase activity between the placebo and sildenafil citrate groups. CONCLUSION Treatment of blood with 100 mg sildenafil citrate has protective effects on oxidative stress by inhibiting free radical formation and by supporting antioxidant redox systems.
Collapse
Affiliation(s)
- H Perk
- Department of Urology, Medical Faculty, Suleyman Demirel University, Isparta, Turkey
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Hotston M, Jeremy JY, Bloor J, Greaves NS, Persad R, Angelini G, Shukla N. Homocysteine and copper interact to promote type 5 phosphodiesterase expression in rabbit cavernosal smooth muscle cells. Asian J Androl 2009; 10:905-13. [PMID: 18097500 DOI: 10.1111/j.1745-7262.2008.00380.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIM To study the effects of homocysteine and copper on type 5 phosphodiesterase (PDE5) expression in cavernosal vascular smooth muscle cells (CVSMCs) and to investigate superoxide (O(2)(.-)) derived from nicotinamide adenine dinucleotide phosphate oxidase as homocysteine and copper generate O(2)(.-), and O(2)(.-) upregulates PDE5 expression. METHODS CVSMCs derived from rabbit penis were incubated with homocysteine or copper chloride with or without superoxide dismutase (SOD), catalase, sildenafil citrate, or apocynin (nicotinamide adenine dinucleotide phosphate inhibitor) for 16 h. The expression of PDE5 and of glyceraldehyde-3-phosphate dehydrogenase (internal standard) was assessed using Western blot analysis. In parallel, O(2)(.-) was measured spectrophotometrically. RESULTS CuCl(2) alone (up to 10 micromol/L) and homocysteine alone (up to 100 micromol/L) had no effect on O(2)(.-) formation in CVSMCs compared to controls. In combination, however, homocysteine and CuCl(2) markedly increased O(2)(.-) formation, an effect blocked by SOD, catalase, apocynin, and sildenafil (1 micromol/L) when co-incubated over the same time course. PDE5 expression was also significantly increased in CVSMCs incubated with homocysteine and CuCl(2), compared to controls. This effect was also negated by 16-h co-incubation with SOD, catalase, apocynin and sildenafil. CONCLUSION This represents a novel pathogenic mechanism underlying ED, and indicates that the therapeutic actions of prolonged sildenafil use are mediated in part through inhibition of this pathway.
Collapse
Affiliation(s)
- Matthew Hotston
- Department of Urology, University of Bristol, 13 Freeland Place, Bristol BS8 4NP, UK.
| | | | | | | | | | | | | |
Collapse
|
37
|
Shukla N, Hotston M, Persad R, Angelini GD, Jeremy JY. The administration of folic acid improves erectile function and reduces intracavernosal oxidative stress in the diabetic rabbit. BJU Int 2008; 103:98-103. [PMID: 18778356 DOI: 10.1111/j.1464-410x.2008.07911.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To test the possibility that folic acid (FA) may be a means of treating erectile dysfunction (ED) in diabetes mellitus (DM), by studying the effect of FA administration to DM rabbits on cavernosal function and intrapenile oxidative stress. MATERIALS AND METHODS To investigate the effect of administering FA to DM rabbits on erectile function and oxidative stress the formation of superoxide (O(2)(-)), 8-isoprostane F(2 alpha) (8-IPF(2 alpha)) and prostacyclin (as 6-keto-PGF(1 alpha)) were assessed, as well as carbachol- and electrical field stimulated (EFS) relaxation and p47(phox) content (active component of NADPH oxidase complex). Non-ketotic DM was induced in New Zealand rabbits with alloxan and FA administered orally daily for 1 month. Rabbits were killed, penises excised and segments prepared. These were mounted in an organ bath and relaxation elicited with carbachol or EFS. O(2)(-) release was measured spectrophotometrically, p47(phox) expression by Western blotting and 8-IPF(2 alpha) and 6-keto-PGF(1 alpha) formation by enzyme-linked immunosorbant assay. Blood was collected for measurement of homocysteine, red blood cell (RBC) folate and glucose. RESULTS In cavernosal tissue from DM rabbits, carbachol-and EFS-induced relaxation was significantly impaired compared with the untreated controls. O(2)(-) release, p47(phox) expression and 8-IPF(2 alpha) formation were all enhanced and 6-keto-PGF(1 alpha) formation reduced compared with the controls. All these effects were reversed by FA. Plasma total homocysteine was reduced and RBC folate elevated. CONCLUSIONS The administration of FA may constitute a strategy for reducing ED in patients with DM.
Collapse
Affiliation(s)
- Nilima Shukla
- Department of Cardiac Surgery, Bristol Royal Infirmary, Bristol, UK
| | | | | | | | | |
Collapse
|
38
|
Muzaffar S, Jeremy JY, Sparatore A, Del Soldato P, Angelini GD, Shukla N. H2S-donating sildenafil (ACS6) inhibits superoxide formation and gp91phox expression in arterial endothelial cells: role of protein kinases A and G. Br J Pharmacol 2008; 155:984-94. [PMID: 18846041 DOI: 10.1038/bjp.2008.326] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE Superoxide (O(2)(*-)), derived from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, is associated with acute respiratory distress syndrome (ARDS). NADPH oxidase activity and expression are blocked by nitric oxide (NO) and sildenafil. As another gas, hydrogen sulphide (H(2)S) is formed by blood vessels, the effect of sodium hydrosulphide (NaHS) and the H(2)S-donating derivative of sildenafil, ACS6, on O(2)(*-) formation and the expression of gp91(phox) (a catalytic subunit of NADPH oxidase) in porcine pulmonary arterial endothelial cells (PAECs) was investigated. EXPERIMENTAL APPROACH PAECs were incubated with 10 ng mL(-1) tumour necrosis factor-alpha (TNFalpha) (+/-NaHS or ACS6), both of which released H(2)S, for 2 h or 16 h. O(2)(*-) was measured. Expression of gp91(phox) was measured by western blotting and the role of cyclic AMP (cAMP) and/or cyclic GMP was assessed using protein kinase inhibitors. KEY RESULTS After either 2- or 16-h incubations, O(2)(*-) formation by PAECs was inhibited by NaHS or ACS6, with IC(50) values of about 10 nM and less than 1 nM, respectively. Both 100 nM NaHS and 1 nM ACS6 completely inhibited gp91(phox) expression induced by TNFalpha. The effects of NaHS were blocked by the inhibition of protein kinase A (PKA), but not PKG, and not by the inhibition of guanylyl cyclase. Effects of ACS6 were blocked by inhibition of both PKA and PKG. Both NaHS and ACS6 augmented cAMP formation. CONCLUSION AND IMPLICATIONS H(2)S inhibited O(2)(*-) formation and upregulation of NADPH oxidase in PAECs through the adenylyl cyclase-PKA pathway. ACS6 may be effective in treating ARDS through both elevation of cAMP and inhibition of phosphodiesterase type 5 activity.
Collapse
Affiliation(s)
- S Muzaffar
- Department of Cardiac Surgery, Bristol Royal Infirmary, Bristol Heart Institute, University of Bristol, Bristol, UK.
| | | | | | | | | | | |
Collapse
|
39
|
Pharmacological characterization of a novel phosphodiesterase type 5 (PDE5) inhibitor lodenafil carbonate on human and rabbit corpus cavernosum. Eur J Pharmacol 2008; 591:189-95. [DOI: 10.1016/j.ejphar.2008.06.055] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 06/10/2008] [Accepted: 06/15/2008] [Indexed: 11/22/2022]
|
40
|
Jiang Z, Hu B, Wang J, Tang Q, Tan Y, Xiang J, Liu J. Effect of icariin on cyclic GMP levels and on the mRNA expression of cGMP-binding cGMP-specific phosphodiesterase (PDE5) in penile cavernosum. ACTA ACUST UNITED AC 2008; 26:460-2. [PMID: 17120748 DOI: 10.1007/s11596-006-0421-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
To further investigate the mechanisms of action of icariin (ICA), we assessed the effects of ICA on the in vitro formation of cGMP and cAMP in isolated rabbit corpus cavernosum. Isolated segments of rabbit corpus cavernosum were exposed to increasing concentrations of ICA and the dose-dependent accumulation of cGMP and cAMP was determined in the tissues samples by means of 125I radioimmunoassay. Responses of the isolated tissues preparations to ICA were compared with those obtained with the reference compounds sildenafil (Sild). Furthermore, the effects of ICA on the mRNA expression of specific cGMP-binding phosphodiesterase type V (PDE5) in rat penis were also observed. After incubation with ICA for 6 h or 14 h respectively, the levels of PDE5 mRNA were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that ICA increased cGMP concentrations directly (P < 0.05), but there was no significant effect on cAMP concentrations (P > 0.05). In the presence of sodium nitroprusside (SNP), a stimulatory agent of cGMP, both ICA and Sild increased cGMP concentrations with increasing dose (P < 0.01). Their EC50 was 4.62 (ICA) and 0.42 (Sild) micromol/L respectively. Under the same condition, ICA and Sild unaltered cAMP level significantly (P > 0.05). There were PDE5A1 and PDE5A2 mRNA expressions in rat corpus cavernosum with PDE5A2 being the dominant isoform. ICA could obviously inhibit these two isoforms mRNA expression in rat penis, and decrease PDE5A1 more pronouncedly (P < 0.01). The present study indicated that the aphrodisiac mechanisms of icariin involved the NO-cGMP signal transduction pathway, with increasing cGMP levels in the corpus cavernosum smooth muscle. The inhibitory effect of icariin on PDE5 mRNA expression, especially on PDE5A1, might account for its molecular mechanisms for its long-term activity.
Collapse
Affiliation(s)
- Zhaojian Jiang
- Department of Pharmacology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | | | | | | | | | | | | |
Collapse
|
41
|
The effect of sildenafil on the altered thoracic aorta smooth muscle responses in rat pre-eclampsia model. Eur J Pharmacol 2008; 589:180-7. [PMID: 18538317 DOI: 10.1016/j.ejphar.2008.04.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 03/31/2008] [Accepted: 04/09/2008] [Indexed: 10/22/2022]
Abstract
The pathophysiology of pre-eclampsia is still unknown thus effective primary prevention is not possible at the stage. The present study was conducted to research the smooth muscle responses in the pre-eclampsia model with suramin treated rats and the effect of phosphodiesterase-5 (PDE5) inhibitor on these responses. Rats of three groups; control, suramin and suramin+sildenafil were given intraperitoneal injections of saline, suramin or sildenafil citrate. Suramin injections caused increased blood pressure, protein in urine and caused fetal growth retardation. The use of sildenafil citrate straightened significantly both blood pressure and average fetus weight, but did not reach to control values. At the end of pregnancy, thoracic aorta rings were exposed to contractile and relaxant agents. KCl contraction responses, sodium nitroprusside and papaverine relaxation responses were similar in three groups. Contraction responses of phenylephrine, increased significantly in suramin group. Relaxation responses of acethylcholine and bradykinin decreased in suramin group. The use of sildenafil citrate partially straightened both relaxation and contraction responses, but did not reach to control values. In all groups in the presence of L-nitromonomethylarginine (L-NAME), 1H-(1, 2, 4) oxadiazole (4, 3-a) guinoxalin-1-one (ODQ) and indomethacin decreased the relaxation responses of acetylcholine and bradykinin. The cyclic guanosine monophosphate (cGMP) content of thoracic aorta tissue was determined by radioimmunoassay technique. The content of cGMP in suramin group decreased and use of sildenafil citrate increased the cGMP content but did not reach to control values. We conclude that in pre-eclampsia, the increase of contraction responses, the decrease of relaxation responses and the decrease of cGMP content can depend on insufficiency about synthesis or release of relaxant factors which was released from the vessel endothelium. The results in this study show that in pre-eclampsia; PDE5 inhibitors enhance endothelial function and may be used for protection. Further studies are needed to clear the efficiency and safety of PDE5 inhibitors.
Collapse
|
42
|
Ishikura F, Beppu S, Ueda H, Nehra A, Khandheria BK. Effect of sildenafil citrate (Viagra) on coronary flow in normal subjects. Echocardiography 2008; 25:72-6. [PMID: 18186782 DOI: 10.1111/j.1540-8175.2007.00557.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. METHODS The study assessed mean blood pressure, left anterior descending coronary artery (LAD) flow, and echocardiographic variables before and 30 and 60 minutes after taking 50 mg of sildenafil citrate. The mean velocity of LAD flow was assessed with Doppler flow imaging. The study subjects were 6 healthy male volunteers (mean age 37 years). RESULTS The mean velocity of LAD flow increased 60 minutes after taking sildenafil citrate, but there were no other changes. Two volunteers felt mild flashing and one had mild headache during the study. CONCLUSION Sildenafil citrate caused vasodilatation in a normal coronary artery without systemic pressure drops. These results suggest that the agent itself did not have negative effects on the heart in normal subjects.
Collapse
Affiliation(s)
- Fuminobu Ishikura
- School of Allied Health Sciences, Osaka University, Faculty of Medicine, Osaka, Japan.
| | | | | | | | | |
Collapse
|
43
|
Gratzke C, Uckert S, Reich O, Schlenker B, Tilki D, Seitz M, Stief CG. [PDE5 inhibitors. A new option in the treatment of ureteral colic?]. Urologe A 2008; 46:1219-23. [PMID: 17604974 DOI: 10.1007/s00120-007-1409-3] [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: 11/24/2022]
Abstract
BACKGROUND PDE5 inhibitors represent the gold standard in the medical therapy of erectile dysfunction (ED). Promising results have been published regarding further urological indications such as treatment of ureteral colic. The aim of the present study was to evaluate the functional effects of the PDE5 inhibitors sildenafil (SIL), vardenafil (VAR), and tadalafil (TAD) on tissue tension and cyclic nucleotide levels of human ureteral smooth muscle segments in vitro. METHODS Relaxant responses of human ureteral smooth muscle were investigated in vitro using the organ bath technique. Cyclic nucleotides cAMP and cGMP were determined by specific radioimmunoassays. RESULTS Relaxing effects of ureteral muscle tension were observed in the rank order VAR>SIL>TAD. While only VAR significantly elevated cGMP levels 3.3-fold over control, no increase for cAMP levels was observed. CONCLUSIONS Our data provide evidence that cGMP is involved in the control of the normal function of the smooth musculature of the human ureter. Our findings suggest the potential of using selective inhibitors of PDE isoenzymes in the treatment of ureteral colic.
Collapse
Affiliation(s)
- C Gratzke
- Klinik und Poliklinik für Urologie, Ludwig-Maximilians-Universität, München.
| | | | | | | | | | | | | |
Collapse
|
44
|
Flores Toque HA, Priviero FBM, Teixeira CE, Perissutti E, Fiorino F, Severino B, Frecentese F, Lorenzetti R, Baracat JS, Santagada V, Caliendo G, Antunes E, De Nucci G. Synthesis and pharmacological evaluations of sildenafil analogues for treatment of erectile dysfunction. J Med Chem 2008; 51:2807-15. [PMID: 18393409 DOI: 10.1021/jm701400r] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The 5-[2-ethoxy-5-(4-methylpiperazin-1-ylsulfonyl)phenyl]-1-methyl-3-propyl-1,6-dihydro-7 H-pyrazolo[4,3-d]pyrimidin-7-one, sildenafil, is a cGMP-specific phosphodiesterase-5 (PDE5) inhibitor used for penile erectile dysfunction. In the search for more potent and selective PDE5 inhibitors, new sildenafil analogues (6a-v), characterized by the presence on the sulfonyl group in the 5' position of novel N-4-substituted piperazines or ethylenediamine moiety, were prepared by traditional and microwave-assisted synthesis and tested in rabbit isolated aorta and corpus cavernosum. Similarly to sildenafil, several analogues showed IC50 values in the nanomolar range. In the in vitro studies, all the tested compounds caused concentration-dependent relaxations in both rabbit isolated aorta and corpus cavernosum. All sildenafil analogues potentiated the nitric oxide-dependent vasodilation in endothelium-intact rabbit aorta. Compound 6f exhibited great pEC50 value in corpus cavernosum, and compounds 6r and 6u in isolated aorta were found as potent as sildenafil for inhibiting PDE5. Because several analogues were significantly more lipophilic than sildenafil, these compounds may offer a new lead for development of new sildenafil analogues.
Collapse
Affiliation(s)
- Haroldo A Flores Toque
- Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas, Campinas, Brazil
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Güler C, Tüzel E, Doğantekin E, Kızıltepe G. Does Sildenafil Affect Uroflowmetry Values in Men with Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Enlargement? Urol Int 2008; 80:181-5. [DOI: 10.1159/000112611] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Accepted: 04/27/2007] [Indexed: 11/19/2022]
|
46
|
Biswas KH, Sopory S, Visweswariah SS. The GAF domain of the cGMP-binding, cGMP-specific phosphodiesterase (PDE5) is a sensor and a sink for cGMP. Biochemistry 2008; 47:3534-43. [PMID: 18293931 DOI: 10.1021/bi702025w] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe here a novel sensor for cGMP based on the GAF domain of the cGMP-binding, cGMP-specific phosphodiesterase 5 (PDE5) using bioluminescence resonance energy transfer (BRET). The wild type GAFa domain, capable of binding cGMP with high affinity, and a mutant (GAFa F163A) unable to bind cGMP were cloned as fusions between GFP and Rluc for BRET (2) assays. BRET (2) ratios of the wild type GAFa fusion protein, but not GAFa F163A, increased in the presence of cGMP but not cAMP. Higher basal BRET (2) ratios were observed in cells expressing the wild type GAFa domain than in cells expressing GAFa F163A. This was correlated with elevated basal intracellular levels of cGMP, indicating that the GAF domain could act as a sink for cGMP. The tandem GAF domains in full length PDE5 could also sequester cGMP when the catalytic activity of PDE5 was inhibited. Therefore, these results describe a cGMP sensor utilizing BRET (2) technology and experimentally demonstrate the reservoir of cGMP that can be present in cells that express cGMP-binding GAF domain-containing proteins. PDE5 is the target for the anti-impotence drug sildenafil citrate; therefore, this GAF-BRET (2) sensor could be used for the identification of novel compounds that inhibit cGMP binding to the GAF domain, thereby regulating PDE5 catalytic activity.
Collapse
Affiliation(s)
- Kabir Hassan Biswas
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012, India
| | | | | |
Collapse
|
47
|
Ishikura F, Beppu S, Asanuma T, Seward JB, Khandheria BK. Sildenafil citrate (Viagra) enhances vasodilatation by atrial natriuretic peptide in normal dogs. Circ J 2008; 71:1965-9. [PMID: 18037755 DOI: 10.1253/circj.71.1965] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Sildenafil citrate (Viagra) is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5, which might enhance the vasorelaxant and natriuretic actions of atrial natriuretic peptide (ANP) in patients with heart failure. The objective of this study was to examine the combined effect of Viagra on hemodynamic changes during infusion of exogenous ANP. METHODS AND RESULTS Healthy male beagles were used to assess systemic blood pressure, pulmonary artery pressure (PAP), and plasma levels of cGMP. After hemodynamic variables were measured, 0.1 microg.kg(-1).min(-1) of ANP was given during this study. One hour after initiating infusion of ANP, 2 mg/kg of sildenafil citrate or vehicle was given orally via a nasogastric tube. Hemodynamic changes were measured before and 1 h after these administrations. Mean systemic and PAP decreased during infusion of ANP, and further decreased after sildenafil citrate administration, however, mean systemic blood pressure decreased within 10 mmHg. Plasma levels of cGMP also increased after sildenafil citrate administration. CONCLUSION In normal dogs, sildenafil citrate enhances the vasodilator effect of ANP by increasing the cGMP level, however, the concomitant use of sildenafil citrate with ANP will not induce severe hypotension.
Collapse
Affiliation(s)
- Fuminobu Ishikura
- School of Allied Health Sciences, Faculty of Medicine, Osaka University, Japan.
| | | | | | | | | |
Collapse
|
48
|
|
49
|
Ballester C, Sarriá B, García-Granero E, Morcillo EJ, Lledó S, Cortijo J. Relaxation of the isolated human internal anal sphincter by sildenafil. Br J Surg 2007; 94:894-902. [PMID: 17335124 DOI: 10.1002/bjs.5724] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Hypertonicity of the internal anal sphincter (IAS) appears to be involved in the pathogenesis of anal fissure. The relaxant effects of sildenafil, a selective phosphodiesterase 5 (PDE5) inhibitor, on isolated human IAS were investigated. METHODS The efficacy (maximal effect, E(max)) and potency (-log IC(50), where IC(50) is half-maximal inhibitory concentration) of the PDE5 inhibitors, sildenafil and zaprinast, and of nitric oxide donors, sodium nitroprusside and glyceryl trinitrate, as relaxants of histamine (0.1 mmol/l)-induced tone were examined in IAS strips under isometric contraction. The presence of PDE5 isoenzymes and changes in intracellular calcium and cyclic nucleotide levels in IAS muscle were tested by real-time reverse transcriptase-polymerase chain reaction, epifluorescence microscopy and enzyme immunoassay respectively. RESULTS Sildenafil produced a concentration-related inhibition of the mean(s.e.m.) histamine-induced tone (E(max) 83(2) per cent, - log IC(50) 7.04(0.05); n = 12). Zaprinast produced relaxation to similar degree, but with lower potency. Nitric oxide donors also relaxed IAS. Sildenafil (1 micromol/l) produced a 1.8-fold increase in guanosine 3',5'-cyclic monophosphate content, with no change in adenosine 3',5'-cyclic monophosphate levels. Sildenafil markedly depressed the peak intracellular calcium increase evoked by histamine. PDE5A1, PDE5A2 and PDE5A3 transcripts were expressed in IAS muscle. CONCLUSION Sildenafil relaxes the augmented tone of human IAS in vitro. These results support the potential use of this PDE5 inhibitor in the treatment of chronic anal fissure.
Collapse
Affiliation(s)
- C Ballester
- Department of Surgery, University of Valencia, Valencia, Spain
| | | | | | | | | | | |
Collapse
|
50
|
Abstract
A wide variety of medications, devices, and surgical interventions are available to patients who have ED. These range from first-line oral agents to second-line therapy with injections or vacuum devices to third-line options, such as penile prosthesis implantation. In this article, we cover available treatments for erectile dysfunction, ranging from first-line to third-line therapies.
Collapse
Affiliation(s)
- William O Brant
- University of Colorado School of Medicine, P.O. Box 40,000, Vail, CO 81658, USA.
| | | | | |
Collapse
|