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Salehiyeh S, Faiz AF, Manzourolhojeh M, Bagheri AM, Lorian K. The functions of hydrogen sulfide on the urogenital system of both males and females: from inception to the present. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:6391-6415. [PMID: 38689070 DOI: 10.1007/s00210-024-03086-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 04/04/2024] [Indexed: 05/02/2024]
Abstract
Hydrogen sulfide (H2S) is known as a chemical gas in nature with both enzymatic and non-enzymatic biosynthesis in different human organs. A couple of studies have demonstrated the function of H2S in regulating the homeostasis of the human body. Additionally, they have shown its synthesis, measurement, chemistry, protective effects, and interaction in various aspects of scientific evidence. Furthermore, many researches have demonstrated the beneficial impacts of H2S on genital organs and systems. According to various studies, it is recognized that H2S-producing enzymes and the endogenous production of H2S are expressed in male and female reproductive systems in different mammalian species. The main goal of this comprehensive review is to assess the potential therapeutic impacts of this gasotransmitter in the male and female urogenital system and find underlying mechanisms of this agent. This narrative review investigated the articles that were published from the 1970s to 2022. The review's primary focus is the impacts of H2S on the male and female urogenital system. Medline, CINAHL, PubMed, and Google scholar databases were searched. Keywords used in this review were "Hydrogen sulfide," "H2S," "urogenital system," and "urogenital tract". Numerous studies have demonstrated the therapeutic and protective effects of sodium hydrosulfide (Na-HS) as an H2S donor on male and female infertility disorders. Furthermore, it has been observed that H2S plays a significant role in improving different diseases such as ameliorating sperm parameters. The specific localization of H2S enzymes in the urogenital system provides an excellent opportunity to comprehend its function and role in various disorders related to this system. It is noteworthy that H2S has been demonstrated to be produced in endocrine organs and exhibit diverse activities. Moreover, it is important to recognize that alterations in H2S biosynthesis are closely linked to endocrine disorders. Therefore, hormones can be pivotal in regulating H2S production, and H2S synthesis pathways may aid in establishing novel therapeutic strategies. H2S possesses pharmacological effects on essential disorders, such as anti-inflammation, anti-apoptosis, and anti-oxidant activities, which render it a valuable therapeutic agent for human urogenital disease. Furthermore, this agent shows promise in ameliorating the detrimental effects of various male and female diseases. Despite the limited clinical research, studies have demonstrated that applying H2S as an anti-oxidant source could ameliorate adverse effects of different conditions in the urogenital system. More clinical studies are required to confirm the role of this component in clinical settings.
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Affiliation(s)
- Sajad Salehiyeh
- Andrology Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Department of Physiology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Research and Clinical Center for Infertility, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Ahmad Faisal Faiz
- Department of Paraclinic, School of Medicine, Herat University, Herat, Afghanistan
| | - Mohammad Manzourolhojeh
- Department of Medical Laboratory Sciences, Gorgan Branch, Islamic Azad University, Gorgan, Iran
| | - Amir Mohammad Bagheri
- Department of Medical Genetics, Shahid Sadoughi university of Medical Sciences, Yazd, Iran
| | - Keivan Lorian
- Andrology Research Center, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
- Research and Clinical Center for Infertility, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
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Cirino G, Szabo C, Papapetropoulos A. Physiological roles of hydrogen sulfide in mammalian cells, tissues and organs. Physiol Rev 2022; 103:31-276. [DOI: 10.1152/physrev.00028.2021] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
H2S belongs to the class of molecules known as gasotransmitters, which also includes nitric oxide (NO) and carbon monoxide (CO). Three enzymes are recognized as endogenous sources of H2S in various cells and tissues: cystathionine g-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current article reviews the regulation of these enzymes as well as the pathways of their enzymatic and non-enzymatic degradation and elimination. The multiple interactions of H2S with other labile endogenous molecules (e.g. NO) and reactive oxygen species are also outlined. The various biological targets and signaling pathways are discussed, with special reference to H2S and oxidative posttranscriptional modification of proteins, the effect of H2S on channels and intracellular second messenger pathways, the regulation of gene transcription and translation and the regulation of cellular bioenergetics and metabolism. The pharmacological and molecular tools currently available to study H2S physiology are also reviewed, including their utility and limitations. In subsequent sections, the role of H2S in the regulation of various physiological and cellular functions is reviewed. The physiological role of H2S in various cell types and organ systems are overviewed. Finally, the role of H2S in the regulation of various organ functions is discussed as well as the characteristic bell-shaped biphasic effects of H2S. In addition, key pathophysiological aspects, debated areas, and future research and translational areas are identified A wide array of significant roles of H2S in the physiological regulation of all organ functions emerges from this review.
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Affiliation(s)
- Giuseppe Cirino
- Department of Pharmacy, School of Medicine, University of Naples Federico II, Naples, Italy
| | - Csaba Szabo
- Chair of Pharmacology, Section of Medicine, University of Fribourg, Switzerland
| | - Andreas Papapetropoulos
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece & Clinical, Experimental Surgery and Translational Research Center, Biomedical Research Foundation of the Academy of Athens, Greece
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Cho HY, Chuang TH, Wu SN. The Effectiveness in Activating M-Type K + Current Produced by Solifenacin ([(3R)-1-azabicyclo[2.2.2]octan-3-yl] (1S)-1-phenyl-3,4-dihydro-1H-isoquinoline-2-carboxylate): Independent of Its Antimuscarinic Action. Int J Mol Sci 2021; 22:ijms222212399. [PMID: 34830281 PMCID: PMC8622881 DOI: 10.3390/ijms222212399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/08/2021] [Accepted: 11/15/2021] [Indexed: 12/18/2022] Open
Abstract
Solifenacin (Vesicare®, SOL), known to be a member of isoquinolines, is a muscarinic antagonist that has anticholinergic effect, and it has been beneficial in treating urinary incontinence and neurogenic detrusor overactivity. However, the information regarding the effects of SOL on membrane ionic currents is largely uncertain, despite its clinically wide use in patients with those disorders. In this study, the whole-cell current recordings revealed that upon membrane depolarization in pituitary GH3 cells, the exposure to SOL concentration-dependently increased the amplitude of M-type K+ current (IK(M)) with effective EC50 value of 0.34 μM. The activation time constant of IK(M) was concurrently shortened in the SOL presence, hence yielding the KD value of 0.55 μM based on minimal reaction scheme. As cells were exposed to SOL, the steady-state activation curve of IK(M) was shifted along the voltage axis to the left with no change in the gating charge of the current. Upon an isosceles-triangular ramp pulse, the hysteretic area of IK(M) was increased by adding SOL. As cells were continually exposed to SOL, further application of acetylcholine (1 μM) failed to modify SOL-stimulated IK(M); however, subsequent addition of thyrotropin releasing hormone (TRH, 1 μM) was able to counteract SOL-induced increase in IK(M) amplitude. In cell-attached single-channel current recordings, bath addition of SOL led to an increase in the activity of M-type K+ (KM) channels with no change in the single channel conductance; the mean open time of the channel became lengthened. In whole-cell current-clamp recordings, the SOL application reduced the firing of action potentials (APs) in GH3 cells; however, either subsequent addition of TRH or linopirdine was able to reverse SOL-mediated decrease in AP firing. In hippocampal mHippoE-14 neurons, the IK(M) was also stimulated by adding SOL. Altogether, findings from this study disclosed for the first time the effectiveness of SOL in interacting with KM channels and hence in stimulating IK(M) in electrically excitable cells, and this noticeable action appears to be independent of its antagonistic activity on the canonical binding to muscarinic receptors expressed in GH3 or mHippoE-14 cells.
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Affiliation(s)
- Hsin-Yen Cho
- Department of Physiology, National Cheng Kung University Medical College, Tainan City 70101, Taiwan; (H.-Y.C.); (T.-H.C.)
| | - Tzu-Hsien Chuang
- Department of Physiology, National Cheng Kung University Medical College, Tainan City 70101, Taiwan; (H.-Y.C.); (T.-H.C.)
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan City 70101, Taiwan; (H.-Y.C.); (T.-H.C.)
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City 70101, Taiwan
- Correspondence: ; Tel.: +886-6-2353535-5334; Fax: +886-6-2362780
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Elias D, Gimenez L, Poletta F, Campaña H, Gili J, Ratowiecki J, Pawluk M, Rittler M, Santos MR, Uranga R, Heisecke SL, Cosentino V, Saleme C, Gadow E, Krupitzki H, Camelo JSL. Preterm birth and genitourinary tract infections: assessing gene-environment interaction. Pediatr Res 2021; 90:678-683. [PMID: 33070163 DOI: 10.1038/s41390-020-01200-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 08/20/2020] [Accepted: 08/25/2020] [Indexed: 11/09/2022]
Abstract
BACKGROUND Preterm birth (PTB) is the leading cause of perinatal morbimortality worldwide. Genetic and environmental factors could raise PTB risk. The aim of this study was to analyze the contribution of the statistical interaction between genes and vaginal-urinary tract infections (VI-UTI) to the risk of PTB by clinical subtype. METHODS Twenty-four SNPs were genotyped in 18 candidate genes from 352 fetal triads and 106 maternal triads. Statistical interactions were evaluated with conditional logistic regression models based on genotypic transmission/disequilibrium test. RESULTS In PTB-idiopathic subtype mothers exposed to UTI, fetal SNPs rs11686474 (FSHR), rs4458044 (CRHR1, allele G), rs883319 (KCNN3), and maternal SNP rs1882435 (COL4A3) showed a nominal significant increment in prematurity risk. In preterm premature rupture of membranes (PPROM), fetal SNP rs2277698 (TIMP2) showed a nominal significant risk increment. In mothers exposed to VI, fetal SNP rs5742612 (IGF1) in PTB-PPROM and maternal SNP rs4458044 (CRHR1, allele C) in spontaneous PTB showed nominal significant increment in prematurity risk. CONCLUSIONS Certain maternal and fetal genes linked to infectious/inflammatory and hormonal regulation processes increase prematurity risk according to clinical subtype when mothers are exposed to UTI or VI. These findings may help in the understanding of PTB etiology and PTB prevention. IMPACT Preterm birth is a major cause of perinatal morbimortality worldwide and its etiology remains unknown. This work provides evidence on the statistical interaction of six genes with gestational vaginal or urinary infections leading to the occurrence of preterm births. Statistical interactions vary according to infection type, genotype (maternal and fetal), and clinical subtype of prematurity. Certain maternal and fetal genetic variants of genes linked to infectious/inflammatory and hormonal regulation processes would increase the risk of prematurity according to clinical subtype and infection type. Our findings may help in the study of etiology of preterm birth and its prevention.
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Affiliation(s)
- Dario Elias
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Lucas Gimenez
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Instituto Nacional de Genética Médica Populacional, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Fernando Poletta
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Instituto Nacional de Genética Médica Populacional, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Hebe Campaña
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Comisión de Investigaciones Científicas, Buenos Aires, Argentina
| | - Juan Gili
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Instituto Académico Pedagógico de Ciencias Humanas, Universidad Nacional de Villa María, Córdoba, Argentina
| | - Julia Ratowiecki
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Mariela Pawluk
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Monica Rittler
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Hospital Materno Infantil Ramón Sarda, Buenos Aires, Argentina
| | - Maria R Santos
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Comisión de Investigaciones Científicas, Buenos Aires, Argentina.,Instituto Multidisciplinario de Biología Celular, Buenos Aires, Argentina
| | - Rocio Uranga
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.,Hospital San Juan de Dios, Buenos Aires, Argentina
| | - Silvina L Heisecke
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Viviana Cosentino
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina.,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina
| | - Cesar Saleme
- Instituto de Maternidad y Ginecología Nuestra Señora de las Mercedes, Tucumán, Argentina
| | - Enrique Gadow
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Hugo Krupitzki
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina
| | - Jorge S Lopez Camelo
- Laboratorio de Epidemiología Genética Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Centro de Educación Médica e Investigaciones Clínicas-Consejo Nacional de Investigaciones Científicas y Técnicas (CEMIC-CONICET), Ciudad Autónoma de Buenos Aires, Argentina. .,Estudio Colaborativo Latino Americano de Malformaciones Congénitas, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina. .,Instituto Nacional de Genética Médica Populacional, CEMIC-CONICET, Ciudad Autónoma de Buenos Aires, Argentina.
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Varghese N, Lauritano A, Taglialatela M, Tzingounis AV. KCNQ3 is the principal target of retigabine in CA1 and subicular excitatory neurons. J Neurophysiol 2021; 125:1440-1449. [PMID: 33729829 DOI: 10.1152/jn.00564.2020] [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] [Indexed: 01/14/2023] Open
Abstract
Retigabine is a first-in-class potassium channel opener approved for patients with epilepsy. Unfortunately, several side effects have limited its use in clinical practice, overshadowing its beneficial effects. Multiple studies have shown that retigabine acts by enhancing the activity of members of the voltage-gated KCNQ (Kv7) potassium channel family, particularly the neuronal KCNQ channels KCNQ2-KCNQ5. However, it is currently unknown whether retigabine's action in neurons is mediated by all KCNQ neuronal channels or by only a subset. This knowledge is necessary to elucidate retigabine's mechanism of action in the central nervous system and its adverse effects and to design more effective and selective retigabine analogs. In this study, we show that the action of retigabine in excitatory neurons strongly depends on the presence of KCNQ3 channels. Deletion of Kcnq3 severely limited the ability of retigabine to reduce neuronal excitability in mouse CA1 and subiculum excitatory neurons. In addition, we report that in the absence of KCNQ3 channels, retigabine can enhance CA1 pyramidal neuron activity, leading to a greater number of action potentials and reduced spike frequency adaptation; this finding further supports a key role of KCNQ3 channels in mediating the action of retigabine. Our work provides new insight into the action of retigabine in forebrain neurons, clarifying retigabine's action in the nervous system.NEW & NOTEWORTHY Retigabine has risen to prominence as a first-in-class potassium channel opener approved by the Food and Drug Administration, with potential for treating multiple neurological disorders. Here, we demonstrate that KCNQ3 channels are the primary target of retigabine in excitatory neurons, as deleting these channels greatly diminishes the effect of retigabine in pyramidal neurons. Our data provide the first indication that retigabine controls neuronal firing properties primarily through KCNQ3 channels.
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Affiliation(s)
- Nissi Varghese
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut
| | - Anna Lauritano
- Department of Neuroscience, University of Naples Federico II, Naples, Italy
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Liu Y, Bian X, Wang K. Pharmacological Activation of Neuronal Voltage-Gated Kv7/KCNQ/M-Channels for Potential Therapy of Epilepsy and Pain. Handb Exp Pharmacol 2021; 267:231-251. [PMID: 33837465 DOI: 10.1007/164_2021_458] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Native M-current is a low-threshold, slowly activating potassium current that exerts an inhibitory control over neuronal excitability. The M-channel is primarily co-assembled by heterotetrameric Kv7.2/KCNQ2 and Kv7.3/KCNQ3 subunits that are specifically expressed in the brain and peripheral nociceptive and visceral sensory neurons in the spinal cord. Reduction of M-channel function leads to neuronal hyperexcitability that defines the fundamental mechanism of neurological disorders such as epilepsy and pain, indicating that pharmacological activation of Kv7/KCNQ/M-channels may serve the basis for the therapy. The well-known KCNQ opener retigabine (ezogabine or Potiga) was approved by FDA in 2011 as an anticonvulsant used for an adjunctive treatment of partial epilepsies. Unfortunately, retigabine was discontinued in 2017 due to its side effects of blue-colored appearance of the skin and eyes after prolonged intake. In addition, flupirtine, a structural derivative of retigabine and a centrally acting non-opioid analgesic, was also withdrawn in 2018 for liver toxicity. Fortunately, these side effects are compound-structures related and can be avoided. Thus, further identification and development of novel potent and selective Kv7 channel openers may lead to an effective therapy with improved safety window for anti-epilepsy and anti-nociception.
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Affiliation(s)
- Yani Liu
- Department of Pharmacology, Qingdao University School of Pharmacy, Qingdao, China
| | - Xiling Bian
- Department of Pharmacology, Peking University School of Pharmaceutical Sciences, Beijing, China
| | - KeWei Wang
- Department of Pharmacology, Qingdao University School of Pharmacy, Qingdao, China. .,Institute of Innovative Drugs Qingdao University, Qingdao, China.
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Tykocki NR, Heppner TJ, Dalsgaard T, Bonev AD, Nelson MT. The K V 7 channel activator retigabine suppresses mouse urinary bladder afferent nerve activity without affecting detrusor smooth muscle K + channel currents. J Physiol 2018; 597:935-950. [PMID: 30536555 DOI: 10.1113/jp277021] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/06/2018] [Indexed: 01/20/2023] Open
Abstract
KEY POINTS KV 7 channels are a family of voltage-dependent K+ channels expressed in many cell types, which open in response to membrane depolarization to regulate cell excitability. Drugs that target KV 7 channels are used clinically to treat epilepsy. Interestingly, these drugs also cause urinary retention, but it was unclear how. In this study, we focused on two possible mechanisms by which retigabine could cause urinary retention: by decreasing smooth muscle excitability, or by decreasing sensory nerve outflow. Urinary bladder smooth muscle had no measurable KV 7 channel currents. However, the KV 7 channel agonist retigabine nearly abolished sensory nerve outflow from the urinary bladder during bladder filling. We conclude that KV 7 channel activation likely affects urinary bladder function by blocking afferent nerve outflow to the brain, which is key to sensing bladder fullness. ABSTRACT KV 7 channels are voltage-dependent K+ channels that open in response to membrane depolarization to regulate cell excitability. KV 7 activators, such as retigabine, were used to treat epilepsy but caused urinary retention. Using electrophysiological recordings from freshly isolated mouse urinary bladder smooth muscle (UBSM) cells, isometric contractility of bladder strips, and ex vivo measurements of bladder afferent activity, we explored the role of KV 7 channels as regulators of murine urinary bladder function. The KV 7 activator retigabine (10 μM) had no effect on voltage-dependent K+ currents or resting membrane potential of UBSM cells, suggesting that these cells lacked retigabine-sensitive KV 7 channels. The KV 7 inhibitor XE-991 (10 μM) inhibited UBSM K+ currents; the properties of these currents, however, were typical of KV 2 channels and not KV 7 channels. Retigabine inhibited voltage-dependent Ca2+ channel (VDCC) currents and reduced steady-state contractions to 60 mM KCl in bladder strips, suggesting that reduction in VDCC current was sufficient to directly affect UBSM function. To determine if retigabine altered ex vivo bladder sensory outflow, we measured afferent activity during simulated transient contractions (TCs) of the bladder wall. Simulated TCs caused bursts of afferent activity that were nearly abolished by retigabine. The effects of retigabine were blocked by co-incubation with XE-991, suggesting specific activation of KV 7 channels on afferent nerves. These results indicate that retigabine primarily affects urinary bladder function by inhibiting TC generation and afferent nerve activity, which are key to sensing bladder fullness. Any direct inhibition of UBSM contractility is likely to be from non-specific effects on VDCCs and KV 2 channels.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, VT, 05405, USA
| | - Thomas J Heppner
- Department of Pharmacology, University of Vermont, Burlington, VT, 05405, USA
| | | | - Adrian D Bonev
- Department of Pharmacology, University of Vermont, Burlington, VT, 05405, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, 05405, USA.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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d'Emmanuele di Villa Bianca R, Fusco F, Mirone V, Cirino G, Sorrentino R. The Role of the Hydrogen Sulfide Pathway in Male and Female Urogenital System in Health and Disease. Antioxid Redox Signal 2017; 27:654-668. [PMID: 28398118 DOI: 10.1089/ars.2017.7079] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
SIGNIFICANCE The endogenous hydrogen sulfide (H2S) pathway produces an array of biological effects that vary depending on the bodily region. In addition, the H2S pathway's relevance often changes depending on a healthy or disease state. There is abundant evidence pointing to a key role for this pathway in male and female genito-urinary diseases, suggesting it as a possible target for new therapeutic approaches. Recent Advances: The tissue-specific localization of the H2S enzymes in the genito-urinary tract has allowed for a better understanding of its role in the body's pathophysiology. Indeed, in humans, cystathionine-γ-lyase (CSE) plays a major role in corpus cavernosum whereas cystathionine-β-synthase (CBS) plays a role in bladder functioning. The prostate epithelium expresses CBS and CSE, but stromal CSE only. In the uterus, up- or downregulation of CBS and CSE varies strongly depending on the female's hormonal cycle or pregnancy. CRITICAL ISSUES There is still the need to better define the male and female's sexual hormonal roles in regulating the H2S pathway, particularly in human pathological conditions. The lack of a correlation between human and animal data should be carefully considered when planning preclinical studies. The unmet need for selective enzymatic inhibitors and the different methodologies for H2S measurements still represent a critical issue in this research field. FUTURE DIRECTIONS It is feasible that the L-cysteine/H2S pathway can represent an alternative therapeutic target in genito-urinary tract disorders. The research should focus on erectile dysfunction and preeclampsia, characterized by vascular defect, as well as on bladder disorders where the urothelium is compromised. Antioxid. Redox Signal. 27, 654-668.
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Affiliation(s)
- Roberta d'Emmanuele di Villa Bianca
- 1 Department of Pharmacy, School of Medicine, University of Naples Federico II , Naples, Italy .,2 Interdepartmental Centre for Sexual Medicine, School of Medicine, University of Naples Federico II , Naples, Italy
| | - Ferdinando Fusco
- 2 Interdepartmental Centre for Sexual Medicine, School of Medicine, University of Naples Federico II , Naples, Italy .,3 Department of Neurosciences, Human Reproduction and Odontostomatology, School of Medicine, University of Naples Federico II , Naples, Italy
| | - Vincenzo Mirone
- 2 Interdepartmental Centre for Sexual Medicine, School of Medicine, University of Naples Federico II , Naples, Italy .,3 Department of Neurosciences, Human Reproduction and Odontostomatology, School of Medicine, University of Naples Federico II , Naples, Italy
| | - Giuseppe Cirino
- 1 Department of Pharmacy, School of Medicine, University of Naples Federico II , Naples, Italy .,2 Interdepartmental Centre for Sexual Medicine, School of Medicine, University of Naples Federico II , Naples, Italy
| | - Raffaella Sorrentino
- 1 Department of Pharmacy, School of Medicine, University of Naples Federico II , Naples, Italy .,2 Interdepartmental Centre for Sexual Medicine, School of Medicine, University of Naples Federico II , Naples, Italy
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Senbel AM, Abd Elmoneim HM, Sharabi FM, Mohy El-Din MM. Neuronal Voltage Gated Potassium Channels May Modulate Nitric Oxide Synthesis in Corpus Cavernosum. Front Pharmacol 2017; 8:297. [PMID: 28603495 PMCID: PMC5445172 DOI: 10.3389/fphar.2017.00297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 05/10/2017] [Indexed: 11/24/2022] Open
Abstract
Potassium channels (K+Ch) in corpus cavernosum play an important role in the regulation of erection. Nitric oxide (NO) acts through opening of K+Ch leading to hyperpolarization and relaxation. Aim : This study aims to update knowledge about the role of voltage-gated K+Ch (KV) channels in erectile machinery and investigate their role in the control of NO action &/or synthesis in the corpus cavernosum. Methods : Tension studies using isolated rabbit corpus cavernosum (CC) strips and rat anococcygeus muscle were conducted. Results are expressed as mean ± SEM. Results : Electric field stimulation (EFS, 2–16 Hz) evoked frequency-dependent relaxations of the PE (phenylephrine)-precontracted CC strips. At 2 Hz, EFS-induced relaxation amounted to 73.17 ± 2.55% in presence 4-AP (10−3 M) compared to 41.98 ± 1.45% as control. None of the other selective K+Ch blockers tested inhibited EFS-induced relaxation. 4-AP (10−3M) significantly attenuated ACh-induced relaxation of rabbit CC where dose-response curve was clearly shifted upward, and attenuated SNP- induced relaxation, for example, to 49.28 ± 4.52% compared to 65.53 ± 3.01% as control at 10−6 M SNP. The potentiatory effect of 4-AP on EFS was abolished or reversed in presence of NG-nitro-L-arginine (L-NNA, non-selective nitric oxide synthase inhibitor, 10−5M, and 2 × 10−4M). Same results were observed in rat anococcygeus muscle which is a part of the erectile machinery in rats. Conclusion : This study provides evidence for the presence of prejunctional voltage-gated K+Ch in CC, the blockade of which may increase the neuronal synthesis of NO.
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Affiliation(s)
- Amira M Senbel
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Heba M Abd Elmoneim
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Fouad M Sharabi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Mahmoud M Mohy El-Din
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
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Opening of the Adenosine Triphosphate-sensitive Potassium Channel Attenuates Morphine Tolerance by Inhibiting JNK and Astrocyte Activation in the Spinal Cord. Clin J Pain 2017; 32:617-23. [PMID: 26626290 DOI: 10.1097/ajp.0000000000000299] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVES In the present study, we investigated the role of adenosine triphosphate (ATP)-sensitive potassium (KATP) channels in chronic morphine tolerance. MATERIALS AND METHODS Male mice were injected intrathecally with morphine or saline, respectively (each in 10 μL). Different doses of the KATP opener cromakalim (0.3, 1, or 3 μg/10 μL/mouse) were administered 15 minutes before the morphine (10 μg/10 μL/mouse) challenge daily for 7 consecutive days. Half an hour after morphine injection, the tail-flick latency was measured to evaluate the antinociceptive effect of morphine. On the seventh day, mice were euthanized with sodium pentobarbital (100 mg/kg) at 1 hour after morphine injection, and their spinal cords were removed for the assays of Western blot, immunofluorescence, and quantitative real-time polymerase chain reaction. RESULTS Opening of the KATP channel attenuates chronic morphine tolerance, suppresses astrocyte activation inhibits the increase in interleukin-1β at the transcriptional and the translational levels, and reduces the upregulation of phosphorylated c-Jun N-terminal kinase mitogen-activated protein kinase in the spinal cord after chronic morphine treatment. Moreover, transcriptional levels of spinal cord astrocyte KATP channel subunits, named the inwardly rectifying potassium (Kir) 6.1 and sulfonylurea receptor 1, are decreased in morphine-tolerant mice. DISCUSSION Cromakalim suppresses morphine-induced astrocyte activation significantly by suppressing the c-Jun N-terminal kinase pathway, resulting in a reduced release of interleukin-1β and the attenuation of morphine chronic antinociceptive tolerance.
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Abstract
In this chapter the role played by H2S in the physiopathology of urogenital tract revising animal and human data available in the current relevant literature is discussed. H2S pathway has been demonstrated to be involved in the mechanism underlying penile erection in human and experimental animal. Both cystathionine-β synthase (CBS) and cystathionine-γ lyase (CSE) are expressed in the human corpus cavernosum and exogenous H2S relaxes isolated human corpus cavernosum strips in an endothelium-independent manner. Hydrogen sulfide pathway also accounts for the direct vasodilatory effect operated by testosterone on isolated vessels. Convincing evidence suggests that H2S can influence the cGMP pathway by inhibiting the phosphodiesterase 5 (PDE-5) activity. All these findings taken together suggest an important role for the H2S pathway in human corpus cavernosum homeostasis. However, H2S effect is not confined to human corpus cavernosum but also plays an important role in human bladder. Human bladder expresses mainly CBS and generates in vitro detectable amount of H2S. In addition the bladder relaxant effect of the PDE-5 inhibitor sildenafil involves H2S as mediator. In conclusion the H2S pathway is not only involved in penile erection but also plays a role in bladder homeostasis. In addition the finding that it involved in the mechanism of action of PDE-5 inhibitors strongly suggests that modulation of this pathway can represent a therapeutic target for the treatment of erectile dysfunction and bladder diseases.
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Malysz J, Rovner ES, Petkov GV. Single-channel biophysical and pharmacological characterizations of native human large-conductance calcium-activated potassium channels in freshly isolated detrusor smooth muscle cells. Pflugers Arch 2013; 465:965-75. [PMID: 23344746 PMCID: PMC3659209 DOI: 10.1007/s00424-012-1214-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 12/27/2012] [Accepted: 12/29/2012] [Indexed: 10/27/2022]
Abstract
Recent studies have demonstrated the importance of large-conductance Ca(2+)-activated K(+) (BK) channels in detrusor smooth muscle (DSM) function in vitro and in vivo. However, in-depth characterization of human native DSM single BK channels has not yet been provided. Here, we conducted single-channel recordings from excised patches from native human DSM cells. Inside-out and outside-out recordings in high K(+) symmetrical solution (containing 140 mM KCl and ~300 nM free Ca(2+)) showed single-channel conductance of 215-220 pS, half-maximum constant for activation of ~+75 to +80 mV, and low probability of opening (P o) at +20 mV that increased ~10-fold at +40 mV and ~60-fold at +60 mV. Using the inside-out configuration at +30 mV, reduction of intracellular [Ca(2+)] from ~300 nM to Ca(2+)-free decreased the P o by ~85 %, whereas elevation to ~800 nM increased P o by ~50-fold. The BK channel activator NS1619 (10 μM) enhanced the P o by ~10-fold at +30 mV; subsequent application of the selective BK channel inhibitor paxilline (500 nM) blocked the activity. Changes in intracellular [Ca(2+)] or the addition of NS1619 did not significantly alter the current amplitude or single-channel conductance. This is the first report to provide biophysical and pharmacological profiles of native human DSM single BK channels highlighting their importance in regulating human DSM excitability.
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Affiliation(s)
- John Malysz
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208
| | - Eric S. Rovner
- Medical University of South Carolina, Charleston, SC 29425
| | - Georgi V. Petkov
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, SC 29208
- Medical University of South Carolina, Charleston, SC 29425
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Further evidence of endogenous hydrogen sulphide as a mediator of relaxation in human and rat bladder. Asian J Androl 2013; 15:692-6. [PMID: 23728586 DOI: 10.1038/aja.2013.32] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Revised: 12/20/2012] [Accepted: 03/14/2013] [Indexed: 01/08/2023] Open
Abstract
We investigated the expression of hydrogen sulphide (H2S) in human and rat lower urinary tract (including bladder, prostate and urethra) tissues, and we sought to determine whether H2S induces relaxation of human and Sprague-Dawley (SD) rat bladder strips. Human normal lower urinary tract tissue was obtained for the evaluation of endogenous H2S productivity using a sulphide-sensitive electrode and for the analysis of the expression levels of all three synthases of endogenous H2S, cystathionine β-synthase (CBS), cystathionine γ lyase (CSE) and 3-mercaptopyruvate sulphur transferase (MPST, as known as 3-MST) by Western blot assay. CBS, CSE and MPST were located in human sample slides by immunohistochemistry. Human and male adult SD rat bladder strips were tested for H2S function with a transducer and recorded. All experiments were repeated six times. The endogenous H2S productivity and the H2S synthases had various distributions in the human and rat lower urinary tract tissues and were located in both epithelial and stromal sections. L-cysteine (L-Cys, a substrate of CBS, CSE and MPST) elicited relaxation in a dose-dependent manner on human bladder strips pre-contracted by acetylcholine chloride. This effect could be diminished by the ATP-sensitive potassium ion (KATP) channel blocker glibenclamide (GLB), the CSE inhibitor DL-propargylglycine (PPG) and the CBS inhibitor hydroxylamine (HA). H2S and its three synthases were present in the human and rat lower urinary tract tissues and relaxed human and rat bladder strips, which implied that endogenous H2S might play a role in physiological function and pathological disorders of the lower urinary tract symptoms (LUTS) or overactive bladder (OAB).
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Petkov GV. Role of potassium ion channels in detrusor smooth muscle function and dysfunction. Nat Rev Urol 2011; 9:30-40. [PMID: 22158596 DOI: 10.1038/nrurol.2011.194] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Contraction and relaxation of the detrusor smooth muscle (DSM), which makes up the wall of the urinary bladder, facilitates the storage and voiding of urine. Several families of K(+) channels, including voltage-gated K(+) (K(V)) channels, Ca(2+)-activated K(+) (K(Ca)) channels, inward-rectifying ATP-sensitive K(+) (K(ir), K(ATP)) channels, and two-pore-domain K(+) (K(2P)) channels, are expressed and functional in DSM. They control DSM excitability and contractility by maintaining the resting membrane potential and shaping the action potentials that determine the phasic nature of contractility in this tissue. Defects in DSM K(+) channel proteins or in the molecules involved in their regulatory pathways may underlie certain forms of bladder dysfunction, such as overactive bladder. K(+) channels represent an opportunity for novel pharmacological manipulation and therapeutic intervention in human DSM. Modulation of DSM K(+) channels directly or indirectly by targeting their regulatory mechanisms has the potential to control urinary bladder function. This Review summarizes our current state of knowledge of the functional role of K(+) channels in DSM in health and disease, with special emphasis on current advancements in the field.
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Affiliation(s)
- Georgi V Petkov
- Department of Pharmaceutical and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Coker Life Sciences Building, Room 609D, 715 Sumter Street, Columbia, SC 29208, USA.
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Athanasopoulos A, Cruz F. The medical treatment of overactive bladder, including current and future treatments. Expert Opin Pharmacother 2011; 12:1041-55. [PMID: 21299469 DOI: 10.1517/14656566.2011.554399] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Rapposelli S. Novel adenosine 5'-triphosphate-sensitive potassium channel ligands: a patent overview (2005-2010). Expert Opin Ther Pat 2011; 21:355-79. [PMID: 21269236 DOI: 10.1517/13543776.2011.553601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION ATP-sensitive potassium channels are important metabolic regulators that link cellular metabolism to excitability. Their wide distribution in various tissues and organs makes them significant and topical targets in a large number of diseases. AREAS COVERED This review summarizes the current understanding of the molecular biology and pharmacology of K(ATP) channels, and the pathological states that result from aberrant expression or function of these proteins. In particular, relevant research, patents and patent applications of the past 5 years are discussed. EXPERT OPINION The tissue-specific K(ATP) channel modulation reflects an early discovery stage in drug design. The wide distribution of K(ATP) channels lets us consider them as valid targets for several pathologies, but on other hand the ubiquitous nature is a relevant drawback in developing an effective therapy because of the onset of side effects related to the lack of selectivity. On this basis, further investigations on both the structures and the localization of each receptor subtype should be carried out either exploring the structure-activity relationship of the already existing K(ATP) ligands or developing new selective fluorescent probes. To date, this research area still strives to design new tissue-targeted ligands that could pave the way to the development of innovative and effective drugs for clinical use.
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Affiliation(s)
- Simona Rapposelli
- Dipartimento di Scienze Farmaceutiche - Università di Pisa, Via Bonanno, 6, 56126 Pisa, Italy.
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Oger S, Behr-Roussel D, Gorny D, Bernabé J, Comperat E, Chartier-Kastler E, Denys P, Giuliano F. Effects of potassium channel modulators on myogenic spontaneous phasic contractile activity in human detrusor from neurogenic patients. BJU Int 2010; 108:604-11. [PMID: 21166758 DOI: 10.1111/j.1464-410x.2010.09935.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE To characterize the spontaneous contractile activity (SCA) developed by detrusor from patients with neurogenic detrusor overactivity (NDO) because the alteration of detrusor properties plays a critical role in the pathogenesis of detrusor overactivity, as well as to evaluate the role of K(ATP) and K(Ca) channels on this SCA because these channels regulate detrusor SCA in many species, including humans without overactive bladder (OAB). PATIENTS AND METHODS Human bladder samples were obtained from 44 patients undergoing cystectomy for bladder cancer with no known OAB symptoms and from 38 patients suffering from urodynamically diagnosed NDO. Detrusor strips with or without urothelium/suburothelium were mounted isometrically in organ baths filled with Krebs-HEPES (37 °C; 95% O(2) /5% CO(2) ). Strips were incubated with 10 µm pinacidil (K(ATP) opener) followed by 10 µm glibenclamide (K(ATP) blocker). In another set of experiments, strips were incubated with 30 µm NS-1619 (BK(Ca) opener) followed by 100 nm iberiotoxin (BK(Ca) blocker) or with 100 nm apamin (SK(Ca) blocker). RESULTS SCA occurred more frequently with larger amplitude and area under the curve in detrusor strips from NDO patients compared to control patients. The presence of urothelium/suburothelium did not significantly modify SCA in either patient population. Pinacidil markedly inhibited SCA of detrusor strips from control and NDO patients. This effect was reversed by glibenclamide. By contrast, NS-1619 followed by iberiotoxin did not elicit any significant changes in SCA from NDO patients, contrary to control patients. CONCLUSIONS K(ATP) and SK(Ca) channels regulate SCA of NDO patients' detrusor strips. By contrast, BK(Ca) channels are not involved in the regulation of detrusor SCA in NDO patients, whereas they regulate SCA in control patients. These results should be considered in the development of K(+) channels openers for the treatment of NDO. Moreover, SCA observed in vitro should be regarded as an in vitro modelling of human NDO.
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Poonia MK, Kaur G, Chintamaneni M, Changela I. New insights into molecular targets for urinary incontinence. Indian J Pharmacol 2010; 42:261-6. [PMID: 21206614 PMCID: PMC2959205 DOI: 10.4103/0253-7613.69980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Revised: 05/29/2010] [Accepted: 07/21/2010] [Indexed: 11/17/2022] Open
Abstract
Urinary incontinence (UI) is a disease affecting quality of life of 200 million patients worldwide. It is characterized by involuntary loss of urine. The factors involved are cystitis, detrusor hyperreflexia, spinal injury, benign prostatic hyperplasia, etc. The surge in the number of reviews on this subject indicates the amount of research devoted to this field. The prevalence is increasing at an alarming rate but unfortunately, only a few medications are currently available for this condition. There are peripheral as well as central targets including cholinergic, vanilloid, prostaglandin, kinin, calcium channel, cannabinoid, serotonin, and GABA-receptors, which act by different mechanisms to treat different types of incontinence. Drugs acting on the central nervous system (CNS) increase urinary bladder capacity, volume, or pressure threshold for micturition reflex activation while peripherally acting drugs decrease the amplitude of micturition contraction and residual volume. Anticholinergic drugs specifically M3 receptor antagonists are the first choice but have frequent side effects such as dry mouth, CNS disturbances, etc. Therefore, there is a need to understand the biochemical pathways that control urinary dysfunction to determine the potential to which they can be exploited in the treatment of this condition. This article reviews the central and peripheral molecular targets and the potential therapeutic approaches to the treatment of UI.
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Affiliation(s)
- Manoj K. Poonia
- School of Pharmacy and Technology Management, SVKM’S NMIMS, V.L. Mehta Road, Vile Parle (W), Mumbai 400 056
| | - Ginpreet Kaur
- School of Pharmacy and Technology Management, SVKM’S NMIMS, V.L. Mehta Road, Vile Parle (W), Mumbai 400 056
| | - Meena Chintamaneni
- School of Pharmacy and Technology Management, SVKM’S NMIMS, V.L. Mehta Road, Vile Parle (W), Mumbai 400 056
| | - Ilesh Changela
- Department of Clinical Pharmacokinetics and Biopharmaceutics, Wockhardt Ltd., Mulund-Goregaon Link Road, Bhandup (W), Mumbai 400 078, India
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Pharmacological treatment of overactive bladder: report from the International Consultation on Incontinence. Curr Opin Urol 2009; 19:380-94. [DOI: 10.1097/mou.0b013e32832ce8a4] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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El-Metwally MA, Sharabi FM, Daabees TT, Senbel AM, Mostafa T. Involvement of alpha-receptors and potassium channels in the mechanism of action of sildenafil citrate. Int J Impot Res 2007; 19:551-7. [PMID: 17673930 DOI: 10.1038/sj.ijir.3901590] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Modulation of the adrenergic activity and interfering with channels such as potassium channels may affect relaxation and contraction of the corpus cavernosum. Sildenafil is a selective phosphodiesterase-5 inhibitor, proven effective in treating erectile dysfunction. In this study, the effect of sildenafil citrate on alpha-receptors modulation and potassium channels was tested. The direct relaxant effect of sildenafil citrate was studied by measuring changes in isometric tension in isolated strips of rabbit corpus cavernosum and rat aortic ring precontracted with phenylephrine or KCl compared to that of diazoxide in the presence and absence of tetraethylammonium. The inhibitory effect of sildenafil on electrical field stimulation-induced contraction of rabbit corpus cavernosum and rat anococcygeus muscle was also studied compared to that of phentolamine. Muscle relaxant effect of sildenafil (1 x 10(-9)-1 x 10(-6) M on phenylephrine-precontracted rabbit corpus cavernosum strips was not attenuated by N(G)-nitro-L-arginine (3 x 10(-5) M). Cumulative addition of sildenafil (1 x 10(-9)-1 x 10(-6) M) and phentolamine (1 x 10(-9)-1 x 10(-6) M) to the organ bath dose-dependently inhibited electrical field stimulation-induced contraction of rabbit corpus cavernosum and rat anococcygeus muscle, with almost similar EC(50) values. Sildenafil (1 x 10(-7) M) also inhibited phenylephrine-induced contraction of rat aortic rings by 39.83+/-3.01%. In addition, tetraethylammonium (1 x 10(-3) M) significantly attenuated the muscle relaxant effect of sildenafil (1 x 10(-9)-1 x 10(-6) M) on phenylephrine-precontracted strips of rabbit corpus cavernosum. Sildenafil citrate is capable of producing cavernosal smooth muscle relaxation by an additional mechanism that may involve alpha-receptors and potassium channel opening.
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Affiliation(s)
- M A El-Metwally
- Department of Pharmacology, Faculty of Pharmacy, University of Alexandria, Alexandria, Egypt
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Shieh CC, Brune ME, Buckner SA, Whiteaker KL, Molinari EJ, Milicic IA, Fabiyi AC, Daza A, Brioni JD, Carroll WA, Matsushita K, Yamada M, Kurachi Y, Gopalakrishnan M. Characterization of a novel ATP-sensitive K+ channel opener, A-251179, on urinary bladder relaxation and cystometric parameters. Br J Pharmacol 2007; 151:467-75. [PMID: 17435796 PMCID: PMC2013963 DOI: 10.1038/sj.bjp.0707249] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE ATP-sensitive K(+) channels (K(ATP)) play a pivotal role in contractility of urinary bladder smooth muscle. This study reports the characterization of 4-methyl-N-(2,2,2-trichloro-1-(3-pyridin-3-ylthioureido)ethyl)benzamide (A-251179) as a K(ATP) channel opener. EXPERIMENTAL APPROACH Glyburide-sensitive membrane potential, patch clamp and tension assays were employed to study the effect of A-251179 in vitro. The in vivo efficacy of A-251179 was characterized by suppression of spontaneous contractions in obstructed rat bladder and by measuring urodynamic function of urethane-anesthetized rat models. KEY RESULTS A-251179 was about 4-fold more selective in activating SUR2B-Kir6.2 derived K(ATP) channels compared to those derived from SUR2A-Kir6.2. In pig bladder smooth muscle strips, A-251179 suppressed spontaneous contractions, about 27- and 71-fold more potently compared to suppression of contractions evoked by low-frequency electrical stimulation and carbachol, respectively. In vivo, A-251179 suppressed spontaneous non-voiding bladder contractions from partial outlet-obstructed rats. Interestingly, in the neurogenic model where isovolumetric contractions were measured by continuous transvesical cystometry, A-251179 at a dose of 0.3 micromol kg(-1), but not higher, was found to increase bladder capacity without affecting either the voiding efficiency or changes in mean arterial blood pressure. CONCLUSIONS AND IMPLICATIONS The thioureabenzamide analog, A-251179 is a potent novel K(ATP) channel opener with selectivity for SUR2B/Kir6.2 containing K(ATP) channels relative to pinacidil. The pharmacological profile of A-251179 is to increase bladder capacity and to prolong the time between voids without affecting voiding efficiency and represents an interesting characteristic to be explored for further investigations of K(ATP) channel openers for the treatment of overactive bladder.
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Affiliation(s)
- C-C Shieh
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064, USA.
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Tiwari A, Naruganahalli KS. Current and emerging investigational medical therapies for the treatment of overactive bladder. Expert Opin Investig Drugs 2007; 15:1017-37. [PMID: 16916270 DOI: 10.1517/13543784.15.9.1017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Overactive bladder (OAB) is a chronic distressing condition characterised by urinary urgency with or without urge incontinence, usually with frequency (voiding at least eight times daily) and nocturia. It affects millions of people worldwide independent of age, sex and race. The prevalence increases with age and is relatively higher in women compared with men. The treatment of OAB is aimed at reducing the debilitating symptoms so as to improve the overall quality of life for patients. Anticholinergic agents targeting the muscarinic receptors in the bladder represent the mainstay of pharmacotherapy for the treatment of OAB. Besides their status as the current standard of care, use of antimuscarinic drugs is limited by certain side effects, particularly dry mouth and constipation; therefore, various attempts have been made to improve the organ selectivity of these drugs to overcome the side effects. These include the development of new antimuscarinic agents with structural modifications and the use of innovative drug delivery methods. The advancement in the drug delivery systems extends to the long-term therapeutic efficacy with improved tolerability and patient compliance; however, future prospective therapies are aimed at novel targets with novel mechanisms of action, including beta3-adrenoceptor agonists, K+ channel openers, 5-HT modulators and botulinum toxin, which are currently under different stages of clinical development. Among other investigational therapies, neurokinin receptor antagonists, alpha-adrenoceptor antagonists, nerve growth factor inhibitors, gene therapy and stem cell-based therapies are of considerable interest. The future for the development of new modalities for the treatment of OAB looks promising.
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Affiliation(s)
- Atul Tiwari
- Ranbaxy Research Laboratories, Urology and Metabolic Group, NDDR, Gurgaon-122001, Haryana, India.
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Moreland RB. In vitro models: research in physiology and pharmacology of the lower urinary tract. Br J Pharmacol 2006; 147 Suppl 2:S56-61. [PMID: 16465184 PMCID: PMC1751497 DOI: 10.1038/sj.bjp.0706505] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The physiology and pharmacology of the lower urinary tract has advanced based, in part, due to the in vitro assays that have facilitated this exploration. Such assays have led to the development of novel and selective molecules that have been used to characterize different receptor and enzyme systems in the larger context of in vivo pharmacology. These assays can be classified by sites of action of drugs into the following categories: receptors, effector enzymes and enzymes that terminate the responses. In this review, representative assays are presented based on our experience in male erectile dysfunction.
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MESH Headings
- Animals
- Binding, Competitive
- Cells, Cultured
- Drug Evaluation, Preclinical/methods
- Enzyme-Linked Immunosorbent Assay
- Erectile Dysfunction/drug therapy
- Erectile Dysfunction/metabolism
- Erectile Dysfunction/physiopathology
- Humans
- Ion Channels/metabolism
- Ligands
- Male
- Muscle Contraction/drug effects
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Penis/blood supply
- Penis/drug effects
- Penis/metabolism
- Radioimmunoassay
- Radioligand Assay
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Signal Transduction/drug effects
- Transfection
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Affiliation(s)
- Robert B Moreland
- Neuroscience Research, Global Pharmaceutical Research and Discovery, Department R4PM, Abbott Laboratories, Abbott Park, IL 60064-6123, USA.
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24
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Argentieri TM, Butera JA. An overview of potassium channel activators for the treatment of overactive bladder: a survey of new structures 2000 – 2005. Expert Opin Ther Pat 2006. [DOI: 10.1517/13543776.16.5.573] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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25
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Chapple CR, Patroneva A, Raines SR. Effect of an ATP-sensitive potassium channel opener in subjects with overactive bladder: a randomized, double-blind, placebo-controlled study (ZD0947IL/0004). Eur Urol 2006; 49:879-86. [PMID: 16517051 DOI: 10.1016/j.eururo.2006.01.037] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Accepted: 01/25/2006] [Indexed: 12/12/2022]
Abstract
OBJECTIVES Improvements over existing treatment standards in overactive bladder (OAB) may only be possible through the development of drugs acting via non-cholinergic pathways. This is the first clinical study to be reported in full for the use of a potassium channel opener in OAB. METHODS This randomized, double-blind, placebo-controlled phase II study evaluated the efficacy and safety of ZD0947 (25mg/day for 12 weeks) in patients with OAB. The primary endpoint was mean volume voided per micturition per 24 hours. Key secondary endpoints were changes from baseline in mean numbers of micturition episodes (total, voluntary, and incontinent) per 24 hours. RESULTS ZD0947 was not superior to placebo for the primary or secondary efficacy variables. The placebo-adjusted magnitude of effect for ZD0947 (approx. 4 mL) was less than the historic data for cholinergic antagonists (approx. 20 mL). Treatment was generally safe and well tolerated. CONCLUSIONS The data for ZD0947 are disappointing. More studies are needed to advance the identification of novel, non-cholinergic therapies for OAB.
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Affiliation(s)
- Christopher R Chapple
- Department of Urology, The Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK.
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26
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Milicic I, Buckner SA, Daza A, Coghlan M, Fey TA, Brune ME, Gopalakrishnan M. Pharmacological characterization of urinary bladder smooth muscle contractility following partial bladder outlet obstruction in pigs. Eur J Pharmacol 2006; 532:107-14. [PMID: 16487510 DOI: 10.1016/j.ejphar.2005.12.076] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2005] [Revised: 11/29/2005] [Accepted: 12/19/2005] [Indexed: 10/25/2022]
Abstract
Partial bladder outlet obstruction of the pig is considered as a valuable preclinical model for evaluating the profile of compounds for the treatment of bladder overactivity. In this study, we characterized the pharmacological properties of isolated bladder smooth muscle from pigs following partial outlet obstruction and its sensitivity to potassium channel openers. Bladder strips from obstructed animals showed significantly lower maximal efficacy (E(max)) and sensitivity to stimulation by ATP and carbachol, but not to those evoked by serotonin, compared to age-matched controls. Tissue strips from obstructed animals also showed a 2.5-fold increase in the potency and significantly reduced maximum response following K+ depolarization. With respect to spontaneous activity, bladder strips from control strips demonstrated little spontaneous phasic activity at all preloads examined. In contrast, bladder strips from obstructed animals showed large preload-dependent increases in spontaneous phasic activity at preload values of 16-32 g. The potencies of K(ATP) channel openers to relax carbachol-evoked contractions showed a good 1:1 correlation (r(2)=0.90) between obstructed and control bladder strips. These studies demonstrate that obstructed pig bladders show enhanced spontaneous phasic activity especially at elevated preloads, which may underlie unstable myogenic bladder contractions reported in cystometrographic measurements in vivo. The impaired responses to electrical field stimulation could be attributed to reduced efficacies and/or lower sensitivities of muscarinic and purinergic signaling pathways. K(ATP) channel sensitivities remain essentially unimpaired in the obstructed bladder and could be effectively modulated by openers with potential for the treatment of overactive bladder secondary to outlet obstruction.
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Affiliation(s)
- Ivan Milicic
- Neuroscience Research, Department R4MN, Building AP9, Global Pharmaceutical Research and Development, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
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27
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Kim DY, Kim JW, Yang EK. Altered Expressions of Calcium-Activated Potassium Channel and Connexin in Bladder Mucosae of Stress Urinary Incontinence Patients with Overactive Bladder Symptoms. Korean J Urol 2006. [DOI: 10.4111/kju.2006.47.7.722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Duk Yoon Kim
- Department of Urology, Catholic University of Daegu School of Medicine, Daegu, Korea
| | - Jung Wook Kim
- Department of Physiology, Kyungpook National University School of Medicine, Daegu, Korea
| | - Eun Kyoung Yang
- Department of Physiology, Kyungpook National University School of Medicine, Daegu, Korea
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28
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Brading AF. Spontaneous activity of lower urinary tract smooth muscles: correlation between ion channels and tissue function. J Physiol 2006; 570:13-22. [PMID: 16210349 PMCID: PMC1464291 DOI: 10.1113/jphysiol.2005.097311] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2005] [Accepted: 09/29/2005] [Indexed: 12/22/2022] Open
Abstract
Smooth muscles from the urethra and bladder display characteristic patterns of spontaneous contractile activity in the filling phase of the micturition cycle. Tonic contractions are seen in the urethral smooth muscles, and phasic contractions occur in the detrusor. Overactivity in the detrusor is a common clinical problem. The ion channels in the smooth muscle membranes play an important role in determining the functional properties, and are obvious targets for treatment of the overactive bladder. Recent evidence suggests that interstitial cells may also play a role in determining the pattern of spontaneous activity, although their precise role is less well established in the urinary tract than in the gut. The ion channels involved in these cells are also of interest. This review discusses what is known of ion channels in these tissues, and their implications for function.
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Affiliation(s)
- A F Brading
- Oxford Continence Group, University Department of Pharmacology, Mansfield Road, Oxford OX1 3QT, UK.
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29
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Kim DY, Yang EK, Kim JW. Alterations in Calcium-Activated Potassium Channel Expressions in Human Prostate Cancer. Korean J Urol 2006. [DOI: 10.4111/kju.2006.47.5.548] [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
Affiliation(s)
- Duk Yoon Kim
- Department of Urology, Catholic University of Daegu School of Medicine, Daegu, Korea
| | - Eun Kyoung Yang
- Department of Physiology, Kyungpook National University School of Medicine, Daegu, Korea
| | - Jung Wook Kim
- Department of Physiology, Kyungpook National University School of Medicine, Daegu, Korea
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30
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Jahangir A, Terzic A. K(ATP) channel therapeutics at the bedside. J Mol Cell Cardiol 2005; 39:99-112. [PMID: 15953614 PMCID: PMC2743392 DOI: 10.1016/j.yjmcc.2005.04.006] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 03/17/2005] [Accepted: 04/26/2005] [Indexed: 11/22/2022]
Abstract
The family of potassium channel openers regroups drugs that share the property of activating adenosine triphosphate-sensitive potassium (K(ATP)) channels, metabolic sensors responsible for adjusting membrane potential-dependent functions to match cellular energetic demands. K(ATP) channels, widely represented in metabolically-active tissue, are heteromultimers composed of an inwardly rectifying potassium channel pore and a regulatory sulfonylurea receptor subunit, the site of action of potassium channel opening drugs that promote channel activity by antagonizing ATP-induced pore inhibition. The activity of K(ATP) channels is critical in the cardiovascular adaptive response to stress, maintenance of neuronal electrical stability, and hormonal homeostasis. Thereby, K(ATP) channel openers have a unique therapeutic spectrum, ranging from applications in myopreservation and vasodilatation in patients with heart or vascular disease to potential clinical use as bronchodilators, bladder relaxants, islet cell protector, antiepileptics and promoters of hair growth. While the current experience in practice with potassium channel openers remains limited, multitude of ongoing investigations aims at defining the benefit of this emerging family of therapeutics in diverse disease conditions associated with metabolic distress.
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Affiliation(s)
- A Jahangir
- Division of Cardiovascular Diseases, Departmentof Medicine, Mayo Clinic College of Medicine, Guggenheim 7, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
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31
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Gopalakrishnan M, Buckner SA, Shieh CC, Fey T, Fabiyi A, Whiteaker KL, Davis-Taber R, Milicic I, Daza AV, Scott VES, Castle NA, Printzenhoff D, London B, Turner SC, Carroll WA, Sullivan JP, Coghlan MJ, Brune ME. In vitro and in vivo characterization of a novel naphthylamide ATP-sensitive K+ channel opener, A-151892. Br J Pharmacol 2004; 143:81-90. [PMID: 15302680 PMCID: PMC1575269 DOI: 10.1038/sj.bjp.0705908] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Revised: 06/03/2004] [Accepted: 06/09/2004] [Indexed: 11/08/2022] Open
Abstract
1. Openers of ATP-sensitive K(+) channels are of interest in several therapeutic indications including overactive bladder and other lower urinary tract disorders. This study reports on the in vitro and in vivo characterization of a structurally novel naphthylamide N-[2-(2,2,2-trifluoro-1-hydroxy-1-trifluoromethyl-ethyl)-naphthalen-1-yl]-acetamide (A-151892), as an opener of the ATP-sensitive potassium channels. 2. A-151892 was found to be a potent and efficacious potassium channel opener (KCO) as assessed by glibenclamide-sensitive whole-cell current and fluorescence-based membrane potential responses (-log EC(50)=7.63) in guinea-pig bladder smooth muscle cells. 3. Evidence for direct interaction with KCO binding sites was derived from displacement of binding of the 1,4-dihydropyridine opener [(125)I]A-312110. A-151892 displaced [(125)I]A-312110 binding to bladder membranes with a -log Ki value of 7.45, but lacked affinity against over 70 neurotransmitter receptor and ion channel binding sites. 4. In pig bladder strips, A-151892 suppressed phasic, carbachol-evoked and electrical field stimulus-evoked contractility in a glibenclamide-reversible manner with -log IC(50) values of 8.07, 7.33 and 7.02 respectively, comparable to that of the potencies of the prototypical cyanoguanidine KCO, P1075. The potencies to suppress contractions in thoracic aorta (-log IC(50)=7.81) and portal vein (-log IC(50)=7.98) were not substantially different from those observed for suppression of phasic contractility of the bladder smooth muscle. 5. In vivo, A-151892 was found to potently suppress unstable bladder contractions in obstructed models of unstable contractions in both pigs and rats with pED(35%) values of 8.05 and 7.43, respectively. 6. These results demonstrate that naphthylamide analogs exemplified by A-151892 are novel K(ATP) channel openers and may serve as chemotypes to exploit additional analogs with potential for the treatment of overactive bladder and lower urinary tract symptoms.
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Affiliation(s)
- Murali Gopalakrishnan
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA.
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