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Balla H, Borsodi K, Őrsy P, Horváth B, Molnár PJ, Lénárt Á, Kosztelnik M, Ruisanchez É, Wess J, Offermanns S, Nyirády P, Benyó Z. Intracellular signaling pathways of muscarinic acetylcholine receptor-mediated detrusor muscle contractions. Am J Physiol Renal Physiol 2023; 325:F618-F628. [PMID: 37675459 DOI: 10.1152/ajprenal.00261.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 08/10/2023] [Accepted: 08/27/2023] [Indexed: 09/08/2023] Open
Abstract
Acetylcholine plays an essential role in the regulation of detrusor muscle contractions, and antimuscarinics are widely used in the management of overactive bladder syndrome. However, several adverse effects limit their application and patients' compliance. Thus, this study aimed to further analyze the signal transduction of M2 and M3 receptors in the murine urinary bladder to eventually find more specific therapeutic targets. Experiments were performed on adult male wild-type, M2, M3, M2/M3, or Gαq/11 knockout (KO), and pertussis toxin (PTX)-treated mice. Contraction force and RhoA activity were measured in the urinary bladder smooth muscle (UBSM). Our results indicate that carbamoylcholine (CCh)-induced contractions were associated with increased activity of RhoA and were reduced in the presence of the Rho-associated kinase (ROCK) inhibitor Y-27632 in UBSM. CCh-evoked contractile responses and RhoA activation were markedly reduced in detrusor strips lacking either M2 or M3 receptors and abolished in M2/M3 KO mice. Inhibition of Gαi-coupled signaling by PTX treatment shifted the concentration-response curve of CCh to the right and diminished RhoA activation. CCh-induced contractile responses were markedly decreased in Gαq/11 KO mice; however, RhoA activation was unaffected. In conclusion, cholinergic detrusor contraction and RhoA activation are mediated by both M2 and M3 receptors. Furthermore, whereas both Gαi and Gαq/11 proteins mediate UBSM contraction, the activation at the RhoA-ROCK pathway appears to be linked specifically to Gαi. These findings may aid the identification of more specific therapeutic targets for bladder dysfunctions.NEW & NOTEWORTHY Muscarinic acetylcholine receptors are of utmost importance in physiological regulation of micturition and also in the development of voiding disorders. We demonstrate that the RhoA-Rho-associated kinase (ROCK) pathway plays a crucial role in contractions induced by cholinergic stimulation in detrusor muscle. Activation of RhoA is mediated by both M2 and M3 receptors as well as by Gi but not Gq/11 proteins. The Gi-RhoA-ROCK pathway may provide a novel therapeutic target for overactive voiding disorders.
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Affiliation(s)
- Helga Balla
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Kinga Borsodi
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Petra Őrsy
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Béla Horváth
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Péter József Molnár
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- Department of Urology, Semmelweis University, Budapest, Hungary
| | - Ádám Lénárt
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Mónika Kosztelnik
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- HUN-REN-SE Cerebrosvascular and Neurodegenerative Disease Research Group, Budapest, Hungary
| | - Éva Ruisanchez
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- HUN-REN-SE Cerebrosvascular and Neurodegenerative Disease Research Group, Budapest, Hungary
| | - Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland, United States
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Péter Nyirády
- Department of Urology, Semmelweis University, Budapest, Hungary
| | - Zoltán Benyó
- Institute of Translational Medicine, Semmelweis University, Budapest, Hungary
- HUN-REN-SE Cerebrosvascular and Neurodegenerative Disease Research Group, Budapest, Hungary
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Erdogan BR, Karaomerlioglu I, Yesilyurt ZE, Ozturk N, Muderrisoglu AE, Michel MC, Arioglu-Inan E. Normalization of organ bath contraction data for tissue specimen size: does one approach fit all? Naunyn Schmiedebergs Arch Pharmacol 2019; 393:243-251. [PMID: 31511953 DOI: 10.1007/s00210-019-01727-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/02/2019] [Indexed: 01/18/2023]
Abstract
Organ bath experiments are a key technology to assess contractility of smooth muscle. Despite efforts to standardize tissue specimen sizes, they vary to a certain degree. As it appears obvious that a larger piece of tissue should develop greater force, most investigators normalize contraction data for specimen size. However, they lack agreement which parameter should be used as denominator for normalization. A pre-planned analysis of data from a recent study was used to compare denominators used for normalization, i.e., weight, length, and cross-sectional area. To increase robustness, we compared force with denominator in correlation analysis and also coefficient of variation with different denominators. This was done concomitantly with urinary bladder strips and aortic rings and with multiple contractile stimuli. Our urinary bladder data show that normalization for strip weight yielded the tightest but still only moderate correlation (e.g., r2 = 0.3582 for peak carbachol responses based on 188 strips). In aorta, correlations were even weaker (e.g., r2 = 0.0511 for plateau phenylephrine responses normalized for weight based on 200 rings). Normalization for strip size is less effective in reducing data variability than previously assumed; the normalization denominator of choice must be identified separately for each preparation.
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Affiliation(s)
- Betul R Erdogan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Irem Karaomerlioglu
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Zeynep E Yesilyurt
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Nihal Ozturk
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - A Elif Muderrisoglu
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
| | - Ebru Arioglu-Inan
- Department of Pharmacology, Faculty of Pharmacy, Ankara University, Ankara, Turkey
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Han JS, Kim SJ, Nam Y, Lee HY, Kim GM, Kim DM, Sohn UD. The Inhibitory Mechanism on Acetylcholine-Induced Contraction of Bladder Smooth Muscle in the Streptozotocin-Induced Diabetic Rat. Biomol Ther (Seoul) 2019; 27:101-106. [PMID: 30419634 PMCID: PMC6319557 DOI: 10.4062/biomolther.2018.136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 09/10/2018] [Accepted: 09/20/2018] [Indexed: 12/19/2022] Open
Abstract
Most diabetic patients experience diabetic mellitus (DM) urinary bladder dysfunction. A number of studies evaluate bladder smooth muscle contraction in DM. In this study, we evaluated the change of bladder smooth muscle contraction between normal rats and DM rats. Furthermore, we used pharmacological inhibitors to determine the differences in the signaling pathways between normal and DM rats. Rats in the DM group received an intraperitoneal injection of 65 mg/kg streptozotocin and measured blood glucose level after 14 days to confirm DM. Bladder smooth muscle contraction was induced using acetylcholine (ACh, 10⁻⁴ M). The materials such as, atropine (a muscarinic receptor antagonist), U73122 (a phospholipase C inhibitor), DPCPX (an adenosine A₁ receptor antagonist), udenafil (a PDE5 inhibitor), prazosin (an α₁-receptor antagonist), papaverine (a smooth muscle relaxant), verapamil (a calcium channel blocker), and chelerythrine (a protein kinase C inhibitor) were pre-treated in bladder smooth muscle. We found that the DM rats had lower bladder smooth muscle contractility than normal rats. When prazosin, udenafil, verapamil, and U73122 were pre-treated, there were significant differences between normal and DM rats. Taken together, it was concluded that the change of intracellular Ca²⁺ release mediated by PLC/IP3 and PDE5 activity were responsible for decreased bladder smooth muscle contractility in DM rats.
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Affiliation(s)
- Jong Soo Han
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Su Jin Kim
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Yoonjin Nam
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Hak Yeong Lee
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Geon Min Kim
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Dong Min Kim
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Uy Dong Sohn
- Signaling and Pharmacological Activity Research Lab, College of Pharmacy, Chung-Ang University, Seoul 06974, Republic of Korea
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Han JS, Min YS, Kim GH, Chae SH, Nam Y, Lee J, Lee SY, Sohn UD. The change of signaling pathway on the electrical stimulated contraction in streptozotocin-induced bladder dysfunction of rats. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2018; 22:577-584. [PMID: 30181704 PMCID: PMC6115354 DOI: 10.4196/kjpp.2018.22.5.577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 05/28/2018] [Indexed: 01/11/2023]
Abstract
Bladder dysfunction is a common complication of diabetes mellitus (DM). However, there have been a few studies evaluating bladder smooth muscle contraction in DM in the presence of pharmacological inhibitors. In the present study, we compared the contractility of bladder smooth muscle from normal rats and DM rats. Furthermore, we utilized pharmacological inhibitors to delineate the mechanisms underlying bladder muscle differences between normal and DM rats. DM was established in 14 days after using a single injection of streptozotocin (65 mg/kg, intraperitoneal) in Sprague-Dawley rats. Bladder smooth muscle contraction was induced electrically using electrical field stimulation consisting of pulse trains at an amplitude of 40 V and pulse duration of 1 ms at frequencies of 2–10 Hz. In this study, the pharmacological inhibitors atropine (muscarinic receptor antagonist), U73122 (phospholipase C inhibitor), DPCPX (adenosine A1 receptor antagonist), udenafil (PDE5 inhibitor), prazosin (α1-receptor antagonist), verapamil (calcium channel blocker), and chelerythrine (protein kinase C inhibitor) were used to pretreat bladder smooth muscles. It was found that the contractility of bladder smooth muscles from DM rats was lower than that of normal rats. In addition, there were significant differences in percent change of contractility between normal and DM rats following pretreatment with prazosin, udenafil, verapamil, and U73122. In conclusion, we suggest that the decreased bladder muscle contractility in DM rats was a result of perturbations in PLC/IP3-mediated intracellular Ca2+ release and PDE5 activity.
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Affiliation(s)
- Jong Soo Han
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Young Sil Min
- Department of Pharmaceutical Engineering, College of Convergence Science and Technology, Jung Won University, Goesan 28054, Korea
| | - Gil Hyung Kim
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Sang-Hyun Chae
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Yoonjin Nam
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
| | - Jaehwi Lee
- Pharmaceutical Formulation Design Laboratory, College of Pharmacy, Chung-Ang University , Seoul 06974, Korea
| | - Seok-Yong Lee
- Department of Pharmacology, School of Pharmacy, Sungkyunkwan University, Suwon 16419, Korea
| | - Uy Dong Sohn
- Department of Pharmacology, College of Pharmacy, Chung-Ang University, Seoul 06974, Korea
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Michel MC, Korstanje C. β3-Adrenoceptor agonists for overactive bladder syndrome: Role of translational pharmacology in a repositioning clinical drug development project. Pharmacol Ther 2016; 159:66-82. [PMID: 26808167 DOI: 10.1016/j.pharmthera.2016.01.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
β3-Adrenoceptor agonists were originally considered as a promising drug class for the treatment of obesity and/or type 2 diabetes. When these development efforts failed, they were repositioned for the treatment of the overactive bladder syndrome. Based on the example of the β3-adrenoceptor agonist mirabegron, but also taking into consideration evidence obtained with ritobegron and solabegron, we discuss challenges facing a translational pharmacology program accompanying clinical drug development for a first-in-class molecule. Challenges included generic ones such as ligand selectivity, species differences and drug target gene polymorphisms. Challenges that are more specific included changing concepts of the underlying pathophysiology of the target condition while clinical development was under way; moreover, a paucity of public domain tools for the study of the drug target and aspects of receptor agonists as drugs had to be addressed. Nonetheless, a successful first-in-class launch was accomplished. Looking back at this translational pharmacology program, we conclude that a specifically tailored and highly flexible approach is required. However, several of the lessons learned may also be applicable to translational pharmacology programs in other indications.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
| | - Cees Korstanje
- Department of Drug Discovery Science & Management-Europe, Astellas Pharma Europe R&D, Leiden, The Netherlands
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Köster U, Nolte I, Michel MC. Preclinical research strategies for newly approved drugs as reflected in early publication patterns. Naunyn Schmiedebergs Arch Pharmacol 2015; 389:187-99. [PMID: 26612507 DOI: 10.1007/s00210-015-1187-1] [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] [Received: 10/05/2015] [Accepted: 10/20/2015] [Indexed: 12/11/2022]
Abstract
The present study aimed to explore early publication patterns (i.e. up to 1 year after obtaining regulatory approval) for newly registered drugs. From the website of the US Food and Drug Administration, all newly approved drugs for 6 calendar years between 1991 and 2011 were identified. Non-clinical original publications for these compounds were retrieved from PubMed and their abstracts analysed for type of study and reported data. This yielded 170 compounds for which 1954 original non-clinical publications were identified, i.e. a median/mean of 5/11.5 publications per compound; however, number of publications per compound varied widely (0-90) and this variation exhibited a non-Gaussian distribution. The earliest non-clinical publication typically was published less than 5 years before regulatory approval and more than 5 years after filing of the primary patent, but some compounds exhibited notable deviations from this pattern. Publications most often reported on efficacy related to the target indication and on potential future indications, with fewer studies addressing mechanisms of action, potency, selectivity, pharmacokinetics and toxic effects. For most compounds, data at the cellular and in vivo level were published, with fewer reports on effects on isolated tissues and even fewer at the molecular level. The preferred species for cellular studies was human, whereas for in vivo studies, it was rats and mice. In 75 % of cases, the lead author of the publication came from an academic institution, and most studies were published in classic pharmacology journals. We conclude that number, timing and scope of early non-clinical publications on newly approved drugs exhibit major variance. Factors potentially associated with such variance are explored in a companion paper.
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Affiliation(s)
- Ursula Köster
- Klinik für Kleintiere, Tierärztliche Hochschule Hannover, Hannover, Germany
| | - Ingo Nolte
- Klinik für Kleintiere, Tierärztliche Hochschule Hannover, Hannover, Germany
| | - Martin C Michel
- Department of Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co KG, Ingelheim, Germany. .,Department of Pharmacology, Johannes Gutenberg University, Obere Zahlbacher Str. 67, 51101, Mainz, Germany.
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7
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Cernecka H, Kersten K, Maarsingh H, Elzinga CR, de Jong IJ, Korstanje C, Michel MC, Schmidt M. β3-Adrenoceptor-mediated relaxation of rat and human urinary bladder: roles of BKCa channels and Rho kinase. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:749-59. [PMID: 25956403 PMCID: PMC4475246 DOI: 10.1007/s00210-015-1128-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/23/2015] [Indexed: 12/18/2022]
Abstract
Previous studies suggest that the large-conductance Ca(2+)-activated K(+) (BKCa) channel and Rho-kinase play major roles in the control of urinary bladder tone. Here, we investigated their involvement in β-adrenoceptor (AR)-mediated relaxation of rat and human bladder. Concentration-response curves of isoprenaline and mirabegron-induced bladder relaxation were generated against passive tension and KCl- and carbachol-induced tone, in the absence or presence of the BKCa channel inhibitor iberiotoxin (100 nM) or the Rho-kinase inhibitor Y27,632 (1 μM). Myosin light chain (MLC) phosphorylation was studied by Western blot. In rat, iberiotoxin only slightly altered isoprenaline- and mirabegron-induced relaxation against KCl-induced tone but attenuated relaxation by both agonists against carbachol-induced tone. Y27,632 enhanced isoprenaline- or mirabegron-induced relaxation only against carbachol-induced tone. In humans, iberiotoxin slightly enhanced relaxation by both agonists against carbachol-induced pre-contraction. Y27,632 did not change isoprenaline-induced relaxation but enhanced that by mirabegron. Under passive tension, MLC phosphorylation was markedly reduced by both β-AR agonists, an effect insensitive to Y27,632. In the presence of carbachol, both β-AR agonists increased MLC phosphorylation, an effect reduced by Y27,632 only in the presence of 1 μM carbachol. These results indicate that the extent of BKCa channel and Rho-kinase involvement in relaxation induced by β-AR agonists depends on pre contractile stimulus and species.
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Affiliation(s)
- Hana Cernecka
- Department of Molecular Pharmacology, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands,
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Michel MC, Igawa Y. Therapeutic targets for overactive bladder other than smooth muscle. Expert Opin Ther Targets 2015; 19:687-705. [DOI: 10.1517/14728222.2015.1009447] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Michel MC, Seifert R. Selectivity of pharmacological tools: implications for use in cell physiology. A review in the theme: Cell signaling: proteins, pathways and mechanisms. Am J Physiol Cell Physiol 2015; 308:C505-20. [PMID: 25631871 DOI: 10.1152/ajpcell.00389.2014] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 01/24/2015] [Indexed: 01/08/2023]
Abstract
Pharmacological inhibitors are frequently used to identify the receptors, receptor subtypes, and associated signaling pathways involved in physiological cell responses. Based on the effects of such inhibitors conclusions are drawn about the involvement of their assumed target or lack thereof. While such inhibitors can be useful tools for a better physiological understanding, their uncritical use can lead to incorrect conclusions. This article reviews the concept of inhibitor selectivity and its implication for cell physiology. Specifically, we discuss the implications of using inhibitor vs. activator approaches, issues of direct vs. indirect pathway modulation, implications of inverse agonism and biased signaling, and those of orthosteric vs. allosteric, competitive vs. noncompetitive, and reversible vs. irreversible inhibition. Additional problems can result from inconsistent estimates of inhibitor potency and differences in potency between cell-free systems and intact cells. These concepts are illustrated by several examples of inhibitors displaying affinity for related but distinct targets or even unrelated targets. Of note, many of the issues being addressed are also applicable to genetic inhibition strategies. The main practical conclusion following from these concepts is that investigators should be critical in the choice of inhibitor, its concentrations, and its mode of application. When this advice is adhered to, small-molecule pharmacological inhibitors can be important experimental tools in the hand of physiologists.
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany; and
| | - Roland Seifert
- Department of Pharmacology, Hannover Medical School, Hannover, Germany
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Ribeiro ASF, Fernandes VS, Martínez MP, López-Oliva ME, Barahona MV, Recio P, Martínez AC, Blaha I, Orensanz LM, Bustamante S, García-Sacristán A, Prieto D, Hernández M. Pre- and post-junctional bradykinin B2 receptors regulate smooth muscle tension to the pig intravesical ureter. Neurourol Urodyn 2014; 35:115-21. [PMID: 25327836 DOI: 10.1002/nau.22685] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 09/02/2014] [Indexed: 02/04/2023]
Abstract
AIMS Neuronal and non-neuronal bradykinin (BK) receptors regulate the contractility of the bladder urine outflow region. The current study investigates the role of BK receptors in the regulation of the smooth muscle contractility of the pig intravesical ureter. METHODS Western blot and immunohistochemistry were used to show the expression of BK B1 and B2 receptors and myographs for isometric force recordings. RESULTS B2 receptor expression was consistently detected in the intravesical ureter urothelium and smooth muscle layer, B1 expression was not detected where a strong B2 immunoreactivity was observed within nerve fibers among smooth muscle bundles. On ureteral strips basal tone, BK induced concentration-dependent contractions, were potently reduced by extracellular Ca(2+) removal and by B2 receptor and voltage-gated Ca(2+) (VOC) channel blockade. BK contraction did not change as a consequence of urothelium mechanical removal or cyclooxygenase and Rho-associated protein kinase inhibition. On 9,11-dideoxy-9a,11a-methanoepoxy prostaglandin F2α (U46619)-precontracted samples, under non-adrenergic non-cholinergic (NANC) and nitric oxide (NO)-independent NANC conditions, electrical field stimulation-elicited frequency-dependent relaxations which were reduced by B2 receptor blockade. Kallidin, a B1 receptor agonist, failed to increase preparation basal tension or to induce relaxation on U46619-induced tone. CONCLUSIONS The present results suggest that BK produces contraction of pig intravesical ureter via smooth muscle B2 receptors coupled to extracellular Ca(2+) entry mainly via VOC (L-type) channels. Facilitatory neuronal B2 receptors modulating NO-dependent or independent NANC inhibitory neurotransmission are also demonstrated.
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Affiliation(s)
- Ana S F Ribeiro
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Vítor S Fernandes
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - María Pilar Martínez
- Departamento de Anatomía y Anatomía Patológica Comparadas, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
| | - María Elvira López-Oliva
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - María Victoria Barahona
- Departamento de Toxicología y Farmacología, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
| | - Paz Recio
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Ana Cristina Martínez
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Igor Blaha
- Departamento de Urología, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Luis M Orensanz
- Departamento de Investigación, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Salvador Bustamante
- Departamento de Urología, Hospital Universitario Puerta de Hierro-Majadahonda, Madrid, Spain
| | - Albino García-Sacristán
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Dolores Prieto
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
| | - Medardo Hernández
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense de Madrid, Madrid, Spain
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Michel MC. How significant are your data? The need for a culture shift. Naunyn Schmiedebergs Arch Pharmacol 2014; 387:1015-6. [PMID: 25172524 DOI: 10.1007/s00210-014-1044-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 08/21/2014] [Indexed: 01/20/2023]
Affiliation(s)
- Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Obere Zahlbacher Str. 67, 55101, Mainz, Germany,
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12
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Petkov GV. Central role of the BK channel in urinary bladder smooth muscle physiology and pathophysiology. Am J Physiol Regul Integr Comp Physiol 2014; 307:R571-84. [PMID: 24990859 DOI: 10.1152/ajpregu.00142.2014] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The physiological functions of the urinary bladder are to store and periodically expel urine. These tasks are facilitated by the contraction and relaxation of the urinary bladder smooth muscle (UBSM), also known as detrusor smooth muscle, which comprises the bladder wall. The large-conductance voltage- and Ca(2+)-activated K(+) (BK, BKCa, MaxiK, Slo1, or KCa1.1) channel is highly expressed in UBSM and is arguably the most important physiologically relevant K(+) channel that regulates UBSM function. Its significance arises from the fact that the BK channel is the only K(+) channel that is activated by increases in both voltage and intracellular Ca(2+). The BK channels control UBSM excitability and contractility by maintaining the resting membrane potential and shaping the repolarization phase of the spontaneous action potentials that determine UBSM spontaneous rhythmic contractility. In UBSM, these channels have complex regulatory mechanisms involving integrated intracellular Ca(2+) signals, protein kinases, phosphodiesterases, and close functional interactions with muscarinic and β-adrenergic receptors. BK channel dysfunction is implicated in some forms of bladder pathologies, such as detrusor overactivity, and related overactive bladder. This review article summarizes the current state of knowledge of the functional role of UBSM BK channels under normal and pathophysiological conditions and provides new insight toward the BK channels as targets for pharmacological or genetic control of UBSM function. Modulation of UBSM BK channels can occur by directly or indirectly targeting their regulatory mechanisms, which has the potential to provide novel therapeutic approaches for bladder dysfunction, such as overactive bladder and detrusor underactivity.
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Affiliation(s)
- Georgi V Petkov
- Department of Drug Discovery and Biomedical Sciences, South Carolina College of Pharmacy, University of South Carolina, Columbia, South Carolina
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