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Maria SA, Kumar A, Wilfred PM, Shanthi M, Peedicayil J. Inhibition of Contractility of Isolated Caprine Detrusor by the Calcium Channel Blocker Cilnidipine and Reversal by Calcium Channel Openers. CURRENT THERAPEUTIC RESEARCH 2023; 99:100717. [PMID: 37869401 PMCID: PMC10589763 DOI: 10.1016/j.curtheres.2023.100717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 09/26/2023] [Indexed: 10/24/2023]
Abstract
Background Cilnidipine is a fourth-generation calcium channel blocker that is clinically used to treat hypertension. It is a dihydropyridine that blocks L- and N-type calcium channels. The inhibitory effect of cilnidipine on isolated detrusor muscle contractility has not been studied. This study investigated the inhibitory effect of cilnidipine on isolated caprine (goat) detrusor muscle contractility and the reversal of the inhibition by calcium channel openers. Methods Fourteen caprine detrusor strips were made to contract using 80 mM potassium chloride before and after addition of three concentrations (20, 40, and 60 µM) of cilnidipine. Two reversal agents, the L-type calcium channel opener FPL64716, and the N-type calcium channel opener GV-58, were investigated for their ability to reverse the inhibitory effect of 40 µΜ cilnidipine on potassium chloride-induced detrusor contractility. Results Cilnidipine caused a dose-dependent and statistically significant inhibition of detrusor contractility at all concentrations of cilnidipine used (20, 40, and 60 µΜ). The inhibitory effect of 40 µM cilnidipine on detrusor contractility was significantly reversed by the addition of FPL64716 and GV-58. Conclusions Cilnidipine inhibits the contractility of the isolated detrusor by blocking L- and N-type calcium channels. Cilnidipine could be evaluated for treating clinical conditions requiring relaxation of the detrusor such as overactive bladder.
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Affiliation(s)
- Steffi A. Maria
- Department of Pharmacology & Clinical Pharmacology, Christian Medical College, Vellore, India
| | - Aniket Kumar
- Department of Pharmacology & Clinical Pharmacology, Christian Medical College, Vellore, India
| | - Premila M. Wilfred
- Department of Pharmacology & Clinical Pharmacology, Christian Medical College, Vellore, India
| | - Margaret Shanthi
- Department of Pharmacology & Clinical Pharmacology, Christian Medical College, Vellore, India
| | - Jacob Peedicayil
- Department of Pharmacology & Clinical Pharmacology, Christian Medical College, Vellore, India
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D’Agostino G, Salvatore S, Calvi P, Condino AM. Inhibition of prejunctional parasympathetic pathways by β 3-adrenoceptor agonists in the isolated pig detrusor: comparison with human detrusor studies. Front Pharmacol 2023; 14:1177653. [PMID: 37234719 PMCID: PMC10206075 DOI: 10.3389/fphar.2023.1177653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Adrenergic receptors of the β3-subtype (β3-ADRs) seem to represent a new target for a more effective pharmacological treatment of overactive bladder (OAB), a wide spread urinary disorder. A promising opportunity for OAB therapy might rely on the development of selective β3-ADR agonists, but an appropriate preclinical screening, as well as investigation of their pharmacological mechanism(s), is limited by poor availability of human bladder samples and of translational animal models. In this study, we used the porcine urinary bladder as experimental tool to ascertain the functions of β3-ADRs in the control the parasympathetic motor drive. Tritiated acetylcholine ([3H]-ACh), mainly originated from neural stores, was released by electrical field stimulation (EFS) in epithelium-deprived detrusor strips from pigs bred without estrogens. EFS produced simultaneously [3H]-ACh release and smooth muscle contraction allowing to asses neural (pre-junctional) and myogenic (postjunctional) effects in the same experiment. Isoprenaline and mirabegron produced on the EFS-evoked effects a concentration-dependent inhibition antagonized by L-748,337, a high selective β3-ADR antagonist. The analysis of the resultant pharmacodynamic parameters supports the notion that in pig detrusors, as well as in previously described human detrusors, the activation of inhibitory β3-ADRs can modulate neural parasympathetic pathways. In such inhibitory control, the involvement of membrane K+ channels, mainly of the SK type, seems to play a pivotal role similarly to what previously described in humans. Therefore, the isolated porcine detrusor can provide a suitable experimental tool to study the mechanisms underlying the clinical efficacy of selective β3-ADR compounds for human use.
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Affiliation(s)
| | - Stefano Salvatore
- Department of Obstetrics and Gynaecology, Vita-Salute San Raffaele University, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Calvi
- Cellini Clinic, Humanitas Group, Torino, Italy
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Wu S, Ootawa T, Sekio R, Smith H, Islam MZ, Uno Y, Shiraishi M, Miyamoto A. Involvement of beta3-adrenergic receptors in relaxation mediated by nitric oxide in chicken basilar artery. Poult Sci 2023; 102:102633. [PMID: 37001317 PMCID: PMC10070147 DOI: 10.1016/j.psj.2023.102633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/21/2023] [Accepted: 03/02/2023] [Indexed: 03/09/2023] Open
Abstract
The response of basilar arteries to noradrenaline varies among many animal species, but remains little studied in poultry. Accordingly, we aimed to characterize the adrenergic receptor (AR) subtypes that modulate vascular response in basilar arteries in the chicken, with isometric recording of arterial ring tension using an organ bath. We demonstrated the presence of both alpha and beta (α and β) receptor subtypes through evaluating the response to noradrenaline, with and without a range of β-AR and α-AR antagonists. The concentration-dependent relaxations then induced by a range of β-AR agonists indicated a potency ranking of isoproterenol > noradrenaline > adrenaline > procaterol. We then investigated the effects of β-AR antagonists that attenuate the effect of isoproterenol (propranolol for β1,2,3-ARs, atenolol for β1-ARs, butoxamine for β2-ARs, and SR 59230A for β3-ARs), with Schild regression analysis, ascertaining multiple β-AR subtypes, with neither the β1-AR nor the β2-AR as the dominant subtype. SR 59230A was the only antagonist to yield a pA2 value (7.52) close to the reported equivalent for the relevant receptor subtype. Furthermore, treatment with SR 58611 (a β3-AR agonist) induced relaxation, which was inhibited (P < 0.01) by L-NNA and SR 59230A. Additionally, treating basilar arterial strips (containing endothelium) with SR 58611 induced nitric oxide (NO) production, which was inhibited (P < 0.01) by L-NNA and SR 59230A. Based on this first characterization of AR subtypes in chicken basilar arteries (to our knowledge), we suggest that α- and β-ARs are involved in contraction and relaxation, and that β3-ARs, especially those on the endothelium, may play an important role in vasodilation via NO release.
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The Influence of an Adrenergic Antagonist Guanethidine on the Distribution Pattern and Chemical Coding of Caudal Mesenteric Ganglion Perikarya and Their Axons Supplying the Porcine Bladder. Int J Mol Sci 2021; 22:ijms22094896. [PMID: 34063103 PMCID: PMC8124201 DOI: 10.3390/ijms22094896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/23/2021] [Accepted: 04/27/2021] [Indexed: 11/17/2022] Open
Abstract
This study was aimed at disclosing the influence of intravesically instilled guanethidine (GUA) on the distribution, relative frequency and chemical coding of both the urinary bladder intramural sympathetic nerve fibers and their parent cell bodies in the caudal mesenteric ganglion (CaMG) in juvenile female pigs. GUA instillation led to a profound decrease in the number of perivascular nerve terminals. Furthermore, the chemical profile of the perivascular innervation within the treated bladder also distinctly changed, as most of axons became somatostatin-immunoreactive (SOM-IR), while in the control animals they were found to be neuropeptide Y (NPY)-positive. Intravesical treatment with GUA led not only to a significant decrease in the number of bladder-projecting tyrosine hydroxylase (TH) CaMG somata (94.3 ± 1.8% vs. 73.3 ± 1.4%; control vs. GUA-treated pigs), but simultaneously resulted in the rearrangement of their co-transmitters repertoire, causing a distinct decrease in the number of TH+/NPY+ (89.6 ± 0.7% vs. 27.8 ± 0.9%) cell bodies and an increase in the number of SOM-(3.6 ± 0.4% vs. 68.7 ± 1.9%), calbindin-(CB; 2.06 ± 0.2% vs. 9.1 ± 1.2%) or galanin-containing (GAL; 1.6 ± 0.3% vs. 28.2 ± 1.3%) somata. The present study provides evidence that GUA significantly modifies the sympathetic innervation of the porcine urinary bladder wall, and thus may be considered a potential tool for studying the plasticity of this subdivision of the bladder innervation.
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Carvalho MFD, Pamplona TL, Barreira MA, Fechine FVJ, Gonzaga-Silva LF, Oliveira RRMD. Effect of co-administration of BRL-37344 and tadalafil on reduction of overactive bladder symptoms after induction of detrusor overactivity in mice1. Acta Cir Bras 2019; 34:e201900205. [PMID: 30843938 PMCID: PMC6585915 DOI: 10.1590/s0102-8650201900205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/14/2019] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To evaluate the impact of the combination of BRL 37344 and tadalafil (TDF) on the reduction of overactive bladder (OB) symptoms. METHODS Thirty mice were randomized into 5 groups (G) of 6 animals each. L-NAME was used to induce DO. G1: Control; G2: L-NAME; G3: L-NAME + TDF; G4: L-NAME + BRL 37344; G5: L-NAME + TDF + BRL 37344. After 30 days of treatment, the animals were submitted to cystometry to evaluate non-voiding contractions (NVC), threshold pressure (TP), baseline pressure (BP), frequency of micturition (FM) and threshold volume (TV). Differences between the groups were analyzed with ANOVA followed by the Tukey test. RESULTS NVC increased in G2 (4.33±2.58) in relation to G1 (1.50±0.55). NVC decreased in G3 (2.00±1.10), G4 (1.50±1.52) and G5 (2.00±1.26) compared to G2 (p<0.05). FM decreased in G3 (0.97±0.71), G4 (0.92±0.38) and G5 (1.05±0.44) compared to G2 (p<0.05). However, the combination of TDF and BRL37344 was not more effective at increasing NVC and improving FM than either drug alone. The five groups did not differ significantly with regard to TV. CONCLUSION The combination of BRL 37344 and TDF produced no measurable additive effect on reduction of OB symptoms.
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Affiliation(s)
- Marcos Fiuza de Carvalho
- Fellow Master degree, Postgraduate Program in Medical Surgical Sciences, Universidade Federal do Ceará (UFC), Fortaleza-CE, Brazil. Conception and design of the study; technical procedures; acquisition, interpretation and analysis of data; manuscript preparation and writing
| | | | - Márcio Alencar Barreira
- Fellow PhD degree, Postgraduate Program in Medical Surgical Sciences, UFC, Fortaleza-CE, Brazil. Manuscript preparation and writing, critical revision
| | - Francisco Vagnaldo Jacuru Fechine
- PhD, Researcher, Nucleus of Research and Development of Medicines, Department of Pharmacology, UFC, Fortaleza-CE, Brazil. Analysis and interpretation of data, statistical analysis
| | - Lúcio Flávio Gonzaga-Silva
- PhD, Urologist, Department of Surgery, UFC, Fortaleza-CE, Brazil. Conception and design of the study, interpretation and analysis of data, critical revision, final approval
| | - Ricardo Reges Maia de Oliveira
- PhD, Urologist, Department of Surgery, UFC, Fortaleza-CE, Brazil. Conception and design of the study, interpretation and analysis of data, critical revision, final approval
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Linhares BL, Nascimento NRF, Gonzaga-Silva LF, Santos CF, Moraes MO, Marinho LB, Silva APG, Fonteles MC, Reges R. Effect of co-administration of two different phosphodiesterase inhibitors and a β3-adrenoceptor agonist in an experimental model of detrusor overactivity. Eur J Pharmacol 2018; 833:425-431. [DOI: 10.1016/j.ejphar.2018.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 02/07/2023]
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Yamanishi T. Editorial Comment from Dr Yamanishi to Long-term safety and efficacy of the novel β 3-adrenoreceptor agonist vibegron in Japanese patients with overactive bladder: A phase III prospective study. Int J Urol 2018; 25:676. [DOI: 10.1111/iju.13714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tomonori Yamanishi
- Department of Urology; Continence Center; Dokkyo Medical University; Mibu, Tochigi Japan
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Propping S, Roedel M, Wirth MP, Ravens U. Pharmacological Modulation of Mucosa-Related Impairment of β-Adrenoceptor-Mediated Relaxation in Human Detrusor. Urol Int 2015; 95:300-8. [DOI: 10.1159/000431260] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 05/07/2015] [Indexed: 11/19/2022]
Abstract
Objectives: The mucosa of human detrusor strips impairs catecholamine-induced relaxation. In order to elucidate which signal transduction pathways are involved in this cross talk between the mucosa and detrusor, we have studied the effects of several pharmacological agonists and antagonists on noradrenaline-mediated relaxation in intact and mucosa-denuded detrusor strips. Patients and Methods: Strips of detrusor tissue were obtained from patients who had undergone cystectomy for bladder cancer and were set up for force measurement. KCl- or carbachol-precontracted strips were relaxed with increasing concentrations of noradrenaline in the absence and in the presence of nitric oxide synthase inhibitor, L-NAME; P2X-receptor antagonist, PPADS; ETA-receptor antagonist, BQ-123; ETB-receptor antagonist, BQ-788; cyclooxygenase inhibitor, diclofenac; AT1-receptor antagonist, candesartan; and NK1-receptor antagonist, L-703,606. Results: In intact strips, KCl-stimulated force was enhanced by all blockers; carbachol-stimulated force increased with L-703,606. In denuded strips, only L-NAME augmented the KCl-stimulated contraction. Noradrenaline relaxed the precontracted detrusor strips to a significantly larger extent and at lower concentrations in denuded than in intact strips. L-NAME, PPADS and BQ-123/BQ-788 had little effect on noradrenaline-induced relaxation, whereas diclofenac, candesartan and L-703,606 sensitized intact carbachol-stimulated detrusor strips to noradrenaline-induced relaxation. Conclusion: Inhibition of the noradrenaline-induced relaxation of precontracted human detrusor strips by the mucosa is attenuated by diclofenac, candesartan and L-703,606 suggesting the involvement of prostanoids, angiotensin and neurokinin pathways. Further experiments are required to unravel the exact mechanisms.
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Propping S, Newe M, Kaumann AJ, Wirth MP, Ravens U. Mucosa of murine detrusor impairs β2 -adrenoceptor-mediated relaxation. Neurourol Urodyn 2014; 34:592-7. [PMID: 24820256 DOI: 10.1002/nau.22627] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 04/14/2014] [Indexed: 11/11/2022]
Abstract
AIMS To investigate the role of the mucosa in (-)-isoprenaline-induced relaxation of mouse detrusor muscle and to characterize the β-adrenoceptor subtypes involved. METHODS Isolated intact and mucosa-denuded muscle strips from the urinary bladder of male C57BL6 mice were pre-contracted with KCl (40 mM) and were relaxed with increasing concentrations of the β-adrenoceptor (β-AR) agonist (-)-isoprenaline and forskolin in the presence and absence of the subtype-selective β-AR blockers CGP20712A (β1 -ARs), ICI118,551 (β2 -ARs), and L748,337 (β3 -ARs). RESULTS Force development in response to KCl was larger in mucosa-denuded than in intact preparations and was almost completely relaxed with increasing concentrations of (-)-isoprenaline. Mucosa-denuded muscles were about 10-fold more sensitive to (-)-isoprenaline than intact muscles. CGP20712A did not affect the concentration-response curves (CRCs) to (-)-isoprenaline, ICI118,551 shifted the CRC further to the right in denuded than in intact strips so that the difference between them was abolished. Combined exposure to β1 -AR and β2 -AR blocker yielded the same result. L748,337 did not significantly affect the CRC to (-)-isoprenaline but caused additional blockade to ICI118,551 in the presence of intact mucosa. CONCLUSIONS The mucosa of mouse detrusor strips impairs KCl-induced force development and reduces the sensitivity to β-AR-induced relaxation. The relaxing response to (-)-isoprenaline as well as the mucosa effect thereupon are mainly mediated by β2 -ARs. A minor involvement of β3 -ARs becomes apparent particularly at high (-)-isoprenaline concentrations.
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Affiliation(s)
- Stefan Propping
- Department of Pharmacology and Toxicology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany.,Department of Urology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Manja Newe
- Department of Pharmacology and Toxicology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | | | - Manfred P Wirth
- Department of Urology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Ursula Ravens
- Department of Pharmacology and Toxicology, Medizinische Fakultät Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
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D'Auria E, Mandelli M, Di Dio F, Riva E. Urine retention in a child treated with oral salbutamol. Indian J Pharmacol 2013; 44:519-20. [PMID: 23087518 PMCID: PMC3469960 DOI: 10.4103/0253-7613.99338] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 04/07/2012] [Accepted: 04/30/2012] [Indexed: 12/02/2022] Open
Abstract
It is known that voiding difficulties can be caused by some drugs, but little is known about the role about the route of administration, especially in children. We report here a case of a 3-year old Italian boy referred to the Pediatric Emergency Unit complaining of two episodes of acute urinary retention, both after therapy with oral salbutamol. In spite of recommendations to use inhaled salbutamol to treat acute wheezing, oral salbutamol is still sometimes used in some settings. Whereas other side effects of systemic salbutamol are described in children, to our knowledge this is the first description of acute urinary retention as an adverse drug reaction to oral salbutamol.
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Affiliation(s)
- Enza D'Auria
- Department of Paediatrics, San Paolo Hospital, University of Milan, Italy
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Propping S, Wuest M, Eichhorn B, Wirth MP, Kaumann AJ, Ravens U. Mucosa of human detrusor impairs contraction and β-adrenoceptor-mediated relaxation. BJU Int 2013; 112:1215-22. [DOI: 10.1111/bju.12267] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Stefan Propping
- Department of Urology; Dresden University of Technology; Dresden Germany
| | - Melinda Wuest
- Department of Pharmacology and Toxicology; Dresden University of Technology; Dresden Germany
| | - Birgit Eichhorn
- Department of Pharmacology and Toxicology; Dresden University of Technology; Dresden Germany
| | - Manfred P. Wirth
- Department of Urology; Dresden University of Technology; Dresden Germany
| | - Alberto J. Kaumann
- Department of Physiology; Development and Neuroscience; University of Cambridge; Cambridge UK
| | - Ursula Ravens
- Department of Pharmacology and Toxicology; Dresden University of Technology; Dresden Germany
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12
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Brosnahan AJ, Vulchanova L, Witta SR, Dai Y, Jones BJ, Brown DR. Norepinephrine potentiates proinflammatory responses of human vaginal epithelial cells. J Neuroimmunol 2013; 259:8-16. [PMID: 23571017 DOI: 10.1016/j.jneuroim.2013.03.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 03/11/2013] [Accepted: 03/15/2013] [Indexed: 11/17/2022]
Abstract
The vaginal epithelium provides a barrier to pathogens and recruits immune defenses through the secretion of cytokines and chemokines. Several studies have shown that mucosal sites are innervated by norepinephrine-containing nerve fibers. Here we report that norepinephrine potentiates the proinflammatory response of human vaginal epithelial cells to products produced by Staphylococcus aureus, a pathogen that causes menstrual toxic shock syndrome. The cells exhibit immunoreactivity for catecholamine synthesis enzymes and the norepinephrine transporter. Moreover, the cells secrete norepinephrine and dopamine at low concentrations. These results indicate that norepinephrine may serve as an autocrine modulator of proinflammatory responses in the vaginal epithelium.
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Affiliation(s)
- Amanda J Brosnahan
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, 75 Animal Science/Veterinary Medicine, 1988 Fitch Ave, Saint Paul, MN 55108, United States
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Moro C, Chess-Williams R. Non-adrenergic, non-cholinergic, non-purinergic contractions of the urothelium/lamina propria of the pig bladder. ACTA ACUST UNITED AC 2013; 32:53-9. [PMID: 22994938 DOI: 10.1111/aap.12000] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Acetylcholine, and to a lesser extent ATP, mediates neurogenic contractions of bladder smooth muscle. Recently, the urothelium and lamina propria have also been shown to have contractile properties, but the neurotransmitters involved in mediating responses to nerve stimulation have not been investigated. Isolated strips of porcine urothelium with lamina propria were electrically field stimulated and contractions recorded. Drugs interfering with neurotransmission were then employed to identify which neurotransmitters mediated responses. Strips of urothelium/lamina propria developed spontaneous contractions with a frequency of 3.5±0.1 cycles min⁻¹ and amplitude of 0.84±0.06 g. Electrical field stimulation at 5, 10, and 20 Hz resulted in frequency-related contractions (1.13±0.36 g, 1.59±0.46 g and 2.20±0.53 g, respectively, n=13), and these were reduced in the presence of tetrodotoxin (1 μm) by 77±20% at 5 Hz, 79±7% at 10 Hz and 74±12% at 20 Hz (all P<0.01), indicating they were predominantly neurogenic in nature. Neither the muscarinic antagonist atropine (10 μm), the adrenergic neurone blocker guanethidine (10 μm) nor desensitization of the purinergic receptors with α,β-methylene ATP (10 μm) affected the contractile amplitude. Similarly, responses were not affected by the nitric oxide synthase inhibitor L-NNA (100 μm) or drugs that interfere with peptide neurotransmission (capsaicin, NK2 antagonist GR159897, protease inhibitors). In conclusion, electrical depolarization of the nerves present in the porcine urothelium/lamina propria results in frequency-dependent contractions, which are predominantly neurogenic in nature. These contractions are resistant to drugs that inhibit the adrenergic, cholinergic and purinergic systems. The neurotransmitter involved in the responses of this tissue is therefore unknown but does not appear to be a peptide.
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Affiliation(s)
- C Moro
- Faculty of Health Sciences and Medicine, Bond University, Queensland, 4229, Australia
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Yamaguchi O. Latest treatment for lower urinary tract dysfunction: therapeutic agents and mechanism of action. Int J Urol 2012. [PMID: 23190275 DOI: 10.1111/iju.12008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Recent studies suggest that antimuscarinics might suppress bladder afferent activity by blocking muscarinic receptors in the urothelium, myofibroblasts and detrusor, thereby improving overactive bladder symptoms. β(3)-Adrenoceptors are predominantly expressed in the human bladder and mediate relaxation of detrusor muscle. β(3)-Adrenoceptor agonists increase bladder capacity and prolong micturition interval. It is assumed that β(3)-adrenoceptor agonists could exert an inhibitory effect on bladder afferent through β(3)-adrenoceptors in the urothelium and detrusor, which eventually improve the symptom of urgency. Mirabegron is a potent and selective β(3)-adrenoceptor agonist. A Japanese phase 3 study showed that mirabegron has excellent efficacy and safety for treating overactive bladder. α(1)-Adrenoceptor antagonists (α(1)-blockers) have become a mainstay of male lower urinary tract symptoms treatment. The α(1)(A) subtype is known to mediate functional obstruction as a result of benign prostatic enlargement. Recent studies have suggested that α(1)(A)-adrenoceptors are additionally involved in the generation of storage symptoms. The α(1)(D) subtype is thought to play a role in the facilitation of voiding reflex; that is; storage symptoms. α(1)-Blockers often fail to alleviate overactive bladder symptoms. In this context, combination therapy with α(1)-blockers and antimuscarinics has been recommended. Treatment with 5α-reductase inhibitor for 1 year improves urinary symptoms and flow rate by reducing prostatic volume in men with benign prostatic enlargement. A pooled analysis showed that the long-term (2 or 4 years) treatment with 5α-reductase inhibitor reduced the rate of progression to acute urinary retention and surgery. Combination therapy with 5α-reductase inhibitor and α(1)-blocker was shown to provide a rapid improvement in lower urinary tract symptoms, and reduce the relative risk of acute urinary retention and benign prostatic hyperplasia-related surgery. Phosphodiesterase inhibitors might target a nitric oxide-cyclic guanosine monophosphate pathway in the prostate, urethra and bladder. Phosphodiesterase-5 inhibitors (sildenafil or tadalafil) were shown to provide clinically relevant improvements in both male lower urinary tract symptoms and erectile dysfunction.
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Affiliation(s)
- Osamu Yamaguchi
- Division of Bioengineering and LUTD Research, Nihon University School of Engineering, Koriyama, Japan.
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Maruyama I, Tatemichi S, Goi Y, Maruyama K, Hoyano Y, Yamazaki Y, Kusama H. Effects of ritobegron (KUC-7483), a novel selective β3-adrenoceptor agonist, on bladder function in cynomolgus monkey. J Pharmacol Exp Ther 2012; 342:163-8. [PMID: 22511202 DOI: 10.1124/jpet.112.191783] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We evaluated the pharmacological profile of ritobegron [KUC-7483; (-)-ethyl 2-[4-(2-{[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino}ethyl)-2,5-dimethylphenyloxy]acetate monohydrochloride] and its effects on the bladder in cynomolgus monkeys by in vitro and in vivo experiments. In vitro, ritobegron decreased the resting tension of the isolated bladder in a concentration-dependent manner (EC(50) 8.2 ± 2.3 × 10(-7) M; maximal relaxation 88.7 ± 3.7%). The β(3)-adrenoceptor (AR) antagonist 3-(2-allylphenoxy)-1-[(1S)-1,2,3,4-tetrahydronaphth-1-ylamino]-(2S)-2-propanol hydrochloride (SR58894A) produced a rightward shift of this concentration-response curve without altering the maximal response (pK(B) value 6.56 ± 0.35). In isolated atria, ritobegron increased the atrial rate only at high concentrations (EC(50) 6.5 ± 1.2 × 10(-5) M). Ritobegron had no effect on tracheal contraction at concentrations from 10(-9) to 10(-4) M, and even at the highest concentration tested, 10(-3) M, the maximal relaxation it induced was only 26.7 ± 8.1%. Tests of the selectivity of ritobegron for the bladder gave values of 79.3- and 1200-fold higher versus atria and trachea, respectively. In the in vivo study ritobegron significantly decreased intravesical pressure (ED(50) 1.44 mg/kg) without affecting either mean blood pressure or heart rate. In conclusion, ritobegron displayed potent and selective β(3)-AR agonistic activity and relaxed the monkey isolated bladder, and in vivo it decreased intravesical pressure without affecting cardiovascular parameters. These results suggest that ritobegron may be a promising potential agent for the treatment of overactive bladder.
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Affiliation(s)
- Itaru Maruyama
- Central Research Laboratories, Kissei Pharmaceutical Co., Ltd., 4365-1, Kashiwabara, Hotaka, Azumino-City, Nagano-Pref. 399-8304, Japan.
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Abstract
Much of the current research on lower urinary tract dysfunction is focused on afferent mechanisms. The main goals are to define and modulate the signaling pathways by which afferent information is generated and conveyed to the central nervous system. Alterations in bladder afferent mechanisms are a potential source of voiding dysfunction and an emerging source of drug targets. Even some established drug therapies such as muscarinic receptor antagonists, as well as emerging therapies such as botulinum toxin type-A, may act partly through afferent mechanisms. This review presents up-to-date findings on the localization of afferent fiber types within the bladder wall, afferent receptors and transmitters, and how these may communicate with the urothelium, interstitial cells, and detrusor smooth muscle to regulate micturition in normal and pathological bladders. Peripheral and central mechanisms of afferent sensitization and myogenic mechanisms that lead to detrusor overactivity, overactive bladder symptoms, and urgency sensations are also covered as well as new therapeutic approaches and new and established methods of measuring afferent activity.
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Affiliation(s)
- Anthony J Kanai
- University of Pittsburgh, School of Medicine, Pittsburgh, PA15261, USA.
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Igawa Y, Aizawa N, Homma Y. Beta3-adrenoceptor agonists: possible role in the treatment of overactive bladder. Korean J Urol 2010; 51:811-8. [PMID: 21221199 PMCID: PMC3016425 DOI: 10.4111/kju.2010.51.12.811] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 12/02/2010] [Indexed: 01/01/2023] Open
Abstract
In the present review article, we present an overview of beta-adrenoceptor (β-AR) subtype expression at the mRNA and receptor protein levels in the human detrusor, the in vitro and in vivo bladder function of the β3-AR, the in vivo effect of β3-AR agonists on detrusor overactivity in animal models, and the available results of clinical trials of β3-AR agonists for treating overactive bladder (OAB). There is a predominant expression of β3-AR mRNA in human bladder, constituting 97% of total β-AR mRNA. Also, functionally, the relaxant response of human detrusor to catecholamines is mainly mediated through the β3-ARs. Moreover, the presence of β1-, β2-, and β3-AR mRNAs in the urothelium and suburothelial layer of human bladder has been identified. Stimulation of urothelial β-ARs results in the release of nitric oxide and an unknown substance inhibiting detrusor contractions from the urothelium. Intravenous application of CL316,243, a selective β3-AR agonist, in rats selectively inhibits mechano-sensitive Aδ-fiber activity of the primary bladder afferents. A number of selective β3-AR agonists are currently being evaluated in clinical trials for OAB with promising preliminary results. In conclusion, the β3-AR agonists are the most notable alternative class of agents to antimuscarinics in the pharmacological treatment of OAB. The β3-AR agonists act to facilitate bladder storage function probably through at least two mechanisms: first, direct inhibition of the detrusor, and second, inhibition of bladder afferent neurotransduction.
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Affiliation(s)
- Yasuhiko Igawa
- Department of Continence Medicine, University of Tokyo Graduate School of Medicine, Tokyo, Japan
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Limberg BJ, Andersson KE, Aura Kullmann F, Burmer G, de Groat WC, Rosenbaum JS. β-Adrenergic receptor subtype expression in myocyte and non-myocyte cells in human female bladder. Cell Tissue Res 2010; 342:295-306. [PMID: 20953633 DOI: 10.1007/s00441-010-1053-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 09/08/2010] [Indexed: 12/15/2022]
Abstract
β(3)-Adrenergic receptor agonists are currently under clinical development for the treatment of overactive bladder, a condition that is prevalent in postmenopausal women. These agents purportedly relax bladder smooth muscle through a direct action at the myocyte β(3)-receptor. The aim of this study was to examine the expression of the individual beta-adrenergic receptors in full thickness sections from ageing human female bladder. We obtained a series of rabbit polyclonal antibodies generated against each of the three β-adrenergic receptors, and validated their receptor specificity in CHOK1 cells expressing each of the individual receptors. Immunostaining for β(1), β(2), and β(3) were each more prominent in the urothelium than in the detrusor, with all receptors expressed in the same cell types, indicating co-expression of all three receptors throughout the urothelium in addition to the detrusor. Staining of all receptors was also observed in suburothelial myofibroblast-like cells, intramural ganglion cells, and in Schwann cells of intramural nerves. The β(3)-receptor in the human urothelium appears to be functional, as two different selective β(3)-receptor agonists, TAK677 and BRL37344, stimulate cAMP formation in URO tsa cells. Densitometry analysis indicates a persistent expression of all receptors throughout the bladder with increasing age, with the exception of the β(2)-receptor in the urothelium of the trigone, which appears to decrease slightly in older women. These data indicate that β(3)-receptor expression is maintained with age, but may function in concert with other β-receptors. Activation of the myocyte receptor may be influenced by action on non-myocyte structures including the intramural ganglion cells and myofibroblasts.
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Affiliation(s)
- Brian J Limberg
- Women's Health New Business Development, Procter & Gamble Pharmaceuticals now Warner Chilcott Pharmaceuticals Inc., Mason, OH, USA.
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Tatsumiya K, Yamanishi T, Watanabe M, Masuda A, Mizuno T, Kamai T, Yoshida KI. Effects of fasudil, a Rho-kinase inhibitor, on contraction of pig bladder tissues with or without urothelium. Int J Urol 2010; 16:959-66. [PMID: 19817915 DOI: 10.1111/j.1442-2042.2009.02397.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVES To investigate the effects of fasudil, a Rho-associated serine-threonine protein kinase inhibitor, on contraction of the pig urinary bladder tissues with or without urothelium. METHODS Cumulative concentration-response curves (CRCs) to carbachol were obtained with and without 3-10 microM fasudil. Drug effects were evaluated in detrusor with and without urothelium. Inhibitory responses to fasudil were also examined in tissues precontracted with KCl and carbachol, and in response to electrical field stimulation, in pig bladder with and without urothelium. RESULTS In detrusor without urothelium, maximum contraction (E(max)) decreased after administration of fasudil at 3 or 10 micromol/L (both P < 0.01), or 30 micromol/L (72.5 + or - 7.43%, 58.4 + or - 8.04% and 68.4 + or - 9.6%, respectively, of the first curve). In detrusor with urothelium, E(max) decreased significantly (all P < 0.05) after the addition of 3, 10 or 30 micromol/L of fasudil (84.9 + or - 6.7%, 67.9 + or - 5.2% and 35.2 + or - 4.1%, respectively). In tissues precontracted with 80 mmol/L KCl or 100 micromol/L carbachol, tension after administration of fasudil (1 nmol/L to 100 micromol/L) decreased (by approximately 40%), only after administration of fasudil at high concentration (>1 micromol/L), in detrusor both with and without urothelium. In tissues with and without urothelium, responses to electrical field stimulation at 1-50 Hz decreased significantly in a concentration-dependent manner after addition of fasudil (3 to 30 micromol/L). CONCLUSIONS Fasudil seems to provoke relaxation of the bladder detrusor via both urothelium-dependent and independent pathways.
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Masunaga K, Chapple CR, McKay NG, Yoshida M, Sellers DJ. The β3
-adrenoceptor mediates the inhibitory effects of β-adrenoceptor agonists via the urothelium in pig bladder dome. Neurourol Urodyn 2010; 29:1320-5. [DOI: 10.1002/nau.20838] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Otsuka A, Shinbo H, Hasebe K, Matsumoto R, Ozono S. Effects of a novel beta(3)-adrenoceptor agonist, AJ-9677, on relaxation of the detrusor muscle: an in vitro study. Int J Urol 2009; 15:1072-6. [PMID: 19120515 DOI: 10.1111/j.1442-2042.2008.02165.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To examine the relaxant effects of AJ-9677, a novel beta(3)-adrenoceptor agonist, on the isolated rat, monkey and human detrusor muscle. METHODS The isolated detrusor strips of rats, monkeys and humans were mounted in organ baths containing Krebs solution. By the cumulative addition of beta-adrenoceptor agonists (isoproterenol, AJ-9677, CL 316,243 and salbutamol in rats; isoproterenol, AJ-9677 and CL 316,243 in monkeys and humans), concentration-relaxation curves were obtained. The maximal relaxation responses and pEC(50) values were calculated. In rats, concentration-relaxation curves to isoproterenol and AJ-9677 were obtained in the presence and absence of propranolol or SR 59230A. RESULTS Isoproterenol, AJ-9677, CL 316,243 and salbutamol induced concentration-dependent relaxation in rats. The rank order of their relaxing potency in the rat detrusor muscle was AJ-9677 > isoproterenol > CL 316,243 > salbutamol. Isoproterenol and AJ-9677 also produced a concentration-dependent relaxation with high potency in monkeys and humans, whilst CL 316,243 had low relaxing potency. According to the antagonist studies in rats, propranolol and SR 59230A caused a rightward shift of the concentration-relaxation curves to isoproterenol or AJ-9677, respectively. CONCLUSIONS AJ-9677 has a high relaxant potency on the rat, monkey and human detrusor smooth muscle, and it may have the potential to treat overactive bladder.
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Affiliation(s)
- Atsushi Otsuka
- Department of Urology, Hamamatsu University School of Medicine, Kamakura, Kanagawa, Japan.
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22
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Rojanathammanee L, Harmon EB, Grisanti LA, Govitrapong P, Ebadi M, Grove BD, Miyagi M, Porter JE. The 27-kDa heat shock protein confers cytoprotective effects through a beta 2-adrenergic receptor agonist-initiated complex with beta-arrestin. Mol Pharmacol 2009; 75:855-65. [PMID: 19176359 DOI: 10.1124/mol.108.053397] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heat shock proteins represent an emerging model for the coordinated, multistep regulation of apoptotic signaling events. Although certain aspects of the biochemistry associated with heat shock protein cytoprotective effects are known, little information is found describing the regulation of heat shock protein responses to harmful stimuli. During screening for noncanonical beta adrenergic receptor signaling pathways in human urothelial cells, using mass spectroscopy techniques, an agonist-dependent interaction with beta-arrestin and the 27-kDa heat shock protein was observed in vitro. Formation of this beta-arrestin/Hsp27 complex in response to the selective beta adrenergic receptor agonist isoproterenol, was subsequently confirmed in situ by immunofluorescent colocalization studies. Radioligand binding techniques characterized a homogeneous population of the beta2 adrenergic receptor subtype expressed on these cells. Using terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling, immunoblot analysis and quantitation of caspase-3 activity to detect apoptosis, preincubation of these cells with isoproterenol was found to be sufficient for protection against programmed cell death initiated by staurosporine. RNA interference strategies confirmed the necessity for Hsp27 as well as both beta-arrestin isoforms to confer this cytoprotective consequence of beta adrenergic receptor activation in this cell model. As a result, these studies represent the first description of an agonist-dependent relationship between a small heat shock protein and beta-arrestin to form a previously unknown antiapoptotic "signalosome."
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Affiliation(s)
- Lalida Rojanathammanee
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota, Grand Forks, ND 58202-9037, USA
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Abstract
PURPOSE OF REVIEW The overactive bladder is a common and distressing condition that has a significant impact on the quality of life of many people worldwide. Anticholinergics remain the first line in pharmacotherapy, however the use of these agents is hindered by adverse effects and limited efficacy. Thus there is a need for more effective treatments. Recently, there has been a move towards targeting novel pathways thought to play a role in overactivity. This review aims to provide an insight into the recent developments in pharmacotherapy of the overactive bladder. RECENT FINDINGS With recent advances in our understanding of the basic science of the overactive bladder it is becoming clear that the control of bladder functioning is far more complex than previously believed. Peripherally, a prominent role has emerged for the urothelium and the underlying suburothelium in mechanosensory control, and the role of afferent pathways in pathophysiology is increasingly recognized. SUMMARY Recent research has highlighted several potential targets for treatment of the overactive bladder, particularly within the mechanosensory pathways. With the exception of botulinum toxin, however, few new therapies have emerged showing clinical benefits. A clearer understanding of the pathophysiology of the bladder will hopefully lead to more effective and tolerated treatments.
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Affiliation(s)
- Donna J Sellers
- Biomedical Research Centre, Sheffield Hallam University, Sheffield, UK.
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Hicks A, McCafferty GP, Riedel E, Aiyar N, Pullen M, Evans C, Luce TD, Coatney RW, Rivera GC, Westfall TD, Hieble JP. GW427353 (solabegron), a novel, selective beta3-adrenergic receptor agonist, evokes bladder relaxation and increases micturition reflex threshold in the dog. J Pharmacol Exp Ther 2007; 323:202-9. [PMID: 17626794 DOI: 10.1124/jpet.107.125757] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Functional studies have demonstrated that adrenoceptor agonist-evoked relaxation is mediated primarily by beta3-adrenergic receptors (ARs) in human bladder. Thus, the use of selective beta3-AR agonists in the pharmacological treatment of overactive bladder is being explored. The present studies investigated the effects of a novel selective beta3-AR agonist, (R)-3'-[[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]amino]ethyl]amino]-[1,1'-biphenyl]-3-carboxylic acid (GW427353; solabegron) on bladder function in the dog using in vitro and in vivo techniques. GW427353 stimulated cAMP accumulation in Chinese hamster ovary cells expressing the human beta3-AR, with an EC50 value of 22 +/- 6 nM and an intrinsic activity 90% of isoproterenol. At concentrations of 10,000 nM, GW427353 produced a minimal response in cells expressing either beta1-ARs or beta2-ARs (maximum response <10% of that to isoproterenol). In dog isolated bladder strips, GW427353 evoked relaxation that was attenuated by the nonselective beta-AR antagonist bupranolol and 1-(2-ethylphenoxy)-3-[[(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]-(2S)-2-propanol (SR59230A) (reported to have beta3-AR antagonist activity). The relaxation was unaffected by atenolol, a selective beta1-AR antagonist, or (+/-)-1-[2,3-(dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol (ICI 118551), a selective beta2-AR antagonist. GW427353 increased the volume required to evoke micturition in the anesthetized dog following acetic acid-evoked bladder irritation, without affecting the ability of the bladder to void. GW427353-evoked effects on bladder parameters in vivo were inhibited by bupranolol. The present study demonstrates that selective activation of beta3-AR with GW427353 evokes bladder relaxation and facilitates bladder storage mechanisms in the dog.
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Affiliation(s)
- Alexandra Hicks
- Department of Cardiovascular and Urogenital Biology, Cardiovascular and Urogenital Center of Excellence for Drug Discovery, GlaxoSmithKline Pharmaceuticals, 709 Swedeland Rd., P.O. Box 1539, King of Prussia, PA 19406, USA
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Murakami S, Chapple CR, Akino H, Sellers DJ, Chess-Williams R. The role of the urothelium in mediating bladder responses to isoprenaline. BJU Int 2007; 99:669-73. [PMID: 17407521 DOI: 10.1111/j.1464-410x.2006.06679.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To investigate whether the responses of the pig bladder to isoprenaline (a nonselective beta-adrenoceptor agonist) are influenced by the presence of an intact urothelium and whether any influence might be attributed to the release of nitric oxide (NO), since stimulation of beta-adrenoceptors induces a direct relaxation of detrusor smooth muscle and beta-adrenoceptors are also present on the urothelium. MATERIAL AND METHODS Paired (in the presence or absence of urothelium) longitudinal strips of pig bladder dome were set up in tissue baths and the developed tension recorded. Relaxation responses to isoprenaline were examined after pre-contraction with carbachol. The inhibitory effects of isoprenaline were examined by comparing responses to carbachol in the absence and presence of isoprenaline. To examine a possible role for NO, similar experiments were performed in the presence of the NO synthase inhibitor N(G)-nitro-L-arginine (L-NNA). RESULTS In the presence of the urothelium, both the potency (pEC(50)) and the maximum contractile responses to carbachol were depressed. In relaxation experiments, isoprenaline relaxed carbachol pre-contracted tissues by approximately 75%, and the potency and maximum relaxation were similar in the absence and presence of the urothelium. In the inhibition experiments, the presence of isoprenaline caused rightward parallel shifts of the concentration-response curves to carbachol, but isoprenaline did not influence the maximum contractions. In the presence of the urothelium there was a greater shift with 0.1 microm isoprenaline than in denuded tissues. Incubation with L-NNA did not affect the influence of the urothelium on responses to isoprenaline in any experimental group. CONCLUSIONS The relaxation responses of the bladder to isoprenaline do not appear to involve the urothelium or NO release in vitro. However, contractile responses to carbachol were inhibited in the presence of an intact urothelium, and this might reflect the release of an inhibitory factor other than NO.
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Affiliation(s)
- Shigetaka Murakami
- Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield, UK
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26
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Vrydag W, Michel MC. Tools to study beta3-adrenoceptors. Naunyn Schmiedebergs Arch Pharmacol 2007; 374:385-98. [PMID: 17211601 DOI: 10.1007/s00210-006-0127-5] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2006] [Accepted: 11/22/2006] [Indexed: 12/21/2022]
Abstract
Beta(3)-adrenoceptors mediate some of the effects of catecholamines on tissues such as blood vessels or the urinary bladder and are putative targets for the treatment of diseases such as the overactive bladder syndrome. Progress in the understanding of the presence, function, and regulation of beta(3)-adrenoceptors has been hampered by a lack of highly specific tools. "Classical" beta(3)-adrenoceptor agonists such as BRL 37,344 [(R*, R*)-(+/-)-4[2-[(3-chlorophenyl)-2-hydroxyethyl) amino] propyl] phenoxyacetic acid] and CGP 12,177 [(+/-)-4-(3-t-butylamino-2-hydroxypropoxy)benzimidazol-2-one] are only partial agonists in many settings, have limited selectivity over other beta-adrenoceptor subtypes, and may additionally act on receptors other than beta-adrenoceptors. More efficacious and more selective agonists have been reported and, in some cases, are in clinical development but are not widely available for experimental studies. The widely used antagonist SR 59,230 [3-(2-ethylphenoxy)-1-[(1,S)-1,2,3,4-tetrahydronapth-1-ylamino]-2S-2-propanoloxalate] is not selective for beta(3)-adrenoceptors, at least in humans, and may actually be a partial agonist. Radioligands, which are suitable either for the selective labeling of beta(3)-adrenoceptors or for the nonselective labeling of all beta-adrenoceptor subtypes, are also missing. beta(3)- and beta(1)/beta(2) double knockout mice have been reported, but their usefulness for extrapolations in humans is questionable based upon major differences between humans and rodents with regard to the ligand recognition and expression profiles of beta(3)-adrenoceptors. While the common availability of more selective agonists and antagonists at the beta(3)-adrenoceptor is urgently awaited, the limitations of the currently available tools need to be considered in studies of beta(3)-adrenoceptor for the time being.
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Affiliation(s)
- Wim Vrydag
- Department Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
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27
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Abstract
The beta-adrenoceptor (AR) is currently classified into beta(1), beta(2), and beta(3) subtypes. A third subtype, beta(3)-AR, was first identified in adipose tissue, but has also been identified in smooth muscle tissue, particularly in the gastrointestinal tract and urinary bladder smooth muscle. There is a predominant expression of beta(3)-AR messenger RNA (mRNA) in human bladder, with 97% of total beta-AR mRNA being represented by the beta(3)-AR subtype and only 1.5 and 1.4% by the beta(1)-AR and beta (2)-AR subtypes, respectively. Moreover, the presence of beta(1)-, beta(2)-, and beta(3)-AR mRNAs in the urothelium of human bladder has been identified. The distribution of beta-AR subtypes mediating detrusor muscle relaxation is species dependent, the predominant subtype being the beta(3)-AR in humans. Recent studies have suggested that cAMP-dependent routes are not exclusive mechanisms triggering the beta-AR-mediated relaxation of smooth muscle. It has been demonstrated in rats detrusor muscle that cAMP plays a greater role in beta-adrenergic relaxation against basal tone than against KCl-induced tone and that conversely calcium-activated K(+) channels (BKca channels) play a greater role under the latter circumstances. In rat models, beta(3)-AR agonists increase bladder capacity without influencing bladder contraction and have only weak cardiovascular side effects. Although this evidence points toward the clinical utility of beta(3)-AR agonists as therapy for overactive bladder (OAB), pharmacological differences exist between rat and human beta(3)-ARs. Development of compounds with high selectivity for the human beta(3)-AR, identified by screening techniques using cell lines transfected with the human beta(1)-, beta(2)-, and beta(3)-AR genes, may mitigate against such problems. The association between the tryptophan 64 arginine polymorphism in the beta(3)-AR gene and idiopathic OAB is discussed.
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28
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Michel MC, Vrydag W. Alpha1-, alpha2- and beta-adrenoceptors in the urinary bladder, urethra and prostate. Br J Pharmacol 2006; 147 Suppl 2:S88-119. [PMID: 16465187 PMCID: PMC1751487 DOI: 10.1038/sj.bjp.0706619] [Citation(s) in RCA: 338] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1 We have systematically reviewed the presence, functional responses and regulation of alpha(1)-, alpha(2)- and beta-adrenoceptors in the bladder, urethra and prostate, with special emphasis on human tissues and receptor subtypes. 2 Alpha(1)-adrenoceptors are only poorly expressed and play a limited functional role in the detrusor. Alpha(1)-adrenoceptors, particularly their alpha(1A)-subtype, show a more pronounced expression and promote contraction of the bladder neck, urethra and prostate to enhance bladder outlet resistance, particularly in elderly men with enlarged prostates. Alpha(1)-adrenoceptor agonists are important in the treatment of symptoms of benign prostatic hyperplasia, but their beneficial effects may involve receptors within and outside the prostate. 3 Alpha(2)-adrenoceptors, mainly their alpha(2A)-subtype, are expressed in bladder, urethra and prostate. They mediate pre-junctional inhibition of neurotransmitter release and also a weak contractile effect in the urethra of some species, but not humans. Their overall post-junctional function in the lower urinary tract remains largely unclear. 4 Beta-adrenoceptors mediate relaxation of smooth muscle in the bladder, urethra and prostate. The available tools have limited the unequivocal identification of receptor subtypes at the protein and functional levels, but it appears that the beta(3)- and beta(2)-subtypes are important in the human bladder and urethra, respectively. Beta(3)-adrenoceptor agonists are promising drug candidates for the treatment of the overactive bladder. 5 We propose that the overall function of adrenoceptors in the lower urinary tract is to promote urinary continence. Further elucidation of the functional roles of their subtypes will help a better understanding of voiding dysfunction and its treatment.
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MESH Headings
- Adrenergic Agonists/pharmacology
- Animals
- Gene Expression Regulation
- Humans
- Male
- Muscle Contraction
- Muscle, Smooth/metabolism
- Prostate/drug effects
- Prostate/metabolism
- Receptors, Adrenergic/drug effects
- Receptors, Adrenergic/genetics
- Receptors, Adrenergic/metabolism
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, beta/metabolism
- Urethra/drug effects
- Urethra/metabolism
- Urinary Bladder/drug effects
- Urinary Bladder/metabolism
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Affiliation(s)
- Martin C Michel
- Department of Pharmacology & Pharmacotherapy, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
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29
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Gu Q, Lin YS, Lee LY. Epinephrine enhances the sensitivity of rat vagal chemosensitive neurons: role of beta3-adrenoceptor. J Appl Physiol (1985) 2006; 102:1545-55. [PMID: 17170206 PMCID: PMC1850626 DOI: 10.1152/japplphysiol.01010.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study was carried out to determine whether epinephrine alters the sensitivity of rat vagal sensory neurons. In anesthetized rats, inhalation of epinephrine aerosol (1 and 5 mg/ml, 3 min) induced an elevated baseline activity of pulmonary C fibers and enhanced their responses to lung inflation (20 cm H(2)O, 10 s) and right atrial injection of capsaicin (0.5 microg/kg). In isolated rat nodose and jugular ganglion neurons, perfusion of epinephrine (3 microM, 5 min) alone did not produce any detectable change of the intracellular Ca(2+) concentration. However, immediately after the pretreatment with epinephrine, the Ca(2+) transients evoked by chemical stimulants (capsaicin, KCl, and ATP) were markedly potentiated; for example, capsaicin (50 nM, 15 s)-evoked Ca(2+) transient was increased by 106% after epinephrine (P < 0.05; n = 11). The effect of epinephrine was mimicked by either BRL 37344 (5 microM, 5 min) or ICI 215,001 (5 microM, 5 min), two selective beta(3)-adrenoceptor agonists, and blocked by SR 59230A (5 microM, 10 min), a selective beta(3)-adrenoceptor antagonist, whereas pretreatment with phenylephrine (alpha(1)-adenoceptor agonist), guanabenz (alpha(2)-adrenoceptor agonist), dobutamine (beta(1)-adrenoceptor agonist), or salbutamol (beta(2)-adrenoceptor agonist) had no significant effect on capsaicin-evoked Ca(2+) transient. Furthermore, pretreatment with SQ 22536 (100-300 microM, 15 min), an adenylate cyclase inhibitor, and H89 (3 microM, 15 min), a PKA inhibitor, completely abolished the potentiating effect of epinephrine. Our results suggest that epinephrine enhances the excitability of rat vagal chemosensitive neurons. This sensitizing effect of epinephrine is likely mediated through the activation of beta(3)-adrenoceptor and intracellular cAMP-PKA signaling cascade.
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Affiliation(s)
- Qihai Gu
- Department of Physiology, University of Kentucky Medical Center, Lexington, Kentucky 40536-0298, USA
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Stevens LA, Sellers DJ, McKay NG, Chapple CR, Chess-Williams R. Muscarinic receptor function, density and G-protein coupling in the overactive diabetic rat bladder. ACTA ACUST UNITED AC 2006; 26:303-9. [PMID: 16879496 DOI: 10.1111/j.1474-8673.2006.00371.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1 Bladder smooth muscle sensitivity to muscarinic agonists is increased in the overactive bladder. Treatment of rats with streptozotocin induces a diabetic state in which the bladder muscle is overactive and also supersensitive to muscarinic agonists. This study has examined bladder contraction, muscarinic receptor density and receptor/G-protein coupling in the streptozotocin-induced overactive bladder of the rat. 2 Diabetes was induced by a single intraperitoneal dose of streptozotocin. Seven days later contraction of isolated detrusor muscle strips was assessed in tissue bath experiments, while receptor density was assayed in saturation experiments with [3H]-QNB (quinuclidinyl benzilate, L-[benzilic-4,4'-3H]) and receptor/G-protein coupling was determined in agonist displacement experiments with this radioligand. 3 Isolated detrusor strips from diabetic animals displayed an enhanced degree of spontaneous activity (0.060 +/- 0.016 g mg(-1), compared with 0.015 +/- 0.004 g mg(-1), P < 0.05). Carbachol produced contractile responses in tissues from both control and diabetic rats, but the diabetic tissues were more sensitive to this agonist, the pEC50 being 6.52 +/- 0.17 compared with 5.93 +/- 0.06 in controls (P < 0.001). Maximum responses to carbachol were similar in both groups of animals. The increase in carbachol potency was accompanied by a 40% increase in receptor density from 158 +/- 5 to 221 +/- 22 fmol mg(-1) protein (P < 0.05), but this was not enough to fully account for the change in tissue sensitivity. 4 In the absence of GTP-gamma-S, carbachol displaced [3H]-QNB from two binding sites, the high-affinity site (pKi = 7.06 +/- 0.26) which represents the receptors coupled to G-proteins made up 43.1 +/- 5.9% of the total binding sites in control tissues and this value was similar (41.0 +/- 4.0%) in the diabetic tissues (pKi = 6.64 +/- 0.31). In the presence of GTP-gamma-S, carbachol displaced [3H]-QNB from a single binding site which had a low-affinity, similar to the low-affinity site observed in the absence of GTP-gamma-S. 5 These data demonstrate that detrusor supersensitivity is observed after only 1 week of untreated diabetes in the rat. The overactivity is associated with an enhanced sensitivity to carbachol, which is partly explained by an increase in receptor density, but there appears to be no change in receptor/G-protein coupling.
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MESH Headings
- Animals
- Binding, Competitive
- Carbachol/metabolism
- Carbachol/pharmacology
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Dose-Response Relationship, Drug
- GTP-Binding Proteins/metabolism
- Guanosine 5'-O-(3-Thiotriphosphate)
- Male
- Muscarinic Agonists/metabolism
- Muscarinic Agonists/pharmacology
- Muscarinic Antagonists
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Quinuclidinyl Benzilate
- Radioligand Assay
- Rats
- Rats, Wistar
- Receptors, Muscarinic/analysis
- Receptors, Muscarinic/drug effects
- Receptors, Muscarinic/metabolism
- Urinary Bladder/drug effects
- Urinary Bladder/metabolism
- Urinary Bladder/physiopathology
- Urinary Incontinence/metabolism
- Urinary Incontinence/physiopathology
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Affiliation(s)
- L A Stevens
- Biomedical Research Centre, Sheffield Hallam University, Sheffield S1 1WB, UK
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Biers SM, Reynard JM, Brading AF. The effects of a new selective beta3-adrenoceptor agonist (GW427353) on spontaneous activity and detrusor relaxation in human bladder. BJU Int 2006; 98:1310-4. [PMID: 17026593 DOI: 10.1111/j.1464-410x.2006.06564.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To examine the effects of a new selective beta3-adrenoceptor agonist, GW427353 on human detrusor function, as beta2- and beta3-adrenoceptors have been identified in the bladder, and can mediate detrusor relaxation, but beta3-adrenoceptors are less widely distributed and beta3-adrenoceptor agonists should have the therapeutic advantage of producing fewer treatment side-effects. PATIENTS AND METHODS 'Normal' human detrusor was retrieved from 12 patients (mean age 56 years) at cystectomy and from organ donors. Detrusor strips (4 x 1 x 1 mm) were mounted in superfused organ baths. Tone was induced with carbachol (5 x 10(-7)m) before applying either a nonselective beta-adrenoceptor agonist (isoprenaline) or GW427353 (with or without the beta3-adrenoceptor antagonist, SR59230A). In addition, the effect of GW427353 was tested on intrinsic nerve-evoked smooth muscle contraction over time. Effects on spontaneous activity were also recorded. RESULTS GW427353 produced significant relaxation at concentrations of >10(-7)m; isoprenaline produced a significant effect from 10(-6)m, but otherwise both agonists had similar effects. The addition of SR59230A (10(-7)m), produced partial inhibition of the GW427353 response. GW427353 at 10(-6)m significantly reduced spontaneous activity within 10 min of incubation, and at higher concentrations (>5 x 10(-6)m) inhibited detrusor contractions evoked by electrical field stimulation. CONCLUSION Neuropathic bladder dysfunction is characterized by increased spontaneous activity and involuntary detrusor contractions, which can result in urinary frequency, urgency, nocturia and incontinence. The novel feature of GW427353 is the ability to suppress spontaneous activity and produce significant relaxation in human detrusor tissue at low concentrations, whilst also inhibiting evoked detrusor contractions at higher concentrations.
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Niclauss N, Michel-Reher MB, Alewijnse AE, Michel MC. Comparison of three radioligands for the labelling of human β-adrenoceptor subtypes. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2006; 374:99-105. [PMID: 17028849 DOI: 10.1007/s00210-006-0104-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 08/07/2006] [Indexed: 11/28/2022]
Abstract
We have compared the ability of three radioligands, [(125)I]-cyanopindolol, [(3)H]-CGP 12,177 and [(3)H]-dihydroalprenolol, to label the three human beta-adrenoceptor subtypes. Saturation and competition binding experiments were performed using membrane preparations from Chinese hamster ovary cells stably transfected with the three subtypes. While [(3)H]-CGP 12,177 had very similar affinity for beta(1)- and beta(2)-adrenoceptors (about 40 pM), [(125)I]-cyanopindolol and [(3)H]-dihydroalprenolol had 4- to 6-fold higher affinity for beta(2)- as compared to beta(1)-adrenoceptors (10 vs 45 and 187 vs 1,021 pM, respectively). The affinity of [(125)I]-cyanopindolol at beta(3)-adrenoceptors was considerably lower (440 pM) than at the other two subtypes. The beta(3)-adrenoceptor affinity of [(3)H]-CGP 12,177 and [(3)H]-dihydroalprenolol was so low that it could not be estimated within the tested range of radioligand concentrations (up to 4,000 pM and 30,000 pM for [(3)H]-CGP 12,177 and [(3)H]-dihydroalprenolol, respectively). We conclude that all three radioligands are ill-suited to label beta(3)-adrenoceptors, particularly in preparations co-expressing multiple subtypes. In the absence of alternatives, [(125)I]-cyanopindolol appears the least unsuitable to label beta(3)-adrenoceptors. There is a need for high-affinity radioligands which are either selective for beta(3)-adrenoceptors or reasonably non-selective among all three beta-adrenoceptor subtypes.
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MESH Headings
- Adrenergic beta-Agonists/metabolism
- Adrenergic beta-Antagonists/metabolism
- Animals
- Binding, Competitive
- CHO Cells
- Cricetinae
- Cricetulus
- Dihydroalprenolol/metabolism
- Ethanolamines/metabolism
- Humans
- Iodine Radioisotopes/metabolism
- Iodocyanopindolol/metabolism
- Isotope Labeling/methods
- Kinetics
- Propanolamines/metabolism
- Protein Binding
- Radioligand Assay/methods
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
- Tetrahydronaphthalenes/metabolism
- Tritium/metabolism
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Affiliation(s)
- Nadja Niclauss
- Department Pharmacology and Pharmacotherapy, Academic Medical Center, University of Amsterdam, Meibergdreef 15, Amsterdam, The Netherlands
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Badawi JK, Uecelehan H, Hatzinger M, Michel MS, Haferkamp A, Bross S. Relaxant effects of beta-adrenergic agonists on porcine and human detrusor muscle. ACTA ACUST UNITED AC 2006; 185:151-9. [PMID: 16168009 DOI: 10.1111/j.1365-201x.2005.01474.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
AIM Relaxant effects of different beta-adrenoceptor agonists on porcine and human detrusor were examined. Thus, the beta-adrenoceptor subtype mainly responsible for relaxation in the detrusor muscle of pigs was characterized. Additionally, different effects of several beta-agonists in both species were shown. METHODS Experiments were performed on muscle strips of porcine and human detrusor suspended in a tissue bath. The relaxant effects of the non-selective beta-agonist isoprenaline, the selective beta2-agonists procaterol, salbutamol and the selective beta3-agonists BRL 37344, CL 316 243 and CGP 12177 on potassium-induced contraction were investigated. The inhibitory effect of different substances on the maximum contraction and the rank order of potency for endogenous catecholamines was determined in pigs. Furthermore, concentration-relaxation curves were performed for pigs and humans. RESULTS Pigs: In the pre-treatment experiments isoprenaline and procaterol showed similar effects. The concentration-response experiments showed that the maximum relaxation induced by procaterol and salbutamol was more than 90%, not significantly different from isoprenaline, whereas the maximum relaxations of CL 316 243, BRL 37344 and CGP 12177 amounted to 68, 70 or 30%, respectively. Rank order of potencies was isoprenaline > or = adrenaline > noradrenaline. Humans: Isoprenaline, procaterol, salbutamol and CL 316 243 showed a maximum relaxation of 80, 41, 24 and 35% and pD2 values of 6.24, 5.65, 5.48 and 5.55, respectively. CONCLUSION Beta2-receptors play a main functional role in mediating relaxation of porcine detrusor. Selective beta2- and beta3-agonists similarly relax the human detrusor. Effects were smaller compared with the pig.
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Affiliation(s)
- J K Badawi
- Department of Urology, University Hospital Mannheim, Theodor-Kutzer-Ufer 1-3, Mannheim, Germany.
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Yamanishi T, Yasuda K, Kitahara S, Nakai H, Yoshida KI, Iizuka H. Effects of 138–355, a β3-adrenoceptor selective agonist, on relaxation of the human detrusor muscle in vitro. Neurourol Urodyn 2006; 25:815-9. [PMID: 16998863 DOI: 10.1002/nau.20231] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AIMS Beta-adrenoceptors are the predominant beta-adrenoceptor subtype present in the bladder and urethra. This study investigates the effects of 138-355, an active-metabolite of TT-138 and beta(3)-adrenoceptor agonist, on relaxation of the human detrusor in vitro. METHODS Tumor-free tissue samples of human bladder muscle from 39 patients undergoing total cystectomy due to bladder cancer were obtained, and the mucosa and serosa were removed. Tissues were mounted in 5 or 10 ml organ baths containing Krebs solution, which was gassed with 95% O(2) and 5% CO(2). Resting tension of 1 g was obtained. When the contraction had stabilized, increasing concentrations of beta adrenoceptor agonists (non-selective, isoprenaline; beta(2)-selective, clenbuterol; beta(3)-selective, 138-355 and BRL37344) and propiverine (a non-selective anti-muscarinic antagonist) were added cumulatively and concentration-relaxation curves (CRCs) were obtained. CRCs to 138-355 were obtained in the absence and presence of SR59230A, a beta(3)-selective antagonist, and antagonist affinity values (pA(2)) were calculated from the Schild plot. RESULTS Isoproterenol, clenbuterol, 138-355 and BRL37344 concentration-dependently relaxed isolated human urinary bladder strips with pEC(50) value being 6.76+/-0.17, 5.23+/-0.22, 5.80+/-0.26 and 5.90+/-0.28, respectively. Following antagonist assay, it was observed that concentration-relaxation curves to 138-355 was competitively antagonized by beta(3)- adrenoceptor antagonist, SR59230A, with a pA(2) value of 7.01+/-0.45 and with a Schild slope of 0.72+/-0.07. CONCLUSIONS Involvement of the beta(3)-adrenoceptor appears to be greater than that of the beta(3)-adrenoceptor for relaxations of the human bladder. The relaxation response of 138-355 appears to be mediated via the beta(3)-adrenoceptor stimulation.
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Affiliation(s)
- Tomonori Yamanishi
- Department of Urology, Dokkyo University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi, 321-0293, Japan.
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Pourageaud F, Leblais V, Bellance N, Marthan R, Muller B. Role of β2-adrenoceptors (ß-AR), but not ß1-, β3-AR and endothelial nitric oxide, in β-AR-mediated relaxation of rat intrapulmonary artery. Naunyn Schmiedebergs Arch Pharmacol 2005; 372:14-23. [PMID: 16133491 DOI: 10.1007/s00210-005-1082-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Accepted: 07/01/2005] [Indexed: 10/25/2022]
Abstract
The aim of this study was to analyze beta-adrenoceptor (beta-AR)-mediated relaxation in rat intralobar pulmonary artery. The relaxant responses of beta-AR agonists were characterized using beta-AR antagonists in prostaglandin F2alpha (PGF2alpha)-precontracted arteries. The role of nitric oxide (NO) and endothelium in beta-AR-mediated relaxation was also investigated. Isoprenaline (a non-selective beta-AR agonist) and salbutamol (a selective beta2-AR agonist) induced vasorelaxation. ICI 118551 (a selective beta2-AR antagonist) antagonized the effect of both isoprenaline and salbutamol (pA2 values of 9.57 and 9.51 respectively). In contrast, atenolol (1 microM) and CGP 20712A (0.1 microM), two beta1-AR antagonists, did not modify the relaxing effect of isoprenaline. The response to isoprenaline obtained in the presence of nadolol (10 microM, a beta1/beta2-AR antagonist) was not further inhibited by SR 59230A (1 microM, a selective beta3-AR antagonist). The non-beta1/beta2-AR agonists studied (BRL 37344, SR 58611A, and CGP 12177A) did not elicit vasorelaxation. Relaxation to isoprenaline and salbutamol was unaffected by L-N(G)-nitro-arginine methyl ester (100 microM, an inhibitor of NO synthase) or after endothelium removal. These results demonstrate the role of beta2-AR in mediating relaxation in rat intralobar pulmonary artery precontracted with PGF2alpha. They indicate that beta2-AR-mediated relaxation in this artery is NO- and endothelium-independent. Furthermore, they do not provide evidence of a relaxant role of either beta1- or beta3-AR in PGF2alpha-precontracted rat intrapulmonary artery.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Albuterol/pharmacology
- Animals
- Atenolol/pharmacology
- Dose-Response Relationship, Drug
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/enzymology
- In Vitro Techniques
- Isoproterenol/pharmacology
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- NG-Nitroarginine Methyl Ester/pharmacology
- Nitric Oxide/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Propanolamines/pharmacology
- Pulmonary Artery/drug effects
- Pulmonary Artery/metabolism
- Rats
- Rats, Wistar
- Receptors, Adrenergic, beta-1/analysis
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-2/analysis
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/analysis
- Receptors, Adrenergic, beta-3/drug effects
- Vasodilation/drug effects
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Affiliation(s)
- Fabrice Pourageaud
- Laboratoire de Pharmacologie de la Faculté de Pharmacie, INSERM EMI-0356, Université Victor Segalen Bordeaux 2, Casier 83, 146 rue Léo Saignat, 33076, Bordeaux cedex, France.
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Chess-Williams R. Potential therapeutic targets for the treatment of detrusor overactivity. Expert Opin Ther Targets 2005; 8:95-106. [PMID: 15102552 DOI: 10.1517/14728222.8.2.95] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Current treatments for the overactive detrusor are poorly tolerated and can exert significant adverse effects. Possible targets for the development of new treatments are considered. Potential targets in four locations are examined: detrusor smooth muscle, urothelium, peripheral nerves and the CNS. In the detrusor, the role of various muscarinic receptor subtypes is discussed and beta-adrenoceptor agonists, phosphodiesterase inhibitors and potassium channel openers, all of which inhibit detrusor contractility, are considered for drug development. In the urothelium, a number of substances are released that affect bladder function including ATP, acetylcholine and an inhibitory factor that has yet to be identified. All three systems have the potential to be novel targets for drug development. Other possible therapeutic targets are the mechanisms influencing transmitter release in the bladder, for example, prejunctional 5-hydroxytryptamine (5-HT) 4 receptors. Finally, targets within the CNS and spinal cord are considered, including opioid receptors, 5-HT receptors and alpha-adrenoceptors.
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Frazier EP, Mathy MJ, Peters SLM, Michel MC. Does cyclic AMP mediate rat urinary bladder relaxation by isoproterenol? J Pharmacol Exp Ther 2004; 313:260-7. [PMID: 15576470 DOI: 10.1124/jpet.104.077768] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cyclic AMP is the prototypical second messenger of beta-adrenergic receptors, but recent findings have questioned its role in mediating smooth muscle relaxation upon beta-adrenergic receptor stimulation. We have investigated the signaling mechanisms underlying beta-adrenergic receptor-mediated relaxation of rat urinary bladder. Concentration-response curves for isoproterenol-induced bladder relaxation were generated in the presence or absence of inhibitors, with concomitant experiments using passive tension and KCl-induced precontraction. The adenylyl cyclase inhibitor 9-(tetrahydro-2-furanyl)-9H-purin-6-amine (SQ 22,536; 1 microM), the protein kinase A inhibitors 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7; 10 microM), N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide (H89; 1 microM), and Rp-adenosine 3',5'-cyclic monophosphorothioate (Rp-cAMPS; 30 microM), and the guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (ODQ; 3 microM) produced only minor if any inhibition of relaxation against passive tension or KCl-induced precontraction. Among various potassium channel inhibitors, BaCl2 (10 microM), tetraethylammonium (3 microM), apamin (300 nM), and glibenclamide (10 microM) did not inhibit isoproterenol-induced relaxation. Some inhibition of the isoproterenol effects against KCl-induced tone but not against passive tension was seen with inhibitors of calcium-dependent potassium channels such as charybdotoxin and iberiotoxin (30 nM each). A combination of SQ 22,536 and ODQ significantly inhibited relaxation against passive tension by about half, but not that against KCl-induced tone. Moreover, the combination failed to enhance inhibition by charybdotoxin against KCl-induced tone. We conclude that cAMP and cGMP each play a minor role in beta-adrenergic receptor-mediated relaxation against passive tension, and calcium-dependent potassium channels play a minor role against active tension.
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Affiliation(s)
- Elfaridah P Frazier
- Department of Pharmacology and Pharmacotherapy, University of Amsterdam, Academisch Medisch Centrum, The Netherlands
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Hutchinson DS, Sato M, Evans BA, Christopoulos A, Summers RJ. Evidence for pleiotropic signaling at the mouse beta3-adrenoceptor revealed by SR59230A [3-(2-Ethylphenoxy)-1-[(1,S)-1,2,3,4-tetrahydronapth-1-ylamino]-2S-2-propanol oxalate]. J Pharmacol Exp Ther 2004; 312:1064-74. [PMID: 15574684 DOI: 10.1124/jpet.104.076901] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examines the action of the beta(3)-adrenoceptor antagonist SR59230A [3-(2-ethylphenoxy)-1-[(1,S)-1,2,3,4-tetrahydronapth-1-ylamino]-2S-2-propanoloxalate] at cloned mouse beta(3)-adrenoceptors expressed in Chinese hamster ovary cells (CHO-K1-beta(3)) or endogenously expressed in 3T3-F442A adipocytes or ileum. SR59230A displayed partial agonist properties compared with the beta(3)-adrenoceptor agonist CL316243 [(R,R)-5-[2-[[2-(3-chlorophenyl)-2-hydroxyethyl]-amino]-propyl]1,3-benzodioxole-2,2-dicarboxylate] in CHO-K1-beta(3) with the intrinsic activity increasing with the level of receptor expression. Functional affinity values for SR59230A at each level of receptor expression were in agreement with pK(I) values determined by binding. In cytosensor microphysiometer studies, SR59230A was a full agonist for increases in extracellular acidification rates (ECARs) at all levels of receptor expression, and antagonist actions were measurable only in medium- or low-expressing cells. In 3T3-F442A adipocytes, SR59230A antagonized CL316243-mediated increases of cAMP and had no agonist actions. However, in the cytosensor micro-physiometer, SR59230A (acting via beta(3)-adrenoceptors) was an agonist with an intrinsic activity greater than CL316243. In mouse ileum, SR59230A relaxed smooth muscle, although concentration-response curves were biphasic. Relaxant effects were produced by concentrations that did not affect cAMP levels. Differences in tissue responses to SR59230A were not caused by major differences in expression of Galphas. ECAR responses were not affected by pretreatment of cells with pertussis toxin, indicating that signaling did not involve Gi. Therefore, SR59230A displays agonist and antagonist actions at the mouse beta(3)-adrenoceptor. Because SR59230A only antagonized accumulation of cAMP in 3T3-F442A adipocytes yet in the same cells was an agonist for ECAR, cAMP-independent signaling pathways must mediate part of the agonist actions in the microphysiometer.
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Affiliation(s)
- Dana S Hutchinson
- Department of Pharmacology, P.O. Box 13E, Monash University, Victoria 3800, Australia
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Andersson KE, Arner A. Urinary bladder contraction and relaxation: physiology and pathophysiology. Physiol Rev 2004; 84:935-86. [PMID: 15269341 DOI: 10.1152/physrev.00038.2003] [Citation(s) in RCA: 607] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The detrusor smooth muscle is the main muscle component of the urinary bladder wall. Its ability to contract over a large length interval and to relax determines the bladder function during filling and micturition. These processes are regulated by several external nervous and hormonal control systems, and the detrusor contains multiple receptors and signaling pathways. Functional changes of the detrusor can be found in several clinically important conditions, e.g., lower urinary tract symptoms (LUTS) and bladder outlet obstruction. The aim of this review is to summarize and synthesize basic information and recent advances in the understanding of the properties of the detrusor smooth muscle, its contractile system, cellular signaling, membrane properties, and cellular receptors. Alterations in these systems in pathological conditions of the bladder wall are described, and some areas for future research are suggested.
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Affiliation(s)
- Karl-Erik Andersson
- Dept. of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
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Abstract
OBJECTIVE To investigate the actions of noradrenaline and the specific alpha-adrenergic agonists cirazoline (alpha1) and UK14304 (alpha2), and beta-receptor agonists formoterol (beta2) and BRL37344 (beta3) on the phasic activity induced by muscarinic stimulation on the isolated guinea pig bladder, as the physiological significance of this activity is unknown but it may underlie non-micturition contractions (NMCs, which can be inhibited by sympathetic nerve stimulation) and the generation of bladder sensations. MATERIALS AND METHODS All experiments were conducted using whole isolated bladders from female guinea pigs (270-300 g). Bladders were cannulated via the urethra and suspended in a heated chamber containing oxygenated Tyrode's solution at 33-35 degrees C and the intravesical pressure recorded. All drugs were added to the solution bathing the abluminal surface. RESULTS Exposure to noradrenaline reduced the amplitude and frequency of the phasic activity. When noradrenaline was washed off there was a transient increase in frequency. There was marked desensitization with repeated applications of noradrenaline. Applying the specific beta3-agonist BRL37344 reduced the amplitude of the phasic activity while formoterol, a specific beta2-agonist, had no effect. Cirazoline, a specific alpha1-agonist, reduced the amplitude of the responses and significantly reduced the frequency of the phasic activity. UK14304, a specific alpha2-agonist, had no effect. Stimulation of the hypogastric nerve to the guinea pig bladder generates contractions. Prolonged nerve stimulation at low frequency (6.5 Hz) generated phasic rises in intravesical pressure which were inhibited by noradrenaline. Using short (5 s) periods of stimulation noradrenaline inhibited nerve-mediated contractions at all frequencies but was more effective at <10 Hz. CONCLUSION These experiments show that sympathomimetic stimulation in the isolated whole bladder results primarily in an inhibition of phasic activity, but also a stimulation. Two receptor subtypes appear to be involved in the inhibition, alpha1 and beta3, suggesting that there may be many sites of action. These results are discussed in terms of the possible physiological significance of phasic activity and the potential importance of its inhibition, in the context of the causes of pathological changes in the bladder, particularly those associated with bladder overactivity, and the pharmacological approach to the alleviation of clinical symptoms.
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Affiliation(s)
- J I Gillespie
- The Urophysiology Research Group, School of Surgical and Reproductive Sciences, The Medical School, The University, Newcastle upon Tyne, UK.
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Yamanishi T, Chapple CR, Yasuda K, Yoshida KI, Chess-Williams R. The Functional Role of β-Adrenoceptor Subtypes in Mediating Relaxation of Pig Urethral Smooth Muscle. J Urol 2003; 170:2508-11. [PMID: 14634461 DOI: 10.1097/01.ju.0000085596.11247.78] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The predominant beta-adrenoceptor subtype present in the bladder and urethra is beta3-adrenoceptors. We investigated the role of beta-adrenoceptors in mediating relaxation of the in vitro female pig urethra. MATERIALS AND METHODS Circular strips of urethral tissues were pre-contracted with KCl. Concentration-relaxation curves (CRCs) to beta-adrenoceptor agonists were obtained in the absence and presence of antagonists. RESULTS The nonselective beta-agonist isoproterenol in 30 animals and the beta3-adrenoceptor agonist BRL37344 in 4 relaxed with high potency (pEC50 7.2 and 8.1, respectively), while the beta2-adrenoceptor agonist salbutamol in 6 had low potency (pEC50 6.1). Mean maximal relaxation responses of BRL37344 and salbutamol relative to maximal isoproterenol responses were 89.8% and 76.7%, respectively. Propranolol (10 to 100 nM) in 18 animals antagonized CRCs to isoproterenol with high affinity (apparent pKB 8.6) but the Schild plot had a slope that was significantly less than unity (0.68, p <0.01). High concentrations of the beta1-antagonist CGP20712A (3 to 30 microM) in 12 animals had no effect on responses to isoproterenol. The beta2-antagonist ICI118551 (30 to 300 nM) in 25 animals antagonized responses to isoproterenol with high affinity (apparent pKB 8.03) with a Schild slope not different from unity (0.79). The beta3-antagonist SR59230A (10 to 100 nM) in 12 animals antagonized CRCs to isoproterenol with an apparent pKB of 7 and with a Schild slope that was again significantly less than unity (0.62, p <0.01), indicating that responses to isoproterenol are mediated by more than 1 beta-adrenoceptor subtype. According to the Schild plot of unity ICI118551 (3 to 30 nM) in 18 animals competitively antagonized responses to salbutamol with high affinity (pA2 8.5). CONCLUSIONS In the pig urethra beta-adrenoceptor mediated relaxations to isoproterenol are mediated via beta2 and beta3-adrenoceptors, while responses to beta2-adrenoceptor agonists such as salbutamol appear to be mediated only via beta2-adrenoceptors.
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Yamanishi T, Chapple CR, Yasuda K, Yoshida KI, Chess-Williams R. Role of beta-adrenoceptor subtypes in mediating relaxation of the pig bladder trigonal muscle in vitro. Neurourol Urodyn 2003; 22:338-42. [PMID: 12808710 DOI: 10.1002/nau.10130] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
AIMS To investigate the role of beta-adrenoceptor subtypes in mediating relaxation of the pig bladder trigonal muscle in vitro. MATERIALS AND METHODS Longitudinal strips of trigonal muscle were isolated, and the mucosa and serosa removed. Tissues were precontracted with KCl, and beta-adrenoceptor agonists (isoprenaline or salbutamol) were added cumulatively, and concentration-relaxation curves (CRCs) were obtained. CRCs to agonists were obtained in the absence and presence of antagonists and antagonist affinity values were calculated. RESULTS Isoprenaline (non-selective beta-agonist) relaxed with high potency (pEC(50) = 7.2). Propranolol antagonized CRCs to isoprenaline with a high affinity (apparent pK(B) = 8.8), but the Schild plot had a slope significantly (P < 0.01) less than unity (0.61), suggesting that responses were mediated by more than one beta-adrenoceptor subtype. CGP20712A (beta(1)-antagonist) antagonized responses to isoprenaline with a low affinity (apparent pK(B) = 5.13), indicating beta(1)-adrenoceptors did not participate in the response. The affinity of ICI118551 (beta(2)-antagonist) for antagonism of responses to isoprenaline was also relatively low (apparent pK(B) = 6.9), and the Schild slopes were significantly (P < 0.01) less than unity (0.58). SR59230A (beta(3)-antagonist) antagonized CRCs to isoprenaline with a relatively low affinity (apparent pK(B) = 7.5), and with a Schild slope significantly (P < 0.01) less than unity (0.86), indicating that responses may be mediated by more than one beta-adrenoceptor subtype. In contrast to that observed with isoprenaline, the beta(2)-adrenoceptor selective agonist salbutamol induced relaxation with a relatively low potency (pEC(50) = 6.6) and with maximum responses of 80% of that to isoprenaline. ICI118551 competitively antagonized (Schild plot of unity) responses to salbutamol with a high affinity (pA2 = 8.3). CONCLUSIONS These data suggest that beta-adrenoceptor mediated responses to isoprenaline of the bladder trigone are mediated via both the beta(2)- and beta(3)-adrenoceptor subtypes whilst responses to salbutamol appear to be mediated only via the beta(2)-adrenoceptor.
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Sum FW, Wong V, Han S, Largis E, Mulvey R, Tillett J. Cyclic amine sulfonamides as linkers in the design and synthesis of novel human beta(3) adrenergic receptor agonists. Bioorg Med Chem Lett 2003; 13:2191-4. [PMID: 12798332 DOI: 10.1016/s0960-894x(03)00387-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Piperidine, pyrrolidine, and azetidine sulfonamides were examined as linkers in designing novel human beta(3) adrenergic receptor (beta(3)-AR) agonists. The azetidine derivative 37, and piperidine derivatives 7, 8, and 13 were found to be potent beta(3)-AR agonists and have good selectivity against beta(1)- and beta(2)-AR.
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Affiliation(s)
- Fuk Wah Sum
- Chemical Sciences, Wyeth Research, 10965, Pearl River, NY, USA.
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Identification of ??-Adrenoceptor Subtypes in Lower Urinary Tract of the Female Pig. J Urol 2002. [DOI: 10.1097/00005392-200212000-00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Yamanishi T, Chapple CR, Yasuda K, Yoshida KI, Chess-Williams R. Identification of beta-adrenoceptor subtypes in lower urinary tract of the female pig. J Urol 2002; 168:2706-10. [PMID: 12442014 DOI: 10.1016/s0022-5347(05)64248-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE We investigated the presence and functional role of beta-adrenoceptor subtypes in the bladder base and proximal urethra of the female pig. MATERIALS AND METHODS Saturation experiments were done with 7 concentrations (0.25 to 16 nM.) of [(3)H]-dihydroalprenolol (NEN Life Science Products, Boston, Massachusetts). Competition experiments with [(3)H]-dihydroalprenolol were performed with unlabeled antagonists (beta1 selective CGP20712A, beta2 selective ICI118551 and beta3 selective SR59230A). In functional studies concentration-relaxation curves to the beta3-agonist BRL37344 were obtained and antagonist affinities for SR59230A were determined. RESULTS CGP20712A displaced [(3)H]-dihydroalprenolol with low affinity, suggesting that beta1-adrenoceptors were not present. Displacement with ICI118551 in the bladder base and urethra best fitted a 2-site model with 20% and 28% high affinity sites (beta2), respectively. Displacement experiments with SR59230A in the bladder base demonstrated that 59% of binding sites had high affinity (beta3). In the urethra displacement with SR59230A best fitted a 1-site model but with a pK(i) of 7.2 that was intermediate between that expected for beta2 and beta3-adrenoceptors. In functional studies BRL37344 induced relaxation with pEC50 values of 5.5 and 8, and a maximum relaxation response relative to 30 microM. isoprenaline of 79% and 90% in the bladder base and urethra, respectively. The affinity value of SR59230A for the response to BRL37344 was 7.87 and 7.71 in the bladder base and urethra, respectively, which were intermediate between those of beta2 and beta3-adrenoceptors. CONCLUSIONS Apparently beta3-adrenoceptors are the predominant beta-adrenoceptor subtype present in the lower urinary tract of the pig.
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Affiliation(s)
- Tomonori Yamanishi
- Department of Biomedical Science, University of Sheffield, Royal Hallamshire Hospital, United Kingdom
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The Role of M2 Muscarinic Receptor Subtypes Mediating Contraction of the Circular and Longitudinal Smooth Muscle of the Pig Proximal Urethra. J Urol 2002. [DOI: 10.1016/s0022-5347(05)64913-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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The Role of M2 Muscarinic Receptor Subtypes Mediating Contraction of the Circular and Longitudinal Smooth Muscle of the Pig Proximal Urethra. J Urol 2002. [DOI: 10.1097/00005392-200207000-00097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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