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Singh N, Mizoguchi S, Suzuki T, Zabbarova I, Ikeda Y, Kanai A, Chermansky C, Yoshimura N, Tyagi P. Excitatory effect of acotiamide on rat and human bladder: Implications for underactive bladder treatment. Life Sci 2020; 258:118179. [PMID: 32758626 DOI: 10.1016/j.lfs.2020.118179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To evaluate whether approved gastroprokinetic agent, acotiamide exerts a direct excitatory effect on bladder to help explain the reported meaningful reduction of post-void residual urine volume (PVR) in detrusor underactivity (DU) patients after thrice daily oral intake of acotiamide 100 mg for 2 weeks. METHODS Effect of acotiamide [1-16 μM] was assessed on nerve-mediated contractions evoked by electrical field stimulation (EFS) for 5 s with 5 ms pulse trains of 10 V in longitudinal, mucosa intact rat and human bladder strips to construct frequency response curve (1-32 Hz) and repeat 10 Hz stimulation at 60s interval. Effect of acotiamide 2 μM on spontaneous and carbachol evoked contractions was also assessed. RESULTS Acotiamide 2 μM significantly enhanced the Atropine and Tetrodotoxin (TTX)-sensitive EFS evoked contractions of rat and human bladder at 8-32 Hz (Two-way ANOVA followed Sidak's multiple comparison; *p < 0.01) and on repeat 10 Hz stimulation (Paired Student's t-test; *p < 0.05), while producing a modest effect on the spontaneous contractions and a negligible effect on the carbachol evoked contractions. CONCLUSIONS Enhancement of TTX-sensitive evoked contractions of rat and human bladder by acotiamide is consistent with the enhancement of excitatory neuro-effector transmission mainly through prejunctional mechanisms. Findings highlight immense therapeutic potential of antimuscarinics with low M3 receptor affinity like acotiamide in Underactive bladder (UAB)/DU treatment.
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Affiliation(s)
- Nishant Singh
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Shinsuke Mizoguchi
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Takahisa Suzuki
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Irina Zabbarova
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Youko Ikeda
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Anthony Kanai
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Christopher Chermansky
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Naoki Yoshimura
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Pradeep Tyagi
- Department of Urology, University of Pittsburgh, Pittsburgh, PA, United States of America.
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2
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Abstract
Understanding the pathophysiologic mechanisms responsible for overactive bladder (OAB) and urgency urinary incontinence (UUI) is critical to advancing the treatment options available to men and women with this prevalent and bothersome condition. Development of novel technologies and advanced functional neuroimaging modalities has provided us with new information to support and refine existing mechanistic theories. Emerging research on central pathophysiologic mechanisms of OAB from functional magnetic resonance imaging may provide new targets for therapeutic interventions and opens the door for novel treatment strategies. Several regions of interest—specifically the anterior cingulate gyrus, insula, and frontal cortices—have been implicated as areas of activation in women with OAB, suggesting a neural correlate of the experience of urgency. The cerebellum and parietal lobe have demonstrated increased activation during inhibition of voiding, and increased connectivity between the cerebellum and parietal lobe and the right insula and anterior cingulate gyrus has been demonstrated in women with UUI compared with controls. Evolving literature is beginning to shed light on the prerequisite effective connections between regions of interest in the healthy bladder and negative connectivity in OAB and UUI. Precision medicine with individualized care pathways may better select available treatment modalities for rightful recipients, thus improving efficacy with prescribed treatment approaches and adherence to therapy.
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Affiliation(s)
- Ariana L Smith
- Division of Urology, University of Pennsylvania , Philadelphia, PA, USA
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3
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Doyle C, Cristofaro V, Sack BS, Mahmood F, Sullivan MP, Adam RM. The role of the mucosa in modulation of evoked responses in the spinal cord injured rat bladder. Neurourol Urodyn 2018; 37:1583-1593. [PMID: 29427331 PMCID: PMC6086770 DOI: 10.1002/nau.23512] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 01/09/2018] [Indexed: 11/27/2022]
Abstract
Aims Mounting evidence indicates that a variety of factors released from the urothelium or suburothelium can modulate smooth muscle activity. Although the relationship between the mucosa and smooth muscle has been investigated, little is known about the pathophysiologic changes in detrusor‐mucosa interactions in neurogenic bladders. The goal of the study was to determine the impact of the mucosa on evoked responses in spinal cord injured (SCI) bladders. Methods Urinary bladders were obtained from 6wk SCI rats or age‐matched uninjured controls. Ex vivo isometric tension studies were performed and muscarinic receptor expression was measured in bladder tissue with and without mucosa. Results The magnitude and area of nerve evoked responses in SCI tissue with mucosa was higher than without mucosa. The duration and decay time of nerve‐evoked responses were longer in SCI than control tissue irrespective of the mucosa. The level of the muscarinic M2 receptor was decreased in the mucosa of SCI bladders. Conclusions Detrusor‐mucosa interactions are substantially altered in the neurogenic bladder. After spinal cord injury, an excitatory modulation of smooth muscle contraction by the mucosa emerges, and could be targeted via intravesical treatment in the context of neurogenic bladder dysfunction.
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Affiliation(s)
- Claire Doyle
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts.,Department of Surgery, Harvard Medical School, Boston, Massachusetts
| | - Vivian Cristofaro
- Department of Surgery, Harvard Medical School, Boston, Massachusetts.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Bryan S Sack
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts.,Department of Surgery, Harvard Medical School, Boston, Massachusetts
| | - Fabliha Mahmood
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts
| | - Maryrose P Sullivan
- Department of Surgery, Harvard Medical School, Boston, Massachusetts.,Division of Urology, VA Boston Healthcare System, Boston, Massachusetts.,Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts
| | - Rosalyn M Adam
- Urological Diseases Research Center, Boston Children's Hospital, Boston, Massachusetts.,Department of Surgery, Harvard Medical School, Boston, Massachusetts
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Jespersen B, Tykocki NR, Watts SW, Cobbett PJ. Measurement of smooth muscle function in the isolated tissue bath-applications to pharmacology research. J Vis Exp 2015:52324. [PMID: 25650585 PMCID: PMC4354551 DOI: 10.3791/52324] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
Isolated tissue bath assays are a classical pharmacological tool for evaluating concentration-response relationships in a myriad of contractile tissues. While this technique has been implemented for over 100 years, the versatility, simplicity and reproducibility of this assay helps it to remain an indispensable tool for pharmacologists and physiologists alike. Tissue bath systems are available in a wide array of shapes and sizes, allowing a scientist to evaluate samples as small as murine mesenteric arteries and as large as porcine ileum - if not larger. Central to the isolated tissue bath assay is the ability to measure concentration-dependent changes to isometric contraction, and how the efficacy and potency of contractile agonists can be manipulated by increasing concentrations of antagonists or inhibitors. Even though the general principles remain relatively similar, recent technological advances allow even more versatility to the tissue bath assay by incorporating computer-based data recording and analysis software. This video will demonstrate the function of the isolated tissue bath to measure the isometric contraction of an isolated smooth muscle (in this case rat thoracic aorta rings), and share the types of knowledge that can be created with this technique. Included are detailed descriptions of aortic tissue dissection and preparation, placement of aortic rings in the tissue bath and proper tissue equilibration prior to experimentation, tests of tissue viability, experimental design and implementation, and data quantitation. Aorta will be connected to isometric force transducers, the data from which will be captured using a commercially available analog-to-digital converter and bridge amplifier specifically designed for use in these experiments. The accompanying software to this system will be used to visualize the experiment and analyze captured data.
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Affiliation(s)
- Brian Jespersen
- Department of Pharmacology and Toxicology, Michigan State University
| | - Nathan R Tykocki
- Department of Pharmacology, University of Vermont College of Medicine
| | - Stephanie W Watts
- Department of Pharmacology and Toxicology, Michigan State University;
| | - Peter J Cobbett
- Department of Pharmacology and Toxicology, Michigan State University
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5
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Triguero D, Lafuente-Sanchis A, Garcia-Pascual A. Changes in nerve-mediated contractility of the lower urinary tract in a mouse model of premature ageing. Br J Pharmacol 2014; 171:1687-705. [PMID: 24372152 DOI: 10.1111/bph.12567] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 12/04/2013] [Accepted: 12/12/2013] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND AND PURPOSE A high incidence of lower urinary tract disorders is associated with ageing. In the senescent-accelerated prone (SAMP8) mouse strain and the senescent-accelerated resistant (SAMR1) strain, we compared smooth muscle contractility in responses to intrinsic neurotransmitters, both in the bladder and urethra. EXPERIMENTAL APPROACH We analysed micturition frequency, the changes in muscle tension induced by electrical field stimulation or agonist administration, the density of nerves (adrenergic, cholinergic and nitrergic) and interstitial cells (ICs), as well as cGMP accumulation in bladder and urethral preparations. KEY RESULTS Senescent mice of the SAMP8 strain displayed increased micturition frequency and excitatory contractility of neurogenic origin in the bladder. While cholinergic nerve density remained unchanged, there was a mild sensitization to ACh in male mice. Potentiation in the detrusor may be also provoked by the stronger contribution of ATP, together with reduced adrenergic innervation in males and COX-derived prostanoid production in females. The greater excitatory contractility in the urethra was probably due to the sensitization to noradrenaline, in conjunction with attenuated nitrergic relaxation. There were also fewer neuronal NOS immunoreactive (ir) nerves and vimentin-positive ICs, although the sildenafil- and diethylamine-NONOate-induced relaxations and cGMP-ir remained unchanged. CONCLUSIONS AND IMPLICATIONS Premature senescent mice exhibit bladder and urethral hyperexcitability, coupled with reduced urethral relaxation of neurogenic origin, which could model the impaired urinary function in elderly humans. We propose that senescence-accelerated mice provide a useful tool to analyse the basic mechanisms of age-related changes in bladder and urethral function.
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Affiliation(s)
- D Triguero
- Department of Physiology, Veterinary School, Complutense University, Madrid, Spain
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Dale PR, Cernecka H, Schmidt M, Dowling MR, Charlton SJ, Pieper MP, Michel MC. The pharmacological rationale for combining muscarinic receptor antagonists and β-adrenoceptor agonists in the treatment of airway and bladder disease. Curr Opin Pharmacol 2014; 16:31-42. [PMID: 24682092 PMCID: PMC4071415 DOI: 10.1016/j.coph.2014.03.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 03/03/2014] [Accepted: 03/04/2014] [Indexed: 02/07/2023]
Abstract
Muscarinic receptors increase smooth muscle tone in airways and urinary bladder. β-Adrenoceptors relax smooth muscle tone and oppose muscarinic contraction. Opposition involves transmitter release, signal transduction and receptor expression. This supports the combined use of muscarinic antagonists and β-adrenoceptor agonists.
Muscarinic receptor antagonists and β-adrenoceptor agonists are used in the treatment of obstructive airway disease and overactive bladder syndrome. Here we review the pharmacological rationale for their combination. Muscarinic receptors and β-adrenoceptors are physiological antagonists for smooth muscle tone in airways and bladder. Muscarinic agonism may attenuate β-adrenoceptor-mediated relaxation more than other contractile stimuli. Chronic treatment with one drug class may regulate expression of the target receptor but also that of the opposing receptor. Prejunctional β2-adrenoceptors can enhance neuronal acetylcholine release. Moreover, at least in the airways, muscarinic receptors and β-adrenoceptors are expressed in different locations, indicating that only a combined modulation of both systems may cause dilatation along the entire bronchial tree. While all of these factors contribute to a rationale for a combination of muscarinic receptor antagonists and β-adrenoceptor agonists, the full value of such combination as compared to monotherapy can only be determined in clinical studies.
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Affiliation(s)
- Philippa R Dale
- Department of Pharmacology, Cambridge University, Cambridge, UK
| | - Hana Cernecka
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - Martina Schmidt
- University of Groningen, Department of Molecular Pharmacology, Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Groningen Research Institute for Asthma and COPD, GRIAC, Groningen, The Netherlands
| | - Mark R Dowling
- Department of Molecular Pharmacology, Respiratory Diseases, Novartis Institutes for Biomedical Research, Horsham, UK
| | - Steven J Charlton
- Department of Molecular Pharmacology, Respiratory Diseases, Novartis Institutes for Biomedical Research, Horsham, UK
| | - Michael P Pieper
- Respiratory Diseases Research and Department of Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany
| | - Martin C Michel
- Respiratory Diseases Research and Department of Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH, Ingelheim, Germany; Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany.
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7
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Creed KE, Loxley RA, Phillips JK. Functional expression of muscarinic and purinoceptors in the urinary bladder of male and female rats and guinea pigs. J Smooth Muscle Res 2011; 46:201-15. [PMID: 20859067 DOI: 10.1540/jsmr.46.201] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE The objectives of this study were to compare the functional expression of muscarinic and purinergic receptors in the urinary bladder of 2 species, rat and guinea pig under comparable experimental conditions; and to test whether the receptors in males and females differ. METHODS Reverse transcription-polymerase chain reaction (RT-PCR) techniques were used to identify gene expression profiles in bladder smooth muscle (total n=8 rats, 7 guinea pigs) and mechanical responses to nerve stimulation and applied acetylcholine (ACh) in the presence of specific antagonists were used to identify functional receptor sub-types (total n=12 rats, 16 guinea pigs). RESULTS RT-PCR indicated that M2 and M3 were the predominant muscarinic receptor genes in both the male and female rat and guinea pig bladders. The phasic component of the nerve-induced contraction was greater in guinea pigs vs. rats. The tonic component and the ACh response were inhibited by the M3 receptor antagonist, darifenacin (10(-6) M, P≤0.05), but not by the M2 receptor antagonist, methoctramine (10(-5) M). The antipurinergic drug α, β-methylene ATP (5 × (-5) M) caused a significant reduction in the amplitude of the phasic response to nerve stimulation in all groups, and this effect was significantly greater in male vs. female rats. mRNA for the purinergic P2X1, P2X2, P2X4, P2X5 and P2X7 receptors was detected in both male and female rats, whereas P2X3 and P2X6 were inconsistently detected in male rats. The P2X1 purinoceptor antagonist pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4', 8'-disulphonate) (PPNDS), only inhibited nerve induced contractions at high concentrations (up to 10(-4) M). CONCLUSIONS While only minor functional differences were documented in cholinergic and purinergic bladder contractile responses between male and female animals, and between rats and guinea pigs, data such as presented in this study are critical in determining how relative functional contributions may change in the diseased state, providing valuable information towards new treatment options.
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Affiliation(s)
- Kate E Creed
- Faculty of Health Sciences, School of Veterinary and Biomedical Science, Murdoch University, Australia
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8
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Lai HH, Smith CP, Munoz A, Boone TB, Szigeti GP, Somogyi GT. Activation of cholinergic receptors blocks non-adrenergic non-cholinergic contractions in the rat urinary bladder. Brain Res Bull 2008; 77:420-6. [PMID: 18755252 DOI: 10.1016/j.brainresbull.2008.07.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Accepted: 07/29/2008] [Indexed: 11/18/2022]
Abstract
In the present study, the plasticity of the non-adrenergic non-cholinergic (NANC) response was investigated. Isolated rat bladder strips were electrically stimulated and the evoked contractions were isometrically recorded. The NANC part of the contractions were unmasked by applying 500 nM 4-DAMP, a potent muscarinic antagonist. Treatment of the bladder strips with 10 microM carbachol (a cholinergic agonist) increased the muscle tone but did not alter the neurally evoked contractions. However, carbachol decreased: (1) the NANC response from 74.6% to 33.3% of control and (2) the purinergic contractile response to alpha,beta-methylene ATP (alpha,beta-mATP) (10 microM) from 97.0% to 43.4% (p<0.05). Treatment with the cholinesterase inhibitor eserine (10 microM) also significantly decreased the NANC response to 21.1% (p<0.0001). The purinergic receptor antagonist suramin (100 microM) did not affect the neurally evoked contractions, however; subsequent addition of 4-DAMP decreased the contractions to 31%. Activation of the smooth muscle cholinergic receptors (with carbachol or eserine) and purinergic receptors (with alpha,beta-mATP) decreased the NANC contractions and the direct contractile response to alpha,beta-mATP. When the electrically evoked contractions were facilitated by the L-type Ca2+ channel activator, Bay-K 8644 the subsequent application of 4-DAMP did not unmask inhibited NANC contractions. We conclude that activation of muscarinic receptors by cholinergic agonist, carbachol or by endogenous acetylcholine (ACh) induce a cascade of events that leads to diminished purinergic response and consequently an inhibition of the bladder NANC response.
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Affiliation(s)
- H Henry Lai
- Neurology Laboratory, Scott Department of Urology, Baylor College of Medicine, Houston, TX 77030, USA
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9
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Activation of muscarinic receptors in rat bladder sensory pathways alters reflex bladder activity. J Neurosci 2008; 28:1977-87. [PMID: 18287514 DOI: 10.1523/jneurosci.4694-07.2008] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Antimuscarinic drugs affect bladder sensory symptoms such as urgency and frequency, presumably by acting on muscarinic acetylcholine receptors (mAChRs) located in bladder sensory pathways including primary afferent nerves and urothelium. However, the expression and the function of these receptors are not well understood. This study investigated the role of mAChRs in bladder sensory pathways in vivo in urethane anesthetized rats. Intravesical administration of the mAChR agonist oxotremorine methiodide (OxoM) elicited concentration-dependent excitatory and inhibitory effects on the frequency of voiding. These effects were blocked by intravesical administration of the mAChR antagonist atropine methyl nitrate (5 microM) and were absent in rats pretreated with capsaicin to desensitize C-fiber afferent nerves. Low concentrations of OxoM (5 microM) decreased voiding frequency by approximately 30%, an effect blunted by inhibiting nitric oxide (NO) synthesis with L-NAME (N(omega)-nitro-L-arginine methyl ester hydrochloride; 5 mg/kg; i.v.). High concentrations of OxoM (40 microM) increased voiding frequency by approximately 45%, an effect blunted by blocking purinergic receptors with PPADS (0.1-1 mM; intravesically). mAChR agonists stimulated release of ATP from cultured urothelial cells. Intravenous administration of OxoM (0.01-5 microg/kg) did not mimic the intravesical effects on voiding frequency. These results suggest that activation of mAChRs located near the luminal surface of the bladder affects voiding functions via mechanisms involving ATP and NO release presumably from the urothelium, that in turn could act on bladder C-fiber afferent nerves to alter their firing properties. These findings suggest that the urothelial-afferent nerve interactions can influence reflex voiding function.
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Christ GJ, Hodges S. Molecular mechanisms of detrusor and corporal myocyte contraction: identifying targets for pharmacotherapy of bladder and erectile dysfunction. Br J Pharmacol 2006; 147 Suppl 2:S41-55. [PMID: 16465183 PMCID: PMC1751499 DOI: 10.1038/sj.bjp.0706627] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The Post-Genomic age presents many new challenges and opportunities for the improved understanding, diagnosis and treatment of human disease. The long-term goal is to identify molecular correlates of disease processes, and use this information to develop novel and more effective therapeutics. A major hurdle in this regard is ensuring that the molecular targets of interest are indeed relevant to the physiology and/or pathophysiology of the processes being studied, and, moreover, to determine if they are specific to the tissue/organ being investigated. As a first step in this direction, we have reviewed the literature pertaining to bladder and erectile physiology/pharmacology and dysfunction and attempted to summarize some of the critical molecular mechanisms regulating detrusor and corporal myocyte tone. Because of the vast amount of published data, we have limited the scope of this review to consideration of the calcium-mobilizing and calcium-sensitizing pathways in these cells. Despite obvious differences in phenotypic characteristics of the detrusor and corporal myocyte, there are some common molecular changes that may contribute to, for example, the increased myocyte contractility characteristic of bladder and erectile dysfunction (i.e. increased Rho kinase activity and decreased K(+) channel function). Of course, there are also some important distinctions in the pathways that modulate contractility in these two cell types (i.e. the contribution of ryanodine-sensitive calcium stores and the nitric oxide/cGMP pathways). This report highlights some of these similarities and distinctions in the hope that it will encourage scientific discourse and research activity in this area, eventually leading to an improved quality of life for those millions of individuals that are afflicted with bladder and erectile dysfunction.
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MESH Headings
- Animals
- Erectile Dysfunction/drug therapy
- Erectile Dysfunction/metabolism
- Erectile Dysfunction/physiopathology
- Humans
- Male
- Muscle Contraction
- Muscle, Smooth/innervation
- Muscle, Smooth/metabolism
- Muscle, Smooth, Vascular/innervation
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/metabolism
- Penile Erection
- Penis/blood supply
- Penis/metabolism
- Signal Transduction
- Urinary Bladder/innervation
- Urinary Bladder/metabolism
- Urinary Bladder, Overactive/drug therapy
- Urinary Bladder, Overactive/metabolism
- Urinary Bladder, Overactive/physiopathology
- Urination
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Affiliation(s)
- George J Christ
- Wake Forest Institute for Regenerative Medicine, Wake Forest University Baptist Medical Center, Winston-Salem, NC 27157, USA.
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Braverman AS, Ruggieri MR. Muscarinic receptor transcript and protein density in hypertrophied and atrophied rat urinary bladder. Neurourol Urodyn 2006; 25:55-61. [PMID: 16304675 PMCID: PMC3277085 DOI: 10.1002/nau.20180] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AIMS Our previous studies showed that bladder hypertrophy shifts the muscarinic receptor subtype mediating contraction from M(3) towards M(2) along with increased M(2) and decreased M(3) protein concentration. We quantified mRNA for M(1) through M(5) receptors to determine whether the changes in M(2) and M(3) protein levels was due to changes in transcription. METHODS Bladder hypertrophy was induced by bladder outlet obstruction (BOO), major pelvic ganglion electrocautery (DEN), and major pelvic ganglion decentralization (DEC). Bladder atrophy was induced by ureteral diversion (DIV). Additional groups included denervated and diverted (DEN-DIV), sham operated (SHAM), and normal (NOR) controls. Transcripts were quantified using a multiplex ribonuclease protection assay (RPA) and receptor protein density was determined by immunoprecipitation. Receptor transcripts were expressed per unit total RNA. RESULTS Although all five receptor subtype transcripts were detected in all experimental groups, the densities of M(1), M(4), and M(5) were much lower than for the M(2) and M(3) subtype. There were more M(2) receptor transcripts than all the others, consistent with M(2) protein determinations. M(2) transcripts were significantly increased in DEN and BOO bladders. Surprisingly, M(3) transcripts were also significantly increased in BOO. There was a significant correlation (r=0.98, P<0.001) between protein density and transcript density for the M(2) but not the M(3) receptor among the different experimental groups. CONCLUSIONS Changes in mRNA concentration are reflected by changes in protein density for the M(2) receptor but not for the M(3) receptor. Extrapolation of functional effects from transcript density data is invalid for M(3) mediated bladder contractions.
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Affiliation(s)
- Alan S. Braverman
- Department of Urology, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - Michael R. Ruggieri
- Department of Urology, Temple University School of Medicine, Philadelphia, Pennsylvania
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania
- Correspondence to: Michael R. Ruggieri, Sr., Temple University School of Medicine, 3400 North Broad Street, 715 OMS, Philadelphia, PA 19140.
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Pontari MA, Braverman AS, Ruggieri MR. The M2 muscarinic receptor mediates in vitro bladder contractions from patients with neurogenic bladder dysfunction. Am J Physiol Regul Integr Comp Physiol 2004; 286:R874-80. [PMID: 14751843 PMCID: PMC3274770 DOI: 10.1152/ajpregu.00391.2003] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bladder muscle specimens from seven patients with neurogenic bladder dysfunction were analyzed to determine whether the muscarinic receptor subtype mediating contraction shifts from M(3) to the M(2) subtype as found in the denervated, hypertrophied rat bladder. Seven bladder specimens were analyzed from six female and one male patients. Six of the patients had traumatic cervical spinal cord injuries (C(4)-C(7)), and the other patient had an L(1) congenital myelomeningocele. This was compared with results from bladder specimens obtained from eight organ transplant donors. The affinities of three subtype-selective muscarinic receptor antagonists for inhibition of carbachol-induced contractions were determined. The affinity of the M(3) selective antagonists darifenacin or p-fluoro-hexahydrosiladifenadol (p-F-HHSiD) was determined in six of the seven spinal injury patient specimens. The affinity was consistent with M(2)-mediated contractions in four of these six specimens, intermediate between M(2) and M(3) in one specimen, and within the M(3) range in one specimen. The other specimen, tested only with the M(2) selective antagonist methoctramine, showed an M(3) affinity. In the organ donors, the affinity of p-F-HHSiD was within the M(2) range for six of seven specimens, whereas the affinity of darifenacin was within the M(3) range for five of six and intermediate between M(2) and M(3) for the other specimen tested. The affinity of methoctramine in both organ donor specimens tested was within the M(3) range. Whereas normal detrusor contractions are mediated by the M(3) receptor subtype, in patients with neurogenic bladder dysfunction as well as certain organ transplant donors, contractions can be mediated by the M(2) muscarinic receptor subtype.
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Affiliation(s)
- Michel A Pontari
- Temple University School of Medicine, 3400 N. Broad St., 715 OMS, Philadelphia, PA 19140-5104, USA
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13
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Braverman AS, Ruggieri MR. Hypertrophy changes the muscarinic receptor subtype mediating bladder contraction from M3 toward M2. Am J Physiol Regul Integr Comp Physiol 2003; 285:R701-8. [PMID: 12763741 PMCID: PMC3277086 DOI: 10.1152/ajpregu.00009.2003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Major pelvic ganglion electrocautery (MPGE) and spinal cord injury in the rat induce bladder hypertrophy and a change in muscarinic receptor subtypes mediating bladder contraction from predominantly M3 to a combination of M2 and M3. To determine whether this is a result of bladder hypertrophy or denervation, we studied the following groups: sham-operated controls, urinary diversion (DIV), MPGE together with urinary diversion (DIV-DEN), bilateral MPGE (DEN), bladder outlet obstruction (BOO), and MPG decentralization (MPGDEC). The degree of bladder denervation was determined by the maximal carbachol response normalized to the response to electric field stimulation. Receptor subtype density was determined by immunoprecipitation. The affinity of subtype-selective muscarinic antagonists for inhibition of carbachol-induced contractions was used to determine the subtype-mediating contraction. DEN, MPG-DEC, and BOO bladders were hypertrophic whereas DIV bladders were atrophic compared with sham operated. Bladder contraction in sham-operated, DIV, and DIV-DEN was mediated by the M3 receptor subtype, whereas the M2 subtype participated in contraction in the DEN, MPG-DEC, and BOO groups. The hypertrophied bladders had an increase in total and M2 receptor density while all experimental groups showed a reduction in M3 receptor density. Thus bladder hypertrophy, independent from bladder denervation, causes a shift in the muscarinic receptor subtype mediating bladder contraction from M3 toward M2.
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Affiliation(s)
- Alan S Braverman
- Temple Univ. School of Medicine, 3400 N. Broad St., 715 OMS, Philadelphia, PA 19140, USA.
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Abstract
The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the urinary bladder, urethra, and external urethral sphincter. This activity is in turn controlled by neural circuits in the brain, spinal cord, and peripheral ganglia. Various neurotransmitters, including acetylcholine, norepinephrine, dopamine, serotonin, excitatory and inhibitory amino acids, adenosine triphosphate, nitric oxide, and neuropeptides, have been implicated in the neural regulation of the lower urinary tract. Injuries or diseases of the nervous system, as well as drugs and disorders of the peripheral organs, can produce voiding dysfunctions such as urinary frequency, urgency, and incontinence or inefficient voiding and urinary retention. This chapter will review recent advances in our understanding of the pathophysiology of voiding disorders and the targets for drug therapy.
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Affiliation(s)
- W C de Groat
- Department of Pharmacology, Medical School, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
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Braverman AS, Ruggieri MR. Selective alkylation of rat urinary bladder muscarinic receptors with 4-DAMP mustard reveals a contractile function for the M2 muscarinic receptor. J Recept Signal Transduct Res 1999; 19:819-33. [PMID: 10349596 PMCID: PMC3277790 DOI: 10.3109/10799899909042875] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Our previous data indicate that M3 muscarinic receptors mediate carbachol induced bladder contractions. The data presented here were obtained by selective alkylation of M3 receptors with 4-DAMP mustard and suggest that the M2 receptor subtype may be involved in inhibition of beta-adrenergic receptor induced relaxation, therefore, allowing recontraction. Alkylation resulted in 85% of M3 receptors and 65% of M2 receptors unable to bind radioligand as demonstrated by subtype selective immunoprecipitation. Rat bladder strips subjected to our alkylation procedure contracted submaximally, and direct carbachol contractions were inhibited by antagonists with affinities consistent with M3 receptor mediated contraction. In contrast, the affinities of antagonists for inhibition of carbachol induced recontractions following isoproterenol stimulated relaxation in the presence of 90 mM KCl, indicated a contractile function for the M2 receptor that was not observed in control strips. In conclusion, these studies demonstrate a possible role for the M2 subtype in bladder smooth muscle contraction.
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Affiliation(s)
- A S Braverman
- Department of Urology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Braverman AS, Luthin GR, Ruggieri MR. M2 muscarinic receptor contributes to contraction of the denervated rat urinary bladder. THE AMERICAN JOURNAL OF PHYSIOLOGY 1998; 275:R1654-60. [PMID: 9791087 PMCID: PMC3275805 DOI: 10.1152/ajpregu.1998.275.5.r1654] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In vitro bladder contractions in response to cumulative carbachol doses were measured in the presence of selective muscarinic antagonists from rats that had their major pelvic ganglion bilaterally removed. Denervation induced both hypertrophy and a supersensitivity of the bladders to agonist. The affinities in control bladders for antagonism of carbachol-induced contractions were consistent with M3-mediated contractions. Affinities in denervated bladders for 4-diphenlacetoxy-N-methylpiperidine methiodide (8.5) and p-fluoro hexahydrosilodifenidol (6.6) were consistent with M2-mediated contractions, although the methoctramine affinity (6.5) was consistent with M3-mediated contractions. Subtype-selective immunoprecipitation of muscarinic receptors revealed a 50% increase in total and a 60% increase in M2 receptor density with no change in M3 receptor density in denervated bladders compared with normal or sham-operated controls. This increase in M2 receptor density is consistent with the change in affinity of the antagonists for inhibition of carbachol-induced contractions and may indicate that M2 receptors or a combination of M2 and M3 receptors directly mediates smooth muscle contraction in the denervated bladder.
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Affiliation(s)
- A S Braverman
- Department of Urology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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