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Wada N, Karnup S, Kadekawa K, Shimizu N, Kwon J, Shimizu T, Gotoh D, Kakizaki H, de Groat W, Yoshimura N. Current knowledge and novel frontiers in lower urinary tract dysfunction after spinal cord injury: Basic research perspectives. UROLOGICAL SCIENCE 2022; 33:101-113. [PMID: 36177249 PMCID: PMC9518811 DOI: 10.4103/uros.uros_31_22] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
This review article aims to summarize the recent advancement in basic research on lower urinary tract dysfunction (LUTD) following spinal cord injury (SCI) above the sacral level. We particularly focused on the neurophysiologic mechanisms controlling the lower urinary tract (LUT) function and the SCI-induced changes in micturition control in animal models of SCI. The LUT has two main functions, the storage and voiding of urine, that are regulated by a complex neural control system. This neural system coordinates the activity of two functional units in the LUT: the urinary bladder and an outlet including bladder neck, urethra, and striated muscles of the pelvic floor. During the storage phase, the outlet is closed and the bladder is quiescent to maintain a low intravesical pressure and continence, and during the voiding phase, the outlet relaxes and the bladder contracts to promote efficient release of urine. SCI impairs voluntary control of voiding as well as the normal reflex pathways that coordinate bladder and sphincter function. Following SCI, the bladder is initially areflexic but then becomes hyperreflexic due to the emergence of a spinal micturition reflex pathway. However, the bladder does not empty efficiently because coordination between the bladder and urethral sphincter is lost. In animal models of SCI, hyperexcitability of silent C-fiber bladder afferents is a major pathophysiological basis of neurogenic LUTD, especially detrusor overactivity. Reflex plasticity is associated with changes in the properties of neuropeptides, neurotrophic factors, or chemical receptors of afferent neurons. Not only C-fiber but also Aδ-fiber could be involved in the emergence of neurogenic LUTD such as detrusor sphincter dyssynergia following SCI. Animal research using disease models helps us to detect the different contributing factors for LUTD due to SCI and to find potential targets for new treatments.
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Heppner TJ, Hennig GW, Nelson MT, Vizzard MA. Rhythmic Calcium Events in the Lamina Propria Network of the Urinary Bladder of Rat Pups. Front Syst Neurosci 2017; 11:87. [PMID: 29321730 PMCID: PMC5732214 DOI: 10.3389/fnsys.2017.00087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/14/2017] [Indexed: 01/23/2023] Open
Abstract
The lamina propria contains a dense network of cells, including interstitial cells (ICs), that may play a role in bladder function by modulating communication between urothelium, nerve fibers and smooth muscle or acting as pacemakers. Transient receptor potential vanilloid 4 (TRPV4) channels allow cation influx and may be involved in sensing stretch or chemical irritation in urinary bladder. Urothelium was removed from rats (P0-Adult), cut into strips, and loaded with a Ca2+ fluorescent dye (Fluo-2 AM leak resistant or Cal 520) for 90 min (35-37°C) to measure Ca2+ events. Ca2+ events were recorded for a period of 60 seconds (s) in control and after drug treatment. A heterogeneous network of cells was identified at the interface of the urothelium and lamina propria of postnatal rat pups, aged ≤ postnatal (P) day 21, with diverse morphology (round, fusiform, stellate with numerous projections) and expressing platelet-derived growth factor receptor alpha (PDGFRα)- and TRPV4-immunoreactivity (IR). Ca2+ transients occurred at a slow frequency with an average interval of 30 ± 8.6 s. Waveform analyses of Ca2+ transients in cells in the lamina propria network revealed long duration Ca2+ events with slow upstrokes. We observed slow propagating waves of activity in the lamina propria network that displayed varying degrees of coupling. Application of the TRPV4 agonist, GSK1016790 (100 nM), increased the duration of Ca2+ events, the number of cells with Ca2+ events and the integrated Ca2+ activity corresponding to propagation of activity among cells in the lamina propria network. However, GSK2193874 (1 μM), a potent antagonist of TRPV4 channels, was without effect. ATP (1 μM) perfusion increased the number of cells in the lamina propria exhibiting Ca2+ events and produced tightly coupled network activity. These findings indicate that ATP and TRPV4 can activate cells in the laminar propria network, leading to the appearance of organized propagating wavefronts.
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Affiliation(s)
- Thomas J Heppner
- Department of Pharmacology, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
| | - Grant W Hennig
- Department of Pharmacology, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
| | - Mark T Nelson
- Department of Pharmacology, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
| | - Margaret A Vizzard
- Department of Neurological Sciences, The Robert Larner, M.D. College of Medicine, University of Vermont, Burlington, VT, United States
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Zhu X, Zhai K, Mi Y, Ji G. Expression and function of phosphodiesterases (PDEs) in the rat urinary bladder. BMC Urol 2017; 17:54. [PMID: 28687079 PMCID: PMC5501575 DOI: 10.1186/s12894-017-0244-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 06/29/2017] [Indexed: 11/10/2022] Open
Abstract
Background It has been shown that hosphodiesterases (PDEs) play an important role in mediating the smooth muscle tone of rat urinary bladder. However, the gene expression profiles of them were still unknown. Methods Urinary bladder Strips were obtained from both neonatal and adult Sprague-Dawley rats. RT-PCR/western blot and organ bath were used to measure the expression and function of PDEs. Results Adult rat urinary bladder expressed various PDE mRNA with the following rank order: PDE5A ≈ PDE9A ≈ PDE10A > PDE2A ≈ PDE4A ≈ PDE4D > PDE4B ≈ PDE3B ≈ PDE8B ≈ PDE7A ≈ PDE7B > PDE1A. PDE1B, PDE1C, PDE3A, PDE4C, PDE8A, and PDE11A were not detected. Of interest, the mRNA and protein of PDE3A were significantly decreased in adult rat urinary bladder compared to neonatal rat urinary bladder. Cilostamide, a specific inhibitor for PDE3, significantly inhibited the amplitude and frequency of carbachol-enhanced phasic contractions of neonatal rat bladder strips by 38.8% and 12.1%, respectively. Compared to the neonatal rat bladder, the effect of cilostamide was significantly blunted in adult rat urinary bladder: the amplitude and frequency of carbachol-enhanced phasic contractions were decreased by 13.4% (P < 0.01 vs neonatal rat bladder) and 4.4%, respectively. However, the mRNA and the protein levels of PDE3B were similar between neonatal and adult rat bladder. Conclusion We found that several PDE isoforms were expressed in the rat urinary bladder with distinct levels. Moreover, we showed that the function of PDE3 was blunted in adult rat bladder likely due to the decreased expression of PDE3A.
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Affiliation(s)
- Xiaofei Zhu
- Department of Urology, Beijing Jishuitan Hospital, Beijing, China
| | - Kui Zhai
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, 100101, China.
| | - Yue Mi
- Department of Urology, Peking University First Hospital, Beijing, China
| | - Guangju Ji
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing, 100101, China.
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Girard B, Peterson A, Malley S, Vizzard MA. Accelerated onset of the vesicovesical reflex in postnatal NGF-OE mice and the role of neuropeptides. Exp Neurol 2016; 285:110-125. [PMID: 27342083 DOI: 10.1016/j.expneurol.2016.06.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 05/30/2016] [Accepted: 06/20/2016] [Indexed: 12/31/2022]
Abstract
The mechanisms underlying the postnatal maturation of micturition from a somatovesical to a vesicovesical reflex are not known but may involve neuropeptides in the lower urinary tract. A transgenic mouse model with chronic urothelial overexpression (OE) of NGF exhibited increased voiding frequency, increased number of non-voiding contractions, altered morphology and hyperinnervation of the urinary bladder by peptidergic (e.g., Sub P and CGRP) nerve fibers in the adult. In early postnatal and adult NGF-OE mice we have now examined: (1) micturition onset using filter paper void assays and open-outlet, continuous fill, conscious cystometry; (2) innervation and neurochemical coding of the suburothelial plexus of the urinary bladder using immunohistochemistry and semi-quantitative image analyses; (3) neuropeptide protein and transcript expression in urinary bladder of postnatal and adult NGF-OE mice using Q-PCR and ELISAs and (4) the effects of intravesical instillation of a neurokinin (NK)-1 receptor antagonist on bladder function in postnatal and adult NGF-OE mice using conscious cystometry. Postnatal NGF-OE mice exhibit age-dependent (R2=0.996-0.998; p≤0.01) increases in Sub and CGRP expression in the urothelium and significantly (p≤0.01) increased peptidergic hyperinnervation of the suburothelial nerve plexus. By as early as P7, NGF-OE mice exhibit a vesicovesical reflex in response to intravesical instillation of saline whereas littermate WT mice require perigenital stimulation to elicit a micturition reflex until P13 when vesicovesical reflexes are first observed. Intravesical instillation of a NK-1 receptor antagonist, netupitant (0.1μg/ml), significantly (p≤0.01) increased void volume and the interval between micturition events with no effects on bladder pressure (baseline, threshold, peak) in postnatal NGF-OE mice; effects on WT mice were few. NGF-induced pleiotropic effects on neuropeptide (e.g., Sub P) expression in the urinary bladder contribute to the maturation of the micturition reflex and are excitatory to the micturition reflex in postnatal NGF-OE mice. These studies provide insight into the mechanisms that contribute to the postnatal development of the micturition reflex.
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Affiliation(s)
- Beatrice Girard
- University of Vermont College of Medicine, Department of Neurological Sciences, Burlington, VT 05405, USA
| | - Abbey Peterson
- University of Vermont College of Medicine, Department of Neurological Sciences, Burlington, VT 05405, USA
| | - Susan Malley
- University of Vermont College of Medicine, Department of Neurological Sciences, Burlington, VT 05405, USA
| | - Margaret A Vizzard
- University of Vermont College of Medicine, Department of Neurological Sciences, Burlington, VT 05405, USA.
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Ehrhardt A, Wang B, Yung AC, Wang Y, Kozlowski P, van Breemen C, Schrader JW. Urinary Retention, Incontinence, and Dysregulation of Muscarinic Receptors in Male Mice Lacking Mras. PLoS One 2015; 10:e0141493. [PMID: 26516777 PMCID: PMC4627820 DOI: 10.1371/journal.pone.0141493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/07/2015] [Indexed: 12/20/2022] Open
Abstract
Here we show that male, but not female mice lacking expression of the GTPase M-Ras developed urinary retention with distention of the bladder that exacerbated with age but occurred in the absence of obvious anatomical outlet obstruction. There were changes in detrusor morphology in Mras-/- males: Smooth muscle tissue, which exhibited a compact organization in WT mice, appeared disorganized and became increasingly ‘layered’ with age in Mras-/- males, but was not fibrotic. Bladder tissue near the apex of bladders of Mras-/- males exhibited hypercontractility in response to the cholinergic agonist carbachol in in vitro, while responses in Mras-/- females were normal. In addition, spontaneous phasic contractions of detrusors from Mras-/- males were increased, and Mras-/- males exhibited urinary incontinence. We found that expression of the muscarinic M2 and M3 receptors that mediate the cholinergic contractile stimuli of the detrusor muscle was dysregulated in both Mras-/- males and females, although only males exhibited a urinary phenotype. Elevated expression of M2R in young males lacking M-Ras and failure to upregulate M3R with age resulted in significantly lower ratios of M3R/M2R expression that correlated with the bladder abnormalities. Our data suggests that M-Ras and M3R are functionally linked and that M-Ras is an important regulator of male bladder control in mice. Our observations also support the notion that bladder control is sexually dimorphic and is regulated through mechanisms that are largely independent of acetylcholine signaling in female mice.
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MESH Headings
- Acetylcholine/physiology
- Aging/genetics
- Aging/physiology
- Animals
- Female
- Gene Expression Regulation
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Monomeric GTP-Binding Proteins/deficiency
- Monomeric GTP-Binding Proteins/genetics
- Monomeric GTP-Binding Proteins/physiology
- Muscle Contraction
- Muscle, Smooth/metabolism
- Phenotype
- Proteinuria/genetics
- Proteinuria/physiopathology
- RNA, Messenger/biosynthesis
- Receptor, Muscarinic M2/biosynthesis
- Receptor, Muscarinic M2/genetics
- Receptor, Muscarinic M2/physiology
- Receptor, Muscarinic M3/biosynthesis
- Receptor, Muscarinic M3/genetics
- Receptor, Muscarinic M3/physiology
- Sex Characteristics
- Urinary Bladder/metabolism
- Urinary Bladder/pathology
- Urinary Bladder, Overactive/genetics
- Urinary Bladder, Overactive/physiopathology
- Urinary Incontinence/genetics
- Urinary Incontinence/physiopathology
- Urinary Retention/genetics
- Urinary Retention/physiopathology
- Urination/physiology
- ras Proteins
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Affiliation(s)
- Annette Ehrhardt
- The Biomedical Research Centre, The University of British Columbia, 2222 Health Sciences Mall, Vancouver, British Columbia, Canada
| | - Bin Wang
- The Biomedical Research Centre, The University of British Columbia, 2222 Health Sciences Mall, Vancouver, British Columbia, Canada
| | - Andrew C. Yung
- The University of British Columbia MRI Research Centre, Life Sciences Centre, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada
| | - Yanni Wang
- The Biomedical Research Centre, The University of British Columbia, 2222 Health Sciences Mall, Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- The University of British Columbia MRI Research Centre, Life Sciences Centre, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada
- The University of British Columbia, Departments of Radiology and Urologic Sciences, 818 West 10th Ave., Vancouver, British Columbia, Canada
| | - Cornelis van Breemen
- The University of British Columbia, Department of Pharmacology and Therapeutics, 2176 Health Sciences Mall, Vancouver, British Columbia, Canada
| | - John W. Schrader
- The Biomedical Research Centre, The University of British Columbia, 2222 Health Sciences Mall, Vancouver, British Columbia, Canada
- * E-mail:
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Kullmann FA, Daugherty SL, de Groat WC, Birder LA. Bladder smooth muscle strip contractility as a method to evaluate lower urinary tract pharmacology. J Vis Exp 2014:e51807. [PMID: 25178111 DOI: 10.3791/51807] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties of the smooth muscle as well as changes induced by pathology. This method provides critical information for understanding bladder function while overcoming major methodological difficulties encountered in in vivo experiments, such as surgical and pharmacological manipulations that affect stability and survival of the preparations, the use of human tissue, and/or the use of expensive chemicals. It also provides a way to investigate the properties of each bladder component (i.e. smooth muscle, mucosa, nerves) in healthy and pathological conditions. The urinary bladder is removed from an anesthetized animal, placed in Krebs solution and cut into strips. Strips are placed into a chamber filled with warm Krebs solution. One end is attached to an isometric tension transducer to measure contraction force, the other end is attached to a fixed rod. Tissue is stimulated by directly adding compounds to the bath or by electric field stimulation electrodes that activate nerves, similar to triggering bladder contractions in vivo. We demonstrate the use of this method to evaluate spontaneous smooth muscle contractility during development and after an experimental spinal cord injury, the nature of neurotransmission (transmitters and receptors involved), factors involved in modulation of smooth muscle activity, the role of individual bladder components, and species and organ differences in response to pharmacological agents. Additionally, it could be used for investigating intracellular pathways involved in contraction and/or relaxation of the smooth muscle, drug structure-activity relationships and evaluation of transmitter release. The in vitro smooth muscle contractility method has been used extensively for over 50 years, and has provided data that significantly contributed to our understanding of bladder function as well as to pharmaceutical development of compounds currently used clinically for bladder management.
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Affiliation(s)
- F Aura Kullmann
- Department of Medicine, Renal division, University of Pittsburgh School of Medicine;
| | - Stephanie L Daugherty
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine
| | - William C de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine
| | - Lori A Birder
- Department of Medicine, Renal division, University of Pittsburgh School of Medicine; Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine
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Zhai K, Chang Y, Wei B, Liu Q, Leblais V, Fischmeister R, Ji G. Phosphodiesterase types 3 and 4 regulate the phasic contraction of neonatal rat bladder smooth myocytes via distinct mechanisms. Cell Signal 2014; 26:1001-10. [PMID: 24463006 DOI: 10.1016/j.cellsig.2014.01.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/20/2013] [Accepted: 01/06/2014] [Indexed: 11/28/2022]
Abstract
Activation of the cyclic AMP (cAMP) pathway reduces bladder contractility. However, the role of phosphodiesterase (PDE) families in regulating this function is poorly understood. Here, we compared the contractile function of the cAMP hydrolyzing PDEs in neonatal rat bladder smooth myocytes. RT-PCR and Western blotting analysis revealed that several isoforms of PDE1-4 were expressed in neonatal rat bladder. While 8-methoxymethyl-3-isobutyl-1-methylxanthine (a PDE1 inhibitor) and BAY-60-7550 (a PDE2 inhibitor) had no effect on the carbachol-enhanced phasic contractions of bladder strips, cilostamide (Cil, a PDE3 inhibitor) and Ro-20-1724 (Ro, a PDE4 inhibitor) significantly reduced these contractions. This inhibitory effect of Ro was blunted by the PKA inhibitor H-89, while the inhibitory effect of Cil was strongly attenuated by the PKG inhibitor KT 5823. Application of Ro in single bladder smooth myocytes resulted in an increase in Ca(2+) spark frequency but a decrease both in Ca(2+) transients and in sarcoplasmic reticulum (SR) Ca(2+) content. In contrast, Cil had no effect on these events. Furthermore, Ro-induced inhibition of the phasic contractions was significantly blocked by ryanodine and iberiotoxin. Taken together, PDE3 and PDE4 are the main PDE isoforms in maintaining the phasic contractions of bladder smooth myocytes, with PDE4 being functionally more active than PDE3. However, their roles are mediated through different mechanisms.
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Affiliation(s)
- Kui Zhai
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; Inserm UMR-S 769, LabEx LERMIT, F-92296 Châtenay-Malabry, France; Université Paris-Sud, Faculté de Pharmacie, F-92296 Châtenay-Malabry, France
| | - Yan Chang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Bin Wei
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Qinghua Liu
- Institute for Medical Biology, College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Véronique Leblais
- Inserm UMR-S 769, LabEx LERMIT, F-92296 Châtenay-Malabry, France; Université Paris-Sud, Faculté de Pharmacie, F-92296 Châtenay-Malabry, France
| | - Rodolphe Fischmeister
- Inserm UMR-S 769, LabEx LERMIT, F-92296 Châtenay-Malabry, France; Université Paris-Sud, Faculté de Pharmacie, F-92296 Châtenay-Malabry, France.
| | - Guangju Ji
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
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Imamura M, Sugino Y, Long X, Slivano OJ, Nishikawa N, Yoshimura N, Miano JM. Myocardin and microRNA-1 modulate bladder activity through connexin 43 expression during post-natal development. J Cell Physiol 2013; 228:1819-26. [PMID: 23359472 DOI: 10.1002/jcp.24333] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 01/18/2013] [Indexed: 12/27/2022]
Abstract
Overactive bladder (OAB) is a pervasive clinical problem involving alterations in both neurogenic and myogenic activity. While there has been some progress in understanding neurogenic inputs to OAB, the mechanisms controlling myogenic bladder activity are unclear. We report the involvement of myocardin (MYOCD) and microRNA-1 (miR-1) in the regulation of connexin 43 (GJA1), a major gap junction in bladder smooth muscle, and the collective role of these molecules during post-natal bladder development. Wild-type (WT) mouse bladders showed normal development from early post-natal to adult including increases in bladder capacity and maintenance of normal sensitivity to cholinergic agents concurrent with down-regulation of MYOCD and several smooth muscle cell (SMC) contractile genes. Myocardin heterozygous-knockout mice exhibited reduced expression of Myocd mRNA and several SMC contractile genes concurrent with bladder SMC hypersensitivity that was mediated by gap junctions. In both cultured rat bladder SMC and in vivo bladders, MYOCD down-regulated GJA1 expression through miR-1 up-regulation. Interestingly, adult myocardin heterozygous-knockout mice showed normal increases in bladder and body weight but lower bladder capacity compared to WT mice. These results suggest that MYOCD down-regulates GJA1 expression via miR-1 up-regulation, thereby contributing to maintenance of normal sensitivity and development of bladder capacity.
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Affiliation(s)
- Masaaki Imamura
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA.
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Phasic contractions in urinary bladder from juvenile versus adult pigs. PLoS One 2013; 8:e58611. [PMID: 23516515 PMCID: PMC3596269 DOI: 10.1371/journal.pone.0058611] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 02/05/2013] [Indexed: 01/18/2023] Open
Abstract
Aims Alterations in properties of the bladder with maturation are relevant physiologically and pathophysiologically. The aim of this study was to investigate alterations in bladder properties with maturation in juvenile vs. adult pig, focussing on differences between layers of the bladder wall (mucosa vs. detrusor) and the presence and functional contribution of interstitial cells (ICs). Methods Basal and cholinergic-induced phasic contractions (PCs) in mucosal and denuded-detrusor strips from juvenile and adult pigs were assessed. Expression of c-kit, a marker of ICs, was investigated in the mucosa and the detrusor layers of the pig bladder. The functional role of ICs in mediating PCs was examined using imatinib. Results Mucosal strips from juvenile and adult pig bladders demonstrated basal PCs whilst denuded-detrusor strips did not. PCs of mucosal strips from juvenile pigs were significantly greater than those from adult bladders. Immunoreactivity for c-kit was detected in mucosa and detrusor layers of pig bladder. Histological studies demonstrated a distinct layer of smooth muscle between the urothelium and bladder detrusor, termed the muscularis mucosa. Imatinib was only effective in inhibiting PCs in mucosal strips from juvenile pigs. Imatinib inhibited the carbachol-induced PCs of both juvenile and adult denuded-detrusor strips, although strips from juvenile bladders demonstrated a trend towards being more sensitive to this inhibition. Conclusions We confirm the presence of c-kit positive ICs in pig urinary bladder. The enhanced PCs of mucosal strips from juvenile animals could be due to altered properties of ICs or the muscularis mucosa in the bladders of these animals.
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10
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Artim DE, Kullmann FA, Daugherty SL, Bupp E, Edwards CL, de Groat WC. Developmental and spinal cord injury-induced changes in nitric oxide-mediated inhibition in rat urinary bladder. Neurourol Urodyn 2011; 30:1666-74. [PMID: 21717503 DOI: 10.1002/nau.21143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 03/28/2011] [Indexed: 12/29/2022]
Abstract
AIMS During postnatal development large amplitude spontaneous activity of the neonatal rat bladder changes to a low amplitude adult pattern of activity that leads to improved storage function. Previously, we have shown that spontaneous activity in neonatal rat bladder strips is inhibited by activation of the nitric oxide (NO)-cGMP signaling pathway. In the present experiments we determined if this inhibitory pathway is altered during postnatal development or spinal cord injury. METHODS Baseline tone and amplitude and frequency of spontaneous contractions were measured in bladder strips from male or female neonatal (days 10-21), juvenile (days 24-39) and adult female spinal cord intact or chronic spinal cord injured Sprague-Dawley rats. RESULTS The inhibitory effects of an NO donor (SNAP) and a PDE-5 inhibitor (zaprinast) on spontaneous activity of bladder strips decreased during postnatal development, while an inhibitory effect of 8-bromo-cGMP, which was blocked by a protein kinase G inhibitor, was detected at all ages tested. However, the effect of NO-cGMP signaling to reduce baseline tone emerged during postnatal development. The inhibition induced by the NO donor was blocked by an inhibitor of soluble guanylyl cyclase (sGC). Chronic spinal cord injury (cSCI), which causes the re-emergence of a neonatal-like pattern of spontaneous activity, did not restore sensitivity to NO-mediated inhibition in adult rat bladders. CONCLUSIONS These data indicate that while cGMP signaling inhibits activity in young and adult bladders as well as after cSCI, there is a developmental decrease in the sensitivity of bladder to NO-mediated inhibition.
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Affiliation(s)
- Debra E Artim
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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11
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de Groat WC, Yoshimura N. Plasticity in reflex pathways to the lower urinary tract following spinal cord injury. Exp Neurol 2011; 235:123-32. [PMID: 21596038 DOI: 10.1016/j.expneurol.2011.05.003] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 04/18/2011] [Accepted: 05/01/2011] [Indexed: 12/25/2022]
Abstract
The lower urinary tract has two main functions, storage and periodic expulsion of urine, that are regulated by a complex neural control system in the brain and lumbosacral spinal cord. This neural system coordinates the activity of two functional units in the lower urinary tract: (1) a reservoir (the urinary bladder) and (2) an outlet (consisting of bladder neck, urethra and striated muscles of the external urethra sphincter). During urine storage the outlet is closed and the bladder is quiescent to maintain a low intravesical pressure. During micturition the outlet relaxes and the bladder contracts to promote efficient release of urine. This reciprocal relationship between bladder and outlet is generated by reflex circuits some of which are under voluntary control. Experimental studies in animals indicate that the micturition reflex is mediated by a spinobulbospinal pathway passing through a coordination center (the pontine micturition center) located in the rostral brainstem. This reflex pathway is in turn modulated by higher centers in the cerebral cortex that are involved in the voluntary control of micturition. Spinal cord injury at cervical or thoracic levels disrupts voluntary control of voiding as well as the normal reflex pathways that coordinate bladder and sphincter function. Following spinal cord injury the bladder is initially areflexic but then becomes hyperreflexic due to the emergence of a spinal micturition reflex pathway. However the bladder does not empty efficiently because coordination between the bladder and urethral outlet is lost. Studies in animals indicate that dysfunction of the lower urinary tract after spinal cord injury is dependent in part on plasticity of bladder afferent pathways as well as reorganization of synaptic connections in the spinal cord. Reflex plasticity is associated with changes in the properties of ion channels and electrical excitability of afferent neurons and appears to be mediated in part by neurotrophic factors released in the spinal cord and/or the peripheral target organs.
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Affiliation(s)
- William C de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Pittsburgh, PA 15261, USA.
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Nielsen JS, Rode F, Rahbek M, Andersson KE, Rønn LC, Bouchelouche K, Nordling J, Bouchelouche P. Effect of the SK/IK channel modulator 4,5-dichloro-1,3-diethyl-1,3-dihydro-benzoimidazol-2-one (NS4591) on contractile force in rat, pig and human detrusor smooth muscle. BJU Int 2011; 108:771-7. [PMID: 21223472 DOI: 10.1111/j.1464-410x.2010.10019.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVE • To investigate the importance of small (SK)- and intermediate (IK)-conductance Ca2(+) -activated K(+) channels on bladder function, by studying the effects of 4,5-dichloro-1,3-diethyl-1,3-dihydro-benzoimidazol-2-one (NS4591), a new modulator of SK/IK channels, on contractions induced by electrical field stimulation (EFS) and carbachol in rat, pig and human detrusor. PATIENTS AND METHODS • Detrusor biopsies were obtained from rats, pigs and male patients undergoing cystectomy because of bladder cancer. • Force was recorded using myographs. • Intracellular free Ca(2+) was measured in myocytes using microfluorimetry. RESULTS • In rat bladder rings subjected to EFS, cumulative addition of NS4591 (0.1-30 µM) decreased force by 82 ± 2.9% (n = 6).This effect was reduced by 64 ± 5.2% in the presence of 0.3 µM apamin, a specific inhibitor of SK channels. Apamin increased the force evoked by EFS significantly: force was increased by 14.2 ± 3.4% (n = 5) and 10.1 ± 2.6% (n = 7) in pig and human detrusor strips, respectively (P = 0.04 and P = 0.02). • The cumulative addition of NS4591 (0.3-30 µM) significantly reduced the amplitude of carbachol-induced rhythmic oscillations by 62.0 ± 12.0% (n = 12) and the minimum force between oscillations by 30 ± 5% (n = 9) in pig detrusor strips (P < 0.005). In the presence of 10 µM NS4591, carbachol (1 µM) induced rhythmic contractions with an amplitude and normalized mean power frequency (nmeanPF) of 8.4 ± 5.1% and 0.11 ± 0.06 mN root mean square (rms) Hz (n = 12), respectively, vs. 21 ± 3.4% and 0.17 ± 0.04 mN rms Hz in control strips (n = 13). Apamin induced 6- and 11-fold increases in amplitude and nmeanPF vs. 1.3- and 2-fold increases in control strips. • In human detrusor strips (n = 15), the cumulative addition of NS4591 (1-30 µM) significantly reduced the amplitude by 69 ± 11%, the nmeanPF by 78 ± 6% and the minimum force between carbachol-induced oscillations by 59 ± 5% (P < 0.008). The addition of apamin (0.3 µM) before application of 1 µM carbachol abolished the effects of NS4591 on amplitude and partially abolished its effect on nmeanPF by 41 ± 7%, vs. a 78 ± 6% reduction in the absence of apamin (n = 8). • In spontaneously active detrusor preparations, NS4591 reduced or abolished contractions. • Furthermore, NS4591 (10 µM) decreased the carbachol-induced increase in the fura-2 ratio by 43 ± 3% compared with control (n = 12) (P < 0.03). CONCLUSIONS • The SK/IK channel modulator NS4591 inhibits EFS- and carbachol-induced contractions in rat, pig and human detrusor muscle. • NS4591 may have therapeutic potential for treatment of detrusor overactivity.
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Abstract
Achievement of urinary continence is an important developmental step that most children attain with the assistance of their parents and caregivers. Debate continues as to the best time to toilet train; in some Asian and African cultures children are trained as infants, while training at age 2-3 years is more typical in Western cultures. Infant voiding is not merely a spinal reflex, as the sensation of bladder filling is relayed to the brain. However, the ability of the brain to inhibit bladder contractions, and to achieve coordinated bladder contraction with sphincter relaxation, matures over time. While there is a concern that later toilet training may be responsible for an increase in urinary incontinence in children, no controlled studies on early versus late toilet training exist to evaluate this hypothesis. A number of medical conditions such as spina bifida, posterior urethral valves, cerebral palsy and autism can cause incontinence and difficulties in toilet training. The decision to start toilet training a child should take into account both the parents' expectation of how independent the child will be in terms of toileting, and the child's developmental readiness, so that a realistic time course for toilet training can be implemented.
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Affiliation(s)
- Hsi-Yang Wu
- Department of Urology, Stanford University School of Medicine, 300 Pasteur Drive, S-287, Stanford, CA 94305-5118, USA.
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Bladder reduction surgery accelerates the appearance of spontaneous voiding in neonatal rats. J Urol 2010; 183:370-7. [PMID: 19914665 DOI: 10.1016/j.juro.2009.08.108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Indexed: 11/21/2022]
Abstract
PURPOSE Patients with nocturnal enuresis may have small functional bladder capacity or altered bladder fullness sensation. We determined whether reducing bladder volume would affect the central inhibition of voiding that is normally present between birth and 2 weeks of life in neonatal rats. MATERIALS AND METHODS One and 3-week-old Sprague-Dawley rats underwent 50% bladder volume reduction by suture closure of the bladder dome. T8-T10 spinal cord injury was done in select animals. Latency of the perigenital-bladder reflex, spontaneous voiding onset and body weight were measured. Cystometry using urethane anesthesia, and measurements of in vitro spontaneous and KCl evoked contractions were done. RESULTS Bladder reduction surgery led to the immediate appearance of spontaneous voiding in 1-week-old rats. Cystometry at 2 weeks showed voiding contractions in rats with bladder reduction, which was abolished by acute T8-T10 spinalization. Voiding contractions were not seen in animals with sham surgery or concurrent T8-T10 spinalization and bladder reduction. The perigenital-bladder reflex, somatic growth, spontaneous bladder contractions and bladder contractility were not affected by bladder reduction. Bladder capacity at 9 weeks was significantly larger in animals that underwent bladder reduction at 1 week than in sham treated animals (540 vs 256 microl, p = 0.04) but not in animals that underwent bladder reduction at 3 weeks. CONCLUSIONS Bladder reduction removes the central inhibition of spontaneous voiding in neonatal rats. This suggests that decreased neonatal bladder capacity may alter how the brain regulates the bladder.
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Büyüknacar HSG, Göçmen C, de Groat WC, Kumcu EK, Wu HY, Onder S. Differential effect of L-cysteine in isolated whole-bladder preparations from neonatal and adult rats. J Pharmacol Exp Ther 2010; 333:228-35. [PMID: 20051484 DOI: 10.1124/jpet.109.161661] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study was undertaken to compare the effects of the thiol reagents L-cysteine and (diazene dicarboxylic acid bis 5N,N-dimethylamide) diamide on contractile activity of neonatal and adult rat bladders. In vitro whole-bladder preparations from Wistar rats were used to study the modulation of spontaneous bladder contractions by thiol reagents. After blocking cholinergic and adrenergic transmission with atropine and guanethidine, L-cysteine facilitated spontaneous bladder contractions in neonatal rat bladders. The effect of L-cysteine was suppressed by diamide. Diamide alone did not change basal activity of the neonatal rat bladder. The facilitatory effects of L-cysteine were reduced by the L-type Ca2+ channel-blocking agent nifedipine and the calcium-activated K+ channel opener NS1619 [1,3-dihydro-1-[2-hydroxy-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2H-benzimidazol-2-one]. ATP or suramin, a purinergic receptor antagonist, significantly inhibited the effect of L-cysteine in neonatal bladders, whereas the nitric-oxide synthase inhibitor N(omega)-nitro-L-arginine was ineffective. L-cysteine did not elicit any detectable effects in the adult rat bladder; whereas diamide caused a large-amplitude sustained tonic contraction. The contraction induced by diamide in adult bladder did not occur when the preparation was pretreated with L-cysteine. Also, L-Cysteine administered during the diamide-evoked contraction completely inhibited the contraction to diamide. In conclusion, our results suggest that L-cysteine has markedly different effects in isolated whole-bladder preparations from neonatal and adult rats. Thus thiol-sensitive mechanisms may modulate contractility by regulation of Ca2+ and K+ channels and/or purinergic transmission in the neonatal bladder. The effects of L-cysteine and diamide were reversed in adult bladders, indicating that the regulation of bladder contractility by thiols is markedly altered during postnatal development.
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Affiliation(s)
- Hacer S G Büyüknacar
- Department of Pharmacology, School of Medicine, University of Cukurova, Adana, Turkey
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Ekman M, Andersson KE, Arner A. Receptor-induced phasic activity of newborn mouse bladders is inhibited by protein kinase C and involves T-type Ca2+channels. BJU Int 2009; 104:690-7. [DOI: 10.1111/j.1464-410x.2009.08576.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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NG YK, WU HY. Postnatal Development of Voiding Reflexes and Bladder Smooth Muscle Properties: An Overview of Recent Findings. Low Urin Tract Symptoms 2009. [DOI: 10.1111/j.1757-5672.2009.00035.x] [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]
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Ekman M, Andersson KE, Arner A. Signal transduction pathways of muscarinic receptor mediated activation in the newborn and adult mouse urinary bladder. BJU Int 2009; 103:90-7. [DOI: 10.1111/j.1464-410x.2008.07935.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Yan H, Keast JR. Neurturin regulates postnatal differentiation of parasympathetic pelvic ganglion neurons, initial axonal projections, and maintenance of terminal fields in male urogenital organs. J Comp Neurol 2008; 507:1169-83. [PMID: 18175352 DOI: 10.1002/cne.21593] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We have investigated the development of autonomic nerves in the urogenital tract of male mice and the effect of neurturin gene deletion on this process. At birth, autonomic innervation of the reproductive organs was sparse, but urinary bladder smooth muscle was well innervated. Further innervation of reproductive tissues occurred until P21, but noradrenergic axons established their complete terminal field later than nitrergic cholinergic axons: in adults the former are more prevalent, yet this became apparent only at P7 (vas deferens, seminal vesicles), P14 (prostate) or after P14 (penis). Neurturin was essential for initial projection of axons (mucosa of vas deferens), maintenance of terminal fields (prostate and seminal vesicles), or both functions (cavernosum of penis). In contrast, some targets (e.g., bladder muscle and suburothelium, vas deferens smooth muscle) were unaffected by neurturin gene deletion. Pelvic ganglion neurons more than doubled between birth and adulthood, probably as aresult of continued maturation of p75-positive undifferentiated neuronal precursors rather than cell division. The adult number of neurons was achieved by P7 (sympathetic) or P21 (parasympathetic). In adult neurturin knockout mice, there were approximately 25% fewer parasympathetic neurons compared with wild types, because of failure of differentiation after P14. This study revealed the complexity of postnatal maturation of urogenital innervation, with each organ showing a distinct chronology of innervation and different requirement for neurturin. Our results also indicate that in adults there will be distinct differences in neurturin dependence between organs, such that proregenerative therapies may have to be tailored specifically for the nerve pathway of interest.
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Affiliation(s)
- Hui Yan
- Pain Management Research Institute, Kolling Institute of Medical Research, University of Sydney at Royal North Shore Hospital, St. Leonards, New South Wales 2065, Australia
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Klinger MB, Dattilio A, Vizzard MA. Expression of cyclooxygenase-2 in urinary bladder in rats with cyclophosphamide-induced cystitis. Am J Physiol Regul Integr Comp Physiol 2007; 293:R677-85. [PMID: 17537839 DOI: 10.1152/ajpregu.00305.2007] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
These studies examined the expression of cyclooxygenase-2 (COX-2) expression in the urothelium and suburothelial space and detrusor from rats treated with cyclophosphamide (CYP) to induce acute (4 h), intermediate (48 h), or chronic (10-day) cystitis. Western blot analysis and immunohistochemistry were used to demonstrate COX-2 expression. In whole mount preparations of urinary bladder, nerve fibers in the suburothelial plexus, and inflammatory cell infiltrates were characterized for COX-2 expression after CYP-induced cystitis. COX-2 expression significantly (P <or= 0.01) increased in the urothelium + suburothelium and detrusor smooth muscle with acute, intermediate, and chronic (10-day) CYP-induced cystitis, but expression in urothelium + suburothelium was significantly greater. CYP-induced upregulation of COX-2 showed by immunostaining in the urothelium + suburothelium was similar to that observed with Western blot analysis and also demonstrated COX-2 inflammatory cell infiltrates (CD86+) and nerve fibers (PGP+) in the suburothelial plexus. Although COX-2 expression was significantly (P <or= 0.01) increased in detrusor smooth muscle, immunohistochemistry failed to demonstrate an obvious change in COX-2-immunoreactivity (IR) in detrusor muscle, but COX-2 inflammatory infiltrates were present throughout the detrusor. COX-2-IR nerve fibers exhibited increased density in the suburothelial plexus with acute or chronic CYP-induced cystitis. COX-2-IR macrophages (CD86+) were present throughout the urinary bladder with acute and chronic CYP-induced cystitis. These studies demonstrate cellular targets in the urinary bladder where COX-2 inhibitors may act.
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Affiliation(s)
- Mary Beth Klinger
- Univ. of Vermont College of Medicine, Dept. of Neurology, D415A Given Research Bldg., Burlington, VT 05405. )
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