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Mitsui R, Chikada Y, Arai K, Hashitani H. Functional nitrergic innervation of smooth muscle structures in the mucosa of pig lower urinary tract. Cell Tissue Res 2021; 386:513-531. [PMID: 34604930 DOI: 10.1007/s00441-021-03521-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 08/15/2021] [Indexed: 11/26/2022]
Abstract
Neurally released nitric oxide (NO) functions as an inhibitory neurotransmitter of urethral but not detrusor smooth muscles while relaxing bladder vasculature and muscularis mucosae (MM). Here, the distribution of nitrergic nerves was examined in the mucosa of pig lower urinary tract using immunohistochemistry, and their vasodilatory functions were studied by measuring arteriolar diameter changes. Properties of smooth muscle cells in the lamina propria (SMC-LP) of urethra and trigone were also investigated using florescence Ca2+ imaging. In the bladder mucosa, neuronal nitric oxide synthase (nNOS)-immunoreactive nitrergic fibres projected to suburothelial arterioles and venules. Perivascular nitrergic nerves were intermingled with but distinct from tyrosine hydroxylase (TH)-immunoreactive sympathetic or calcitonin gene-related peptide (CGRP)-immunoreactive afferent nerves. MM receive a nitrergic but not sympathetic or afferent innervation. In the mucosa of urethra and trigone, nitrergic nerves were in close apposition with sympathetic or afferent nerves around suburothelial vasculature but did not project to SMC-LP. In suburothelial arterioles of bladder and urethra, N ω-nitro-L-arginine (L-NA, 100 μM), an NOS inhibitor, enhanced electrical field stimulation (EFS)-induced sympathetic vasoconstrictions, while tadalafil (10 nM), a phosphodiesterase type 5 (PDE5) inhibitor, suppressed the vasoconstrictions. SMC-LP developed asynchronous spontaneous Ca2+ transients without responding to EFS. The spontaneous Ca2+ transients were enhanced by acetylcholine (1 μM) and diminished by noradrenaline (1 μM) but not SIN-1 (10 μM), an NO donor. In the lower urinary tract mucosa, perivascular nitrergic nerves appear to counteract the sympathetic vasoconstriction to maintain the mucosal circulation. Bladder MM but not SMC-LP receive an inhibitory nitrergic innervation.
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Affiliation(s)
- Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
| | - Yota Chikada
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Keiji Arai
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Fry CH, Chakrabarty B, Hashitani H, Andersson KE, McCloskey K, Jabr RI, Drake MJ. New targets for overactive bladder-ICI-RS 2109. Neurourol Urodyn 2020; 39 Suppl 3:S113-S121. [PMID: 31737931 PMCID: PMC8114459 DOI: 10.1002/nau.24228] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 10/31/2019] [Indexed: 12/16/2022]
Abstract
AIM To review evidence for novel drug targets that can manage overactive bladder (OAB) symptoms. METHODS A think tank considered evidence from the literature and their own research experience to propose new drug targets in the urinary bladder to characterize their use to treat OAB. RESULTS Five classes of agents or cellular pathways were considered. (a) Cyclic nucleotide-dependent (cyclic adenosine monophosphate and cyclic guanosine monophosphate) pathways that modulate adenosine triphosphate release from motor nerves and urothelium. (b) Novel targets for β3 agonists, including the bladder wall vasculature and muscularis mucosa. (c) Several TRP channels (TRPV1 , TRPV4 , TRPA1 , and TRPM4 ) and their modulators in affecting detrusor overactivity. (d) Small conductance Ca2+ -activated K+ channels and their influence on spontaneous contractions. (e) Antifibrosis agents that act to modulate directly or indirectly the TGF-β pathway-the canonical fibrosis pathway. CONCLUSIONS The specificity of action remains a consideration if particular classes of agents can be considered for future development as receptors or pathways that mediate actions of the above mentioned potential agents are distributed among most organ systems. The tasks are to determine more detail of the pathological changes that occur in the OAB and how the specificity of potential drugs may be directed to bladder pathological changes. An important conclusion was that the storage, not the voiding, phase in the micturition cycle should be investigated and potential targets lie in the whole range of tissue in the bladder wall and not just detrusor.
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Affiliation(s)
- Christopher Henry Fry
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Basu Chakrabarty
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University, Nagoya, Japan
| | - Karl-Erik Andersson
- Institute of Laboratory Medicine, Lund University, Lund, Sweden
- Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - Karen McCloskey
- School of Medicine, Dentistry and Biomedical Sciences, Queens University Belfast, Belfast, UK
| | - Rita I. Jabr
- Division of Biochemical Sciences, Faculty of Health and Biomedical Sciences, University of Surrey, Guildford, UK
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Tykocki NR, Monson FC. Excitability and contractility in arterioles and venules from the urinary bladder. CURRENT TOPICS IN MEMBRANES 2020; 85:301-326. [DOI: 10.1016/bs.ctm.2020.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mitsui R, Lee K, Uchiyama A, Hayakawa S, Kinoshita F, Kajioka S, Eto M, Hashitani H. Contractile elements and their sympathetic regulations in the pig urinary bladder: a species and regional comparative study. Cell Tissue Res 2019; 379:373-387. [PMID: 31446446 DOI: 10.1007/s00441-019-03088-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 08/05/2019] [Indexed: 12/18/2022]
Abstract
Contractile behaviour of the urinary bladder and its sympathetic inhibition during storage phases are not well understood. Here, we explore muscularis mucosae (MM) as a predominant mucosal contractile element and the capability of sympathetic nerves to relax detrusor smooth muscle (DSM) or MM. Distribution of α-smooth muscle actin (α-SMA)-immunoreactive cells was compared in pig, human, guinea pig, rat and mouse bladders by immunohistochemistry, while contractility of the bladder mucosa was compared in these species by isometric tension recordings. In pig, human and guinea pig bladders, DSM and MM located in the lamina propria expressed α-SMA immunoreactivity, while both rat and mouse bladders lacked a MM. Consistent with this presence or absence of MM, bladder mucosa of pig, human and guinea pig but not rat and mouse developed spontaneous phasic contractions (SPCs). Distribution of tyrosine hydroxylase (TH)-immunoreactive sympathetic nerve fibres was compared in pig DSM, MM, trigone and urethra, as were their sympathetic nerve-evoked contractile/relaxing responses examined. In pig DSM or MM, where TH-immunoreactive sympathetic fibres exclusively projected to the vasculature, sympathetic relaxations were difficult to demonstrate. In contrast, sympathetic contractions were invariably evoked in pig trigone and urethra where the smooth muscle cells receive TH-immunoreactive sympathetic innervations. Thus, SPCs of bladder mucosa appear to predominantly arise from the MM displaying species differences. Despite the currently accepted concept of sympathetic nerve-mediated DSM relaxation during the storage phase, it is unlikely that neurally released noradrenaline acts on β-adrenoceptors to relax either DSM or MM due to the anatomical lack of sympathetic innervation.
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Affiliation(s)
- Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, 467-8601, Japan.
| | - Ken Lee
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Aoi Uchiyama
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, 467-8601, Japan
| | - Shunta Hayakawa
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, 467-8601, Japan
| | - Fumio Kinoshita
- Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Shunichi Kajioka
- Department of Applied Urology and Molecular Medicine, Kyushu University, Fukuoka, Japan
| | - Masatoshi Eto
- Department of Urology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, 467-8601, Japan
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Role of Pericytes in the Initiation and Propagation of Spontaneous Activity in the Microvasculature. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1124:329-356. [PMID: 31183834 DOI: 10.1007/978-981-13-5895-1_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The microvasculature is composed of arterioles, capillaries and venules. Spontaneous arteriolar constrictions reduce effective vascular resistance to enhance tissue perfusion, while spontaneous venular constrictions facilitate the drainage of tissue metabolites by pumping blood. In the venules of visceral organs, mural cells, i.e. smooth muscle cells (SMCs) or pericytes, periodically generate spontaneous phasic constrictions, Ca2+ transients and transient depolarisations. These events arise from spontaneous Ca2+ release from the sarco-endoplasmic reticulum (SR/ER) and the subsequent opening of Ca2+-activated chloride channels (CaCCs). CaCC-dependent depolarisation further activates L-type voltage-dependent Ca2+ channels (LVDCCs) that play a critical role in maintaining the synchrony amongst mural cells. Mural cells in arterioles or capillaries are also capable of developing spontaneous activity. Non-contractile capillary pericytes generate spontaneous Ca2+ transients primarily relying on SR/ER Ca2+ release. Synchrony amongst capillary pericytes depends on gap junction-mediated spread of depolarisations resulting from the opening of either CaCCs or T-type VDCCs (TVDCCs) in a microvascular bed-dependent manner. The propagation of capillary Ca2+ transients into arterioles requires the opening of either L- or TVDCCs again depending on the microvascular bed. Since the blockade of gap junctions or CaCCs prevents spontaneous Ca2+ transients in arterioles and venules but not capillaries, capillary pericytes appear to play a primary role in generating spontaneous activity of the microvasculature unit. Pericytes in capillaries where the interchange of substances between tissues and the circulation takes place may provide the fundamental drive for upstream arterioles and downstream venules so that the microvasculature network functions as an integrated unit.
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Mitsui R, Hashitani H. Role of K + channels in maintaining the synchrony of spontaneous Ca 2+ transients in the mural cells of rat rectal submucosal arterioles. Pflugers Arch 2019; 471:1025-1040. [PMID: 30982085 DOI: 10.1007/s00424-019-02274-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/13/2019] [Accepted: 03/27/2019] [Indexed: 02/07/2023]
Abstract
Mural cells in precapillary arterioles (PCAs) generate spontaneous Ca2+ transients primarily arising from the periodic release of Ca2+ from sarcoendoplasmic reticulum (SR/ER). The Ca2+ release induces Ca2+-activated chloride channel (CaCC)-dependent depolarisations that spread to neighbouring mural cells to develop the synchrony of their Ca2+ transients. Here, we explored the roles of K+ channels in maintaining the synchrony of spontaneous Ca2+ transients. Intracellular Ca2+ dynamics in mural cells were visualised by Cal-520 fluorescence Ca2+ imaging in the submucosal PCAs of rat rectum. Increasing extracellular K+ concentration ([K+]o) from 5.9 to 29.7 mM converted synchronous spontaneous Ca2+ transients into asynchronous, high-frequency Ca2+ transients. Similarly, the blockade of inward rectifier K+ (Kir) channels with Ba2+ (50 μM) or Kv7 voltage-dependent K+ (Kv7) channels with XE 991 (10 μM) disrupted the synchrony of spontaneous Ca2+ transients, while the blockers for large-, intermediate- or small-conductance Ca2+-activated K+ channels had no effect. Kir2.1 immunoreactivity was detected in the arteriolar endothelium but not mural cells. In the PCAs that had been pretreated with XE 991 or Ba2+, nifedipine (1 μM) attenuated the asynchronous Ca2+ transients but failed to restore their synchrony. In contrast, levcromakalim, an ATP-sensitive K+ channel opener, restored the synchronous Ca2+ transients. Thus, constitutively active Kv7 and Kir channels appear to be involved in maintaining the relatively hyperpolarised membrane of mural cells. The hyperpolarised membrane prevents depolarisation-induced 'premature' Ca2+ transients to ensure sufficient SR/ER Ca2+ refilling that is required for regenerative Ca2+ release resulting in synchronous Ca2+ transients amongst the mural cells.
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Affiliation(s)
- Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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Hashitani H, Mitsui R, Miwa-Nishimura K, Lam M. Role of capillary pericytes in the integration of spontaneous Ca 2+ transients in the suburothelial microvasculature in situ of the mouse bladder. J Physiol 2018; 596:3531-3552. [PMID: 29873405 DOI: 10.1113/jp275845] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/21/2018] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS In the bladder suburothelial microvasculature, pericytes in different microvascular segments develop spontaneous Ca2+ transients with or without associated constrictions. Spontaneous Ca2+ transients in pericytes of all microvascular segments primarily rely on the cycles of Ca2+ uptake and release by the sarco- and endoplasmic reticulum. The synchrony of spontaneous Ca2+ transients in capillary pericytes exclusively relies on the spread of depolarizations resulting from the opening of Ca2+ -activated chloride channels (CaCCs) via gap junctions. CaCC-dependent depolarizations further activate L-type voltage-dependent Ca2+ channels as required for the synchrony of Ca2+ transients in pericytes of pre-capillary arterioles, post-capillary venules and venules. Capillary pericytes may drive spontaneous Ca2+ transients in pericytes within the suburothelial microvascular network by sending CaCC-dependent depolarizations via gap junctions. ABSTRACT Mural cells in the microvasculature of visceral organs develop spontaneous Ca2+ transients. However, the mechanisms underlying the integration of these Ca2+ transients within a microvascular unit remain to be clarified. In the present study, the origin of spontaneous Ca2+ transients and their propagation in the bladder suburothelial microvasculature were explored. Cal-520 fluorescence Ca2+ imaging and immunohistochemistry were carried out on mural cells using mice expressing red fluorescent protein (DsRed) under control of the NG2 promotor. NG2(+) pericytes in both pre-capillary arterioles (PCAs) and capillaries developed synchronous spontaneous Ca2+ transients. By contrast, although NG2-DsRed also labelled arteriolar smooth muscle cells, these cells remained quiescent. Both NG2(+) pericytes in post-capillary venules (PCVs) and NG2(-) venular pericytes exhibited propagated Ca2+ transients. L-type voltage-dependent Ca2+ channel (LVDCC) blockade with nifedipine prevented Ca2+ transients or disrupted their synchrony in PCA, PCV and venular pericytes without dis-synchronizing Ca2+ transients in capillary pericytes. Blockade of gap junctions with carbenoxolone or Ca2+ -activated chloride channels (CaCCs) with 4,4'-diisothiocyanato-2,2'-stilbenedisulphonic acid disodium salt prevented Ca2+ transients in PCA and venular pericytes and disrupted the synchrony of Ca2+ transients in capillary and PCV pericytes. Spontaneous Ca2+ transients in pericytes of all microvascular segments were abolished or suppressed by cyclopiazonic acid, caffeine or tetracaine. The synchrony of Ca2+ transients in capillary pericytes arising from spontaneous Ca2+ release from the sarco- and endoplasmic reticulum appears to rely exclusively on CaCC activation, whereas subsequent LVDCC activation is required for the synchrony of Ca2+ transients in pericytes of other microvascular segments. Capillary pericytes may drive spontaneous activity in the suburothelial microvascular unit to facilitate capillary perfusion.
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Affiliation(s)
- Hikaru Hashitani
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Retsu Mitsui
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Kyoko Miwa-Nishimura
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Michelle Lam
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
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Urine: Waste product or biologically active tissue? Neurourol Urodyn 2018; 37:1162-1168. [PMID: 29464759 DOI: 10.1002/nau.23414] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/18/2017] [Indexed: 01/01/2023]
Abstract
AIMS Historically, urine has been viewed primarily as a waste product with little biological role in the overall health of an individual. Increasingly, data suggest that urine plays a role in human health beyond waste excretion. For example, urine might act as an irritant and contribute to symptoms through interaction with-and potential compromise of-the urothelium. METHODS To explore the concept that urine may be a vehicle for agents with potential or occult bioactivity and to discuss existing evidence and novel research questions that may yield insight into such a role, the National Institute of Diabetes and Digestive and Kidney Disease invited experts in the fields of comparative evolutionary physiology, basic science, nephrology, urology, pediatrics, metabolomics, and proteomics (among others) to a Urinology Think Tank meeting on February 9, 2015. RESULTS This report reflects ideas that evolved from this meeting and current literature, including the concept of urine quality, the biological, chemical, and physical characteristics of urine, including the microbiota, cells, exosomes, pH, metabolites, proteins, and specific gravity (among others). Additionally, the manuscript presents speculative, and hopefully testable, ideas about the functional roles of urine constituents in health and disease. CONCLUSION Moving forward, there are several questions that need further understanding and pursuit. There were suggestions to consider actively using various animal models and their biological specimens to elaborate on basic mechanistic information regarding human bladder dysfunction.
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Mitsui R, Hashitani H. Properties of synchronous spontaneous Ca 2+ transients in the mural cells of rat rectal arterioles. Pflugers Arch 2017; 469:1189-1202. [PMID: 28429070 DOI: 10.1007/s00424-017-1978-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/20/2017] [Accepted: 04/05/2017] [Indexed: 10/19/2022]
Abstract
Synchrony of spontaneous Ca2+ transients among venular mural cells (smooth muscle cells and pericytes) in visceral organs relies on the intercellular spread of L-type voltage-dependent Ca2+ channel (LVDCC)-dependent depolarisations. However, the mechanisms underlying the synchrony of spontaneous Ca2+ transients between arteriolar mural cells are less understood. The spontaneous intracellular Ca2+ dynamics of arteriolar mural cells in the rat rectal submucosa were visualised by Cal-520 Ca2+ imaging to analyse their synchrony. The mural cells in fine arterioles that had a rounded cell body with several extended processes developed spontaneous 'synchronous' Ca2+ transients arising from Ca2+ released from sarcoendoplasmic reticulum Ca2+ stores. Gap junction blockers (3 μM carbenoxolone, 10 μM 18β-glycyrrhetinic acid), a Ca2+-activated Cl- channel (CaCC) blocker (100 μM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) or lowering extracellular Cl- concentration (from 134.4 to 12.4 mM) disrupted the synchrony of Ca2+ transients between arteriolar mural cells. Blockers of T-type voltage-dependent Ca2+ channels (TVDCCs, 1 μM mibefradil or ML218) or LVDCCs (1 μM nifedipine) reduced the Ca2+ transient frequency or their area under curve (AUC), respectively. However, neither TVDCC nor LVDCC blockers disrupted the synchrony of Ca2+ transients among arteriolar mural cells. This is in contrast with rectal venules in which nifedipine disrupted the synchrony of spontaneous Ca2+ transients. Thus, spontaneous transient depolarisations arising from the opening of CaCCs may effectively spread to neighbouring arteriolar mural cells via gap junctions to maintain the Ca2+ transient synchrony. Activation of TVDCCs appears to accelerate spontaneous Ca2+ transients, while LVDCCs predominantly contribute to the duration of Ca2+ transients.
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Affiliation(s)
- Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, 1, Kawasumi, Mizuho-cho, Mizuho-Ku, Nagoya, 467-8601, Japan.
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, 1, Kawasumi, Mizuho-cho, Mizuho-Ku, Nagoya, 467-8601, Japan
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Andersson KE, Boedtkjer DB, Forman A. The link between vascular dysfunction, bladder ischemia, and aging bladder dysfunction. Ther Adv Urol 2016; 9:11-27. [PMID: 28042309 DOI: 10.1177/1756287216675778] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The vascular supply to the human bladder is derived mainly from the superior and inferior vesical arteries, the latter being directly connected to the internal iliac artery. Aging is associated with an impairment of blood vessel function and changes may occur in the vasculature at the molecular, cellular and functional level. Pelvic arterial insufficiency may play an important role in the development of bladder dysfunctions such as detrusor overactivity (DO) and the overactive bladder syndrome. Chronic ischemia-related bladder dysfunction may progress to bladder underactivity and it would be desirable to treat not only lower urinary tract symptoms (LUTS) induced by chronic ischemia, but also the progression of the morphological bladder changes. Studies in experimental models in rabbits and rats have shown that pelvic arterial insufficiency may result in significant bladder ischemia with reduced bladder wall oxygen tension. In turn, this will lead to oxidative stress associated with upregulation of oxidative stress-sensitive genes, increased muscarinic receptor activity, ultrastructural damage, and neurodegeneration. The phosphodiesterase type 5 (PDE5) inhibitor tadalafil, the α1-adrenoceptor (AR) blocker silodosin, the β3-AR agonist mirabegron, and the free radical scavenger melatonin, exerted a protecting effect on urodynamic parameters, and on functional and morphological changes of the bladder demonstrable in vitro. Since the agents tested are used clinically for relieving LUTS, the results from the animal models seem to have translational value, and may be of relevance for designing clinical studies to demonstrate if the drugs may prevent progression of ischemia-related functional and morphological bladder changes.
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Affiliation(s)
- Karl-Erik Andersson
- Institute of Clinical Medicine, Department of Obstetrics and Gynecology, Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, DK 8200 Aarhus N, Denmark
| | | | - Axel Forman
- Department of Gynecology and Obstetrics, Aarhus University Hospital, Denmark
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Hashitani H, Lang RJ. Spontaneous activity in the microvasculature of visceral organs: role of pericytes and voltage-dependent Ca(2+) channels. J Physiol 2016; 594:555-65. [PMID: 26607499 DOI: 10.1113/jp271438] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 10/31/2015] [Indexed: 12/21/2022] Open
Abstract
The microvasculature plays a primary role in the interchange of substances between tissues and the circulation. In visceral organs that undergo considerable distension upon filling, the microvasculature appears to display intrinsic contractile properties to maintain their flow. Submucosal venules in the bladder or gastrointestinal tract generate rhythmic spontaneous phasic constrictions and associated Ca(2+) transients. These events are initiated within either venular pericytes or smooth muscle cells (SMCs) arising from spontaneous Ca(2+) release from the sarcoplasmic reticulum (SR) and the opening of Ca(2+) -activated chloride channels (CaCCs) that trigger Ca(2+) influx through L-type voltage-dependent Ca(2+) channels (VDCCs). L-type VDCCs also play a critical role in maintaining synchrony within the contractile mural cells. In the stomach myenteric layer, spontaneous Ca(2+) transients originating in capillary pericytes appear to spread to their neighbouring arteriolar SMCs. Capillary Ca(2+) transients primarily rely on SR Ca(2+) release, but also require Ca(2+) influx through T-type VDCCs for their synchrony. The opening of T-type VDCCs also contribute to the propagation of Ca(2+) transients into SMCs. In visceral microvasculature, pericytes act as either spontaneously active contractile machinery of the venules or as pacemaker cells generating synchronous Ca(2+) transients that drive spontaneous contractions in upstream arterioles. Thus pericytes play different roles in different vascular beds in a manner that may well depend on the selective expression of T-type and L-type Ca(2+) channels.
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Affiliation(s)
- Hikaru Hashitani
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Richard J Lang
- Department of Physiology, School of Biomedical Sciences, Monash University, Clayton, Victoria, 3800, Australia
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Mechanisms underlying spontaneous constrictions of postcapillary venules in the rat stomach. Pflugers Arch 2015; 468:279-91. [PMID: 26530829 DOI: 10.1007/s00424-015-1752-y] [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: 09/13/2015] [Revised: 10/22/2015] [Accepted: 10/26/2015] [Indexed: 10/22/2022]
Abstract
Postcapillary venules (PCVs) play a critical role in regulating capillary hydrostatic pressure, but their contractile mechanisms are not well understood. We examined the properties of spontaneous vasomotion and corresponding Ca(2+) transients in gastric PCV. In the rat gastric submucosa, changes in PCV diameter and intracellular Ca(2+) dynamics were visualised by video tracking system and fluorescent Ca(2+) imaging, respectively, while PCV morphology was examined by immunohistochemistry. Stellate-shaped PCV mural cells expressing α-smooth muscle actin exhibited synchronised spontaneous Ca(2+) transients to develop vasomotion which was abolished by nifedipine (1 μM), cyclopiazonic acid (10 μM), or Ca(2+)-activated Cl(-) channel inhibitors (100 μM niflumic acid, 1 μM T16Ainh-A01). A gap junction blocker (3 μM carbenoxolone) disrupted the synchrony of spontaneous Ca(2+) transients amongst PCV mural cells and attenuated spontaneous vasomotion. Low chloride solution ([Cl(-)]0 = 12.4 mM) also disrupted the synchrony of spontaneous Ca(2+) transients and abolished vasomotion. Na(+)-K(+)-Cl(-) co-transporter inhibitors (10 μM bumetanide, 30 μM furosemide) suppressed spontaneous Ca(2+) transients and vasoconstrictions. A phosphodiesterase type 5 (PDE5) inhibitor (1 μM tadalafil) disrupted the spontaneous Ca(2+) transient synchrony and abolished vasomotion in a nitric oxide (NO)-dependent manner. Thus, gastric PCVs exhibit spontaneous vasomotion, resulting from synchronised spontaneous Ca(2+) transients within a network of stellate-shaped PCV mural cells. An active Cl(-) accumulation partly via Na(+)-K(+)-Cl(-) co-transport appears to be fundamental in maintaining depolarisation upon the opening of Ca(2+)-activated Cl(-) channels that triggers Ca(2+) influx via voltage-dependent L-type Ca(2+) channels. Basal PDE5 activity may continuously counteract vaso-relaxing effects of endothelial NO to maintain spontaneous vasomotion.
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Chai TC, Russo A, Yu S, Lu M. Mucosal signaling in the bladder. Auton Neurosci 2015; 200:49-56. [PMID: 26422993 DOI: 10.1016/j.autneu.2015.08.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 08/27/2015] [Indexed: 01/09/2023]
Abstract
The bladder mucosa is comprised of the multilayered urothelium, lamina propria (LP), microvasculature, and smooth muscle fibers (muscularis mucosae). The muscularis mucosae is not always present in the mucosa, and its presence is related to the thickness of the LP. Since there are no mucus secreting cells, "mucosa" is an imprecise term. Nerve fibers are present in the LP of the mucosa. Efferent nerves mediate mucosal contractions which can be elicited by electrical field stimulation (EFS) and various agonists. The source of mucosal contractility is unknown, but may arise from the muscularis mucosae or myofibroblasts. EFS also increases frequency of mucosal venule contractions. Thus, efferent neural activity has multiple effects on the mucosa. Afferent activity has been measured when the mucosa is stimulated by mechanical and stretch stimuli from the luminal side. Nerve fibers have been shown to penetrate into the urothelium, allowing urothelial cells to interact with nerves. Myofibroblasts are specialized cells within the LP that generate spontaneous electrical activity which then can modulate both afferent and efferent neural activities. Thus mucosal signaling is defined as interactions between bladder autonomic nerves with non-neuronal cells within the mucosa. Mucosal signaling is likely to be involved in clinical functional hypersensory bladder disorders (e.g. overactive bladder, urgency, urgency incontinence, bladder pain syndrome) in which mechanisms are poorly understood despite high prevalence of these conditions. Targeting aberrant mucosal signaling could represent a new approach in treating these disorders.
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Affiliation(s)
- Toby C Chai
- Department of Urology, United States; Department of Obstetrics, Gynecology and Reproductive Science, Yale School of Medicine, New Haven, CT, United States.
| | - Andrea Russo
- Department of Obstetrics, Gynecology and Reproductive Science, Yale School of Medicine, New Haven, CT, United States
| | - Shan Yu
- Department of Urology, United States
| | - Ming Lu
- Department of Urology, United States
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Hashitani H, Mitsui R, Masaki S, Van Helden DF. Pacemaker role of pericytes in generating synchronized spontaneous Ca2+ transients in the myenteric microvasculature of the guinea-pig gastric antrum. Cell Calcium 2015; 58:442-56. [PMID: 26153078 DOI: 10.1016/j.ceca.2015.06.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/08/2015] [Accepted: 06/28/2015] [Indexed: 11/25/2022]
Abstract
Properties of spontaneous Ca(2+) transients in the myenteric microvasculature of the guinea-pig stomach were investigated. Specifically, we explored the spatio-temporal origin of Ca(2+) transients and the role of voltage-dependent Ca(2+) channels (VDCCs) in their intercellular synchrony using fluorescence Ca(2+) imaging and immunohistochemistry. The microvasculature generated spontaneous Ca(2+) transients that were independent of both Ca(2+) transients in interstitial cells of Cajal (ICC) and neural activity. Spontaneous Ca(2+) transients were highly synchronous along the length of microvasculature, and appeared to be initiated in pericytes and spread to arteriolar smooth muscle cells (SMCs). In most cases, the generation or synchrony of Ca(2+) transients was not affected by blockers of L-type VDCCs. In nifedipine-treated preparations, synchronous spontaneous Ca(2+) transients were readily blocked by Ni(2+), mibefradil or ML216, blockers for T-type VDCCs. These blockers also suppressed the known T-type VDCC dependent component of ICC Ca(2+) transients or slow waves. Spontaneous Ca(2+) transients were also suppressed by caffeine, tetracaine or cyclopiazonic acid (CPA). After the blockade of both L- and T-type VDCCs, asynchronous Ca(2+) transients were generated in pericytes on precapillary arterioles and/or capillaries but not in arteriolar SMCs, and were abolished by CPA or nominally Ca(2+) free solution. Together these data indicate that pericytes in the myenteric microvasculature may act as the origin of synchronous spontaneous Ca(2+) transients. Pericyte Ca(2+) transients arise from Ca(2+) release from the sarco-endoplasmic reticulum and the opening of T-type Ca(2+) VDCCs is required for their synchrony and propagation to arteriolar SMCs.
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Affiliation(s)
- Hikaru Hashitani
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan.
| | - Retsu Mitsui
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Shota Masaki
- Department of Cell Physiology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Dirk F Van Helden
- School of Biomedical Sciences and Pharmacy, University of Newcastle, NSW, Australia
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15
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Bai Y, Wang X, Li X, Pu C, Yuan H, Tang Y, Li J, Wei Q, Han P. Management of Catheter-Related Bladder Discomfort in Patients Who Underwent Elective Surgery. J Endourol 2014; 29:640-9. [PMID: 25335575 DOI: 10.1089/end.2014.0670] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE Despite the various treatment and prevention options for catheter-related bladder discomfort (CRBD), many uncertainties persist in clinical practice. To systematically review the literature on the management of CRBD in patients who underwent surgery. MATERIALS AND METHODS Eligible, randomized controlled trials were identified from electronic databases (Cochrane Central Register of Controlled Trials, Medline, and EMBASE) without language restrictions. Selection criteria, methodological rigor, and risk of bias were evaluated by two independent reviewers using Cochrane Collaboration's tools. RESULTS A total of 1441 patients from 14 articles published between 2005 and 2014 were included. Data heterogeneity precluded meta-analysis; therefore, data were synthesized narratively. Compared with nonurological surgery, CRBD is frequent and occurred immediately after urological surgery, especially after transurethral resection of the bladder tumor (TURBT). Data from included studies suggested that muscarinic antagonists, anesthetics, antiepileptics, and analgesics were associated with significant improvement in symptoms and reducing the incidence of CRBD, compared with placebo. Anticholinergic agents and antiepileptics (gabapentin and pregabalin) administered 1 hour before surgery reduced the incidence and severity of CRBD in the immediate postoperative period. Tramadol and ketamine are centrally acting opioid analgesics with antimuscarinic actions, which effectively prevent CRBD when administered intravenously. Paracetamol administered was also effective for the management of CRBD. Additionally, we perceived that TURBT is the surgical procedure that is the most refractory to treatment. CONCLUSIONS Muscarinic antagonists, anesthetics, antiepileptics, and paracetamol appear to achieve the greatest improvement in the clinical symptoms and a significant reduction in the incidence of CRBD compared with placebo. Although these studies observed a high incidence of intervention-related side effects, in general, patients tolerated these treatments well.
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Affiliation(s)
- Yunjin Bai
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Xianding Wang
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Xiaoqiang Li
- 2 Department of Anesthesiology, West China Hospital, Sichuan University , Chengdu, China
| | - Chunxiao Pu
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Haichao Yuan
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Yin Tang
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Jinhong Li
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Qiang Wei
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
| | - Ping Han
- 1 Department of Urology, West China Hospital, Sichuan University , Chengdu, China
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16
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Functional properties of submucosal venules in the rat stomach. Pflugers Arch 2014; 467:1327-42. [PMID: 25066613 DOI: 10.1007/s00424-014-1576-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/12/2014] [Accepted: 07/04/2014] [Indexed: 10/25/2022]
Abstract
Venules in the stomach may have intrinsic properties for maintaining active microcirculation drainage even during gastric filling. Properties of spontaneous and nerve-mediated activity of submucosal venules in the rat stomach were investigated. Changes in vasodiameter and intracellular Ca(2+) in venular smooth muscle cells (SMCs) were monitored by video tracking and Fluo-8 Ca(2+) imaging, respectively. Venular SMCs developed synchronous spontaneous Ca(2+) transients and corresponding rhythmic constrictions of the venules. Nominally Ca(2+)-free solution or an L-type Ca(2+) channel blocker (1 μM nifedipine) disrupted the Ca(2+) transient synchrony and abolished spontaneous constrictions. Spontaneous constrictions were also prevented by inhibitors of sarcoplasmic reticulum Ca(2+)-ATPase (10 μM cyclopiazonic acid (CPA)), IP3 receptors (100 μM 2-APB) or Ca(2+)-activated Cl(-) channels (100 μM niflumic acid). Transmural nerve stimulation (TNS) induced a long-lasting venular constriction that was abolished by α-adrenoceptor antagonist (1 μM phentolamine), while TNS evoked a sympathetic transient constriction of arterioles that was abolished by a combination of phentolamine and a P2 purinoceptor antagonist (10 μM pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS)). Consistently, P2X1 purinoceptor immunoreactivity was detected in arteriolar but not venular SMCs. Primary afferent nerve stimulation (300 nM capsaicin) caused a venular dilatation by releasing calcitonin gene-related peptide. Thus, Ca(2+) release from the sarcoplasmic reticulum may play a fundamental role in the generation of spontaneous Ca(2+) transients, while electrical coupling amongst venular SMCs via L-type Ca(2+) channel activation appears to be critical for Ca(2+) transient synchrony as well as spontaneous contractions. Sympathetic venular constrictions appear to be exclusively mediated by noradrenaline due to the lack of P2X1 receptor in venular SMCs.
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