Name: detrusor underactivity model in rats by conus medullaris transection
Uploaded: 2020-08-28T13:00:00.000+00:00
Duration: 3 min 26 s
Description: Watch this Scientific Journal Video about Detrusor Underactivity Model in Rats by Conus Medullaris Transection at JoVE.com

Alle Ratten wurden gemäß den Protokollen verwendet, die vom Animal Experimental Committee des Beijing Friendship Hospital der Capital Medical University genehmigt wurden.
1. Chirurgische Vorbereitung, Anästhesie und Operationstechniken
HINWEIS: Für die vorliegende Studie wurden insgesamt 40 weibliche Wistar-Ratten mit einem Gewicht von 200 bis 220 g kommerziell erhalten. Von den 40 Ratten wurden 10 nach dem Zufallsprinzip als Kontrollgruppe ausgewählt, und der Rest wurde als Testgruppe behandelt. Alle Tiere wurden in einer sterilen Umgebung in den Tiereinrichtungen des Beijing Friendship Hospital der Capital Medical University untergebracht.
<ol><li>Führen Sie eine Vollnarkose durch intraperitoneale Verabreichung von Natriumpentobarbital (40 mg/kg) durch. Alternativ können Sie eine Anästhesie mit 3% -4% Isofluran einleiten und bei 1% -3% (inhaliert) halten. Tragen Sie Augensalbe auf die Augen auf, um Trockenheit zu verhindern. Legen Sie dann die Ratte auf die chirurgische Plattform und bieten Sie thermische Unterstützung. HINWEIS: Verabreichen Sie Analgetika wie Buprenorphin, 0,05 mg/kg, SC, 0,1-0,2 ml zu Beginn des Verfahrens.</li>
	<li>Überprüfen Sie die Tiefe der Anästhesie durch die fehlende Reaktion auf die Zehenklemme. Rasieren Sie das Fell vom gesamten Rückenbereich mit einem Rasiermesser.</li>
	<li>Sterilisieren Sie die Operationsstelle mit mindestens 3 Zyklen eines zweistufigen Peelings wie Chlorhexidin oder Povidonjod, gefolgt von Isopropylalkohol. Sichern Sie die Gliedmaßen mit chirurgischem Klebeband und machen Sie mit einer chirurgischen Schere einen mittleren Schnitt von ca. 3 cm auf dem Rücken.</li>
	<li>Vertiefen Sie den Schnitt durch das Unterhautgewebe mit einer chirurgischen Schere und schneiden Sie die an der Wirbelsäule befestigten Muskeln ab.</li>
	<li>Identifizieren und entblößen Sie die 13. Rippe visuell (der mit dieser Rippe verbundene Zwischenwirbelraum ist das Intervall T13-L1). Markieren Sie die 13. Rippe mit einer Naht.</li>
	<li>Nach der Identifizierung die an der Wirbelsäule befestigten Muskeln vorsichtig resezieren und die Wirbelsäule freilegen. Resektionieren Sie das supraspinöse Band und das interspinöse Ligamentum für eine genaue Identifizierung der Wirbelsäule. Belichten Sie den L4-L5-Pegel mit einer chirurgischen Schere und einer Pinzette. HINWEIS: Das supraspinöse Ligamentum kann aufgrund des Vorhandenseins von dünnem Unterhautgewebe leicht identifiziert werden. Nach der Resektion des supraspinösen Bandes ist das Band zwischen dem Dornfortsatz interspinöses Ligament.</li>
	<li>Den Wirbelspinnfortsatz L4-L5 und Teile des Querfortsatzes werden vorsichtig mit einer Kelly-Pinzette entfernt, um das Rückenmark freizulegen (Abbildung 1).</li>
	<li>Den Conus medullaris auf der Ebene L4-L5 vollständig freilegen und den Conus medullaris vollständig mit einer Iridektomieschere transkektieren. Legen Sie etwas Gewebepackung ein, um die Erholung des Rückenmarks zu blockieren.</li>
	<li>Schließen Sie den darüber liegenden Muskel und die Haut auf der äußeren Hautschicht mit einer nicht resorbierbaren 4-0-Naht.</li>
	<li>Führen Sie für die Kontrollgruppe die Schritte 1.1 bis 7 aus und lassen Sie den Conus medullaris intakt. Schließen Sie den Schnitt gemäß Schritt 1.9.</li>
</ol>2. Wiederauffüllung der Tiere
<ol><li>Halten Sie die Ratten in der ersten Stunde nach der Operation in einem temperierten Inkubator (37 °C) und überwachen Sie sie, bis sie sternal sind oder sich aktiv bewegen. HINWEIS: Es dauert etwa eine halbe Stunde, bis die Wiederherstellung vollständig ist.</li>
	<li>Bringen Sie das Tier in einen sauberen Käfig mit ausreichend Futter und Wasser. Halten Sie die Ratten in getrennten Käfigen. HINWEIS: Der Erfolg der Durchtrennung ist angezeigt, wenn sich die Ratten in der Testgruppe nur mit Hilfe der Vorderbeine bewegen, während die Ratten in der Kontrollgruppe normal gehen konnten.</li>
</ol>3. Post-Operation-Management
<ol><li>Injizieren Sie Penicillin G, ein Antibiotikum (50.000 U/ml pro Tier) intraperitoneal. Verabreichen Sie Analgetika wie Buprenorphin, 0,05 mg / kg, SC, 0,1-0,2 ml alle 6-12 Stunden für 48 Stunden nach der Operation.</li>
	<li>Komprimieren Sie die Harnblase im Hypogastrium, um bei der Entleerung zu helfen. Führen Sie dies zweimal täglich zur gleichen Zeit (8 Uhr und 20 Uhr) für sechs Wochen durch. HINWEIS: Der Verlust der normalen Einschnürung des Detrusors ist das Symbol von DU.</li>
	<li>Halten Sie alle Ratten in metabolischen Käfigen, die jeweils einen Urinsammeltrichter enthalten, der über ein zuvor gewogenes, absorbierendes Papier gelegt wird, um die Miktion und Inkontinenz zu überwachen.</li>
	<li>Erfassen und notieren Sie die Gewichtsänderung des saugfähigen Papiers, die das entleerte Volumen (VV) und das Restharnvolumen separat angibt.</li>
</ol>4. Urodynamische Tests
<ol><li>Führen Sie sechs Wochen nach der Operation ein Zystometrogramm mit urodynamischen Messgeräten wie folgt durch.<ol><li>Anästhesieren Sie Ratten, indem Sie 10% Chloralhydrat in die Peritonealhöhle (3 ml/kg) injizieren.</li>
		<li>Komprimieren Sie die Blase zur Entleerung und fixieren Sie die Ratte dann mit einem Klebeband auf der chirurgischen Plattform.</li>
		<li>Führen Sie den Epiduralkatheter (3F) in die Blase ein und verbinden Sie das urodynamische Messgerät, den Epiduralkatheter und die Infusionspumpe mit dem dreigliedrigen Schlauch.</li>
		<li>Pumpen Sie physiologische Kochsalzlösung mit einer Geschwindigkeit von 0,2 ml/min für die urodynamische Messung (siehe Materialtabelle). Notieren Sie den MCC und DOP sowie die Compliance der Blase (berechnet durch Division δ Blasenvolumens mit δ Druck des Detrusors).</li>
	</ol></li>
</ol>5. Statistische Auswertung
<ol><li>Führen Sie statistische Analysen mit handelsüblicher Software durch.</li>
	<li>Verwenden Sie den Kolmogorov-Smirnov-Test, um die Normalität der Daten zu testen.</li>
	<li>Drücken Sie die normalverteilten Variablen als Mittelwerte mit Standardabweichungen aus. Verwenden Sie die zweiseitigen gepaarten Student-t-Tests, um die Parameter des Zystometrogramms in beiden Gruppen zu vergleichen. ANMERKUNG: p < 0,05 zeigt an, dass die Differenz statistisch signifikant war.</li>
</ol>

<ol>
	<li>van Koeveeringe, G. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detrusor+underactivity:+Pathophysiological+considerations,+models+and+proposals+for+future+research.">Detrusor underactivity: Pathophysiological considerations, models and proposals for future research.</a> Neurourology and Urodynamics. 33 (5), 591-596 (2014).</li><li>Osman, N. I., Esperto, F., Chapple, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detrusor+Underactivity+and+the+Underactive+Bladder:+A+Systematic+Review+of+Preclinical+and+Clinical+Studies.">Detrusor Underactivity and the Underactive Bladder: A Systematic Review of Preclinical and Clinical Studies.</a> European Urology. 74 (5), 633-643 (2018).</li><li>Osman, N. I., Chapple, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contemporary+concepts+in+the+aetiopathogenesis+of+detrusor+underactivity.">Contemporary concepts in the aetiopathogenesis of detrusor underactivity.</a> Nature Reviews. Urology. 11 (11), 639-648 (2014).</li><li>Panicker, J. N., Nagaraja, D., Kovoor, J. M. E., Nair, K. P. S., Subbakrishna, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lower+urinary+tract+dysfunction+in+acute+disseminated+encephalomyelitis.">Lower urinary tract dysfunction in acute disseminated encephalomyelitis.</a> Multiple Sclerosis. 15 (9), 1118-1122 (2009).</li><li>Lee, W. C., Wu, H. P., Tai, T. Y., Yu, H. J., Chiang, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+of+urodynamic+characteristics+and+bladder+sensory+function+in+the+early+stages+of+diabetic+bladder+dysfunction+in+women+with+type+2+diabetes.">Investigation of urodynamic characteristics and bladder sensory function in the early stages of diabetic bladder dysfunction in women with type 2 diabetes.</a> The Journal of Urology. 181 (1), 198-203 (2009).</li><li>Araki, I., Kitachara, M., Oida, T., Kuno, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Voiding+dysfunction+and+Parkinson’s+disease:+urodynamic+abnormalities+and+urinary+symptoms.">Voiding dysfunction and Parkinson’s disease: urodynamic abnormalities and urinary symptoms.</a> The Journal of Urology. 164 (5), 1640-1643 (2000).</li><li>Meng, N. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Incomplete+bladder+emptying+in+patients+with+stroke:+is+detrusor+external+sphincter+dyssynergia+a+potential+cause.">Incomplete bladder emptying in patients with stroke: is detrusor external sphincter dyssynergia a potential cause.</a> Archives of Physical Medicine and Rehabilitation. 91 (7), 1105-1109 (2010).</li><li>FitzGerald, M. P., Brubaker, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+etiology+of+urinary+retention+after+surgery+for+genuine+stress+incontinence.">The etiology of urinary retention after surgery for genuine stress incontinence.</a> Neurourology and Urodynamics. 20 (1), 13-21 (2001).</li><li>Rahman, M., Siddik, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neuroanatomy,+Pontine+Micturition+Center.">Neuroanatomy, Pontine Micturition Center.</a> StatPearls. , (2020).</li><li>Wrobel, A., Lancut, M., Rechberger, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+model+of+detrusor+overactivity+in+conscious+rats+induced+by+retinyl+acetate+instillation.">A new model of detrusor overactivity in conscious rats induced by retinyl acetate instillation.</a> Journal of Pharmacological and Toxicological Methods. 74 (7), 16 (2015).</li><li>Rosenzweig, E. S., McDonald, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rodent+models+for+treatment+of+spinal+cord+injury:+research+trends+and+progress+toward+useful+repair.">Rodent models for treatment of spinal cord injury: research trends and progress toward useful repair.</a> Current Opinion in Neurology. 17 (2), 121-131 (2004).</li><li>Yoo, K. H., Lee, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+animal+models+of+neurogenic+bladder+dysfunction.">Experimental animal models of neurogenic bladder dysfunction.</a> International Neurourology Journal. 14 (1), 1-6 (2010).</li><li>Kanai, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sophisticated+models+and+methods+for+studying+neurogenic+bladder+dysfunction.">Sophisticated models and methods for studying neurogenic bladder dysfunction.</a> Neurourology and Urodynamics. 30 (5), 658-667 (2011).</li><li>Nomiya, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Progressive+vascular+damage+may+lead+to+bladder+underactivity+in+rats.">Progressive vascular damage may lead to bladder underactivity in rats.</a> The Journal of Urology. 191 (5), 1462-1469 (2014).</li><li>Seki, T., Hida, K., Tada, M., Koyanagi, I., Iwasaki, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Graded+contusion+model+of+the+mouse+spinal+cord+using+a+pneumatic+impact+device.">Graded contusion model of the mouse spinal cord using a pneumatic impact device.</a> Neurosurgery. 50 (5), 1075-1081 (2002).</li><li>Yeo, S. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+rat+model+of+graded+contusive+spinal+cord+injury+using+a+pneumatic+impact+device.">Development of a rat model of graded contusive spinal cord injury using a pneumatic impact device.</a> Journal of Korean Medical Science. 19 (4), 574-580 (2004).</li><li>Bergman, B. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spinal+cord+transplants+permit+the+growth+of+serotonergic+axons+across+the+site+of+neonatal+spinal+cord+transection.">Spinal cord transplants permit the growth of serotonergic axons across the site of neonatal spinal cord transection.</a> Brain Research. 431 (2), 265-279 (1987).</li><li>Chancellor, M. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Underactive+bladder;+Review+of+progress+and+impact+from+the+International+CURE-UAB+Initiative.">Underactive bladder; Review of progress and impact from the International CURE-UAB Initiative.</a> International Neurourology Journal. 24 (1), 3-11 (2020).</li><li>Pfisterer, M. H. D., Griffiths, D. J., Schaefer, W., Resnick, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+age+on+lower+urinary+tract+function:+a+study+in+women.">The effect of age on lower urinary tract function: a study in women.</a> Journal of the American Geriatrics Society. 54 (3), 405-412 (2006).</li><li>Duchen, L. W., Anjorin, A., Watkins, P. J., Mackay, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathology+of+autonomic+neuropathy+in+diabetes+mellitus.">Pathology of autonomic neuropathy in diabetes mellitus.</a> Annals of Internal Medicine. 92 (2), 301-303 (1980).</li><li>Schneider, T., Hein, P., Bai, J., Michel, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+role+for+muscarinic+receptors+or+rho-kinase+in+hypertension+associated+rat+bladder+dysfunction.">A role for muscarinic receptors or rho-kinase in hypertension associated rat bladder dysfunction.</a> The Journal of Urologoy. 173 (6), 2178-2181 (2005).</li><li>Drake, M. J., Harvey, I. J., Gillespie, J. I., Van Duyl, W. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localized+contractions+in+the+normal+human+bladder+and+in+urinary+urgency.">Localized contractions in the normal human bladder and in urinary urgency.</a> BJU International. 95 (7), 1002-1005 (2005).</li><li>Suskind, A. M., Smith, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+look+at+detrusor+underactivity:+impaired+contractility+versus+afferent+dysfunction.">A new look at detrusor underactivity: impaired contractility versus afferent dysfunction.</a> Current Urology Reports. 10 (5), 347-351 (2009).</li><li>Osman, N. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detrusor+underactivity+and+the+underactive+bladder:+A+new+clinical+entity?+A+review+of+current+terminology,+definitions,+epidemiology,+aetiology,+and+diagnosis.">Detrusor underactivity and the underactive bladder: A new clinical entity? A review of current terminology, definitions, epidemiology, aetiology, and diagnosis.</a> European Urology. 65 (2), 389-398 (2014).</li></ol>

Die Autoren haben nichts zu offenbaren.

DU ist eine häufige Ursache für Symptome der unteren Harnwege bei Männern und Frauen. Es handelt sich um eine komplexe Symptomkonstellation mit wenigen Behandlungsmöglichkeiten, die die Lebensqualität (Qol) der Betroffenen deutlich beeinträchtigen kann18. Obwohl angenommen wird, dass DU multifaktoriell ist, bleibt das Verständnis seiner Pathogenese rudimentär. Studien haben gezeigt, dass die Pathogenese von DU mit myogenen und neurogenen Faktoren zusammenhängen könnte.
<p class="jove...

Detrusor-Unteraktivität (DU) ist eine typische Dysfunktion der unteren Harnwege, die noch nicht untersucht wurde. Obwohl DU von der International Continence Society (ICS)1 definiert wurde, werden zahlreiche verschiedene Terminologien verwendet, um sich auf diese Krankheit zu beziehen, z. B. "Detrusorversagen", "kontraktile Blase", "Detrusor-Areflexie"2. DU, wie von der International Continence Society (ICS) im Jahr 2002 definiert, ist eine Kontraktion von reduzierter Stärke und Dauer, die zu einer verlängerten Verlängerung der Zeit für die Blasenentleerung führt, was dazu führt, dass keine vollständige Blasenentleerung innerhalb eines normalen Zeitraums erreicht wird.
DU kann 48 % der Männer und 12 % der Frauen (im Alter von >70 Jahren)3 mit Symptomen der unteren Harnwege betreffen. Es scheint multifaktoriell zu sein, und es gibt keine wirksame Behandlung. Es wird berichtet, dass DU bei Patienten mit neurogener Blasenfunktionsstörung wie Multipler Sklerose4, Diabetes mellitus5, Parkinson-Krankheit6 oder Schlaganfall7 allgegenwärtig ist. DU kann auch durch iatrogene Nervenschäden verursacht werden, wie z. B. laparoskopische Hysterektomie, Prostatektomie oder andere chirurgische Eingriffe im kleinen Becken8. Die pathophysiologischen Veränderungen und die verfügbaren Behandlungen von DU sind immer noch verwirrend, da es kein geeignetes Tiermodell für die Studie gibt.
Der Miktionsreflex wird durch spino-bulbospinale Bahnen gesteuert, die das pontine Miktionszentrum, den sakralen parasympathischen Kern und die höheren Kortexzentren kombinieren9. Aktivierung und Aufrechterhaltung des Miktionsreflexes hängen vor allem vom regelmäßigen Transport von Sinnessignalen aus der Blase zu den höheren Kortexzentren ab. Es kann postuliert werden, dass sensorische Dysfunktion zu DU beiträgt.
Die meisten experimentellen Tierstudien im Zusammenhang mit Funktionsstörungen der unteren Harnwege konzentrierten sich auf Modelle der überaktiven Blase (OAB)10. Diese Modelle bieten ein angemessenes Verständnis der OAB-Pathophysiologie und -Prognose. Es wurden jedoch nur wenige DU-Modelle beschrieben, z. B. supraspinale Verletzungen (lokale Läsionen, Dezerebration und Verschluss der mittleren Hirnarterie), Rückenmarksdurchtrennung oder Kontusionsverletzungen, systemische (z. B. Cyclophosphamid) oder intravesikale Verabreichung von Reiz- oder Entzündungsstoffen (z. B. Säure, Acrolein und Lipopolysaccharid)11,12,13,14 . Unter diesen Methoden kann nur die Methode der Rückenmarksdurchtrennung oder der Kontusionsverletzung verwendet werden, um ein Tiermodell von DU13 zu erstellen. Versuche, das pontine Miktionszentrum und die höheren Kortexzentren zu verletzen, wurden wegen des schweren Traumas abgebrochen. Daher wird erhöhte Aufmerksamkeit darauf gelegt, eine genaue Position im Miktionsreflexzentrum zu finden, um das DU mit minimalen Nebenwirkungen zu induzieren.
Wie bereits erwähnt, besteht einer der Mechanismen zur Induktion von DU darin, das Rückenmark zu verletzen, um den Signalweg des Miktionsreflexes zu schädigen. Allens Weight-Drop-Methode wurde entwickelt, um Labortiere mit verletztem Rückenmarkzu etablieren 15. Es liegen jedoch keine weiteren experimentellen Daten zu dieser Methode vor. Da Teile der Tiere die Wirbelsäulenfunktion nach einem Schlaganfall ohne DU wiedererlangten, kann dies nicht als perfekte Methode zur Erstellung eines DU-Tiermodells angesehen werden16.
Im Jahr 1987 entwickelte Bregman einen Prozess der Durchtrennung des Rückenmarks zur Generierung des DU-Tiermodells und erwarb experimentelle Daten17. Diese Methode wurde jedoch nicht zur Etablierung des DU-Tiermodells angewendet. Zu dieser Zeit waren die Forscher noch verwirrt über die Pathogenese von DU. Da Stellen im Rückenmark, die mit der Induktion von OAB oder DU assoziiert sind, nebeneinander liegen, konnten sie nicht den genauen Ort der Schädigung des Rückenmarks finden, um DU17 zu induzieren. OAB und DU wurden entweder zusammen oder getrennt durch diese Methode eingeführt. Obwohl diese Methode DU einführte, war sie ungenau und konnte nicht zum Verständnis des Auftretens und der Verarbeitung von DU verwendet werden.
Wie bereits erwähnt, ist das Fehlen eines geeigneten Tiermodells für DU eines der Haupthindernisse für die Untersuchung von DU. Forscher sind ständig auf der Suche nach einem genauen und handhabbaren Modell, das die Pathologie von DU simulieren kann. Selbst die Behandlungsmöglichkeiten für DU haben sich in den letzten 20 Jahren nicht signifikant verbessert. Insgesamt besteht ein großer Bedarf, ein Standardprotokoll für die Erstellung eines Tiermodells von DU zu beschreiben.
In diesem Artikel beschreiben wir eine Methode, um erfolgreich ein Rattenmodell von DU durch Conus medullaris-Transektion zu etablieren. Die Transektion wurde auf der Ebene L4-L5 durchgeführt, um den Conus medullaris zu trennen. Die maximale zystometrische Kapazität (MCC), der Detrusoröffnungsdruck (DOP) und die Compliance der Blase wurden aufgezeichnet und analysiert, um das Protokoll zu validieren. Das unten aufgeführte Protokoll kombiniert sowohl die Machbarkeit als auch die Zuverlässigkeit auf standardisierte Weise, um das DU-Tiermodell zu erstellen und das Auftreten und die Verarbeitung von DU zu simulieren. Das Protokoll kann als Technik für die weitere Untersuchung von DU verwendet werden.

<table><tbody><tr><td>0.9% saline</td><td>Wuhan Prosai Company</td><td>EY-C1178</td><td>pump for urodynamic measurement</td></tr><tr><td>10% chloral hydrate</td><td>Shandong Yulong Co., Ltd</td><td>H37022673</td><td>3mL/kg, administered intraperitoneally</td></tr><tr><td>Buprenorphine Hydrochloride Injection</td><td>Tianjin Pharmaceutical Research Institute Pharmaceutical Co. LTD</td><td>H12020275</td><td>0.05mg/kg subcutaneously 24h and 48h postoperation</td></tr><tr><td>Epidural Catheter</td><td>Shandong Xinghua Co, Ltd</td><td>VABR3L</td><td>for urodynamic measurement</td></tr><tr><td>Penicillin G</td><td>Alta Technology Co., Ltd</td><td>1ST5637</td><td>50,000 unit/ml per animal</td></tr><tr><td>pentobarbital</td><td>Beijing solabo Technology Co., Ltd</td><td>NK-WF0001</td><td>40 mg/kg, administered intraperitoneally</td></tr><tr><td>Suture line(4-0)</td><td>ETHICON</td><td>VCP422H</td><td>suture the injury</td></tr><tr><td>Three-limb tube</td><td>Shandong Xinghua Co, Ltd</td><td>VAB3T</td><td>for urodynamic measurement</td></tr><tr><td>Trace infusion pump</td><td>Zhejiang Smith Medical Instrument Co., Ltd</td><td>20162540335</td><td>Pump the saline at a speed of 0.2ml/min for urodynamic measurement</td></tr><tr><td>Urodynamic measurement equipment</td><td>Medical Measurement SystemsB.V.</td><td>08-0467</td><td>urodynamic measurement equipment can not only help the diagnosis of dysuria, but also provide objective materials for treatment and therapeutic effect. It is the most commonly used examination method in clinical diagnosis and treatment of lower urinary tract functional diseases</td></tr><tr><td>Wistar Rats</td><td>HFK Biotechnology Co.Ltd,Beijing ,China</td><td>SCXK2012-0023</td><td>200-220g</td></tr></tbody></table>

detrusor underactivity model in rats by conus medullaris transection

Das Ziel des vorgestellten Protokolls war es, ein Detrusor-Unteraktivitätsmodell (DU) in der Ratte durch Conus medullaris-Transektion zu etablieren. Die Laminektomie wurde an insgesamt 40 weiblichen Wistar-Ratten (Kontrollgruppe: 10 Ratten; Testgruppe: 30 Ratten) mit einem Gewicht von 200–220 g durchgeführt, wobei der Conus medullaris in der Testgruppe auf der Ebene L4-L5 transeziert wurde. Alle Ratten wurden sechs Wochen lang unter den gleichen Umweltbedingungen untergebracht und gefüttert. In der Testgruppe wurde die Urinentleerung sechs Wochen lang zweimal täglich durchgeführt, und das mittlere Restharnvolumen wurde aufgezeichnet. In beiden Gruppen wurde ein Zystometrogramm durchgeführt. Die maximale zystometrische Kapazität (MCC), der Detrusoröffnungsdruck (DOP) und die Compliance der Blase wurden aufgezeichnet und berechnet. Die Testgruppe zeigte nach der Operation einen signifikanten Harnverhalt, sowohl während als auch nach dem Wirbelsäulenschock. In der Kontrollgruppe wurde jedoch keine Anomalie beobachtet. Im Vergleich zur Kontrollgruppe waren der MCC und die Compliance der Blase in der Testgruppe signifikant höher als in der Testgruppe (3,24 ± 2,261 ml versus 1,04 ± 0,571 ml; 0,43 ± 0,578 ml/cmH 2 O versus 0,032 ± 0,016 ml/cmH 2 O), während der DOP in der Testgruppe niedriger war als der der Kontrollgruppe (20,28 ± 14,022 cmH 2 O versus 35 ± 13,258 cmH2 Diese Methode zur Etablierung eines Tiermodells von DU durch die Conus medullaris-Durchtrennung bietet eine hervorragende Möglichkeit, die Pathophysiologie von DU besser zu verstehen.

Der gesamte Eingriff der Conus medullaris-Durchtrennung kann innerhalb von 45 Minuten von erfahrenen Chirurgen durchgeführt werden. Unser Labor hat über 100 Fälle von Conus medullaris-Durchschnittsoperationen durchgeführt. Die Erfolgsrate liegt bei über 95%, definiert durch das Überleben der Ratten und die erfolgreiche Induktion von DU. Der urodynamische Test bestätigte die Induktion von DU.
Basierend auf unseren Erfahrungen kann die Induktion von DU durch das Restharnvolumen vorläufig...

Watch this Scientific Journal Video about Detrusor Underactivity Model in Rats by Conus Medullaris Transection at JoVE.com

Detrusor Underactivity Model in Rats by Conus Medullaris Transection

Wir stellen eine Methode zur Etablierung eines Detrusor-Unteraktivitätsmodells durch Conus medullaris-Transsektion bei Ratten vor. Die Detrusor-Unteraktivität wurde bei diesen Tieren erfolgreich stimuliert. Das Modell kann zur Untersuchung der Harnwegsfunktion verwendet werden.

Detrusor-Unteraktivitätsmodell bei Ratten durch Conus medullaris-Durchtrennung

The goal of the presented protocol was to establish a detrusor underactivity (DU) model in the rat through conus medullaris transection. Laminectomy was ...

detrusor-underactivity-model-in-rats-by-conus-medullaris-transection

Research

JoVE Journal

Neuroscience

2.0K Aufrufe.  Capital Medical University. Wir stellen eine Methode zur Etablierung eines Detrusor-Unteraktivitätsmodells durch Conus medullaris-Transsektion bei Ratten vor. Die Detrusor-Unteraktivität wurde bei diesen Tieren erfolgreich stimuliert. Das Modell kann zur Untersuchung der Harnwegsfunktion verwendet werden.

Serie: Detrusor Underactivity Model in Rats by Conus Medullaris Transection

Evaluation of Biomaterials for Bladder Augmentation using Cystometric Analyses in Various Rodent Models

Renal function and continence of urine are critically dependent on the proper function of the urinary bladder, which stores urine at low pressure and expels it with a precisely orchestrated contraction. A number of congenital and acquired urological anomalies including posterior urethral valves, benign prostatic hyperplasia, and neurogenic bladder secondary to spina bifida/spinal cord injury can result in pathologic tissue remodeling leading to impaired compliance and reduced capacity1. Functional or anatomical obstruction of the urinary tract is frequently associated with these conditions, and can lead to urinary incontinence and kidney damage from increased storage and voiding pressures2. Surgical implantation of gastrointestinal segments to expand organ capacity and reduce intravesical pressures represents the primary surgical treatment option for these disorders when medical management fails3. However, this approach is hampered by the limitation of available donor tissue, and is associated with significant complications including chronic urinary tract infection, metabolic perturbation, urinary stone formation, and secondary malignancy4,5.
Current research in bladder tissue engineering is heavily focused on identifying biomaterial configurations which can support regeneration of tissues at defect sites. Conventional 3-D scaffolds derived from natural and synthetic polymers such as small intestinal submucosa and poly-glycolic acid have shown some short-term success in supporting urothelial and smooth muscle regeneration as well as facilitating increased organ storage capacity in both animal models and in the clinic6,7. However, deficiencies in scaffold mechanical integrity and biocompatibility often result in deleterious fibrosis8, graft contracture9, and calcification10, thus increasing the risk of implant failure and need for secondary surgical procedures. In addition, restoration of normal voiding characteristics utilizing standard biomaterial constructs for augmentation cystoplasty has yet to be achieved, and therefore research and development of novel matrices which can fulfill this role is needed.
In order to successfully develop and evaluate optimal biomaterials for clinical bladder augmentation, efficacy research must first be performed in standardized animal models using detailed surgical methods and functional outcome assessments. We have previously reported the use of a bladder augmentation model in mice to determine the potential of silk fibroin-based scaffolds to mediate tissue regeneration and functional voiding characteristics.11,12 Cystometric analyses of this model have shown that variations in structural and mechanical implant properties can influence the resulting urodynamic features of the tissue engineered bladders11,12. Positive correlations between the degree of matrix-mediated tissue regeneration determined histologically and functional compliance and capacity evaluated by cystometry were demonstrated in this model11,12. These results therefore suggest that functional evaluations of biomaterial configurations in rodent bladder augmentation systems may be a useful format for assessing scaffold properties and establishing in vivo feasibility prior to large animal studies and clinical deployment. In the current study, we will present various surgical stages of bladder augmentation in both mice and rats using silk scaffolds and demonstrate techniques for awake and anesthetized cystometry.

Surgical stages of bladder augmentation are described using 3-D scaffolds in murine and rat models. To test the efficacy of biomaterial configurations for use in bladder augmentation, techniques for both awake and anesthetized cystometry are presented.

Bewertung von Biomaterialien für Blasenvergrößerung mit Zystometrische Analysen in verschiedenen Tiermodellen

Renal function and continence of urine are critically dependent on the proper function of the urinary bladder, which stores urine at low pressure and ...

Forschung

Biotechnik

The Use of Cystometry in Small Rodents: A Study of Bladder Chemosensation

The lower urinary tract (LUT) functions as a dynamic reservoir that is able to store urine and to efficiently expel it at a convenient time. While storing urine, however, the bladder is exposed for prolonged periods to waste products. By acting as a tight barrier, the epithelial lining of the LUT, the urothelium, avoids re-absorption of harmful substances. Moreover, noxious chemicals stimulate the bladder's nociceptive innervation and initiate voiding contractions that expel the bladder's contents. Interestingly, the bladder's sensitivity to noxious chemicals has been used successfully in clinical practice, by intravesically infusing the TRPV1 agonist capsaicin to treat neurogenic bladder overactivity1. This underscores the advantage of viewing the bladder as a chemosensory organ and prompts for further clinical research. However, ethical issues severely limit the possibilities to perform, in human subjects, the invasive measurements that are necessary to unravel the molecular bases of LUT clinical pharmacology. A way to overcome this limitation is the use of several animal models2. Here we describe the implementation of cystometry in mice and rats, a technique that allows measuring the intravesical pressure in conditions of controlled bladder perfusion.
	After laparotomy, a catheter is implanted in the bladder dome and tunneled subcutaneously to the interscapular region. Then the bladder can be filled at a controlled rate, while the urethra is left free for micturition. During the repetitive cycles of filling and voiding, intravesical pressure can be measured via the implanted catheter. As such, the pressure changes can be quantified and analyzed. Moreover, simultaneous measurement of the voided volume allows distinguishing voiding contractions from non-voiding contractions3.
	Importantly, due to the differences in micturition control between rodents and humans, cystometric measurements in these animals have only limited translational value4. Nevertheless, they are quite instrumental in the study of bladder pathophysiology and pharmacology in experimental pre-clinical settings. Recent research using this technique has revealed the key role of novel molecular players in the mechano- and chemo-sensory properties of the bladder.

Cystometry is an efficient technique to measure bladder function of small animals in vivo. The bladder is continuously infused at rates controlled through an intravesical catheter, whereas the urethra is left free for micturition. This allows for repetitive filling and emptying of the bladder, while intravesical pressure and voided volume are recorded.

Die Verwendung von Zystometrie in kleine Nagetiere: A Study of Bladder Chemosensorik

	The lower urinary tract (LUT) functions as a  dynamic reservoir that is able to store urine and to efficiently expel it at a  convenient time. While ...

Medizin

Urinary Bladder Distention Evoked Visceromotor Responses as a Model for Bladder Pain in Mice

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition characterized by increased urgency and frequency of urination, as well as nocturia and general pelvic pain, especially upon bladder filling or voiding. Despite years of research, the cause of IC/BPS remains elusive and treatment strategies are unable to provide complete relief to patients. In order to study nervous system contributions to the condition, many animal models have been developed to mimic the pain and symptoms associated with IC/BPS. One such murine model is urinary bladder distension (UBD). In this model, compressed air of a specific pressure is delivered to the bladder of a lightly anesthetized animal over a set period of time. Throughout the procedure, wires in the superior oblique abdominal muscles record electrical activity from the muscle. This activity is known as the visceromotor response (VMR) and is a reliable and reproducible measure of nociception. Here, we describe the steps necessary to perform this technique in mice including surgical manipulations, physiological recording, and data analysis. With the use of this model, the coordination between primary sensory neurons, spinal cord secondary afferents, and higher central nervous system areas involved in bladder pain can be unraveled. This basic science knowledge can then be clinically translated to treat patients suffering from IC/BPS.

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition characterized in part by pelvic pain. In order to study nervous system contributions to the condition, a physiological model of urinary bladder pain is used in mice and rats.

Harnblase Aufdehnung evozierte viszeromotorische Antworten als Modell für Bladder Pain in Mäuse

Approximately 3-8 million people in the United States suffer from interstitial cystitis/bladder pain syndrome (IC/BPS), a debilitating condition ...

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology

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.

This manuscript presents a simple, yet powerful, in vitro method for evaluating smooth muscle contractility in response to pharmacological agents or nerve stimulation. Main applications are drug screening and understanding tissue physiology, pharmacology,&#160;and pathology.

Glatten Muskulatur der Blase Streifen Kontraktilität als eine Methode zur unteren Harnwege Pharmakologie Bewerten

We describe an in vitro method to measure bladder smooth muscle contractility, and its use for investigating physiological and pharmacological properties ...

Nerve-sparing Mid-urethral Obstruction (NeMO) in Female Small Rodents

Partial bladder outlet obstruction (pBOO) has a high prevalence, causes significant patient burden, and immense health care costs. The most common animal model to investigate bladder remodeling in pBOO are female rodents undergoing partial obstruction at the proximal urethra. Variability in the degree of obstruction and animal mortality are major concerns with proximal obstruction. Furthermore, dissecting around the proximal urethra and bladder neck jeopardizes bladder innervation.
We developed a nerve-sparing mid-urethral obstruction (NeMO) model for pBOO avoiding the disadvantages of the traditional model. We approached the urethra just inferior to the pubic symphysis, which obviated the need for laparotomy as well as for dissection in this area; also, the striated urethral sphincter remained untouched. We performed NeMO in female Sprague-Dawley rats (12 obstructions, 6 sham animals) as well as in female C57/bl6 mice (20 obstructions, 18 sham animals). After two weeks, we evaluated bladder function, bladder mass, and body mass.
We had no mortalities among obstructed- or sham-operated female rats; as described for the traditional proximal pBOO-method, we tied the suture around the proximal urethra and a temporarily placed 0.9 mm metal rod. NeMO induced an 85% increase in bladder mass after two weeks, average residual urine volume was 0.4 mL in partially obstructed rats while only 0.03 mL in sham animals. In mice, we tested 3 sizes of cannulas that we placed along the urethra when tying the suture. We found that using a 27-gauge cannula resulted in over 50% animal mortality; placing the 25-gauge cannula did not yield the desired response in increasing bladder mass; utilizing a 26-gauge cannula yielded favorable results with minimal animal mortality (1/8) yet a significant 2-fold increase in bladder mass.

Nerve-sparing Mid-urethral Obstruction NeMO in Female Small Rodents

Traditional modeling of partial bladder outlet obstruction in rodents is fraught with animal mortality. A denervation injury from dissection around the proximal urethra and bladder neck is also of major concern. We developed and evaluated a safe and reliable mid-urethral obstruction model, avoiding the shortcomings of the traditional model.

Nerve sparende Mittelharnröhrenobstruktion (NEMO) in Female Kleine Nagetiere

Partial bladder outlet obstruction (pBOO) has a high prevalence, causes significant patient burden, and immense health care costs. The most common animal ...

Evaluating the Procedure for Performing Awake Cystometry in a Mouse Model

Awake filling cystometry has been used for a long time to evaluate bladder function in freely moving mice, however, the specific methods used, vary among laboratories. The goal of this study was to describe the microsurgical procedure used to implant an intravesical tube and the experimental technique for recording urinary bladder pressure in an awake, freely moving mouse. In addition, experimental data is presented to show how surgery, as well as tubing type and size, affect lower urinary tract function and recording sensitivity. The effect of tube diameter on pressure recording was assessed in both polyethylene and polyurethane tubing with different internal diameters. Subsequently, the best performing tube from both materials was surgically implanted into the dome of the urinary bladder of male C57BL/6 mice. Twelve-hour, overnight micturition frequency was recorded in healthy, intact animals and animals 2, 3, 5, and 7 days post-surgery. At harvest, bladders were assessed for signs of swelling using gross observation and were subsequently processed for pathological analysis. The greatest extent of bladder swelling was observed on day 2 and 3, which correlated with behavioral voiding data showing significantly impaired bladder function. By day 5, bladder histology and voiding frequency had normalized. Based on the literature and evidence provided by our studies, we propose the following steps for in vivo recording of intravesical pressure and voided volume in an awake mouse: 1) Perform the surgery using an operating microscope and microsurgical tools, 2) Use polyethylene-10 tubing to minimize movement artifacts, and 3) Perform cystometry on post-operative day 5, when bladder swelling resolves.

This study describes the surgical procedures and experimental techniques for performing awake cystometry in a freely moving mouse. In addition, it provides experimental evidence to support its optimization and standardization.

Auswertung der Prozedur für die Durchführung einer wachen Zystometrie in einem Mausmodell

Awake filling cystometry has been used for a long time to evaluate bladder function in freely moving mice, however, the specific methods used, vary among ...

A Decentralized (Ex Vivo) Murine Bladder Model with the Detrusor Muscle Removed for Direct Access to the Suburothelium during Bladder Filling

Previous studies have established the release of chemical substances from flat bladder mucosa sheets affixed in Ussing chambers and exposed to changes in hydrostatic pressure or mechanical stretch and from cultured urothelial cells upon hydrostatic pressure changes, stretch, cell swelling, or drag forces, and in bladder lumen at end of filling. Such findings led to the assumption that these mediators are also released in suburothelium (SubU)/lamina propria (LP) during bladder filling, where they affect cells deep in the bladder wall to ultimately regulate bladder excitability. There are at least two obvious limitations in such studies: 1) none of these approaches provide direct information about the presence of mediators in SubU/LP, and 2) the stimuli used are not physiological and do not recapitulate authentic filling of the bladder. Here, we discuss a procedure that enables direct access to the suburothelial surface of the bladder mucosa in the course of bladder filling. The murine detrusor-free preparation we created closely resembles filling of the intact bladder and allows pressure-volume studies to be performed on the bladder in the absence of confounding signaling from spinal reflexes and detrusor smooth muscle. Using the novel detrusor-free bladder model, we recently demonstrated that intravesical measurements of mediators cannot be used as a proxy to what has been released or present in the SubU/LP during bladder filling. The model enables examination of urothelium-derived signaling molecules that are released, generated by metabolism and/or transported into the SubU/LP during the course of bladder filling to transmit information to neurons and smooth muscle of the bladder and regulate its excitability during continence and micturition.

A Decentralized Ex Vivo Murine Bladder Model with the Detrusor Muscle Removed for Direct Access to the Suburothelium during Bladder Filling

The detrusor-free bladder model enables direct access to the suburothelium to study local mechanisms for regulation of biologically active mediator availability in suburothelium/lamina propria during storage and voiding of urine. The preparation closely resembles filling of an intact bladder and allows pressure-volume studies to be performed without systemic influences.

Ein dezentralisiertes (Ex Vivo) Murine Blasenmodell mit dem Detrusormuskel entfernt für direkten Zugang zum Suburothelium während der Blasenfüllung

Previous studies have established the release of chemical substances from flat bladder mucosa sheets affixed in Ussing chambers and exposed to changes in ...

Cystometric and External Urethral Sphincter Measurements in Awake Rats with Implanted Catheter and Electrodes Allowing for Repeated Measurements

Lower urinary tract function is mainly assessed by means of cystometric bladder function analysis in rodents. Conventional cystometries are usually performed as terminal analysis under urethane anesthesia. It is well known that anesthetic drugs can influence bladder function. Hence, the aim of this technique is to perform cystometric measurements of the urinary bladder and external urethral sphincter in lightly restrained awake rats. For this purpose, a bladder catheter is implanted into the bladder dome. Subsequently, two electrodes are implanted bilateral to the external urethral sphincter and a ground electrode is sutured to a non-responsive skeletal muscle. The bladder catheter and the three electrodes are finally tunneled subcutaneously to the neck region and affixed to a harness. With this technique, the lower urinary tract can be measured at multiple time points in the same animal to assess lower urinary tract function. The main application of this technique is the follow-up of simultaneous urinary bladder and external urethral sphincter function in awake healthy rats and after induction of a disease or injury. Moreover, subsequent lower urinary tract monitoring can be performed during evaluation of the disease/injury and to monitor treatment efficacy.

This protocol first describes the surgical procedure of the permanent implantation of a urinary bladder catheter combined with external urethral sphincter electrodes, and second, the measurement of the function of the urinary bladder and external urethral sphincter in implanted awake animals.

Zystometrischen und externen urethralen Sphincter Messungen in wach Ratten mit implantierten Katheter und Elektroden für wiederholte Messungen

Lower urinary tract function is mainly assessed by means of cystometric bladder function analysis in rodents. Conventional cystometries are usually ...

Biologie

Urethral Stricture Induction Followed by Buccal Mucosa Graft Urethroplasty in a Rat Model

Urethral reconstruction is an important area of expertise for urologists. The buccal mucosa is considered the best option when urethral grafting is necessary, although in some cases, it is inappropriate or needs to be optimized to repair a given stricture. Therefore, developing innovative procedures and evaluating their putative success in experimental models is crucial to fit the clinical need. With this goal, this study describes a protocol in which urethral stricture was induced by electrocautery in Wistar rats. Urethral reconstruction was performed 1 week later with a buccal mucosa graft, harvested from the lower lip, and placed in a ventral onlay fashion. A retrograde urethrogram showed a significant improvement in urethral diameter after urethroplasty compared to the respective value after stricture induction. Additionally, the graft placement was assessed by blood perfusion analysis using laser Doppler. As expected, a dark blue area corresponded to the non-vascularized buccal mucosa graft. This procedure can successfully simulate the normal pathophysiological process of urethral injury and tissue modulation, as well as urethral reconstruction using a buccal mucosa graft in a reproducible manner, and serve as the basis for future research based on tissue engineering or urethral grafts.

In the present protocol, a urethral stricture induction was developed in Wistar rats, followed by urethral reconstruction with a buccal mucosa graft. A retrograde urethrogram and laser Doppler assessment were performed, validating urethral reconstruction (after stricture formation) and graft placement.

Induktion einer Harnröhrenstriktur mit anschließender Urethroplastik der Wangenschleimhauttransplantation im Rattenmodell

Urethral reconstruction is an important area of expertise for urologists. The buccal mucosa is considered the best option when urethral grafting is ...

Efficient Rat Model for Urethral Stricture: Electric Knife Method

Iatrogenic Injury Recapitulated: Electroexcision Technique for Urethral Stricture Modeling in Rats

Urethral stricture (US) is a common clinical condition in urology, characterized by high prevalence and morbidity across all ages. Current treatments for US, such as urethral dilatation and internal urethrotomy, fail to fully resolve the condition and are associated with high rates of recurrence and complications. 
Additionally, the pathogenesis of US is not well understood. To explore the pathogenesis of US and develop new therapeutic strategies, it is crucial to establish a standardized rat model that accurately reflects the clinical manifestations. This study outlines a straightforward and repeatable method for inducing US in rats using a high-frequency electric knife. The method involves making a longitudinal incision with the electric knife set to a unipolar mixed cutting mode at 4 W, which inflicts significant urethral damage. Histopathological analysis shows thickening of the urothelium, inflammatory infiltration, and disorganized collagen fibers. This model effectively replicates iatrogenic injury through electroexcision in the rat urethra. In summary, this study successfully establishes a new, efficient, and stable rat model of US that closely mimics the clinical scenario, providing a valuable tool for further research into the mechanisms and novel treatments for US.

In this study, we present a novel, efficient, and stable rat model of urethral stricture created through electroexcision of the rat urethra, which effectively simulates iatrogenic injury observed in clinical settings.

Urethral stricture (US) is a common clinical condition in urology, characterized by high prevalence and morbidity across all ages. Current treatments for ...