Special thanks to the Gidday lab for their work in developing the RHP protocol, as well as the Neuro-Models Facility (UTSW) for their assistance in the tMCAo surgeries. This work was supported by grants from the American Heart Association (AMS), The Haggerty Center for Brain Injury and Repair (UTSW; AMS), and The Spastic Paralysis Research Foundation of the Illinois-Eastern Iowa District of Kiwanis International (JMG).

The authors have nothing to disclose.

Eine einmalige Exposition, um systemische Hypoxie (dh 2 Stunden von 11% O 2) bei Mäusen &quot;transient&quot; schützt das Gehirn vor tMCAo, 29 bedeutet, die epigenetische Antwort auf die hypoxische Präkonditionierung Herausforderung ist von kurzer Dauer, und die Grundlinie Phänotyp innerhalb restauriert Tagen. Repetitive Präsentationen des hypoxischen Präkonditionierung Reiz dramatisch verlängern die Dauer der neuroprotektiven Phänotyp. 6 Viele Studien haben gezeigt, das...

Als die führende Ursache für Invalidität bei Erwachsenen und die vierte führende Ursache des Todes ist der Schlaganfall eine der am stärksten beeinträchtigenden Krankheitszuständen vor der erwachsenen Bevölkerung der Vereinigten Staaten. 1 Tiermodellen von Schlaganfall ermöglichen experimentelle Erforschung neuer Methoden zur Reduzierung ischämischer Verletzung und Verbesserung der post-Wiederherstellung nach Schlaganfall. Ein neuartiger Weg für solche translationale Forschung ist Präkonditionierung. Vorkonditionierung ist die vorsätzliche Verwendung eines nicht-schädigenden Stimulus, um Schäden durch eine nachfolgende, und schwerer, Verletzungen zu vermeiden. 2 hypoxische Präkonditionierung hat sich gezeigt, pleiotrope Veränderungen im Gehirn, die Schutz vor Schlaganfall in vivo und in vitro Studien in produzieren . 3 jedoch eine einzige Forderung zu Hypoxie bietet nur kurzfristige Neuroprotektion, induzieren weniger als 72 Stunden von Toleranz gegenüber Ischämie in erwachsenen Mäusen. 4 Auch nach vier Wochen 14 Stunden tägliche Exposition bis hypobaren Hypoxie, Lin et al. found dass die Neuroprotektion wurde nur für eine Woche. 5 Repetitive hypoxischen Präkonditionierung (RHP) aufrechterhalten wird durch stochastische Schwankungen der Häufigkeit, Dauer und Intensität der hypoxischen Exposition aus. Im Gegensatz zu einem einzigen Präkonditionierung Herausforderung, RHP induziert eine cerebroprotektive Phänotyp, für bis zu 8 Wochen bei Mäusen. 6 RHP reduzierte Infarktvolumen, Blut-Hirn-Schranke (BHS) Störungen, Gefäßentzündung, und Leukozyten Diapedese für Wochen nach der letzten hypoxischen Exposition . RHP spezifisch verringert Entzündungen im ischämischen Gehirn durch Reduzieren T-Zelle, Monozyt und Makrophage-Populationen, und gleichzeitig B-Zellpopulationen in der ischämischen Hemisphäre. 7 Tatsächlich induzierte RHP immunsuppressiv Phänotyp bei Mäusen vor einer ZNS-Verletzung, einschließlich Schlaganfall. RHP-behandelten B-Zellen aus RHP-behandelten gesunden Mäusen isoliert zeigte eine einzigartige entzündungshemmende Phänotyp, mit einer Herabregulation der beiden Antigen-Präsentation und Antikörperproduktion. DieGesamtreduzierung der proinflammatorischen adaptiven Immunmechanismen macht RHP eine hervorragende Methode, um die endogene Immunsuppression nicht nur für ZNS-spezifische Entzündungserkrankungen zu induzieren, aber auch systemische Verletzungen oder Krankheitsmodelle, die eine pro-inflammatorischen Pathologie gehören. RHP reduziert sowohl Infarktvolumen und BBB Störung nach einer transienten mittleren Hirnarterie (tMCAo). Tiermodellen von Schlaganfall, wie die üblicherweise verwendeten tMCAo, dramatisch verbessern das Verständnis der Pathophysiologie von Schlaganfall, sowie die Gestaltung effektiver Neurotherapie. Zuerst von Koizumi et al., 1986, 8 die tMCAo Verfahren ein weit verbreitetes Verfahren zur Induzierung von Schlaganfall bei Nagern und eine der bevorzugten Methoden zur Untersuchung von Entzündungen nach Reperfusion. Da die Methoden zur tMCAo entwickeln, die neuere Verwendung von silikonbeschichteten Filamente weiter zu reduzieren das Risiko einer Subarachnoidalblutung Vergleich zu anderen Modellen 9,10 &lt;/ Sup&gt; und die Zuverlässigkeit zu erhöhen, wenn auch leider tMCAo oft produziert eine breite Variation in der Infarktvolumen 11-13. Die meisten dieser Studien Abgrenzung Infarkt Regionen in koronalen Hirnschnitten durch Färbung mit 2,3,5- Triphenyltetrazoliumchlorid (TTC), als Gold-Standard für die Quantifizierung der Infarkt, weil es ist eine einfache und kostengünstige Möglichkeit, um lebendige, reproduzierbare Ergebnisse zu erzielen. TTC dient als Substrat in Mitochondrien Dehydrogenasen. Bei Gehirnschnitten sind dem TTC-Lösung ausgesetzt wird, wird TTC selektiv in lebende Zellen aufgenommen, wo ihre nichtlöslichen Reduktionsprodukt, Formazan- fällt auf eine tiefrote Farbe in lebensfähige Mitochondrien. Wegen mitochondriale Dysfunktion in der ischämischen Gewebe bleibt diese Gewebe weiß, so dass für die Differenzierung von beschädigten und gesundem Gewebe. 14 RHP reduziert auch BBB Störung in der ischämischen Hemisphäre. 6 daher den doppelten Quantifizierung BBB Integrität innerhalb der gleichen bRegenfälle als TTC-basierte Infarktvolumen Bestimmungen 15 würde nützliche Informationen über die volle Wirksamkeit der körpereigenen Schutz und mögliche kausale Beziehungen zwischen BBB Störung und Infarkt in unbehandelten und behandelten Tieren zu schaffen. Der Zustrom von peripheren Blut durch einen gestörten BBB, sekundäre Schlaganfall, erhöht Leukozyten-Populationen, proinflammatorische Zytokine, oxidativer Stress, vasogenen Ödeme und hämorrhagischen Transformation in der ischämischen Hemisphäre, letztlich die Erhöhung der Infektionsraten und Mortalität bei Patienten mit ischämischem Schlaganfall . 16,17 Ein übliches Verfahren zur Messung der BBB Störungen in Tiermodellen ist durch Quantifizierung von Evans-Blau (EB) Farbstoff Leck in das Gehirn. 15,18-21 EB selektiv an Albumin, eine globuläre Proteinserum (MW = 65 kDa) das bedeutet nicht die BBB nicht überqueren in unverletzten Tiere 22. Nach ischämischen Schlaganfall, infiltriert EB das Gehirn, und fluoresziert bei 620 nm, so dass für die Messung der optischen Dichte within perfundierten verletzt Parenchym. 22. Die optische Dichte ist direkt proportional zu der Permeabilität der BBB bei EB aus der Post-mortem kortikalen Vaskulatur von transcardiac Perfusion gewaschen. Mit der unmittelbaren Bearbeitung der TTC-gefärbten Gehirn bei Tieren mit EB Applikation können sowohl die Infarktvolumen und BBB Störung effektiv quantifiziert werden. Es sollte jedoch angemerkt werden, dass neuronale Schädigung und BBB Störung nicht gleichzeitige Prozesse in der post stroke Gehirn, 23,24, so dass die Auswahl der Tötungszeitpunkt ist ein wichtiger Gesichtspunkt. Das folgende Protokoll beschreibt die RHP-Methode, die tMCAo Verfahren zur Induktion einer vorübergehenden Arterienverschluss, dass Modelle mittleren Hirnarterie Verschlüssen bei menschlichen Patienten, und die Dual histologischen Methoden zur Bestimmung der neuronalen und vaskulären Schlaganfall Verletzungen Endpunkte. TTC misst Zelltod und kumulative Gewebeschädigung, so dass für die Quantifizierung eines Gesamtinfarkt volume, während EB sieht die hemisphärische Quantifizierung BBB Schäden.

<table border="0" cellpadding="0" cellspacing="0" width="830">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:249px;">Material/ Equipment</td>
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			<td style="width:283px;">Comments/Description</td>
		</tr>
		<tr height="220">
			<td height="220" style="height:220px;width:249px;">Flowmeters, regulators</td>
			<td style="width:171px;">VetEquip, Inc</td>
			<td style="width:127px;">Specialty order</td>
			<td style="width:283px;">Four flowmeters are attached to 6.0 mm flexible PVC tubing which connects to the inlet port on each induction chamber with a plastic female connector. These flowmeters are bolted to a 6.5&#34; x 1&#34; x 1&#34; metal bar. This metal bar is bolted to a MI-246-P pressure gauge with a DISS outlet. This pressure gauge and flowmeter equipment can be attached to each new gas cylinder with a wrench.</td>
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		<tr height="26">
			<td height="26" style="height:26px;width:249px;">21% O2 tank</td>
			<td style="width:171px;">AirGas</td>
			<td style="width:127px;">OX USP200</td>
			<td style="width:283px;"></td>
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		<tr height="26">
			<td height="26" style="height:26px;width:249px;">11% O2 tank</td>
			<td style="width:171px;">AirGas</td>
			<td style="width:127px;">Specialty order</td>
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			<td height="26" style="height:26px;width:249px;">8% O2 tank&#160;</td>
			<td style="width:171px;">AirGas</td>
			<td style="width:127px;">Specialty order</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">15L induction chambers</td>
			<td style="width:171px;">VetEquip</td>
			<td style="width:127px;">941454</td>
			<td style="width:283px;"></td>
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			<td height="40" style="height:40px;width:249px;">Moor Laber Dopper Flow&#160;</td>
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			<td style="width:127px;">moorVMS-LDF1-HP</td>
			<td style="width:283px;">0.8mm diameter probe&#160;</td>
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			<td height="20" style="height:20px;width:249px;">High Intensity Illuminator&#160;</td>
			<td style="width:171px;">Nikon</td>
			<td style="width:127px;">NI-150</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">Zoom Stereo Microscope&#160;</td>
			<td style="width:171px;">NIkon</td>
			<td style="width:127px;">SMZ800</td>
			<td style="width:283px;">Other surgical microscopes may be used.&#160;</td>
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		<tr height="100">
			<td height="100" style="height:100px;width:249px;">Kent Scientific Right Temperature CODA</td>
			<td style="width:171px;">Kent Scientific Corporation</td>
			<td style="width:127px;">Discontinued</td>
			<td style="width:283px;">Recommended replacement is PhysioSuite with RightTemp Temperature Monitoring and Homeothermic Control (Kent Scientific, #PS-RT).</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:249px;">Hovabator Incubator</td>
			<td style="width:171px;">Stromberg&#39;s</td>
			<td style="width:127px;">2362-E</td>
			<td style="width:283px;">Our model is the 2362N. 2362E is a later model and includes an electronic thermostat.&#160;</td>
		</tr>
		<tr height="120">
			<td height="120" style="height:120px;width:249px;">V010 Anesthesia system&#160;</td>
			<td style="width:171px;">VetEquip</td>
			<td style="width:127px;">901807</td>
			<td style="width:283px;">Includes: ten foot high-pressure oxygen hose, frame, flowmeter, oxygen flush assembly, vaporizer, breathing circuit, chamber, nosecones, waste gas evacuation tubing and two VapoGuard filters</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">250 mL isoflurane&#160;</td>
			<td style="width:171px;">Butler Schein</td>
			<td style="width:127px;">NDC-11695</td>
			<td style="width:283px;"></td>
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			<td height="40" style="height:40px;width:249px;">D-6 Vet Trim Animal Cordless Trimmer&#160;</td>
			<td style="width:171px;">Andis&#160;</td>
			<td style="width:127px;">#23905</td>
			<td style="width:283px;">Replacement blades are available from Andis (#23995)</td>
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			<td height="20" style="height:20px;width:249px;">Betadine&#160;</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">19-898-867&#160;</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">Q-tips</td>
			<td style="width:171px;">Multiple sellers&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;"></td>
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			<td height="20" style="height:20px;width:249px;">Gauze Pads</td>
			<td style="width:171px;">Fisher Scientific</td>
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			<td style="width:283px;"></td>
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			<td height="20" style="height:20px;width:249px;">Surgical drape</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">GM300&#160;</td>
			<td style="width:283px;"></td>
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			<td height="40" style="height:40px;width:249px;">Silk Sutures&#160;</td>
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			<td style="width:127px;">SP115</td>
			<td style="width:283px;"></td>
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			<td height="40" style="height:40px;width:249px;">Nylon Sutures</td>
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			<td height="20" style="height:20px;width:249px;">Durmont #5 forceps (2)&#160;</td>
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			<td height="20" style="height:20px;width:249px;">Surgical Scissors</td>
			<td style="width:171px;">Fine Science Tools&#160;</td>
			<td style="width:127px;">14028-10</td>
			<td style="width:283px;"></td>
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			<td height="40" style="height:40px;width:249px;">3mm Vannas</td>
			<td style="width:171px;">Kent Scientific Corporation</td>
			<td style="width:127px;">INS600177</td>
			<td style="width:283px;">Straight blade</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Hartman Hemostats&#160;</td>
			<td style="width:171px;">Fine Scientific Tools</td>
			<td style="width:127px;">13002-10</td>
			<td style="width:283px;"></td>
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			<td height="60" style="height:60px;width:249px;">Occluding filaments</td>
			<td style="width:171px;">Washington University</td>
			<td style="width:127px;">Specialty order</td>
			<td style="width:283px;">Filaments are silicone coated at Washington Univeristy and provided to UTSW facilities for a fee.&#160;</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Evans Blue</td>
			<td style="width:171px;">Sigma Aldritch</td>
			<td style="width:127px;">E2129-10G</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Filter Paper&#160;</td>
			<td style="width:171px;">Sigma Aldritch</td>
			<td style="width:127px;">WHA1001150</td>
			<td style="width:283px;">150 mm, circles, Grade 1&#160;</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Weigh Boats</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">02-202-101</td>
			<td style="width:283px;">2.5&#34; diameter</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:249px;">0.9% Sodium Chloride Injection USP&#160;</td>
			<td style="width:171px;">Baxter Pharmaceutics&#160;</td>
			<td style="width:127px;">2B1321</td>
			<td style="width:283px;"></td>
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			<td style="width:171px;">Becton Dickinson Labware</td>
			<td style="width:127px;">309301</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Flat bottom restrainer&#160;</td>
			<td style="width:171px;">Braintree Scientific&#160;</td>
			<td style="width:127px;">FB&#160;M</td>
			<td style="width:283px;">2.0&#34; diameter</td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">TTC</td>
			<td style="width:171px;">Sigma</td>
			<td style="width:127px;">T8877</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">10X PBS, pH 7.4</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">BP399-20</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="80">
			<td height="80" style="height:80px;width:249px;">Water Bath</td>
			<td style="width:171px;">Multiple sellers&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;">Scintillation tubes with TTC may be manually held under running warm water as an alternative to the water bath.</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:249px;">Styrofoam board</td>
			<td style="width:171px;">Multiple sellers&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Large Syringe Kit</td>
			<td style="width:171px;">PumpSystems Inc</td>
			<td style="width:127px;">P-SYRKIT-LG</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Perfusion Pump</td>
			<td style="width:171px;">PumpSystems Inc</td>
			<td style="width:127px;">NE-300&#160;</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">60 cc syringe</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">NC9203256</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:249px;">27g winged infusion set</td>
			<td style="width:171px;">Kawasumi Laboratories, Inc</td>
			<td style="width:127px;">D3K1-25G 1</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">20 ml scintillation vial</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">50-367-126</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Stainless steel spatula</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">14-373-25A</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:249px;">Alto acrylic 1.0 mm mouse brain, coronal</td>
			<td style="width:171px;">CellPoint Scientific&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:249px;">0.21 mm stainless steel blades, 25 pk</td>
			<td style="width:171px;">CellPoint Scientific&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;">Reusable cryostat blades are an inexpensive alternative.</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">4% paraformaldehyde</td>
			<td style="width:171px;">Santa Cruz Biotechnology&#160;</td>
			<td style="width:127px;">SC-281692</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Superfrost microscope slides&#160;</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">12-550-15</td>
			<td style="width:283px;"></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">HP Scanjet G4050</td>
			<td style="width:171px;">Multiple sellers&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;">Other commercial scanners are suitable for this step in the protocol.</td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">ImageJ&#160;</td>
			<td style="width:171px;">National Institute of Health</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Analytical Balance</td>
			<td style="width:171px;">Mettler Toledo&#160;</td>
			<td style="width:127px;">XSE 205U</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Precision Compact Oven&#160;&#160;</td>
			<td style="width:171px;">Thermo Scientific&#160;</td>
			<td style="width:127px;">PR305225M</td>
			<td style="width:283px;"></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">1.7 mL microcentrifuge tubes (Eppendorfs)</td>
			<td style="width:171px;">Denville Scientific&#160;</td>
			<td style="width:127px;">C2170</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">Formamide</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">BP228-100</td>
			<td style="width:283px;"></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:249px;">96-well plates</td>
			<td style="width:171px;">Fisher Scientific</td>
			<td style="width:127px;">07-200-9</td>
			<td style="width:283px;"></td>
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		<tr height="40">
			<td height="40" style="height:40px;width:249px;">Epoch Microplate Spectrophotometer&#160;</td>
			<td style="width:171px;">BioTek&#160;</td>
			<td style="width:127px;">Catalog number not available&#160;</td>
			<td style="width:283px;"></td>
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quantification of neurovascular protection following repetitive hypoxic preconditioning and transient middle cerebral artery occlusion in mice

Experimentellen Tiermodellen von Schlaganfall sind wertvolle Werkzeuge für das Verständnis Schlaganfall Pathologie und Entwicklung wirksamerer Behandlungsstrategien. A 2 Wochen Protokoll für sich wiederholende hypoxischen Präkonditionierung (RHP) induziert langfristigen Schutz gegen das zentrale Nervensystem (ZNS) verletzt in einem Mausmodell der fokalen ischämischen Schlaganfall. RHP besteht aus 9 stochastischen Belichtungen auf Hypoxie, die sowohl in der Zeitdauer (2 bzw. 4 h) und die Intensität (8% und 11% O 2) zu variieren. RHP reduziert Infarktvolumen, Blut-Hirn-Schranke (BHS) Störung, und die nach einem Schlaganfall entzündliche Reaktion für Wochen nach dem letzten Auftreten von Hypoxie, was auf eine langfristige Induktion einer endogenen ZNS-Schutz Phänotyp. Die Methodik für die Dual-Quantifizierung der Infarktvolumen und BBB Störung wirksam ist bei der Beurteilung der neurovaskulären Schutz bei Mäusen mit RHP oder andere vermeintliche Neuroprotektoren. Erwachsene männliche Swiss Webster-Mäuse wurden durch RHP oder Dauer-äquivalenten Belichtungen auf 21% O vorkonditioniert <sub&gt; 2 (dh Raumluft). A 60 min transiente mittleren Hirnarterie (tMCAo) wurde 2 Wochen nach der letzten induzierten hypoxischen Exposition. Sowohl der Okklusion und Reperfusion wurden durch transkranielle Laser-Doppler-Flussmessung bestätigt. Zweiundzwanzig Stunden nach der Reperfusion, Evans Blue (EB) wurde intravenös durch eine Injektion in die Schwanzvene verabreicht. 2 Stunden später wurden die Tiere mit Isofluran Dosierung und Gehirnschnitte geopfert wurden mit 2,3,5-Triphenyltetrazoliumchlorid (TTC) angefärbt. Infarkte Volumina wurden dann quantifiziert. Als nächstes wurde EB aus dem Gewebe über 48 Stunden extrahiert, um BBB-Störung nach tMCAo bestimmen. Zusammenfassend ist RHP ein einfaches Protokoll, repliziert werden kann, mit minimalen Kosten, um langfristige endogenen neurovaskulären Schutz vor Schlaganfall Verletzungen bei Mäusen zu induzieren, mit der Translationspotential anderen ZNS-basierte und systemische proinflammatorische Krankheitszuständen.

An dieser Studie nahmen 25 männliche Swiss Webster-Mäuse, die 10 Wochen alt waren zu Beginn der Randomisierung in RHP (n = 10) oder 21% O 2 (n = 15) Gruppen. Zwei Wochen nach der letzten RHP Belichtung wurden chirurgische Verfahren durchgeführt, wobei Gruppen verblindet und zwischen den Tagen ausgeglichen. Nach tMCAo starb 1 Maus während der postoperativen Erholung und 1 Maus wurde von der Studie ausgeschlossen, weil sie nicht die Reperfusion CBF Kriterium erfüllen. Beide Mäuse waren ausgeschlossen von ...

Watch this Scientific Journal Video about Quantification of Neurovascular Protection Following Repetitive Hypoxic Preconditioning and Transient Middle Cerebral Artery Occlusion in Mice at JoVE.com

Quantification of Neurovascular Protection Following Repetitive Hypoxic Preconditioning and Transient Middle Cerebral Artery Occlusion in Mice

This protocol describes repetitive hypoxic preconditioning, or brief exposures to systemic hypoxia that reduce infarct volumes and blood-brain barrier disruption following transient middle cerebral artery occlusion in mice. It also details dual quantification of infarct volume and blood-brain barrier disruption after stroke to assess the efficacy of neurovascular protection.

Die Quantifizierung der neurovaskulären Schutz Nach Repetitive hypoxische Präkonditionierung und Transient mittleren Hirnarterie Occlusion in Mice

Experimental animal models of stroke are invaluable tools for understanding stroke pathology and developing more effective treatment strategies. A 2 week ...

quantification-neurovascular-protection-following-repetitive-hypoxic

Research

JoVE Journal

Medicine

13.6K Aufrufe.  University of Texas Southwestern Medical Center. This protocol describes repetitive hypoxic preconditioning, or brief exposures to systemic hypoxia that reduce infarct volumes and blood-brain barrier disruption following transient middle cerebral artery occlusion in mice. It also details dual quantification of infarct volume and blood-brain barrier disruption after stroke to assess the efficacy of neurovascular protection.

Serie: Quantification of Neurovascular Protection Following Repetitive Hypoxic Preconditioning and Transient Middle Cerebral Artery Occlusion in Mice

Modeling Stroke in Mice - Middle Cerebral Artery Occlusion with the Filament Model

Stroke is among the most frequent causes of death and adult disability, especially in highly developed countries. However, treatment options to date are very limited. To meet the need for novel therapeutic approaches, experimental stroke research frequently employs rodent models of focal cerebral ischaemia. Most researchers use permanent or transient occlusion of the middle cerebral artery (MCA) in mice or rats.
Proximal occlusion of the middle cerebral artery (MCA) via the intraluminal suture technique (so called filament or suture model) is probably the most frequently used model in experimental stroke research. The intraluminal MCAO model offers the advantage of inducing reproducible transient or permanent ischaemia of the MCA territory in a relatively non-invasive manner. Intraluminal approaches interrupt the blood flow of the entire territory of this artery. Filament occlusion thus arrests flow proximal to the lenticulo-striate arteries, which supply the basal ganglia. Filament occlusion of the MCA results in reproducible lesions in the cortex and striatum and can be either permanent or transient. In contrast, models inducing distal (to the branching of the lenticulo-striate arteries) MCA occlusion typically spare the striatum and primarily involve the neocortex. In addition these models do require craniectomy. In the model demonstrated in this article, a silicon coated filament is introduced into the common carotid artery and advanced along the internal carotid artery into the Circle of Willis, where it blocks the origin of the middle cerebral artery. In patients, occlusions of the middle cerebral artery are among the most common causes of ischaemic stroke. Since varying ischemic intervals can be chosen freely in this model depending on the time point of reperfusion, ischaemic lesions with varying degrees of severity can be produced. Reperfusion by removal of the occluding filament at least partially models the restoration of blood flow after spontaneous or therapeutic (tPA) lysis of a thromboembolic clot in humans.
In this video we will present the basic technique as well as the major pitfalls and confounders which may limit the predictive value of this model.

Filamentous occlusion of the Middle cerebral artery is a common model for studying ischemic stroke in mice.

Modeling Stroke in Mice - Middle Zerebralarterie mit dem Filament-Modell

Stroke is among the most frequent causes of death and adult disability, especially in highly developed countries. However, treatment options to date are ...

Forschung

Medizin

Mouse Model of Middle Cerebral Artery Occlusion

Stroke is the most common fatal neurological disease in the United States 1. The majority of strokes (88%) result from blockage of blood vessels in the brain (ischemic stroke) 2. Since most ischemic strokes (~80%) occur in the territory of middle cerebral artery (MCA) 3, many animal stroke models that have been developed have focused on this artery. The intraluminal monofilament model of middle cerebral artery occlusion (MCAO) involves the insertion of a surgical filament into the external carotid artery and threading it forward into the internal carotid artery (ICA) until the tip occludes the origin of the MCA, resulting in a cessation of blood flow and subsequent brain infarction in the MCA territory 4. The technique can be used to model permanent or transient occlusion 5. If the suture is removed after a certain interval (30 min, 1 h, or 2 h), reperfusion is achieved (transient MCAO); if the filament is left in place (24 h) the procedure is suitable as a model of permanent MCAO. This technique does not require craniectomy, a neurosurgical procedure to remove a portion of skull, which may affect intracranial pressure and temperature 6. It has become the most frequently used method to mimic permanent and transient focal cerebral ischemia in rats and mice 7,8. To evaluate the extent of cerebral infarction, we stain brain slices with 2,3,5-triphenyltetrazolium chloride (TTC) to identify ischemic brain tissue 9. In this video, we demonstrate the MCAO method and the determination of infarct size by TTC staining.

We demonstrate in the video a method for producing a middle cerebral artery occlusion in adult mice using an intraluminal monofilament. We also show how to evaluate the extent of cerebral infarction by 2,3,5-triphenyltetrazolium chloride (TTC) staining.

Mouse Model of Middle Zerebralarterie

Stroke is the most common fatal neurological disease in the United States 1. The majority of strokes (88%) result from blockage of blood vessels in the ...

Intraluminal Middle Cerebral Artery Occlusion (MCAO) Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice

Stroke is the third leading cause of death and the leading cause of disability in the world, with an estimated cost of near $70 billion 
in the United States in 20091,2. The intraluminal middle cerebral artery occlusion (MCAO) model was developed by Koizumi4 in 1986 to simulate this 
impactful human pathology in the rat. A modification of the MCAO method was later presented by Longa3. Both techniques have been widely used to identify 
molecular mechanisms of brain injury resulting from ischemic stroke and potential therapeutic modalities5. This relatively noninvasive method in rats has been 
extended to use in mice to take advantage of transgenic and knockout strains6,7. To model focal cerebral ischemia, an intraluminal suture is advanced via 
the internal carotid artery to occlude the base of the MCA. Retracting the suture after a specified period of time mimics spontaneous reperfusion, but the 
suture can also be permanently retained. This video will be demonstrating the two major approaches for performing intraluminal MCAO procedure in mice in a 
stepwise fashion, as well as providing insights for potential drawbacks and pitfalls. The ischemic brain tissue will subsequently be stained by 
2,3,5-triphenyltetrazolium chloride (TTC) to evaluate the extent of cerebral infarction8.

Intraluminal Middle Cerebral Artery Occlusion MCAO Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Mice

The intraluminal middle cerebral artery occlusion (MCAO) model is the most frequent used model among experimental ischemic stroke models. Here we will demonstrate the entire model in detail with the guide of Laser Doppler flowmetry, and its representative results.

Intraluminale Nahen Zerebralarterie (MCAO) Modell des ischämischen Schlaganfalls mit Laser-Doppler-Flussmessung Guidance in Mäuse

Stroke is the third leading cause of death and the leading cause of disability in the world, with an estimated cost of near $70 billion 
in the United ...

Endothelin-1 Induced Middle Cerebral Artery Occlusion Model for Ischemic Stroke with Laser Doppler Flowmetry Guidance in Rat

Stroke is the number one cause of disability and third leading cause of death in the world, costing an estimated $70 billion in the United States in 20091, 2. Several models of cerebral ischemia have been developed to mimic the human condition of stroke. It has been suggested that up to 80% of all strokes result from ischemic damage in the middle cerebral artery (MCA) area3. In the early 1990s, endothelin-1 (ET-1) 4 was used to induce ischemia by applying it directly adjacent to the surface of the MCA after craniotomy. Later, this model was modified 5 by using a stereotaxic injection of ET-1 adjacent to the MCA to produce focal cerebral ischemia. The main advantages of this model include the ability to perform the procedure quickly, the ability to control artery constriction by altering the dose of ET-1 delivered, no need to manipulate the extracranial vessels supplying blood to the brain as well as gradual reperfusion rates that more closely mimics the reperfusion in humans5-7. On the other hand, the ET-1 model has disadvantages that include the need for a craniotomy, as well as higher variability in stroke volume8. This variability can be reduced with the use of laser Doppler flowmetry (LDF) to verify cerebral ischemia during ET-1 infusion. Factors that affect stroke variability include precision of infusion and the batch of the ET-1 used6. Another important consideration is that although reperfusion is a common occurrence in human stroke, the duration of occlusion for ET-1 induced MCAO may not closely mimic that of human stroke where many patients have partial reperfusion over a period of hours to days following occlusion9, 10. This protocol will describe in detail the ET-1 induced MCAO model for ischemic stroke in rats. It will also draw attention to special considerations and potential drawbacks throughout the procedure.

Several animal models of cerebral ischemia have been developed to simulate the human condition of stroke. This protocol describes the endothelin-1 (ET-1) induced middle cerebral artery occlusion (MCAO) model for ischemic stroke in rats. In addition, important considerations, advantages, and shortcomings of this model are discussed.

Endothelin-1 induzierte Middle Cerebral Artery Occlusion Modell für ischämischen Schlaganfall mit Laser Doppler Flowmetrie Guidance in Rat

Stroke is the number one cause of disability and third leading cause of death in the world, costing an estimated $70 billion in the United States in ...

Utilizing a Cranial Window to Visualize the Middle Cerebral Artery During Endothelin-1 Induced Middle Cerebral Artery Occlusion

Creation of a cranial window is a method that allows direct visualization of structures on the cortical surface of the brain1-3. This technique can be performed in many locations overlying the rat cerebrum, but is most easily carried out by creating a craniectomy over the readily accessible frontal or parietal bones. Most frequently, we have used this technique in combination with the endothelin-1 middle cerebral artery occlusion model of ischemic stroke to quantify the changes in middle cerebral artery vessel diameter that occur with injection of endothelin-1 into the brain parenchyma adjacent to the proximal MCA4, 5. In order to visualize the proximal portion of the MCA during endothelin -1 induced MCAO, we use a technique to create a cranial window through the temporal bone on the lateral aspect of the rat skull (Figure 1). Cerebral arteries can be visualized either with the dura intact or with the dura incised and retracted. Most commonly, we leave the dura intact during visualization since endothelin-1 induced MCAO involves delivery of the vasoconstricting peptide into the brain parenchyma. This bypasses the need to incise the dura directly over the visualized vessels for drug delivery. This protocol will describe how to create a cranial window to visualize cerebral arteries in a step-wise fashion, as well as how to avoid many of the potential pitfalls pertaining to this method.

This article describes a method for visualizing rat cerebral arteries through a cranial window using temporal craniectomy in order to view proximal portions of the middle cerebral artery (Figure 1). This versatile method can be combined with various techniques of drug delivery to measure cerebral artery reactivity in vivo.

Mit Hilfe eines Cranial Fenster, um den Nahen Cerebral Artery Während Endothelin-1 induzierte Middle Cerebral Artery Occlusion Visualisieren

Creation of a cranial window is a method that allows direct visualization of structures on the cortical surface of the brain1-3. This technique can be ...

Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal models of acute ischemic stroke allows to confirm successful arterial occlusion and exclude subarachnoid hemorrhage. Cerebral perfusion monitoring can also be used to study intracranial collateral circulation, which is emerging as a powerful determinant of stroke outcome and a possible therapeutic target. Despite a recognized role of Laser Doppler perfusion monitoring as part of the current guidelines for experimental cerebral ischemia, a number of technical difficulties exist that limit its widespread use. One of the major issues is obtaining a secure and prolonged attachment of a deep-penetration Laser Doppler probe to the animal skull. In this video, we show our optimized system for cerebral perfusion monitoring during transient middle cerebral artery occlusion by intraluminal filament in the rat. We developed in-house a simple method to obtain a custom made holder for twin-fibre (deep-penetration) Laser Doppler probes, which allow multi-site monitoring if needed. A continuous and prolonged monitoring of cerebral perfusion could easily be obtained over the intact skull.

Cerebral perfusion monitoring has been demonstrated to improve accuracy in ischemic stroke models. Technical difficulties often limit the use of this essential tool for cerebrovascular research. In this video, an optimized system is shown to obtain a single or multi-site hemodynamic monitoring during intraluminal middle cerebral artery occlusion in rats.

Optimierte System for Cerebral Perfusion Überwachung im Rat Stroke Modell Intraluminal Middle Cerebral Artery Occlusion

The translational potential of pre-clinical stroke research depends on the accuracy of experimental modeling. Cerebral perfusion monitoring in animal ...

Modeling Stroke in Mice: Permanent Coagulation of the Distal Middle Cerebral Artery

Stroke is the third most common cause of death and a main cause of acquired adult disability in developed countries. Only very limited therapeutical options are available for a small proportion of stroke patients in the acute phase. Current research is intensively searching for novel therapeutic strategies and is increasingly focusing on the sub-acute and chronic phase after stroke because more patients might be eligible for therapeutic interventions in a prolonged time window. These delayed mechanisms include important pathophysiological pathways such as post-stroke inflammation, angiogenesis, neuronal plasticity and regeneration. In order to analyze these mechanisms and to subsequently evaluate novel drug targets, experimental stroke models with clinical relevance, low mortality and high reproducibility are sought after. Moreover, mice are the smallest mammals in which a focal stroke lesion can be induced and for which a broad spectrum of transgenic models are available. Therefore, we describe here the mouse model of transcranial, permanent coagulation of the middle cerebral artery via electrocoagulation distal of the lenticulostriatal arteries, the so-called &#8220;coagulation model&#8221;. The resulting infarct in this model is located mainly in the cortex; the relative infarct volume in relation to brain size corresponds to the majority of human strokes. Moreover, the model fulfills the above-mentioned criteria of reproducibility and low mortality. In this video we demonstrate the surgical methods of stroke induction in the &#8220;coagulation model&#8221; and report histological and functional analysis tools.

Various murine models of middle cerebral artery occlusion (MCAO) are widely used in experimental brain research. Here, we demonstrate the model of transcranial permanent distal MCAO which produces consistent cortical infarction of a size corresponding to damage imposed by the majority of human ischemic strokes.

Modellierung Schlaganfall bei Mäusen: Permanent Koagulation der distalen A. cerebri media

Stroke is the third most common cause of death and a main cause of acquired adult disability in developed countries. Only very limited therapeutical ...

Embolic Middle Cerebral Artery Occlusion (MCAO) for Ischemic Stroke with Homologous Blood Clots in Rats

Clinically, thrombolytic therapy with use of recombinant tissue plasminogen activator (tPA) remains the most effective treatment for acute ischemic stroke. However, the use of tPA is limited by its narrow therapeutic window and by increased risk of hemorrhagic transformation. There is an urgent need to develop suitable stroke models to study new thrombolytic agents and strategies for treatment of ischemic stroke. At present, two major types of ischemic stroke models have been developed in rats and mice: intraluminal suture MCAO and embolic MCAO. Although MCAO models via the intraluminal suture technique have been widely used in mechanism-driven stroke research, these suture models do not mimic the clinical situation and are not suitable for thrombolytic studies. Among these models, the embolic MCAO model closely mimics human ischemic stroke and is suitable for preclinical investigation of thrombolytic therapy. This embolic model was first developed in rats by Overgaard et al.1 in 1992 and further characterized by Zhang et al. in 19972. Although embolic MCAO has gained increasing attention, there are technical problems faced by many laboratories. To meet increasing needs for thrombolytic research, we present a highly reproducible model of embolic MCAO in the rat, which can develop a predictable infarct volume within the MCA territory. In brief, a modified PE-50 tube is gently advanced from the external carotid artery (ECA) into the lumen of the internal carotid artery (ICA) until the tip of the catheter reaches the origin of the MCA. Through the catheter, a single homologous blood clot is placed at the origin of the MCA. To identify the success of MCA occlusion, regional cerebral blood flow was monitored, neurological deficits and infarct volumes were measured. The techniques presented in this paper should help investigators to overcome technical problems for establishing this model for stroke research.

Embolic Middle Cerebral Artery Occlusion MCAO for Ischemic Stroke with Homologous Blood Clots in Rats

In this paper, we demonstrate a standard method for producing an embolic middle cerebral artery occlusion with homologous blood clots (fibrin-rich) in adult rat. This model closely mimics human ischemic stroke and is suitable for preclinical study of thrombolytic therapy for ischemic stroke.

Embolischen mittleren Hirnarterie Okklusion (MCAO) für ischämischen Schlaganfall mit homologen Blutgerinnsel in Ratten

Clinically, thrombolytic therapy with use of recombinant tissue plasminogen activator (tPA) remains the most effective treatment for acute ischemic ...

Surgical Approach for Middle Cerebral Artery Occlusion and Reperfusion Induced Stroke in Mice

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ischemic in origin and occur in the territory of the middle cerebral artery (MCA). Currently the only Food and Drug Administration (FDA) approved drug for the treatment of this devastating disease is tissue plasminogen activator (tPA). However, tPA has a small therapeutic window for administration (3 - 6 hr), and is only effective in 4% of the patients who actually receive it. Current research focuses on understanding the pathophysiology of stroke in order to find potential therapeutic targets. Thus, reliable models are crucial, and the MCA occlusion (MCAo) model (also termed the intraluminal filament or suture model) is deemed to be the most clinically relevant surgical model of ischemic stroke, and is fairly non-invasive and easily reproducible. Typically the MCAo model is used with rodents, especially with mice due to all the genetic variations available for this species. Here we describe (and present in the video) how to successfully perform the MCAo model (with reperfusion) in mice to generate reliable and reproducible data.

In order to understand the pathophysiology of stroke, it is important to use reliable models. This paper will describe one of the most frequently used stroke models in mice, termed the middle cerebral artery occlusion (MCAo) model (also termed the intraluminal filament or suture model) with reperfusion.

Chirurgische Ansatz für Arteria cerebri media Occlusion und Reperfusion fokaler zerebraler Ischämie bei Mäusen

Stroke is a leading cause of death worldwide and continues to be one of the major causes of long-term adult disabilities. About 87% of strokes are ...

Transient Middle Cerebral Artery Occlusion Model of Neonatal Stroke in P10 Rats

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature and mature brain. Stroke occurs commonly in the perinatal period in humans, and transient ischemia-reperfusion is the most common form of stroke in neonates. The reperfusion phase is a critical component of injury progression, which occurs over a period of days to weeks, and of the endogenous response to injury. This postnatal day 10 (p10) rat model of transient middle cerebral artery occlusion (tMCAO) creates a unilateral, non-hemorrhagic focal ischemia-reperfusion injury that can be utilized to study the mechanisms of focal injury and repair in the full-term-equivalent brain. The injury pattern that is produced by tMCAO is consistent and highly reproducible and can be confirmed with MRI or histological analyses. The severity of injury can be manipulated through changes in occlusion time and other methods that will be discussed.

Neonatal stroke is a significant cause of early brain injury requiring a translational model with consistent focal injury patterns and high reproducibility in order to enable study. This study describes the detailed surgical procedure for creating a non-hemorrhagic, unilateral focal ischemia-reperfusion injury in full-term-equivalent rodents.

Transient Middle Cerebral Artery Occlusion Modell von Neugeborenen Stroke in P10 Ratten

A number of animal models have been used to study hypoxic-ischemic injury, traumatic injury, global hypoxia, or permanent ischemia in both the immature ...