This work was supported by the National Institutes of Health (NIH/NHLBI) [Grant no. HL114869] and the support from UTHSC to SM.

Etica dichiarazione: Tutte le procedure origine animale di cui in questo video-articolo è stato esaminato e approvato dal Comitato di cura e l&#39;uso di animali (IACUC) presso l&#39;Università del Tennessee Health Science Center. Nota: utilizzare gli strumenti di microchirurgia sterili durante tutta la procedura chirurgica. Gli strumenti chirurgici possono essere sterilizzati utilizzando uno sterilizzatore infrarossa ad una temperatura ottimale di sterilizzazione 1.500 ° F (815,6 ° C). Telemetri possono essere riutilizzati, tuttavia, prima di inserirla nell&#39;animale assicurarsi di sterilizzare l&#39;intero trasmettitore secondo le istruzioni del produttore e che la punta del catetere è stata riempita con un gel speciale fornito dal produttore. 1. Gli animali sperimentali <ol><li> Ottenere l&#39;approvazione IACUC per tutti gli esperimenti che verranno eseguite. La consultazione con IACUC istituzionale è altamente raccomandato per quanto riguarda i requisiti per l&#39;uso di analgesici post-operatorio dopo questa procedura. </li><li> Tenere gli animali in ccamere limate controllata aventi una temperatura ambiente di 21 ° C, 60% umidità relativa, e un ciclo luce-buio di 12 ore con libero accesso a cibo e acqua. Nota: Perché il corpo del mouse deve accogliere la sonda telemetria (approssimativamente 1 cm di diametro x 2 cm di lunghezza), è preferibile utilizzare i topi che pesano 20 grammi. </li></ol> 2. Anestesia e preparazione Operativo <ol><li> Pesare il mouse usando una bilancia di precisione e registrare il suo peso. Assicurati di gestire l&#39;animale dolcemente e silenziosamente. </li><li> Posto l&#39;animale nella camera di induzione e chiuderlo. Impostare la velocità del flusso di ossigeno a 0,5 L / min e impostare la concentrazione isoflurano al 4-5%. </li><li> Quando il mouse perde conoscenza, metterlo su un piatto corpo riscaldamento mantenuto a 36-37 ° C. Mantenere l&#39;anestesia tramite nosecone con set isoflurano al 2% (tenere a portata di 0,5 l / min). </li><li> Preparare le regioni di funzionamento rimuovendo i capelli dalla parte posteriore del collo e tegli faccia ventrale del collo mediante l&#39;applicazione di crema depilatoria. </li><li> Trattare il sito di incisione con 3 applicazioni di lavaggio chirurgico (soluzione betadine) in alternanza con il 70% di alcol isopropilico. </li></ol> 3. Chirurgia <ol><li> Posizionare il mouse in posizione supina. Verificare la presenza di riflessi pizzicare il piede, e regolare l&#39;anestesia fino a quando non vi è alcuna risposta. Effettuare un approssimativamente 1 cm incisione mediana sotto il collo del mouse con un bisturi. Nel lato sinistro del taglio creare uno spazio sottocutaneo separando accuratamente la pelle dal tessuto connettivo sottostante. </li><li> Capovolgere il mouse, e utilizzare un bisturi per fare una incisione cutanea di circa 1,5 cm di lato dorsale sinistro dietro la scapola. Creare una tasca sottocutanea lungo il fianco dell&#39;animale sufficientemente grande per il dispositivo. Inserire il trasmettitore nella tasca. </li><li> Inserire un piccolo pinza emostatica nell&#39;incisione posteriore e manovrarlo sottocutanea verso la parte anterioreapertura del collo. Utilizzando la fascetta inserita-emostatico, prenda delicatamente un tubo in polietilene atossico (4 cm Lunghezza x 1 mm ID). <ol><li> Tirare il hemostat indietro attraverso il tunnel l&#39;incisione laterale nella parte posteriore finché il tubo sporge da entrambi addominale e dorsale incisione, rilasciare il tubo dal emostatico. Dalla parte posteriore, inserire il sensore catetere nel tubo per tunnel la punta del catetere di rilevamento della pressione attraverso il collo. Dalla anteriore del collo, tirare e rimuovere il tubo in polietilene e chiudere l&#39;incisione dorsale mediante clip metalliche. </li></ol></li><li> separare con cura le ghiandole mandibolari utilizzando applicatori di punta di cotone sterile e ritrarre la ghiandola mandibolare sinistra utilizzando un gancio elastico soggiorno. Utilizzando pinze curve punta fine, individuare la carotide lungo il lato sinistro della trachea. Mantenere il sito chirurgico sterile, mettendo e garantire un telino sterile. <ol><li> isolare con cura il recipiente dal tessuto circostante e delicatamente separare lanervo vago (colore biancastro) che si trova lungo l&#39;arteria carotide lontano dalla arteria. Fare attenzione a non tagliare o danneggiare il nervo o l&#39;arteria. </li></ol></li><li> Passare tre pezzi di non assorbibile 7-0 sutura sotto la sezione carotide isolato. Legare la sutura cranica per chiudere il flusso di sangue. Estrarre la sutura che è più vicino allo sterno per occludere temporaneamente il flusso di sangue dall&#39;aorta. </li><li> Fare un nodo sciolto utilizzando la sutura centrale. Questo verrà utilizzato per fissare il catetere nel vaso. Tagliare una piccola incisione nell&#39;arteria tra il cranio e le suture sternale con micro-forbici. </li><li> Afferra il catetere con una pinza speciale nave incannulamento, facendo attenzione a non comprimere il catetere per prevenire la perdita di gel dalla sonda. Delicatamente, afferrare l&#39;arteria con una pinzetta punta fine curvo pinze, recuperare il catetere, e inserirla nel vaso attraverso la piccola incisione. </li><li> Stringere il nodo di sutura intorno all&#39;arteria centrale e far avanzare con delicatezza il gattoheter. rilasciare delicatamente la sutura che è prossimale allo sterno e continuare ad avanzare il catetere verso l&#39;aorta trasversale. <ol><li> Osservare il contrassegno sul catetere che fornisce un indice approssimativa di quanto il catetere deve essere inserito. Una volta che il punto è raggiunto, delicatamente stringere sia inferiore e la sutura superiore intorno al catetere. Il catetere è fissato alla carotide dai nodi di sutura. </li></ol></li><li> Chiudere l&#39;incisione cutanea con non assorbibile 5-0 di sutura. Una volta chiusa, sigillare l&#39;incisione con tessuto adesivo. </li></ol> 4. chirurgico di recupero e BP Misure <ol><li> Monitorare animali da vicino per il ritorno di posture normali e comportamenti. Durante il periodo post-operatorio amministrare analgesia 24 ore come indicato da un veterinario del personale. </li><li> Una volta che gli animali hanno recuperato (5 - 7 giorni dopo l&#39;intervento), li alloggiare individualmente in una gabbia regolare del mouse posizionato sulla parte superiore della piastra ricevitore di telemetria. </li><li> Ruotare il TR impiantatoansmitters &quot;on&quot; e &quot;off&quot; utilizzando un dispositivo magnetico posizionati brevemente vicino all&#39;animale dall&#39;esterno della gabbia. </li></ol>

<ol>
	<li>Danaei, G., 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=The+preventable+causes+of+death+in+the+United+States:+comparative+risk+assessment+of+dietary,+lifestyle,+and+metabolic+risk+factors.">The preventable causes of death in the United States: comparative risk assessment of dietary, lifestyle, and metabolic risk factors.</a> PLoS Med. 6 (4), e1000058 (2009).</li><li>Dornas, W. C., Silva, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+for+the+study+of+arterial+hypertension.">Animal models for the study of arterial hypertension.</a> J Biosci. 36 (4), 731-737 (2011).</li><li>Henze, 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=Persistent+alterations+in+heart+rate+variability,+baroreflex+sensitivity,+and+anxiety-like+behaviors+during+development+of+heart+failure+in+the+rat.">Persistent alterations in heart rate variability, baroreflex sensitivity, and anxiety-like behaviors during development of heart failure in the rat.</a> Am J Physiol Heart Circ Physiol. 295 (1), H29-H38 (2008).</li><li>Hoffmann, D. S., 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=Chronic+tempol+prevents+hypertension,+proteinuria,+and+poor+feto-placental+outcomes+in+BPH/5+mouse+model+of+preeclampsia.">Chronic tempol prevents hypertension, proteinuria, and poor feto-placental outcomes in BPH/5 mouse model of preeclampsia.</a> Hypertension. 51 (4), 1058-1065 (2008).</li><li>Lerman, L. O., Chade, A. R., Sica, V., Napoli, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+hypertension:+an+overview.">Animal models of hypertension: an overview.</a> J Lab Clin Med. 146 (3), 160-173 (2005).</li><li>Johns, C., Gavras, I., Handy, D. E., Salomao, A., Gavras, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Models+of+experimental+hypertension+in+mice.">Models of experimental hypertension in mice.</a> Hypertension. 28 (6), 1064-1069 (1996).</li><li>Vatner, S. F., Braunwald, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiovascular+control+mechanisms+in+the+conscious+state.">Cardiovascular control mechanisms in the conscious state.</a> N Engl J Med. 293 (19), 970-976 (1975).</li><li>Zhao, X., 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=Arterial+Pressure+Monitoring+in+Mice.">Arterial Pressure Monitoring in Mice.</a> Curr Protoc Mouse Biol. 1, 105-122 (2011).</li><li>Whitesall, S. E., Hoff, J. B., Vollmer, A. P., D'Alecy, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+simultaneous+measurement+of+mouse+systolic+arterial+blood+pressure+by+radiotelemetry+and+tail-cuff+methods.">Comparison of simultaneous measurement of mouse systolic arterial blood pressure by radiotelemetry and tail-cuff methods.</a> Am J Physiol Heart Circ Physiol. 286 (6), H2408-H2415 (2004).</li><li>Kurtz, T. W., 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=Recommendations+for+blood+pressure+measurement+in+humans+and+experimental+animals.+Part+2:+Blood+pressure+measurement+in+experimental+animals:+a+statement+for+professionals+from+the+subcommittee+of+professional+and+public+education+of+the+American+Heart+Association+council+on+high+blood+pressure+research.">Recommendations for blood pressure measurement in humans and experimental animals. Part 2: Blood pressure measurement in experimental animals: a statement for professionals from the subcommittee of professional and public education of the American Heart Association council on high blood pressure research.</a> Hypertension. 45 (2), 299-310 (2005).</li><li>Kurtz, T. W., 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=Recommendations+for+blood+pressure+measurement+in+animals:+summary+of+an+AHA+scientific+statement+from+the+Council+on+High+Blood+Pressure+Research,+Professional+and+Public+Education+Subcommittee.">Recommendations for blood pressure measurement in animals: summary of an AHA scientific statement from the Council on High Blood Pressure Research, Professional and Public Education Subcommittee.</a> Arterioscler Thromb Vasc Biol. 25 (3), 478-479 (2005).</li></ol>

The authors have nothing to disclose.

Impiantabile radio-telemetria è migliorata significativamente negli ultimi dieci anni; dimensioni più piccole della sonda rende l&#39;impianto meno traumatica per l&#39;animale, la durata della batteria prolungata aiuta a ridurre i costi, e le frequenze telemetro indipendenti eliminare le interferenze tra i ricevitori. Telemetria è considerato il metodo allo stato dell&#39;arte per la raccolta di una vasta gamma di parametri fisiologici da animali liberi di muoversi senza artefatti dovuti all&#39;uso di contenzione, ...

L&#39;ipertensione è uno dei principali fattori di rischio per le malattie cardiovascolari, senza dubbio si tratta di un grave problema di salute pubblica sia nei paesi sviluppati e in via di sviluppo 1. Diversi modelli animali di ipertensione sperimentale sono stati sviluppati per imitare risposte ipertensive come quelle osservate nell&#39;uomo 2. Tra gli altri, il mouse ambulatoriale rappresenta un ottimo modello per studiare la genesi e la progressione dell&#39;ipertensione permettendo nell&#39;analisi vivo delle conseguenze dell&#39;esposizione cronica a ipertensione. La pressione sanguigna (BP) monitoraggio nei topi ha aiutato i ricercatori a svelare diversi meccanismi coinvolti nella fisiologia e fisiopatologia delle malattie come l&#39;ipertensione e insufficienza cardiaca 3, 4. Infatti, la manipolazione del genoma del topo permesso generazione di transgenici o modelli gene targeting adatto per studiare l&#39;ipertensione 5, 6. Tuttavia, anche la manipolazione delicatadi topi consapevole induce emozioni che possono potenzialmente introdurre artefatti durante l&#39;acquisizione dei dati, mentre l&#39;uso di sedazione o tranquillanti profondamente influenzare la pressione sanguigna 7. Questi aspetti sono particolarmente importanti e devono essere presi in considerazione quando si tenta di monitoraggio a lungo termine BP. Ci sono diversi modi per registrare BP nei topi, e un confronto tra le tecniche più comuni attualmente disponibili sono stati discussi altrove 8, 9. Tuttavia, le raccomandazioni AHA per la misurazione BP concluso che la misurazione endoarteriosa di BP sono generalmente preferiti per la loro capacità di misurare direttamente BP per un periodo prolungato di tempo 10. Radio-telemetria accoppiato con la misura diretta della pressione arteriosa è il metodo di state-of-the-art per il monitoraggio delle funzioni fisiologiche in sveglio e liberi di muoversi animali da laboratorio, riducendo al minimo lo stress e manufatti per l&#39;ambiente associati 9, 11.Radio-telemetria offre la possibilità di raccogliere automaticamente la pressione arteriosa, frequenza cardiaca, la temperatura corporea e l&#39;attività degli animali provenienti da animali coscienti multipli. Anche se questa metodologia sta diventando molto popolare in molti laboratori, radio-telemetria impianto in topi può essere tecnicamente impegnativo. Qui mostriamo un protocollo passo-passo che illustra come impiantare un trasduttore di pressione nei topi. La tecnica prevede l&#39;inserimento sottocutaneo della sonda nel corpo del mouse, incanalare il catetere al collo e in avanti vicino all&#39;arco aortico attraverso l&#39;arteria carotide sinistra. dati in remoto catturati vengono trasmesse in diretta sul monitor del computer. I dati sono memorizzati anche per l&#39;analisi &quot;off-line&quot;.

<table>
	<tbody>
		<tr>
			<td>Small animal anesthesia system</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td></td>
			<td>low-Flow small animal anesthesia system</td>
		</tr>
		<tr>
			<td>Pad warmer and mouse termometer</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td></td>
			<td>allows monitoring body temperature,&#160; and homeothermic control in small animals.</td>
		</tr>
		<tr>
			<td>Binocular Microscope</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td>KSCXTS-1121</td>
			<td>binocular body with boom stand pole and top LED.</td>
		</tr>
		<tr>
			<td>Hemostat Forceps</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td>INS750451</td>
			<td>used to clamp blood vessels or tag sutures</td>
		</tr>
		<tr>
			<td>Small metal Clips, 7mm, Stainless Steel</td>
			<td>Kent Scientific Corp, Torrington, Connecticut, USA</td>
			<td>INS750344</td>
			<td>used for skin closure</td>
		</tr>
		<tr>
			<td>Betadine solution</td>
			<td>Purdue Products L.P., Stamford, CT, USA</td>
			<td>NDC-67618-150-01</td>
			<td>10% povidone iodine topical solution</td>
		</tr>
		<tr>
			<td>Normal saline solution</td>
			<td>Abott Laboratories</td>
			<td>04930-04-10</td>
			<td>Needed for preventing tissue from drying.</td>
		</tr>
		<tr>
			<td>Nair (Hair remover lotion)</td>
			<td></td>
			<td></td>
			<td>Needed for fur removal from the site of incision/surgery.</td>
		</tr>
		<tr>
			<td>Braide silk suture</td>
			<td>Teleflex Medical OEM, Coventry, Connecticut, USA</td>
			<td></td>
			<td>Size 5.0, 6.0, 7.0</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td></td>
			<td>2716</td>
			<td>70% ethanol for disinfection</td>
		</tr>
		<tr>
			<td>Spring scissors&#160;</td>
			<td>Fine Science Tool</td>
			<td>15000-10</td>
			<td>for minor dissection</td>
		</tr>
		<tr>
			<td>Scissors (angled to side)</td>
			<td>Fine Science Tool</td>
			<td>14063-011</td>
			<td>No. 3 handle</td>
		</tr>
		<tr>
			<td>Scalpel blade</td>
			<td></td>
			<td>2976-0</td>
			<td>No. 10</td>
		</tr>
		<tr>
			<td>Forceps (curved)</td>
			<td>Fine Science Tool</td>
			<td>11150-10</td>
			<td>for holding tissue</td>
		</tr>
		<tr>
			<td>Forceps (straight)</td>
			<td>Fine Science Tool</td>
			<td>11151-10</td>
			<td>for holding tissue</td>
		</tr>
		<tr>
			<td>Needle holder&#160;</td>
			<td>Fine Science Tool</td>
			<td>12002-12</td>
			<td>for suturing</td>
		</tr>
		<tr>
			<td>Fine needle nose Forceps</td>
			<td>Fine Science Tool</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>Henry Schein&#160;Animal Health, Melville, New York, USA</td>
			<td></td>
			<td>a general inhalation anesthetic agent</td>
		</tr>
		<tr>
			<td>Sterilizer</td>
			<td>Benchmark Scientific, 116 Corporate Blvd, South Plainfield, NJ, USA</td>
			<td>B1000</td>
			<td>sterilize surgical tools&#160;in 5-10 seconds using infrared heating</td>
		</tr>
		<tr>
			<td>Gauze Pads</td>
			<td>Johnson &#38; Johnson, New Brunswick, NJ, USA</td>
			<td>JJ8513</td>
			<td>to use for wound cleaning, prepping, scrubbin or dressing.</td>
		</tr>
		<tr>
			<td>Telemetry Device</td>
			<td>Data Sciences International, St. Paul, MN, USA</td>
			<td>DSI-PA-C10</td>
			<td>to record blood pressure in freely moving mice</td>
		</tr>
		<tr>
			<td>Telemetry receiver system&#160; coumpled with a PC</td>
			<td>Data Sciences International, St. Paul, MN, USA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>small Tubing</td>
			<td>Instech Laboratories, Plymouth Meeting, PA USA</td>
			<td>BTPE-90</td>
			<td></td>
		</tr>
		<tr>
			<td>Vessel Cannulation Forceps, 13cm, 0.5mm OD</td>
			<td>World Precision Instruments</td>
			<td>503374</td>
			<td>special vessel cannulation forceps.</td>
		</tr>
		<tr>
			<td>Tissue adhesive</td>
			<td>3M Animal Care Products, St. Paul, MN, USA</td>
			<td>NAC No.:&#160;11380041</td>
			<td>&#160;use to close minor wounds, often eliminating the need for sutures and/or bandages</td>
		</tr>
		<tr>
			<td>Weighing scale&#160;</td>
			<td></td>
			<td>BB300</td>
			<td>&#160;Precision Analytical Laboratory Balance</td>
		</tr>
	</tbody>
</table>

long-term blood pressure measurement in freely moving mice using telemetry

Durante lo sviluppo di nuovi agenti vasoattivi, monitoraggio della pressione arteriosa è cruciale per valutare l&#39;efficacia di nuovi farmaci proposti. In effetti, la ricerca incentrata sulla scoperta di nuovi potenziali bersagli terapeutici utilizzando topi geneticamente modificati richiede un giudizio affidabile a lungo termine della variazione di pressione arteriosa sistemica. Attualmente, il gold standard per l&#39;ottenimento di misure a lungo termine della pressione sanguigna nei topi ambulatoriali utilizza impiantabili di radio-trasmettitori, che richiedono incannulamento arteria. Questa tecnica elimina la necessità di legare, immobilizzare o anestetizzare gli animali che introducono stress e manufatti durante il campionamento dei dati. Tuttavia, il monitoraggio della pressione arteriosa nei topi tramite cateterizzazione può essere piuttosto difficile a causa delle ridotte dimensioni delle arterie. Qui vi presentiamo una guida passo-passo per illustrare i passaggi chiave cruciali per un impianto sottocutaneo di successo di radio-trasmettitori e carotide cannulation nei topi. Abbiamo anche esempi di attività di pressione sanguigna a lungo termine presi dai topi liberi di muoversi dopo un periodo di recupero post-operatorio. A seguito di questa procedura consentirà registrazioni della pressione sanguigna diretta affidabili da più animali contemporaneamente.

I dati possono essere acquisiti in remoto da un ricevitore; tracce vengono visualizzate su uno schermo di computer per il controllo di qualità (Figura 1a). Dettagli come ID animale, pressione diastolica e pressione arteriosa sistolica sono indicate anche (Figura 1b). Arteriosa BP può essere registrata in continuo (24/7), o per brevi intervalli programmati (ad esempio, 60 sec acquisizione ogni ora). I dati possono essere memorizzati automaticam...

Watch this Scientific Journal Video about Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry at JoVE.com

Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry

Misurazione della pressione sanguigna a lungo termine in topi liberi di muoversi utilizzando la telemetria

The goal of this protocol is to assess systemic blood pressure in conscious freely moving mice using implantable radio-telemetry devices.

During the development of new vasoactive agents, arterial blood pressure monitoring is crucial for evaluating the efficacy of the new proposed drugs. ...

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JoVE Journal

Medicine

18.3K Views.  University of Tennessee Health Sciences Center. The goal of this protocol is to assess systemic blood pressure in conscious freely moving mice using implantable radio-telemetry devices.

Video: Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry

Pressure Controlled Ventilation to Induce Acute Lung Injury in Mice

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged mechanical ventilation, contributes to morbidity and mortality of critical illness, and studies on novel genetic or pharmacological targets are areas of intense investigation (1-3, 5, 8, 26, 30, 33-36). ALI is defined by the acute onset of the disease, which leads to non-cardiac pulmonary edema and subsequent impairment of pulmonary gas exchange (36). We have developed a murine model of ALI by using a pressure-controlled ventilation to induce ventilator-induced lung injury (2). For this purpose, C57BL/6 mice are anesthetized and a tracheotomy is performed followed by induction of ALI via mechanical ventilation. Mice are ventilated in a pressure-controlled setting with an inspiratory peak pressure of 45 mbar over 1 - 3 hours. As outcome parameters, pulmonary edema (wet-to-dry ratio), bronchoalveolar fluid albumin content, bronchoalveolar fluid and pulmonary tissue myeloperoxidase content and pulmonary gas exchange are assessed (2). Using this technique we could show that it sufficiently induces acute lung inflammation and can distinguish between different treatment groups or genotypes (1-3, 5). Therefore this technique may be helpful for researchers who pursue molecular mechanisms involved in ALI using a genetic approach in mice with gene-targeted deletion.

A murine model for ventilator induced lung injury is an important tool to study an acute lung injury in vivo. Here, we report an easy applicable in situ model for acute lung injury using high-pressure mechanical ventilation to induce acute failure of the lung.

Pressione di ventilazione controllata per indurre lesioni polmonari acute nei topi

Murine models are extensively used to investigate acute injuries of different organs systems (1-34). Acute lung injury (ALI), which occurs with prolonged ...

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Epidural Intracranial Pressure Measurement in Rats Using a Fiber-optic Pressure Transducer

Elevated intracranial pressure (ICP) is a significant problem in several forms of ischemic brain injury including stroke, traumatic brain injury and cardiac arrest. This elevation may result in further neurological injury, in the form of transtentorial herniation1,2,3,4, midbrain compression, neurological deficit or increased cerebral infarct2,4. Current therapies are often inadequate to control elevated ICP in the clinical setting5,6,7 . Thus there is a need for accurate methods of ICP measurement in animal models to further our understanding of the basic mechanisms and to develop new treatments for elevated ICP.
In both the clinical and experimental setting ICP cannot be estimated without direct measurement. Several methods of ICP catheter insertion currently exist. Of these the intraventricular catheter has become the clinical 'gold standard' of ICP measurement in humans8. This method involves the partial removal of skull and the instrumentation of the catheter through brain tissue. Consequently, intraventricular catheters have an infection rate of 6-11%9. For this reason, subdural and epidural cannulations have become the preferred methods in animal models of ischemic injury. 
Various ICP measurement techniques have been adapted for animal models, and of these, fluid-filled telemetry catheters10 and solid state catheters are the most frequently used11,12,13,14,15. The fluid-filled systems are prone to developing air bubbles in the line, resulting in false ICP readings. Solid state probes avoid this problem (Figure 1). An additional problem is fitting catheters under the skull or into the ventricles without causing any brain injury that might alter the experimental outcomes. Therefore, we have developed a method that places an ICP catheter contiguous with the epidural space, but avoids the need to insert it between skull and brain. 
An optic fibre pressure catheter (420LP, SAMBA Sensors, Sweden) was used to measure ICP at the epidural location because the location of the pressure sensor (at the very tip of the catheter) was found to produce a high fidelity ICP signal in this model. There are other manufacturers of similar optic fibre technologies13 that may be used with our methodology. Alternative solid state catheters, which have the pressure sensor located at the side of the catheter tip, would not be appropriate for this model as the signal would be dampened by the presence of the monitoring screw. 
Here, we present a relatively simple and accurate method to measure ICP. This method can be used across a wide range of ICP related animal models.

A novel technique to record the pressures within the skull is described. The minimally invasive method uses a fibre-optic pressure sensing system to accurately measure intracranial pressure (ICP) in anaesthetized rats without causing significant brain trauma. The technique may be used in a wide range of experimental models.

Epidurale Misurazione della pressione intracranica in ratto utilizzando una fibra ottica trasduttore di pressione

Elevated intracranial pressure (ICP) is a significant problem in several forms of ischemic brain injury including stroke, traumatic brain injury and ...

Measurement of the Pressure-volume Curve in Mouse Lungs

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential phenotypic changes are best assessed by measurement of the changes in lung elasticity. To best understand specific mechanisms underlying such pathologies in mice, it is essential to make functional measurements that can reflect the developing pathology. Although there are many ways to measure elasticity, the classical method is that of the total lung pressure-volume (PV) curve done over the whole range of lung volumes. This measurement has been made on adult lungs from nearly all mammalian species dating back almost 100 years, and such PV curves also played a major role in the discovery and understanding of the function of pulmonary surfactant in fetal lung development. Unfortunately, such total PV curves have not been widely reported in the mouse, despite the fact that they can provide useful information on the macroscopic effects of structural changes in the lung. Although partial PV curves measuring just the changes in lung volume are sometimes reported, without a measure of absolute volume, the nonlinear nature of the total PV curve makes these partial ones very difficult to interpret. In the present study, we describe a standardized way to measure the total PV curve. We have then tested the ability of these curves to detect changes in mouse lung structure in two common lung pathologies, emphysema and fibrosis. Results showed significant changes in several variables consistent with expected structural changes with these pathologies. This measurement of the lung PV curve in mice thus provides a straightforward means to monitor the progression of the pathophysiologic changes over time and the potential effect of therapeutic procedures.

Here we present a protocol to simply and reliably measure the lung pressure-volume curve in mice, showing that it is sufficiently sensitive to detect phenotypic parenchymal changes in two common lung pathologies, pulmonary fibrosis and emphysema. This metric provides a means to quantify the lung&#8217;s structural changes with developing pathology.

Misura della curva di pressione-volume in mouse polmoni

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential ...

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. Despite the discovery of key regulators of uterine contractility, this process is still not fully understood. Transgenic mice provide an ideal model in which to study parturition. Previously, the only method to study uterine contractility in the mouse was ex vivo isometric tension recordings, which are suboptimal for several reasons. The uterus must be removed from its physiological environment, a limited time course of investigation is possible, and the mice must be sacrificed. The recent development of radiometric telemetry has allowed for longitudinal, real-time measurements of in vivo intrauterine pressure in mice. Here, the implantation of an intrauterine telemeter to measure pressure changes in the mouse uterus from mid-pregnancy until delivery is described. By comparing differences in pressures between wild type and transgenic mice, the physiological impact of a gene of interest can be elucidated. This technique should expedite the development of therapeutics used to treat myometrial disorders during pregnancy, including preterm labor.

Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo

This manuscript provides a protocol for implanting telemeters in the mouse for the purpose of measuring intrauterine pressures during pregnancy.

Telemetria intrauterina misurare mouse contrattile Pressione<em&gt; In Vivo</em

A complex integration of molecular and electrical signals is needed to transform a quiescent uterus into a contractile organ at the end of pregnancy. ...

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early cardiopulmonary dysfunction is difficult to diagnose, particularly in animal models, as cardiopulmonary function is often measured invasively, requiring anesthesia. As many anesthetic agents are cardiodepressive, subtle changes in cardiovascular function may be masked. In contrast, chronic instrumentation allows for measurement of cardiopulmonary function in the awake state, so that measurements can be obtained under quiet resting conditions, without the effects of anesthesia and acute surgical trauma. Furthermore, when animals are properly trained, measurements can also be obtained during graded treadmill exercise.
Flow probes are placed around the aorta or pulmonary artery for measurement of cardiac output and around the left anterior descending coronary artery for measurement of coronary blood flow. Fluid-filled catheters are implanted in the aorta, pulmonary artery, left atrium, left ventricle and right ventricle for pressure measurement and blood sampling. In addition, a 20 G&#160;catheter is positioned in the anterior interventricular vein to allow coronary venous blood sampling.
After a week of recovery, swine are placed on a motor-driven treadmill, the catheters are connected to pressure and flow meters, and swine are subjected to a five-stage progressive exercise protocol, with each stage lasting 3 min. Hemodynamic signals are continuously recorded and blood samples are taken during the last 30 sec of each exercise stage.
The major advantage of studying chronically instrumented animals is that it allows serial assessment of cardiopulmonary function, not only at rest but also during physical stress such as exercise. Moreover, cardiopulmonary function can be assessed repeatedly during disease development and during chronic treatment, thereby increasing statistical power and hence limiting the number of animals required for a study.

Here we present a protocol to assess cardiopulmonary function in awake swine, at rest and during graded treadmill exercise. Chronic instrumentation allows for repeated hemodynamic measurements uninfluenced by cardiodepressive anesthetic agents.

Posizionamento chirurgico di cateteri per durata Esercizio cardiovascolare test in Swine

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early ...

Transdermal Measurement of Glomerular Filtration Rate in Mice

Transdermal analysis of glomerular filtration rate (GFR) is an established technique that is used to assess renal function in mouse and rat models of acute kidney injury and chronic kidney disease. The measurement system consists of a miniaturized fluorescence detector that is directly attached to the skin on the back of conscious, freely moving animals, and measures the excretion kinetics of the exogenous GFR tracer, fluorescein-isothiocyanate (FITC) conjugated sinistrin (an inulin analog). This system has been described in detail in rats. However, because of their smaller size, measurement of transcutaneous GFR in mice presents additional technical challenges. In this paper we therefore provide the first detailed practical guide to the use of transdermal GFR monitors in mice based on the combined experience of three different investigators who have been performing this assay in mice over a number of years.

Here we describe a protocol to measure glomerular filtration rate (GFR) in conscious, freely moving mice using a transdermal GFR monitor.

Transdermico misurazione del tasso di filtrazione glomerulare in topi

Transdermal analysis of glomerular filtration rate (GFR) is an established technique that is used to assess renal function in mouse and rat models of ...

Simultaneous Electrocardiography Recording and Invasive Blood Pressure Measurement in Rats

For studies related to cardiovascular physiology or pathophysiology, blood pressure (BP) and electrocardiography are basic observational parameters. Research focusing on cardiovascular disease models, potential cardiovascular therapeutic targets or pharmaceutical agents requires assessment of systemic arterial pressure and heart rhythm changes. In situations where radio telemetry systems are not available or affordable, the technique of femoral artery cannulation is an alternative way to obtain intra-arterial pressure waveform recordings and systemic BP measurements. This technique is economical and can be performed with standard equipment in animal facilities. However, invasive arterial pressure recording requires cannulation of small arteries, which can be a challenging surgical skill. Here, we present step-by-step protocols for femoral artery cannulation procedures. Key procedures include the calibration of the data acquisition system, tissue dissection and femoral artery cannulation, and setup of the arterial cannulation system for pressure recording. Surface electrocardiography recording procedures are also included. We also present examples of BP recordings from normotensive and hypertensive rats. This protocol allows reliable direct recordings of systemic BP with simultaneous electrocardiography.

Here, we describe a setup for simultaneous recording of electrocardiography and intra-arterial blood pressure (BP) in experimental rats, which can be done with standard equipment in animal facilities and can be applied to physiological or pharmacological studies to investigate pathogenic or therapeutic mechanisms in cardiovascular medicine.

Elettrocardiografia simultanea registrazione e invasiva sangue pressione misura in ratti

For studies related to cardiovascular physiology or pathophysiology, blood pressure (BP) and electrocardiography are basic observational parameters. ...

Blood Collection Through Subclavian Vein Puncture in Mice

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in research work. Tail blood collection is a popular method when a small amount of blood sample is needed. Orbital artery could be considered if a large amount of blood is needed but this blood collection method has ethical issues. Formerly, we demonstrated the feasibility and safety of blood sample collection through subclavian vein puncture in rats, and here we investigate whether this method could be used in mice. We report that this method is safe and practical for blood collection in mice. Blood collection through the subclavian vein puncture in mice can be a convenient method in daily research works.

Here, we present a protocol to take blood samples from the subclavian vein of mice.

Prelievo di sangue attraverso la puntura della vena subclavia nei topi

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in ...

Implantation of Combined Telemetric ECG and Blood Pressure Transmitters to Determine Spontaneous Baroreflex Sensitivity in Conscious Mice

Blood pressure (BP) and heart rate (HR) are both controlled by the autonomic nervous system (ANS) and are closely intertwined due to reflex mechanisms. The baroreflex is a key homeostatic mechanism to counteract acute, short-term changes in arterial BP and to maintain BP in a relatively narrow physiological range. BP is sensed by baroreceptors located in the aortic arch and carotid sinus. When BP changes, signals are transmitted to the central nervous system and are then communicated to the parasympathetic and sympathetic branches of the autonomic nervous system to adjust HR. A rise in BP causes a reflex decrease in HR, a drop in BP causes a reflex increase in HR.
Baroreflex sensitivity (BRS) is the quantitative relationship between changes in arterial BP and corresponding changes in HR. Cardiovascular diseases are often associated with impaired baroreflex function. In various studies reduced BRS has been reported in e.g., heart failure, myocardial infarction, or coronary artery disease. 
Determination of BRS requires information from both BP and HR, which can be recorded simultaneously using telemetric devices. The surgical procedure is described beginning with the insertion of the pressure sensor into the left carotid artery and positioning of its tip in the aortic arch to monitor arterial pressure followed by the subcutaneous placement of the transmitter and ECG electrodes. We also describe postoperative intensive care and analgesic management. After a two-week period of post-surgery recovery long-term ECG and BP recordings are performed in conscious and unrestrained mice. Finally, we include examples of high-quality recordings and the analysis of spontaneous baroreceptor sensitivity using the sequence method.

The baroreflex is a heart-rate regulation mechanism by the autonomic nervous system in response to blood-pressure changes. We describe a surgical technique to implant telemetry transmitters for continuous and simultaneous measurement of electrocardiogram and blood pressure in mice. This can determine spontaneous baroreflex sensitivity, an important prognostic marker for cardiovascular disease.

Impianto combinato di ECG telemetrico e trasmettitori di pressione sanguigna per determinare la sensibilità baroriflessa spontanea in topi coscienti

Blood pressure (BP) and heart rate (HR) are both controlled by the autonomic nervous system (ANS) and are closely intertwined due to reflex mechanisms. ...

Analyzing Long-Term Electrocardiography Recordings to Detect Arrhythmias in Mice

Arrhythmias are common, affecting millions of patients worldwide. Current treatment strategies are associated with significant side effects and remain ineffective in many patients. To improve patient care, novel and innovative therapeutic concepts causally targeting arrhythmia mechanisms are needed. To study the complex pathophysiology of arrhythmias, suitable animal models are necessary, and mice have been proven to be ideal model species to evaluate the genetic impact on arrhythmias, to investigate fundamental molecular and cellular mechanisms, and to identify potential therapeutic targets.
Implantable telemetry devices are among the most powerful tools available to study electrophysiology in mice, allowing continuous ECG recording over a period of several months in freely moving, awake mice. However, due to the huge number of data points (&gt;1 million QRS complexes per day), analysis of telemetry data remains challenging. This article describes a step-by-step approach to analyze ECGs and to detect arrhythmias in long-term telemetry recordings using the software, Ponemah, with its analysis modules, ECG Pro and Data Insights, developed by Data Sciences International (DSI). To analyze basic ECG parameters, such as heart rate, P wave duration, PR interval, QRS interval, or QT duration, an automated attribute analysis was performed using Ponemah to identify P, Q, and T waves within individually adjusted windows around detected R waves. 
Results were then manually reviewed, allowing adjustment of individual annotations. The output from the attribute-based analysis and the pattern recognition analysis was then used by the Data Insights module to detect arrhythmias. This module allows an automatic screening for individually defined arrhythmias within the recording, followed by a manual review of suspected arrhythmia episodes. The article briefly discusses challenges in recording and detecting ECG signals, suggests strategies to improve data quality, and provides representative recordings of arrhythmias detected in mice using the approach described above.

Here we present a step-by-step protocol for a semiautomated approach to analyze murine long-term electrocardiography (ECG) data for basic ECG parameters and common arrhythmias. Data are obtained by implantable telemetry transmitters in living and awake mice and analyzed using Ponemah and its analysis modules.

Analisi delle registrazioni elettrocardiografiche a lungo termine per rilevare le aritmie nei topi

Arrhythmias are common, affecting millions of patients worldwide. Current treatment strategies are associated with significant side effects and remain ...