The study was supported by the Swiss National Foundation [SNF 310030-149986 to MNG], the University of Fribourg, and Fribourg Hospital.

Tutti gli animali hanno ricevuto cura umana nel rispetto della Convenzione europea sulla cura degli animali. Le procedure chirurgiche sono state eseguite in conformità con la legge svizzera sulla protezione degli animali dopo aver ottenuto l&#39;autorizzazione del veterinario di Stato, Friborgo, approvato dal veterinario, la Svizzera federale. Raccolta 1. Cuore NOTA: Tutti gli interventi chirurgici sono stati eseguiti in anestesia isoflurano. Gli sforzi sono stati fatti per ridurre la sofferenza degli animali. In particolare, tutti gli animali hanno ricevuto una iniezione sottocutanea di 0,1 mg / kg buprenorfina pre-anestesia. Il protocollo chirurgico per induzione di infarto miocardico è stato precedentemente descritto altrove 13. <ol><li> Eseguire una sternotomia su un animale myocardially infartuato in anestesia (animale intubato, 2,5% isoflurano, anestesia corretta confermati dalla zampa pizzico reflex). <ol><li> Aprire l&#39;animale tagliando la pelle e poi i muscolicon le forbici chirurgiche. Tagliare le costole a sinistra ea destra, e quindi rimuovere il petto. </li><li> Rimuovere le adesioni rimanenti dopo l&#39;intervento chirurgico precedente (LAD legatura). Tagliare l&#39;aorta e rimuovere il cuore. Mettere il tessuto in 1 M KCl (in PBS), e poi lavare con PBS. </li></ol></li></ol> 2. Preparazione del tessuto <ol><li> Mettere il cuore infartuato longitudinalmente in una matrice acrilica cuore di ratto. Tenerlo a -20 ° C per 1 ora. </li><li> Tagliare cuore direttamente nella matrice con una lama di rasoio con una trasversale. Assicurarsi che ogni fetta ha uno spessore di 2 mm. Tagliare circa 5 - 7 diapositive per ogni cuore (in base al livello rimodellamento); questo è chiamato campionamento sistematico. </li><li> A questo punto, eseguire la colorazione cloruro di 2,3,5-trifeniltetrazolio (TTC) è facoltativo (mantenere l&#39;orientamento del cuore fette base-apice). <ol><li> Incubare in 1% TTC in PBS per 50 min a 37 ° C. Incubare in 4% paraformaldeide (PFA) per 20 minuti a 1 ora. Mettere le sezioni between due lastre di vetro con distanziatori 2 mm e scattare foto con un microscopio stereologica accoppiato con una macchina fotografica a 15X di ingrandimento. ATTENZIONE! Paraformaldeide è tossico. </li></ol></li><li> Far scorrere il congelamento (1 opzione st) <ol><li> Mettere ciascun vetrino in uno stampo di plastica (10 x 10 x 5 mm) con supporto per cryotomy (temperatura di taglio ottimale, OCT) di montaggio, mantenere l&#39;orientamento (posizionare il lato apice orientata della sezione giù sul fondo dello stampo). Congelare i blocchi con vapori 2-metilbutano sotto azoto liquido di raffreddamento per 10 - 15 minuti. Infine, memorizzare il tessuto a -80 ° C. </li></ol></li><li> Paraffinization (opzione 2 nd) <ol><li> Posizionare ciascuna diapositiva incorporamento cassette (mantenere l&#39;orientamento posizionando il lato apice orientata della sezione sul fondo della cassetta) e poi in 4% PFA per 24 ore. Mettere in una macchina durante la notte processatore. <ol><li> Incubare in etanolo al 70% per 2 ore. Incubare a Ethanol 95% per 2 ore. Incubare in etanolo 100% per 3 ore. Incubare in xilolo per 4 ore. Incubare in paraffina (fuso a 60 ° C in forno) per 5 ore. Infine, fare blocchi, grazie all&#39;integrazione di ogni diapositiva cuore in paraffina. </li></ol></li></ol></li></ol> 3. Masson-Goldner colorazione tricromica <ol><li> Rendere sezioni di tessuto da blocchi di paraffina con un microtomo manuale (spessore 5 um) o dai blocchi oltremare con un criostato impostato a -18 ° C (spessore 7 micron). </li><li> Macchia un vetrino da ogni parte del cuore per ogni ratto (3 - 4 sezioni trasversali per vetrino) con Masson-Goldner colorazione tricromica (vedi allegato). NOTA: Inizia da questo passaggio per le sezioni di paraffina. <ol><li> Sciogliere i vetrini a 60 ° C in un forno. Sotto una cappa aspirante, li Deparaffinare in xilolo due volte per 10 minuti ciascuno. li Reidratare in 100% di etanolo, 95% di etanolo, 70% di etanolo e acqua distillata per 3 minuti ciascuno. NOTA: Inizia da questo passaggio per il cryosectionS. </li><li> fissarli in Bouin soluzione durante la notte. Poi, sciacquarli sotto acqua corrente per 10 - 15 minuti. Sciacquare con acqua distillata. incubare in ematossilina di Mayer per 3 min. </li><li> Rimuovere le diapositive e lasciarli in acqua distillata per 5 min. Poi, incubare in acido Fuchsin-Ponceau per 5 min. Risciacquare in acido acetico 1% per 1 min. </li><li> Poi, incubare in acido fosfomolibdico Arancio G per 1 min. Risciacquare in acido acetico 1% per 1 min, incubare a colorante verde luce per 10 minuti, e sciacquare in acido acetico 1% per 1 min. </li><li> li Disidratare in etanolo al 70% (30 sec), 95% di etanolo (30 sec), e il 100% di etanolo (5 min). Mettere una goccia di un mezzo di montaggio resinoso sulle sezioni di tessuto, coprire con coprioggetto, e lasciarli asciugare. </li></ol></li></ol> 4. Infarct Size Analysis <ol><li> Acquisire una immagine da ogni diapositiva su uno stereomicroscopio (15x) accoppiato con una macchina fotografica. Fotografare un righello con la stessa impostazioneS. </li><li> Utilizzare immagine software di analisi per misurare lo spessore della cicatrice in mezzo dell&#39;infarto, lo spessore del setto, la zona della cavità ventricolo sinistro (LV), la zona dell&#39;infarto, e l&#39;area di tessuto LV utilizzando. <ol><li> Impostare la scala con l&#39;immagine righello (Figura 1A). <ol><li> Clicca su misurazioni quindi selezionare Imposta fattore di conversione. Tracciare una linea sulla barra di calibrazione. Fare clic destro sull&#39;immagine e cliccare su taratura finale. Si noti il valore bar, e quindi fare clic su OK. </li></ol></li><li> Selezionare il LV dalla foto del cuore colorato (Figura 1B). Utilizzare lo strumento segmento multiplo. Selezionare il punto per punto LV, e quindi fare clic destro Copia / incolla da nessuna parte. </li><li> Misurare lo spessore della cicatrice e membrana con lo strumento di misurazione singolo segmento (Figura 1C </strong&gt;). </li><li> Rileva automaticamente il LV cavità, infarto, e le aree LV utilizzando lo strumento di misurazione locale automatico in modalità RGB (Figura 1D). <ol><li> Fare clic sullo strumento. Attiva solo Bordi e Contigui in modalità RGB. Infine, fare clic all&#39;interno dell&#39;area di interesse per rilevarla. Se necessario, utilizzare strumenti di precisione. </li></ol></li></ol></li><li> Calcolare le dimensioni dell&#39;infarto come rapporto dell&#39;area infartuata all&#39;area LV. </li><li> Calcolare l&#39;indice di espansione come segue: [LV zona cavità / intera area LV] / [spessore infarto / spessore del setto], con l&#39;intera area LV comprendente sia la cavità LV e aree di tessuto LV. </li><li> Infine, calcolare un &quot;medio&quot; per ogni cuore come segue: [media dell&#39;indice di espansione dalle diapositive infartuati] * [numero di diapositive infartuati / numero totale di diapositive]. </li></ol>

<ol>
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The authors have nothing to disclose.

I passaggi critici all&#39;interno del protocollo tessuto fibrotico può essere valutata con precisione in un modello di ratto MI cronica con campionamento sistematico del cuore e l&#39;immagine raccolta analisi di sezioni istologiche tricromatiche macchiato ottenuti dalla base all&#39;apice. Due passi sono particolarmente importanti per l&#39;attuazione del protocollo di successo. In primo luogo, l&#39;uso di KCl per la raccolta cardiaca permette il muscolo cardiaco per ess...

Infarto del miocardio (MI) è una delle principali cause di morte e disabilità in tutto il mondo. La malattia coronarica è la causa principale; MI deriva da ischemia consecutivo a eventi coronarici quali l&#39;occlusione. Quando riperfusione non viene eseguita entro le prime 6 ore, ischemia induce necrosi miocardica irreversibile. Nei pazienti, la caratterizzazione di MI si basa su diversi strumenti diagnostici, tra cui i segni clinici, elettrocardiogramma, valutazione dei livelli plasmatici di biomarcatori, l&#39;ecocardiografia, risonanza magnetica per immagini, e istologica analisi 1. Acuta e cronica MI sono classificati in due diverse fasi di pregiudizio secondo i tempi della necrosi miocardica rispetto al tempo della occlusione coronarica. La fase acuta, che si verificano durante i primi 7 giorni, è associato con la perdita di cardiomiociti, infiammazione estesa, e il reclutamento di fibroblasti. La fase sub-acuta, caratterizzata da guarigione del tessuto cardiaco e la formazione di una cicatrice, si verificatra 1 e 4 - 6 settimane. Espansione dell&#39;infarto, assottigliamento della parete del ventricolo, e il ventricolo dilatazione caratterizzano la fase cronica. Ampia rimodellamento del ventricolo sinistro si traduce progressivamente in grave insufficienza cardiaca 2. MI indotta da permanente discendente anteriore sinistra (LAD) legatura rappresenta il modello roditore livello di infarto miocardico cronico. I imita legatura coronarie l&#39;occlusione coronarica. Le dimensioni dell&#39;infarto dipende dal sito della legatura. Caratterizzazione di danno ischemico del miocardio in un modello di roditore è classicamente eseguita utilizzando i livelli plasmatici di biomarker, come la troponina I e T 3, l&#39;ecocardiografia, risonanza magnetica, e istologia 4,5. livelli di biomarker sono correlati con l&#39;entità della morte dei cardiomiociti. L&#39;ecocardiografia valuta la funzione ventricolare sinistra di valore derivante da anomalie di movimento della parete regionali. Inoltre, le tecniche di imaging non invasive, come la risonanza magnetica o ad alta risoluzioneecocardiografia, permetta la valutazione della riduzione di movimento della parete, il volume dell&#39;area cicatriziale con ridotta perfusione e miocardio vitale, e l&#39;assottigliamento della parete. dimensioni LV permettono la valutazione accurata della dimensione dell&#39;infarto. Infine, la quantificazione del miocardio vitale e morti può essere eseguita un&#39;autopsia con macchie specifiche di sezioni istologiche di cuori raccolte e consente la verifica della dimensione dell&#39;infarto (IS). Un&#39;altra caratteristica importante è la valutazione dell&#39;indice di espansione dell&#39;infarto (EI) 6. L&#39;EI è associato con l&#39;infarto transmurale e inizia entro i primi 3 giorni. L&#39;EI è caratterizzata da una progressiva riduzione di spessore della parete, un aumento delle dimensioni della cavità LV, e conseguenti cambiamenti di forma LV. Per valutare l&#39;efficacia terapeutica di nuovi trattamenti - in particolare, le strategie di rigenerazione basata su cellule, matrici, e gene valutazione delivery-accurata MI nei roditori è di fondamentale importanza.Quando misurato su una singola sezione trasversale ottenuta a livello muscolo papillare, la dimensione IS può essere polarizzato a causa della grande variabilità che esiste nello sviluppo dell&#39;infarto seguente legatura LAD; l&#39;infarto apice potrebbe essere poi occultato. È importante sottolineare che le metodologie più accurate alle dimensioni MI determinato sono stati descritti per topi o ratti 7-9 10. Tuttavia, IS è insufficiente per quantificare con precisione LV rimodellamento o riduzioni terapeuticamente indotte (o prevenzioni) del rimodellamento. Infatti, IS è comunemente espressa come percentuale del volume totale LV valutata su sezioni trasversali del cuore. Anche se questo metodo è valido per infarto miocardico acuto, l&#39;assottigliamento della parete LV si verificano durante il rimodellamento rimane sotto-valutato 11,12. Una completa quantificazione morfometrica delle dimensioni dell&#39;infarto e cambiamenti strutturali dovrebbe quantificare diversi parametri, quali la lunghezza endocardici ed epicardici e diametri, così come infarto e zone sane. Descriviamo un appr metodologicaoach per valutare con precisione MI e rimodellamento in un modello di ratto cronica.

<table border="0" cellpadding="0" cellspacing="0" width="775">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Acrylic rat heart matrix 2mm</td>
			<td style="width:119px;">72-5015</td>
			<td style="width:136px;">Harvard Appartus</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:247px;">INSPIRA ADVANCED VOLUME CONTROLLED VENTILATOR</td>
			<td style="width:119px;">HARVARD APPARATUS</td>
			<td style="width:136px;">557058</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">CATHETER INSYTE 14G</td>
			<td style="width:119px;">BD</td>
			<td style="width:136px;">381267</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:247px;">O.C.T</td>
			<td style="width:119px;">BDHA361603E</td>
			<td style="width:136px;">VWR</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">TTC</td>
			<td style="width:119px;">T8877-10G</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Mayer hematoxylin</td>
			<td style="width:119px;">MHS32-1L</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Acid Fuchsin 
			CI 42685</td>
			<td style="width:119px;">F8129-50G</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Ponceau Xylidin 
			CI 16150</td>
			<td style="width:119px;">P2395-25G</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Orange G 
			CI 16230</td>
			<td style="width:119px;">O3756-100G</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:247px;">Light green 
			CI 42095</td>
			<td style="width:119px;">L5382-25G</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">KCl</td>
			<td style="width:119px;">P9333-500G</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Xylol</td>
			<td style="width:119px;">10315083</td>
			<td style="width:136px;">HoneyWell</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Ethanol absolute</td>
			<td style="width:119px;">10303990</td>
			<td style="width:136px;">HoneyWell</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">2-methylbutane</td>
			<td style="width:119px;">M32631-1L</td>
			<td style="width:136px;">Sigma Aldrich</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Stereogical microscope</td>
			<td style="width:119px;">SM2800</td>
			<td style="width:136px;">Nikon</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Formaldehyde</td>
			<td style="width:119px;">99340</td>
			<td style="width:136px;">Reactolab</td>
			<td style="width:273px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Embedding cassette</td>
			<td style="width:119px;">K113.1</td>
			<td style="width:136px;">Carl Roth</td>
			<td style="width:273px;"></td>
		</tr>
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histological quantification of chronic myocardial infarct in rats

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ischemic injury. Following the initial acute phase, chronic remodeling of the left ventricle (LV) modifies the structure and function of the heart. Permanent coronary ligation in small animals has been widely used as a reference model for a chronic model of MI. Thinning of the infarcted wall progressively develops to transmural fibrosis. Histological assessment of infarct size is commonly performed; nevertheless, a standardization of the methods for quantification is missing. Indeed, important methodological aspects, such as the number of sections analyzed and the sampling and quantification methods, are usually not described and therefore preclude comparison across investigations. Too often, quantification is performed on a single section obtained at the level of the papillary muscles. Because novel strategies aimed at reducing infarct expansion and remodeling are under investigation, there is an important need for the standardization of accurate heart sampling protocols. We describe an accurate method to quantify the infarct size using a systematic sampling of harvested rat heart and image analyses of trichromatic stained histological sections obtained from base to apex. We also provide evidence that calculating the expansion index (EI) allowed for infarct size assessment, taking into account changes of the left ventricle throughout the remodeling.

Sei settimane post-LAD legatura, cuori sono state raccolte da ratti di Lewis. sezioni di tessuto 2 mm, sono state ottenute dall&#39;apice alla base. Una procedura di colorazione TTC è stata effettuata per visualizzare l&#39;area infartuale, che appare in bianco, e il miocardio sano, che appare in rosso (Figura 2). A seconda del sito di legatura LAD, le dimensioni dell&#39;infarto varia. Per le grandi MI, infarti transmurale sono stati osservati dal vertice alla base <st...

Watch this Scientific Journal Video about Histological Quantification of Chronic Myocardial Infarct in Rats at JoVE.com

Histological Quantification of Chronic Myocardial Infarct in Rats

The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections.

Quantificazione istologica di cronica Myocardial Infarto in Rats

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ...

histological-quantification-of-chronic-myocardial-infarct-in-rats

Research

JoVE Journal

Medicine

14.4K Views.  University of Fribourg. The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections. 

Video: Histological Quantification of Chronic Myocardial Infarct in Rats

Acute Myocardial Infarction in Rats

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial infarction (AMI). This model is also referred to as an acute ischemic cardiomyopathy or ischemia followed by reperfusion (IR); which is induced by an acute 30-minute period of ischemia by ligation of the left anterior descending artery (LAD) followed by reperfusion of the tissue by releasing the LAD ligation (Vasilyev and McConnell). This protocol will focus on assessment of the infarct size and the area-at-risk (AAR) by Evan's blue dye and triphenyl tetrazolium chloride (TTC) following 4-hours of reperfusion; additional comments toward the evaluation of cardiac function and remodeling by modifying the duration of reperfusion, is also presented. Overall, this AMI rat animal model is useful for studying the consequence of a myocardial infarction on cardiac pathophysiological and physiological function.

The rat model of acute myocardial infarction (AMI) is useful to study the consequence of a MI on cardiac pathophysiological and physiological function.

Infarto acuto del miocardio in topi

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular ...

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Medicina

Acute and Chronic Tactile Sensory Testing after Spinal Cord Injury in Rats

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory testing in rat SCI models is needed. However, until recently, no single testing approach had been validated for SCI so that standardized methods have not been implemented across labs. Additionally, available testing methods could not be implemented acutely or when severe motor impairments existed, preventing studies of the development of SCI-induced allodynia3. Here we present two validated sensory testing methods using von Frey Hair (VFH) monofilaments which quantify changes in tactile sensory thresholds after SCI4-5. One test is the well-established Up-Down test which demonstrates high sensitivity and specificity across different SCI severities when tested chronically5. The other test is a newly-developed dorsal VFH test that can be applied acutely after SCI when allodynia develops, prior to motor recovery4-5. Each VFH monofilament applies a calibrated force when touched to the skin of the hind paw until it bends. In the up-down method, alternating VFHs of higher or lower forces are used on the plantar L5 dermatome to delineate flexor withdrawal thresholds. Successively higher forces are applied until withdrawal occurs then lower force VFHs are used until withdrawal ceases. The tactile threshold reflects the force required to elicit withdrawal in 50% of the stimuli. For the new test, each VFH is applied to the dorsal L5 dermatome of the paw while the rat is supported by the examiner. The VFH stimulation occurs in ascending order of force until at least 2 of 3 applications at a given force produces paw withdrawal. Tactile sensory threshold is the lowest force to elicit withdrawal 66% of the time. Acclimation, testing and scoring procedures are described. Aberrant trials that require a retest and typical trials are defined. Animal use was approved by Ohio State University Animal Care and Use Committee.

We describe two tactile sensory testing methods for acute or chronic periods of spinal cord injury in rats. These validated procedures can detect the development and maintenance of allodynia-like sensations.

Acuta e Cronica test sensoriale tattile dopo lesione del midollo spinale in ratti

Spinal cord injury (SCI) impairs sensory systems causing allodynia1-8. To identify cellular and molecular causes of allodynia, sensitive and valid sensory ...

Chronic Constriction of the Sciatic Nerve and Pain Hypersensitivity Testing in Rats

Chronic neuropathic pain, resulting from damage to the central or peripheral nervous system, is a prevalent and debilitating condition, affecting 7-18% of the population1,2. Symptoms include spontaneous (tingling, burning, electric-shock like) pain, dysaesthesia, paraesthesia, allodynia (pain resulting from normally non-painful stimuli) and hyperalgesia (an increased response to painful stimuli). The sensory symptoms are co-morbid with behavioural disabilities, such as insomnia and depression. To study chronic neuropathic pain several animal models mimicking peripheral nerve injury have been developed, one of the most widely used is Bennett and Xie's (1988) unilateral sciatic nerve chronic constriction injury (CCI)3 (Figure 1). Here we present a method for performing CCI and testing pain hypersensitivity.
CCI is performed under anaesthesia, with the sciatic nerve on one side exposed by making a skin incision, and cutting through the connective tissue between the gluteus superficialis and biceps femoris muscles. Four chromic gut ligatures are tied loosely around the sciatic nerve at 1 mm intervals, to just occlude but not arrest epineural blood flow. The wound is closed with sutures in the muscle and staples in the skin. The animal is then allowed to recover from surgery for 24 hrs before pain hypersensitivity testing begins.
For behavioural testing, rats are placed into the testing apparatus and are allowed to habituate to the testing procedure. The area tested is the mid-plantar surface of the hindpaw (Figure 2), which falls within the sciatic nerve distribution. Mechanical withdrawal threshold is assessed by mechanically stimulating both injured and uninjured hindpaws using an electronic dynamic plantar von Frey aesthesiometer or manual von Frey hairs4. The mechanical withdrawal threshold is the maximum pressure exerted (in grams) that triggers paw withdrawal. For measurement of thermal withdrawal latency, first described by Hargreaves et al (1988), the hindpaw is exposed to a beam of radiant heat through a transparent glass surface using a plantar analgesia meter5,6. The withdrawal latency to the heat stimulus is recorded as the time for paw withdrawal in both injured and uninjured hindpaws. Following CCI, mechanical withdrawal threshold, as well as thermal withdrawal latency in the injured paw are both significantly reduced, compared to baseline measurements and the uninjured paw (Figure 3). The CCI model of peripheral nerve injury combined with pain hypersensitivity testing provides a model system to investigate the effectiveness of potential therapeutic agents to modify chronic neuropathic pain. In our laboratory, we utilise CCI alongside thermal and mechanical sensitivity of the hindpaws to investigate the role of neuro-immune interactions in the pathogenesis and treatment of neuropathic pain.

Due to the simplicity of surgery and the robust behavioural outcome, chronic constriction of the sciatic nerve is one of the pre-eminent animal models of neuropathic pain. Within 24 hrs following surgery, pain hypersensitivity is established and can be quantitatively measured using a von Frey aesthesiometer (mechanical test) and plantar analgesia meter (thermal test).

La costrizione cronica del nervo sciatico e Ipersensibilità Testing Pain in Rats

Chronic neuropathic pain, resulting from damage to the central or peripheral nervous system, is a prevalent and debilitating condition, affecting 7-18% of ...

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery (SALLI) MRI in Rats

Small animal magnetic resonance imaging is an important tool to study cardiac function and changes in myocardial tissue. The high heart rates of small animals (200 to 600 beats/min) have previously limited the role of CMR imaging. Small animal Look-Locker inversion recovery (SALLI) is a T1 mapping sequence for small animals to overcome this problem 1. T1 maps provide quantitative information about tissue alterations and contrast agent kinetics. It is also possible to detect diffuse myocardial processes such as interstitial fibrosis or edema 1-6. Furthermore, from a single set of image data, it is possible to examine heart function and myocardial scarring by generating cine and inversion recovery-prepared late gadolinium enhancement-type MR images 1.
	The presented video shows step-by-step the procedures to perform small animal CMR imaging. Here it is presented with a healthy Sprague-Dawley rat, however naturally it can be extended to different cardiac small animal models.

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

Contrast enhanced cardiac magnetic resonance (CMR) imaging allows comprehensive in vivo assessment of the heart in small animal models of cardiovascular disease. Here we detail the procedures to perform CMR imaging, reconstruction and analysis using Small Animal Lock-Locker Inversion Recovery (SALLI) in rats.

Valutazione della funzione cardiaca e Morfologia miocardica Utilizzando Small Animal Look-Locker Inversion Recovery (SALLI) MRI nei ratti

Small animal magnetic resonance  imaging is an important tool to study cardiac function and changes in myocardial  tissue. The high heart rates of small ...

MRI and PET in Mouse Models of Myocardial Infarction

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies.
In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment.
In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.

We describe how to perform MRI and PET imaging of the mouse heart. The protocol is tailored to assess treatment efficacy in models of myocardial infarction and heart failure.

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ...

Ultrasonic Assessment of Myocardial Microstructure

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. Ultrasonic assessments of cardiac tissue can include analyses of backscatter signal intensity within a given region of interest. Previously established techniques have relied predominantly on the integrated or mean value of backscatter signal intensities, which may be susceptible to variability from aliased data from low frame rates and time delays for algorithms based on cyclic variation. Herein, we describe an ultrasound-based imaging algorithm that extends from previous methods, can be applied to a single image frame&#160;and accounts for the full distribution of signal intensity values derived from a given myocardial sample. When applied to representative mouse and human imaging data, the algorithm distinguishes between subjects with and without exposure to chronic afterload resistance. The algorithm offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

Echocardiography is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. We describe an ultrasound-based imaging algorithm that offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

Valutazione ad ultrasuoni della microstruttura miocardica

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and ...

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

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

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

Vescica urinaria Distensione Evocati visceromotoria Risposte come un modello per il dolore della vescica nei topi

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

Echocardiographic and Histological Examination of Cardiac Morphology in the Mouse

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed in mice is high. Phenotypic characterization of these mouse models also requires the examination of cardiac function and morphology. Echocardiography and magnetic resonance imaging (MRI) are commonly used approaches to characterize cardiac function and morphology in mice. Echocardiographic and MRI equipment specialized for use in small rodents is&#160;expensive and requires a dedicated space. This protocol describes cardiac measurements in mice using a clinical echocardiographic system with a 15 MHz human vascular probe. Measurements are performed on anesthetized adult mice. At least three image sequences are recorded and analyzed for each animal in M-mode in the parasternal short-axis view. Afterwards, cardiac histological examination is performed, and cardiomyocyte diameters are determined on hematoxylin-eosin- or wheat germ agglutinin (WGA)-stained paraffin sections. Vessel density is determined morphometrically after Pecam-1 immunostaining. The protocol has been applied successfully to pharmacological studies and different genetic animal models under baseline conditions, as well as after experimental myocardial infarction by the permanent ligation of the left anterior descending coronary artery (LAD). In our experience, echocardiographic investigation is limited to anesthetized animals and is feasible in adult mice weighing at least 25 g.

Echocardiographic examination is frequently used in mice. Expensive high-resolution ultrasound devices have been developed for this purpose. This protocol describes an affordable echocardiographic procedure combined with histological morphometric analyses to determine cardiac morphology.

Esame ecocardiografico ed istologico della morfologia cardiaca nel topo

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed ...

Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via recanalization of the coronary artery is the most effective strategy for reducing the size of ischemic myocardium. The coronary microvasculature cannot be visualized and imaged&#160;in vivo, but there are several invasive and noninvasive techniques that can be used to assess parameters which depend directly on coronary microvascular function. The endothelial function after ischemia reperfusion can be assessed also at the level of the coronary circulation via the coronary flow reserve (CFR).&#160;In this study, peak velocity of left anterior descending (LAD) coronary arteries was measured in rats in vivo via Transthoracic Doppler Echocardiography during resting and stress challenge (induced by Dobutamine). A normal heart can increase its coronary blood flow up to four times above the resting values during stress induction. Following ischemia reperfusion, we found a significantly diminished CFR, which can be used as a marker of coronary microvascular dysfunction. CFR has opened a window on the importance of microvascular dysfunction and has been shown to predict cardiovascular risk independent of whether the severe obstructive disease is present.

Coronary flow reserve (CFR), is defined as the ratio of maximal coronary blood flow to the resting coronary blood flow. We present a protocol for evaluating CFR in rats via ultrasound, which offers the opportunity to predict cardiovascular risk factors in the absence of obstructive coronary disease.

Valutazione della riserva del flusso coronario dopo la miaocardia Ischemia Reperfusione nei ratti

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via ...

Semi-Minimal Invasive Method to Induce Myocardial Infarction in Rats and the Assessment of Cardiac Function by an Isolated Working Heart System

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily and highly reproducible MI induction procedure is required to obtain further insight and better understanding of the underlying pathological changes. This procedure can also be used to evaluate the effects or potency of new and promising treatments (as drugs or interventions) in acute MI, subsequent remodeling and heart failure (HF). After intubation and pre-operative preparation of the animal, an anesthetic protocol with isoflurane was performed, and the surgical procedure was conducted&#160;quickly. Using a minimally invasive approach, the left anterior descending artery (LAD) was located and occluded by a ligature. The occlusion can be performed acutely for subsequent reperfusion (ischemia/reperfusion injury). Alternatively, the vessel can be ligated permanently to investigate the development of chronic MI, remodeling or HF. Despite common pitfalls, the drop-out rates are minimal. Various treatments such as remote ischemic conditioning can be examined for their cardioprotective potential pre-, peri- and post-operatively. The post-operative recovery was quick as the anesthesia was precisely controlled and the duration of the operation was short. Post-operative analgesia was administered for three days. The minimally invasive procedure reduces the risk of infection and inflammation. Furthermore, it facilitates rapid recovery. The &#8220;working heart&#8221; measurements were performed ex vivo and enabled precise control of preload, afterload and flow. This procedure requires specific equipment and training for adequate performance. This manuscript provides a detailed step-by-step introduction for conducting these measurements.

This article presents an efficient method to perform myocardial ischemia and subsequent chronic reperfusion in rats using a minimally invasive approach. In addition, left ventricular hemodynamic function of rats is assessed by echocardiography and isolated working heart methods.&#160;

Metodo semi-minimo invasivo per indurre l'infarto miocardico nei ratti e la valutazione della funzione cardiaca da parte di un sistema cardiaco funzionante isolato

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily ...