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

declaração de ética: Todos os procedimentos com animais mencionados neste vídeo-artigo foram revistos e aprovados pela Comissão de animal Cuidado e Uso (IACUC) da Universidade de Tennessee Health Science Center. Nota: Utilize instrumentos de microcirurgia estéreis durante todo o procedimento cirúrgico. Os instrumentos cirúrgicos podem ser esterilizadas utilizando um esterilizador de infravermelhos a uma temperatura de esterilização óptima de 1500 ° F (815,6 ° C). Telémetros pode ser reutilizado, no entanto, antes de o introduzir no animal certificar-se para esterilizar todo o transmissor de acordo com as instruções do fabricante e que a ponta do cateter foi novamente cheio com um gel especial fornecida pelo fabricante. 1. Animais Experimentais <ol><li> Obter uma aprovação IACUC para todos os experimentos que serão executadas. Consulta com IACUC institucional é altamente recomendado em relação aos requisitos para uso de analgésicos no pós-operatório após este procedimento. </li><li> Manter os animais em cquartos controlados por limate com uma temperatura ambiente de 21 ° C, 60% de humidade relativa, e um ciclo de luz-escuro de 12 h com livre acesso a comida e água. Observação: Uma vez que o corpo do ratinho tem para acomodar a sonda de telemetria (approximatively 1 cm de diâmetro x 2 cm de comprimento), é preferível utilizar ratinhos que pesam de 20 g ou mais. </li></ol> 2. Anestesia e Preparação operativo <ol><li> Pesar o rato usando uma balança de precisão e registar o peso. Certifique-se de lidar com o animal suavemente e silenciosamente. </li><li> Colocar o animal na câmara de indução e fechá-lo. Ajustar a taxa de fluxo de oxigênio em 0,5 L / min e definir concentração de isoflurano em 4-5%. </li><li> Quando o mouse perde a consciência, coloque-o em uma placa de aquecimento corporal mantida a 36-37 ° C. Manter a anestesia via nosecone com o conjunto de isoflurano a 2% (manter a taxa de fluxo de 0,5 L / min). </li><li> Preparar as regiões de operação, removendo o cabelo da parte de trás do pescoço e tele aspecto ventral do pescoço, aplicando creme de depilação. </li><li> Tratar o local da incisão com 3 aplicações de paramentação (solução de betadine) alternando com álcool isopropílico 70%. </li></ol> 3. Cirurgia <ol><li> Posicione o mouse na posição supina. Verifique se há reflexos comprimindo o pé, e ajustar a anestesia até que não haja resposta. Realizar uma incisão na linha média, aproximadamente, 1 cm abaixo do pescoço do rato com um bisturi. No lado esquerdo do corte criar um espaço subcutâneo, separando cuidadosamente a pele a partir do tecido conjuntivo subjacente. </li><li> Virar o mouse e usar um bisturi para fazer uma incisão na pele de aproximadamente 1,5 cm de lado dorsal deixou para trás a escápula. Criar uma bolsa subcutânea ao longo do flanco do animal grande o suficiente para acomodar o dispositivo. Insira o transmissor no bolso. </li><li> Insira uma pequena pinça hemostática na incisão para trás e manobrá-lo por via subcutânea para a anteriorabertura do pescoço. Usando a pinça hemostática-inserido, suavemente compreender um tubo de polietileno não-tóxico (4 cm de comprimento x 1 mm de diâmetro). <ol><li> Puxar a hemostática de volta através do túnel para a incisão lateral na parte de trás até que o tubo se projecta a partir de ambos incisão abdominal e dorsal, libertar o tubo a partir da pinça hemostática. A partir da parte traseira, inserir o sensor de cateter para dentro do tubo de túnel a ponta do cateter de detecção de pressão através do pescoço. Do anterior do pescoço, puxar e retirar o tubo de polietileno e fechar a incisão dorsal utilizando grampos metálicos. </li></ol></li><li> Separe cuidadosamente as glândulas mandibulares, utilizando aplicadores com ponta de algodão estéril e retirar a glândula mandibular esquerda, utilizando uma estadia gancho elástico. Usando uma pinça curva de ponta fina, localize a artéria carótida ao longo do lado esquerdo da traquéia. Mantenha o local da cirurgia estéril, colocando e garantir uma cortina estéril. <ol><li> Cuidadosamente isolar o vaso do tecido circundante e suavemente separar onervo vago (de cor esbranquiçada) que está ao longo da artéria carótida de distância a partir da artéria. Tenha cuidado para não cortar ou danificar o nervo ou artéria. </li></ol></li><li> Passe três pedaços de não-absorvível 7-0 sutura abaixo da seção artéria carótida isolado. Amarre a sutura craniana para fechar o fluxo de sangue. Puxar o fio de sutura que está mais próxima do esterno para ocluir temporariamente o fluxo de sangue a partir da aorta. </li><li> Faça um nó frouxo usando a sutura do meio. Isto irá ser utilizado para segurar o cateter no vaso. Corte uma pequena incisão na artéria entre o crânio e as suturas esternais usando micro-tesoura. </li><li> Agarre o cateter com uma pinça especial de punção embarcação, tendo o cuidado de não apertar o cateter para evitar a perda de gel da sonda. Gentilmente, pegue a artéria com uma ponta fina curvas pinças pinças, recuperar o cateter, e inseri-lo no vaso através da pequena incisão. </li><li> Apertar o nó de sutura meio ao redor da artéria e gentilmente avançar o gatoheter. Gentilmente liberar a sutura que é proximal ao esterno e continuar a avançar o cateter para a aorta transversal. <ol><li> Observar a marca no cateter que dá um índice aproximado de quão longe o cateter tem de ser inserido. Uma vez que o ponto é atingido, apertar ligeiramente inferior tanto a sutura e a parte superior em torno do cateter. O cateter é fixado ao da artéria carótida por nós de sutura. </li></ol></li><li> Feche a incisão na pele com os não-absorvível 5-0 sutura. Uma vez fechado, selar a incisão com adesivo de tecido. </li></ol> 4. Medidas de recuperação e BP cirúrgicos <ol><li> Monitorar animais de perto para o retorno de posturas e comportamentos normais. Durante a 24 horas pós-cirurgia analgesia período de administrar como dirigido por um veterinário equipe. </li><li> Uma vez que os animais se recuperaram (5 - 7 dias após a cirurgia), abrigá-los individualmente em uma gaiola regular de rato colocado em cima do prato receptor de telemetria. </li><li> Vire o tr implantadoansmitters &quot;ON&quot; e &quot;OFF&quot; usando um dispositivo magnético brevemente posicionado perto do animal a partir do lado de fora da gaiola. </li></ol>

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	<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.

Implantável radio-telemetria tem melhorado significativamente ao longo da última década; o tamanho da sonda menor faz o implante menos traumática para o animal, a vida da bateria prolongada ajuda a reduzir os custos e frequências Telemeter independentes eliminar crosstalk entre receptores. Telemetria é considerado o método state-of-the-art para a recolha de uma grande variedade de parâmetros fisiológicos de se mover livremente animais sem os artefatos associados com o uso da contenção, a interação humana, o...

A hipertensão arterial é um dos principais fatores de risco para doenças cardiovasculares, sem dúvida, é um grande problema de saúde pública tanto nos países desenvolvidos e em desenvolvimento 1. Vários modelos animais de hipertensão experimentais têm sido desenvolvidos para imitar respostas hipertensivas, como as observadas em humanos 2. Entre outros, o mouse ambulatório representa um excelente modelo para o estudo da gênese e progressão da hipertensão permitindo a análise in vivo das consequências da exposição crônica à hipertensão. Pressão arterial (PA) de monitoramento em camundongos tem ajudado os pesquisadores a desvendar vários mecanismos envolvidos na fisiologia e fisiopatologia de doenças como hipertensão e insuficiência cardíaca 3, 4. Com efeito, a manipulação do genoma de ratinho permitiu a geração de modelos transgénicos ou alvejado para o gene apropriado para o estudo da hipertensão 5, 6. No entanto, mesmo a manipulação suavede ratos conscientes induz excitações que podem potencialmente causadores de artefatos durante a aquisição de dados, enquanto o uso de sedação ou tranquilizantes afetar profundamente a pressão arterial 7. Estes aspectos são particularmente importantes e devem ser levados em consideração ao tentar monitoramento BP longo prazo. Existem várias maneiras de gravar BP em ratos, e uma comparação entre as técnicas mais comuns atualmente disponíveis tem sido discutido em outra parte 8, 9. No entanto, as recomendações da AHA de medição BP concluiu que a medição intra-arterial da pressão arterial são geralmente preferidos devido à sua capacidade para medir directamente PA ao longo de um período prolongado de tempo 10. Radiotelemetria juntamente com medida direta da pressão arterial é o método state-of-the-art para monitorar as funções fisiológicas no acordado e movendo-se livremente animais de laboratório, minimizando o estresse e artefatos ambientalmente associados 9, 11.Radiotelemetria oferece a capacidade de recolher automaticamente a pressão arterial, freqüência cardíaca, temperatura corporal e atividade animal provenientes de vários animais conscientes. Embora esta metodologia está se tornando muito popular em muitos laboratórios, implantação de rádio-telemetria em camundongos pode ser tecnicamente desafiadora. Aqui, mostramos um protocolo passo-a-passo que ilustra como a implantação de um transdutor de pressão em ratinhos. A técnica envolve a inserção subcutânea da sonda no corpo do rato, canalizar o cateter para o pescoço e para a frente perto do arco aórtico através da artéria carótida esquerda. dados remotamente capturados são mostrados ao vivo no monitor do computador. Os dados também são armazenados para análise &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 o desenvolvimento de novos agentes vasoativos, monitorização da pressão sanguínea arterial é crucial para avaliar a eficácia dos novos medicamentos propostos. De fato, a pesquisa com foco na descoberta de novos alvos terapêuticos potenciais usando ratos geneticamente modificados exige uma avaliação fiável e de longo prazo da variação da pressão arterial sistêmica. Atualmente, o padrão ouro para a obtenção de medidas de longo prazo da pressão arterial em ratos ambulatoriais utiliza rádio-transmissores implantáveis, que exigem canulação da artéria. Esta técnica elimina a necessidade de tethering, restringindo ou anestesiar os animais que introduzem o stress e artefatos durante a amostragem de dados. No entanto, a monitorização da pressão arterial em ratos através de cateterismo pode ser bastante desafiador, devido ao pequeno tamanho das artérias. Aqui nós apresentamos um guia passo-a-passo para ilustrar as passagens-chave cruciais para a implantação subcutânea bem sucedida de rádio-transmissores e artéria carótida cannulation em ratinhos. Nós também incluímos exemplos de atividade pressão arterial a longo prazo retiradas de ratos movimentando-se livremente após um período de recuperação pós-cirurgia. Após este procedimento permitirá gravações de pressão arterial direta de confiança de vários animais ao mesmo tempo.

Os dados podem ser adquiridos à distância através de um receptor; traços são visualizados na tela do computador para controle de qualidade (Figura 1a). Detalhes como ID animal, pressão diastólica e pressão arterial sistólica também são mostrados (Figura 1b). Arterial BP podem ser gravadas continuamente (24/7), ou por curtos intervalos programados (ou seja, 60 seg aquisição a cada hora). Os dados podem ser automaticamente armazenada ...

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

Longo prazo medição de pressão arterial em ratos movimentando-se livremente utilizar 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. ...

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

Research

JoVE Journal

Medicine

18.3K visualizações.  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.

Vídeo: 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.

Ventilação a pressão controlada para induzir lesão pulmonar aguda em ratos

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

Medicina

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.

Medida da Pressão Intracraniana peridural em ratos, utilizando um transdutor de pressão de fibra óptica

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.

Medição da curva pressão-volume no 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 ...

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 Intrauterine medir Rato contrátil Pressão<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.

Cirurgia de colocação de cateteres para Cardiovascular Testes exercício de longo prazo em Suínos

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.

Transdermal medição da taxa de filtração Glomerular em ratos

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.

Gravação simultânea de eletrocardiografia e sangue invasiva pressão medida em ratos

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.

Coleta de sangue por punção da veia subclávia em camundongos

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.

Implantação de ECG Telemétrico Combinado e Transmissores de Pressão Arterial para Determinação da Sensibilidade Barorreflexa Espontânea em Camundongos Conscientes

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.

Analisando gravações de eletrocardiografia de longo prazo para detectar arritmias em camundongos

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