Name: long-term blood pressure measurement in freely moving mice using telemetry
Uploaded: 2016-05-17T14:00:00.000+00:00
Duration: 7 min 54 s
Description: Watch this Scientific Journal Video about Long-term Blood Pressure Measurement in Freely Moving Mice Using Telemetry at JoVE.com

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, 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, 7 mm, 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&amp;nbsp;</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&amp;nbsp;</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&amp;nbsp;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&amp;nbsp;in 5-10 seconds using infrared heating</td></tr><tr><td>Gauze Pads</td><td>Johnson &amp;amp; Johnson, New Brunswick, NJ, USA</td><td>JJ8513</td><td>to use for wound cleaning, prepping, scrubbing 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&amp;nbsp; coumpled with a PC</td><td>Data Sciences International, St. Paul, MN, USA</td><td></td><td></td></tr><tr><td>Tubing</td><td>Instech Laboratories, Plymouth Meeting, PA USA</td><td>BTPE-90</td><td></td></tr><tr><td>Vessel Cannulation Forceps, 13 cm, 0.5 mm 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.:&amp;nbsp;11380041</td><td>use to close minor wounds, often eliminating the need for sutures and/or bandages</td></tr><tr><td>Weighing scale&amp;nbsp;</td><td></td><td>BB300</td><td>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. ...

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Research

JoVE Journal

Medicine

18.6K 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

Implantation of Radiotelemetry Transmitters Yielding Data on ECG, Heart Rate, Core Body Temperature and Activity in Free-moving Laboratory Mice

The laboratory mouse is the animal species of choice for most biomedical research, in both the academic sphere and the pharmaceutical industry. Mice are a manageable size and relatively easy to house. These factors, together with the availability of a wealth of spontaneous and experimentally induced mutants, make laboratory mice ideally suited to a wide variety of research areas.
In cardiovascular, pharmacological and toxicological research, accurate measurement of parameters relating to the circulatory system of laboratory animals is often required. Determination of heart rate, heart rate variability, and duration of PQ and QT intervals are based on electrocardiogram (ECG) recordings. However, obtaining reliable ECG curves as well as physiological data such as core body temperature in mice can be difficult using conventional measurement techniques, which require connecting sensors and lead wires to a restrained, tethered, or even anaesthetized animal. Data obtained in this fashion must be interpreted with caution, as it is well known that restraining and anesthesia can have a major artifactual influence on physiological parameters1, 2.
Radiotelemetry enables data to be collected from conscious and untethered animals. Measurements can be conducted even in freely moving animals, and without requiring the investigator to be in the proximity of the animal. Thus, known sources of artifacts are avoided, and accurate and reliable measurements are assured. This methodology also reduces interanimal variability, thus reducing the number of animals used, rendering this technology the most humane method of monitoring physiological parameters in laboratory animals3, 4. Constant advancements in data acquisition technology and implant miniaturization mean that it is now possible to record physiological parameters and locomotor activity continuously and in realtime over longer periods such as hours, days or even weeks3, 5.
Here, we describe a surgical technique for implantation of a commercially available telemetry transmitter used for continuous measurements of core body temperature, locomotor activity and biopotential (i.e. onelead ECG), from which heart rate, heart rate variability, and PQ and QT intervals can be established in freeroaming, untethered mice. We also present pre-operative procedures and protocols for post-operative intensive care and pain treatment that improve recovery, well-being and survival rates in implanted mice5, 6.

A surgical technique for implantation of commercially available telemetry transmitters used for continuous measurement of biopotential (one-lead ECG), heart rate, core body temperature and locomotor activity in freely moving mice is shown. Recommendations and protocols for post-operative care and pain relief, improving recovery, well being and survival rate are also presented.

Implantação de Transmissores de radiotelemetria Cedendo Dados sobre ECG, freqüência cardíaca, temperatura corporal e atividade em camundongos de laboratório de movimento livre

The laboratory mouse is the animal species of choice for most biomedical research, in both the academic sphere and the pharmaceutical industry. Mice are a ...

Medicina

Measuring Blood Pressure in Mice using Volume Pressure Recording, a Tail-cuff Method

The CODA 8-Channel High Throughput Non-Invasive Blood Pressure system measures the blood pressure in up to 8 mice or rats simultaneously. The CODA tail-cuff system uses Volume Pressure Recording (VPR) to measure the blood pressure by determining the tail blood volume. A specially designed differential pressure transducer and an occlusion tail-cuff measure the total blood volume in the tail without the need to obtain the individual pulse signal. Special attention is afforded to the length of the occlusion cuff in order to derive the most accurate blood pressure readings. VPR can easily obtain readings on dark-skinned rodents, such as C57BL6 mice and is MRI compatible. The CODA system provides you with measurements of six (6) different blood pressure parameters; systolic and diastolic blood pressure, heart rate, mean blood pressure, tail blood flow, and tail blood volume. Measurements can be made on either awake or anesthetized mice or rats. The CODA system includes a controller, laptop computer, software, cuffs, animal holders, infrared warming pads, and an infrared thermometer. There are seven different holder sizes for mice as small as 8 grams to rats as large as 900 grams.

The CODA 8-Channel High Throughput Non-Invasive Blood Pressure system measures the blood pressure in up to 8 mice or rats simultaneously. This tail-cuff system uses Volume Pressure Recording (VPR) to measure the blood pressure by determining the tail blood volume.

Medição da pressão arterial em ratos usando Recording Volume de pressão, um método de cauda-manguito

The CODA 8-Channel High Throughput Non-Invasive Blood Pressure system measures the blood pressure in up to 8 mice or rats simultaneously. The CODA ...

Biologia

Monitoring of Systemic and Hepatic Hemodynamic Parameters in Mice

The use of mouse models in experimental research is of enormous importance for the study of hepatic physiology and pathophysiological disturbances. However, due to the small size of the mouse, technical details of the intraoperative monitoring procedure suitable for the mouse were rarely described. Previously we have reported a monitoring procedure to obtain hemodynamic parameters for rats. Now, we adapted the procedure to acquire systemic and hepatic hemodynamic parameters in mice, a species ten-fold smaller than rats. This film demonstrates the instrumentation of the animals as well as the data acquisition process needed to assess systemic and hepatic hemodynamics in mice. Vital parameters, including body temperature, respiratory&#160;rate&#160;and heart&#160;rate were recorded throughout the whole procedure. Systemic hemodynamic parameters consist of carotid artery pressure (CAP) and central venous pressure (CVP). Hepatic perfusion parameters include portal vein pressure (PVP), portal flow rate as well as the flow rate of the common hepatic artery (table 1). Instrumentation and data acquisition to record the normal values was completed within 1.5 h. Systemic and hepatic hemodynamic parameters remained within normal ranges during this procedure.
This procedure is challenging but feasible. We have already applied this procedure to assess hepatic hemodynamics in normal mice as well as during 70% partial hepatectomy and in liver lobe clamping experiments. Mean PVP after resection (n= 20), was 11.41&#177;2.94 cmH2O which was significantly higher (P&#60;0.05) than before resection (6.87&#177;2.39 cmH2O). The results of liver lobe clamping experiment indicated that this monitoring procedure is sensitive and suitable for detecting small changes in portal pressure and portal flow rate. In conclusion, this procedure is reliable in the hands of an experienced micro-surgeon but should be limited to experiments where mice are absolutely needed.

This film demonstrates how to acquire systemic and hepatic hemodynamics in mice. The whole monitoring includes acquisition of vital parameters, systemic blood pressure, central venous pressure, common hepatic artery flow rate, and portal vein pressure as well as the portal flow rate in mice.

Monitoramento da sistêmicas e hepática Hemodinâmica em Ratos

The use of mouse models in experimental research is of enormous importance for the study of hepatic physiology and pathophysiological disturbances. ...

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. ...

Novel Approach for Simultaneous Recording of Renal Sympathetic Nerve Activity and Blood Pressure with Intravenous Infusion in Conscious, Unrestrained Mice.

Renal sympathetic nerves contribute significantly to both physiological and pathophysiological phenomena. Evaluating renal sympathetic nerve activity (RSNA) is of great interest in many areas of research such as chronic kidney disease, hypertension, heart failure, diabetes and obesity. Unequivocal assessment of the role of the sympathetic nervous system is thus imperative for proper interpretation of experimental results and understanding of disease processes. RSNA has been traditionally measured in anesthetized rodents, including mice. However, mice usually exhibit very low systemic blood pressure and hemodynamic instability for several hours during anesthesia and surgery. Meaningful interpretation of RSNA is confounded by this non-physiological state, given the intimate relationship between sympathetic nervous tone and cardiovascular status. To address this limitation of traditional approaches, we developed a new method for measuring RSNA in conscious, freely-moving mice. Mice were chronically instrumented with radio-telemeters for continuous monitoring of blood pressure as well as a jugular venous infusion catheter and custom-designed bipolar electrode for direct recording of RSNA. Following a 48-72 hour recovery period, survival rate was 100% and all mice behaved normally. At this time-point, RSNA was successfully recorded in 80% of mice, with viable signals acquired up to 4 and 5 days post-surgery in 70% and 50% of mice, respectively. Physiological blood pressures were recorded in all mice (116&plusmn;2 mmHg; n=10). Recorded RSNA increased with eating and grooming, as well-established in the literature. Furthermore, RSNA was validated by ganglionic blockade and modulation of blood pressure with pharmacological agents. Herein, an effective and manageable method for clear recording of RSNA in conscious, freely-moving mice is described.

Anesthetized mice exhibit non-physiological systemic blood pressure, which precludes meaningful assessment of autonomic tone given the intimate relationship between blood pressure and the autonomic nervous system. Thus, a novel method to simultaneously record renal sympathetic nerve activity and blood pressure with intravenous infusion in conscious mice is outlined.

Nova abordagem para gravação simultânea da atividade do nervo simpático Renal e pressão arterial com infusão intravenosa em consciente, ratos desenfreados.

Renal sympathetic nerves contribute significantly to both physiological and pathophysiological phenomena. Evaluating renal sympathetic nerve activity ...

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. ...

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. ...

Long-Term Continuous Measurement of Renal Blood Flow in Conscious Rats

The kidneys play a crucial role in maintaining the homeostasis of body fluids. The regulation of renal blood flow (RBF) is essential to the vital functions of filtration and metabolism in kidney function. Many acute studies have been carried out in anesthetized animals to measure RBF under various conditions to determine mechanisms responsible for the regulation of kidney perfusion. However, for technical reasons, it has not been possible to measure RBF continuously (24 h/day) in unrestrained unanesthetized rats over prolonged periods. These methods allow the continuous determination of RBF over many weeks while also simultaneously recording blood pressure (BP) with implanted catheters (fluid-filled or by telemetry). RBF monitoring is carried out with rats placed in a circular servo-controlled rat cage that enables the unrestrained movement of the rat throughout the study. At the same time, the tangling of cables from the flow probe and arterial catheters is prevented. Rats are first instrumented with an ultrasonic flow probe placement on the left renal artery and an arterial catheter implanted in the right femoral artery. These are routed subcutaneously to the nape of the neck, and connected to the flowmeter and pressure transducer, respectively, to measure RBF and BP. Following surgical implantation, rats are immediately placed in the cage to recover for at least one week and stabilize the ultrasonic probe recordings. Urine collection is also feasible in this system. The surgical and post-surgical procedures for continuous monitoring are demonstrated in this protocol.

The present protocol describes a long-term continuous measurement of renal blood flow in conscious rats and simultaneously recording blood pressure with implanted catheters (fluid-filled or by telemetry).

Medição Contínua a Longo Prazo do Fluxo Sanguíneo Renal em Ratos Conscientes

The kidneys play a crucial role in maintaining the homeostasis of body fluids. The regulation of renal blood flow (RBF) is essential to the vital ...

Multiple Intravenous Bolus Dosing and Invasive Hemodynamic Assessment in a Hypoxia-Induced Mouse Pulmonary Artery Hypertension Model

Pulmonary arterial hypertension (PAH) is a progressive life-threatening disease, primarily affecting small pulmonary arterioles of the lung. Currently, there is no cure for PAH. It is important to discover new compounds that can be used to treat PAH. The mouse hypoxia-induced PAH model is a widely used model for PAH research. This model recapitulates human clinical manifestations of PAH Group 3 disease and is an important research tool to evaluate the effectiveness of new experimental therapies for PAH. Research using this model often requires the administration of compounds in mice. For a compound that needs to be given directly into the bloodstream, optimizing intravenous (IV) administration is a key part of the experimental procedures. Ideally, the IV injection system should permit multiple injections over a set time course. Although the mouse hypoxia-induced PAH model is very popular in many laboratories, it is technically challenging to perform multiple IV bolus dosing and invasive hemodynamic assessment in this model. In this protocol, we present step-by-step instructions on how to carry out multiple IV bolus dosing via mouse jugular vein and perform arterial and right ventricle catheterization for hemodynamic assessment in mouse hypoxia-induced PAH model.

This protocol provides a step-by-step procedure for executing multiple intravenous bolus dose administration and invasive hemodynamic monitoring in mice. Investigators can use this protocol for future therapeutic compound screening for pulmonary artery hypertension.

Dosagem Múltipla em Bolus Intravenoso e Avaliação Hemodinâmica Invasiva em Modelo de Hipertensão Arterial Pulmonar em Camundongos Induzida por Hipóxia

Pulmonary arterial hypertension (PAH) is a progressive life-threatening disease, primarily affecting small pulmonary arterioles of the lung. Currently, ...

Simple Continuous Glucose Monitoring in Freely Moving Mice

Mice are a common model organism used to study metabolic diseases such as diabetes mellitus. Glucose levels are typically measured by tail-bleeding, which requires handling the mice, causes stress, and does not provide data on freely behaving mice during the dark cycle. State-of-the-art continuous glucose measurement in mice requires inserting a probe into the aortic arch of the mouse, as well as a specialized telemetry system. This challenging and expensive method has not been adopted by most labs. Here, we present a simple protocol involving the utilization of commercially available continuous glucose monitors used by millions of patients to measure glucose continuously in mice as a part of basic research. The glucose-sensing probe is inserted into the subcutaneous space in the back of the mouse through a small incision to the skin and is held in place tightly using a couple of sutures. The device is sutured to the mouse skin to ensure it remains in place. The device can measure glucose levels for up to 2 weeks and sends the data to a nearby receiver without any need to handle the mice. Scripts for the basic data analysis of glucose levels recorded are provided. This method, from surgery to computational analysis, is cost-effective and potentially very useful in metabolic research.

Here, we describe a simple method to implant a commercial continuous glucose monitor designed for patients onto mice and provide the scripts to analyze the results.

Monitoramento Contínuo Simples de Glicose em Camundongos em Movimento Livre

Mice are a common model organism used to study metabolic diseases such as diabetes mellitus. Glucose levels are typically measured by tail-bleeding, which ...