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1. Pré-operatório Preparação e Anestesia <ol><li> Não deixe de observar técnica estéril durante todo o procedimento. Deite fora todos os instrumentos. </li><li> Ligue o leito de controlo da temperatura antes da indução da anestesia de modo que ele pode aquecer até à temperatura apropriada (36,5 ° C). Ligue o monitor de laser Doppler perfusão de modo que ele pode iniciar durante a indução. </li><li> Posicione o mouse na câmara de indução. <ol><li> Monitorar cuidadosamente a frequência respiratória do mouse durante a indução. </li><li> Assim que a taxa respiratória abrandou visualmente, remover o rato da câmara de indução. </li><li> Realize toe pitada para avaliar a adequação de anestésico. </li></ol></li><li> Com o mouse devidamente anestesiados, lugar do mouse na posição supina. </li><li> Insira rosto no nariz cone e proteger todos os membros para a mesa de aquecimento. <ol><li> Preste atenção especial para garantir que as extremidades estão garantidos na posição anatômica, sem deviatiem que um dos lados. Se o mouse é posicionado de forma inadequada, é difícil evitar a transecção da artéria torácica interna durante a esternotomia. </li></ol></li><li> Usando clippers ou disponíveis comercialmente creme de depilação, remover os pêlos da linha média do tórax e deixou extremidade superfície ventral inferior. <ol><li> Se estiver usando creme de depilação, evite deixar o creme no lugar por mais de 30 segundos, as queimaduras como alcalinos podem ocorrer. </li></ol></li><li> Titular concentração vaporizador de anestesia volátil para manter a anestesia adequada. <ol><li> Frações vaporizador esperados são entre 1-5% utilizando isoflurano com alto fluxo de O 2. </li><li> Concentração vaporizador anestésico volátil deve ser ajustada para manter a anestesia durante a estimulação cirúrgica, mantendo a respiração espontânea. </li></ol></li></ol> 2. Colocação retal Probe Laser Doppler <ol><li> Insira sonda retal lubrificado no reto do mouse. Seguro em lugar para operAting cama. </li><li> Ajuste a cama de aquecimento para um alvo a temperatura retal de 36,5 ° C. </li><li> Faça pequena incisão ao longo da artéria femoral de rato e dissecar a pele longe do tecido subcutâneo. </li><li> Insira sonda laser Doppler ao longo da artéria femoral. </li><li> Ajuste as posições da sonda até o monitor de perfusão registra maior do que 800 unidades de perfusão. <ol><li> Sonda firmemente seguro no lugar. Sondas Indevidamente garantidos pode ter medições de perfusão falsamente baixos. </li></ol></li></ol> 3. Dissecção da aorta Arch / artéria subclávia <ol><li> Faça uma incisão de pele 2 cm acima da fúrcula e gentilmente dissecar a pele longe do tecido subcutâneo. </li><li> Dissecar a glândula submandibular livre. <ol><li> Se ocorrer sangramento, pressão suave pode ser aplicado com um cotonete. </li><li> Dividir a glândula submandibular, através da linha média, no plano avascular. </li></ol></li><li> Levante cuidadosamente esterno com uma pinça e usando o scissors fazer um centímetro da linha média esternotomia através da linha média do esterno. Qualquer desvio da linha média pode resultar em hemorragia artéria mamária interna, que será difícil de controlar. </li><li> Coloque 5-0 retração de cada lado na borda do esterno e retrair esterno lateralmente garantir suturas para a cama em funcionamento. Evite colocar suturas de retração também lateralmente para evitar pneumotórax. </li><li> Usando dissecção romba músculos cinta livre junto traquéia. O músculo cinta à esquerda pode ser dividida com uma tesoura para melhorar a exposição. </li><li> Dissecar libertar o timo a partir do tecido circundante. Continuar dissecção romba até os grandes vasos são visualizados. Tenha muito cuidado para evitar a entrada no espaço pleural. </li><li> Coloque grampos vasculares no arco aórtico e artéria subclávia esquerda. </li><li> Verifique o fluxo distal foi devidamente interrompida. Isto irá ser visto como uma redução&gt; 90% nas unidades de perfusão. <ol><li> Continuar oclusão para desivermelho para 4-8 min. </li></ol></li><li> Remover grampo vascular e verificar a hemostasia antes do fechamento do tórax. </li></ol> 4. Encerramento da esternotomia e Pele <ol><li> Retirar a sutura retracção no lado esquerdo do rato. </li><li> Feche a esternotomia com a sutura retração direita. <ol><li> A única sutura esternal (usando o ponto de retração previamente colocado) é adequada para fechamento do esterno. Colocar outro ponto é desnecessário e aumenta os riscos de pneumotórax e hemorragia. </li></ol></li><li> Fechar pele com o funcionamento de 5-0 ponto. </li></ol> 5. Avaliação de recuperação pós-operatória e <ol><li> Transfira o mouse para gaiola de recuperação. Gaiola deve ser colocado sobre uma almofada de aquecimento para aumentar a temperatura ambiente da câmara de recuperação e reduzir a perda de calor para o ambiente. </li><li> Acompanhar de perto o mouse em busca de sinais de dificuldade respiratória ou atividade convulsiva. Administrar analgesia por diretrizes da instituição. Euthacamundongos Nize imediatamente se apreensão ou desconforto respiratório é observado. <ol><li> CO 2 eutanásia câmara é o nosso método preferido. Deslocação cervical é uma outra opção se CO 2 não está disponível. </li><li> A recuperação completa pode ser esperado em 1-2 horas, dependendo do comprimento de anestésico volátil e a concentração usadas. </li></ol></li><li> Retorne o mouse para gaiola normal. Coloque os alimentos e coloque água no chão da gaiola. </li><li> Avaliar o estado neurológico em 12 intervalos hr usando Basso Rato Escala para Locomotion 8. </li></ol>

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Os autores declaram não haver interesses financeiros concorrentes.

Paraplegia secundária a isquemia reperfusão medular, é o resultado de um complexo de patologias mal compreendidos 9. Embora este é mais comumente visto após a cirurgia da aorta toracoabdominal, uma variedade de outros insultos, como dissecções aórticas, trauma, fenômenos embólicos, vasculite e hipotensão sistêmica 10 pode resultar em paraplegia. Para obter uma maior compreensão desta lesão e fornecer metas futuras para eliminar esse prejuízo, os modelos animais se tornaram uma necess...

Menor paralisia extremidade continua a complicar as intervenções toracoabdominal. A lesão, conhecido como medula espinhal lesão de isquemia-reperfusão (SCIR), resulta em paralisia em até 20% dos pacientes de alto risco 1. Adjuntos cirúrgicos, tais como desvio esquerda coração, drenos fluidos cerbrospinal lombares, parada circulatória hipotérmica e reimplante da artéria intercostal ter reduzido a incidência desta complicação 2, no entanto, demasiado muitos pacientes continuam a ser afetados. Clinicamente, a isquemia medular e reperfusão é visto como imediatos ou retardados paralisia após a intervenção 3. No entanto, a nossa compreensão desta lesão foi sufocada pela falta de detalhes mecanicista. Como resultado, algumas opções estão disponíveis para atenuar a lesão, uma vez que tenha ocorrido. Temos, assim, se alistou um animal pequeno, murino, o modelo de isquemia medular, e reperfusão demelhor caracterizar sua patogênese. A maioria dos estudos até agora usaram modelos animais maiores para caracterizar esta lesão, ou seja, 4 rato, coelho 5, e porco 6 modelos. No entanto, estes são limitados pelo seu custo, complexidade, reprodutibilidade variável, e, mais importante, a falta de técnicas disponíveis para a manipulação genética. O mais confiável desses modelos animais publicados envolve pinçamento infra-renal da aorta abdominal em coelhos. No entanto, anterior humana neurônios espinhais na maioria das vezes derivam seu suprimento vascular dos ramos mais proximais 7. Anatomia vascular variável da medula espinal em modelos estes adiciona à dificuldade em fazer a transição seus resultados em utilização clínica. Este manuscrito apresenta um modelo de paraplegia imediato ou tardio, após oclusão da aorta torácica que é clinicamente relevante e fácil de empregar. A exposição do arco aórtico via mini-esternotomiao meu é menos invasiva e pode provocar resultados altamente reprodutíveis com morbidade e mortalidade mínima. Embora este modelo em não sem desafios e nuances técnicas, estas podem ser superadas com dissecção cuidadosa e manipulação de tecidos para produzir um modelo de paralisia dos membros traseiros que podem ser facilmente implementados.

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			<td height="21" style="height:21px;width:216px;">VMS Anesthesia Machine</td>
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			<td style="width:167px;"></td>
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			<td height="21" style="height:21px;width:216px;">Isoflurane</td>
			<td style="width:247px;">Vet One</td>
			<td style="width:119px;">13985-528-60</td>
			<td>2.0% through nose cone&#160;</td>
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			<td height="21" style="height:21px;width:216px;">Induction Chamber</td>
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			<td>941444</td>
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			<td height="21" style="height:21px;width:216px;">Heating Bed</td>
			<td style="width:247px;">Vestavia Scientific</td>
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			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Laser Doppler Monitor</td>
			<td style="width:247px;">Moor Instruments</td>
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			<td height="21" style="height:21px;width:216px;">5-0 Suture, Polyester</td>
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			<td>Forceps, needle holder</td>
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reproducable paraplegia by thoracic aortic occlusion in a murine model of spinal cord ischemia-reperfusion

Fundo Baixa paralisia extremidade continua a complicar intervenções aorta. A falta de compreensão da patologia subjacente tem dificultado avanços para diminuir a ocorrência desta lesão. O modelo atual demonstra reprodutível menor paralisia extremidade após oclusão da aorta torácica. Métodos Camundongos C57BL6 machos adultos foram anestesiados com isoflurano. Através de uma incisão cervicosternal a aorta foi exposta. A aorta e subclávia esquerda descendente artérias torácicas foram identificados sem entrada para o espaço pleural. Esqueletização destas artérias foi seguido pelo fechamento imediato (Sham) ou oclusão de 4 min (isquemia moderada) ou 8 min (isquemia prolongada). A esternotomia e pele foram fechados eo rato foi transferido para a cama aquecimento para a recuperação. Após a recuperação, análise funcional foi obtida em 12 intervalos hr até 48 horas. Resultados jove_content Os ratos que foram submetidos à cirurgia sham não mostraram déficit membro posterior observável. Ratos submetidos à isquemia moderada por 4 min teve déficit funcional mínimo em 12 horas seguido de progressão para completar a paralisia em 48 horas. Ratos submetidos à isquemia prolongada teve uma paralisia imediata com qualquer movimento posterior de membros observável em qualquer ponto no pós-operatório. Não houve mortalidade intra-operatória observada ou pós-operatório. Conclusão Reprodutível menor paralisia extremidade imediato ou retardado pode ser alcançado em um modelo murino. Além disso, usando uma esternotomia mediana e cuidadosa dissecação, as taxas de sobrevivência elevadas, e reprodutibilidade pode ser conseguida.

Ratos foram submetidos a cirurgia sham (n = 3) ou oclusão aórtica por 4 (n = 3) a 8 min (n = 3). Camundongos pós-operatório foram classificados pelo Índice de Basso Mouse (Figura 1). Os ratos que foram submetidos à cirurgia sham não tinha déficits funcionais observáveis ​​em qualquer ponto no pós-operatório. Ratos submetidos à isquemia moderada (4 min) tiveram perto de função normal traseira de membros em 12 horas com o declínio funcional progressivo para completar paralisia por 48 ho...

Watch this Scientific Journal Video about Reproducable Paraplegia by Thoracic Aortic Occlusion in a Murine Model of Spinal Cord Ischemia-reperfusion at JoVE.com

Reproducable Paraplegia by Thoracic Aortic Occlusion in a Murine Model of Spinal Cord Ischemia-reperfusion

A falta de entendimento mecanicista da medula espinhal lesão de isquemia-reperfusão tem dificultado mais adjuntos para evitar paraplegia após operação da aorta alto risco. Assim, o desenvolvimento de modelos animais é imperativo. Este manuscrito demonstra reprodutível menor paralisia extremidade após oclusão da aorta torácica em um modelo murino.

Reproducable Paraplegia por Thoracic Aorta Oclusão em um modelo murino de Medula Espinhal A isquemia-reperfusão

Background
Lower extremity paralysis continues to complicate aortic interventions. The lack of understanding of the underlying pathology has hindered ...

reproducable-paraplegia-thoracic-aortic-occlusion-murine-model-spinal

Research

JoVE Journal

Medicine

11.9K visualizações.  University of Colorado.  A falta de entendimento mecanicista da medula espinhal lesão de isquemia-reperfusão tem dificultado mais adjuntos para evitar paraplegia após operação da aorta alto risco. Assim, o desenvolvimento de modelos animais é imperativo. Este manuscrito demonstra reprodutível menor paralisia extremidade após oclusão da aorta torácica em um modelo murino. 

Vídeo: Reproducable Paraplegia by Thoracic Aortic Occlusion in a Murine Model of Spinal Cord Ischemia-reperfusion

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.

Aguda e crônica teste sensorial tátil após a lesão medular em ratos

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

Medicina

A Contusion Model of Severe Spinal Cord Injury in Rats

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is described to obtain a consistent model of severe SCI. Use of a stereotactic frame and computer controlled impactor allows for creation of reproducible injury. Hypothermia and urinary tract infection pose significant challenges in the post-operative period. Careful monitoring of animals with daily weight recording and bladder expression allows for early detection of post-operative complications. The functional results of this contusion model are equivalent to transection models. The contusion model can be utilized to evaluate the efficacy of both neuroprotective and neuroregenerative approaches.

A contusion model of severe spinal cord injury is described. Detailed pre-operative, operative and post-operative steps are described to obtain a consistent model.

Um modelo de contusão grave de lesão medular em ratos

The translational potential of novel treatments should be investigated in severe spinal cord injury (SCI) contusion models. A detailed methodology is ...

A Murine Model of Cervical Spinal Cord Injury to Study Post-lesional Respiratory Neuroplasticity

A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed to improve/ameliorate the respiratory failure following high cervical spinal cord injury (SCI). Here we propose a murine pre-clinical model of high SCI at the cervical 2 (C2) metameric level to study diverse post-lesional respiratory neuroplasticity. The technique consists of a surgical partial injury at the C2 level, which will induce a hemiparalysis of the diaphragm due to a deafferentation of the phrenic motoneurons from the respiratory centers located in the brainstem. The contralateral side of the injury remains intact and allows the animal recovery. Unlike other SCIs which affect the locomotor function (at the thoracic and lumbar level), the respiratory function does not require animal motivation and the quantification of the deficit/recovery can be easily performed (diaphragm and phrenic nerve recordings, whole body ventilation). This pre-clinical C2 SCI model is a powerful, useful, and reliable pre-clinical model to study various respiratory and non-respiratory neuroplasticity events at different levels (molecular to physiology) and to test diverse putative therapeutic strategies which might improve the respiration in SCI patients.

Respiratory failure is the leading cause of death following a cervical spinal cord injury. Having a reproducible, quantifiable, and reliable pre-clinical animal model of respiratory failure induced by a partial cervical injury will help to understand the subsequent respiratory and non-respiratory neuroplasticity and allow testing putative repair strategies.

Um modelo murino de Spinal Cord Injury do colo do útero para o Estudo de pós-lesional respiratória Neuroplasticidade

A cervical spinal cord injury induces permanent paralysis, and often leads to respiratory distress. To date, no efficient therapeutics have been developed ...

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

Um modelo murino de isquemia-reperfusão, através da ligadura da artéria Descendente Anterior Esquerda

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

A Radio-telemetric System to Monitor Cardiovascular Function in Rats with Spinal Cord Transection and Embryonic Neural Stem Cell Grafts

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter connected to a radio transmitter into the femoral artery of rats that underwent a T4 spinal cord transection with or without grafting of embryonic brainstem-derived neural stem cells expressing green fluorescent protein. Compared to other methods such as cannula insertion or tail-cuff, telemetry is advantageous to continuously monitor blood pressure and heart rate in freely moving animals. It is also capable of long term multiple data acquisitions. In spinal cord injured rats, basal cardiovascular data under unrestrained condition and autonomic dysreflexia in response to colorectal distension were successfully recorded. In addition, cardiovascular parameters before and after SCI can be compared in the same rat if a transmitter is implanted before a spinal cord transection. One limitation of the described telemetry procedure is that implantation in the femoral artery may influence the blood supply to the ipsilateral hindlimb.

We present a protocol for using a radio-telemetric system to record cardiovascular parameters in T4 spinal cord transected rats eight weeks after embryonic brainstem neural stem cell grafting into the lesion site. Telemetry is an advanced technique to accurately evaluate cardiovascular function in conscious freely moving spinal cord injured rats.

Um sistema de rádio-telemetria para monitorar a função cardiovascular em ratos com Medula Espinhal transecção e Embryonic Stem Neural enxertos de células-

High thoracic or cervical spinal cord injury (SCI) can lead to cardiovascular dysfunction. To monitor cardiovascular parameters, we implanted a catheter ...

Murine Model of Intestinal Ischemia-reperfusion Injury

Intestinal ischemia is a life-threatening condition associated with a broad range of clinical conditions including atherosclerosis, thrombosis, hypotension, necrotizing enterocolitis, bowel transplantation, trauma and chronic inflammation. Intestinal ischemia-reperfusion (IR) injury is a consequence of acute mesenteric ischemia, caused by inadequate blood flow through the mesenteric vessels, resulting in intestinal damage. Reperfusion following ischemia can further exacerbate damage of the intestine. The mechanisms of IR injury are complex and poorly understood. Therefore, experimental small animal models are critical for understanding the pathophysiology of IR injury and the development of novel therapies.
Here we describe a mouse model of acute intestinal IR injury that provides reproducible injury of the small intestine without mortality. This is achieved by inducing ischemia in the region of the distal ileum by temporally occluding the peripheral and terminal collateral branches of the superior mesenteric artery for 60 min using microvascular clips. Reperfusion for 1 hr, or 2 hr after injury results in reproducible injury of the intestine examined by histological analysis. Proper position of the microvascular clips is critical for the procedure. Therefore the video clip provides a detailed visual step-by-step description of this technique. This model of intestinal IR injury can be utilized to study the cellular and molecular mechanisms of injury and regeneration.

Here we describe the detailed procedure of intestinal ischemia-reperfusion in mice which results in reproducible injury without mortality to encourage the standardization of this technique across the field. This model of intestinal ischemia-reperfusion injury can be utilized to study the cellular and molecular mechanisms of injury and regeneration.

Modelo murino de isquemia-reperfusão

Intestinal ischemia is a life-threatening condition associated with a broad range of clinical conditions including atherosclerosis, thrombosis, ...

Reproducible Motor Deficit Following Aortic Occlusion in a Rat Model Of Spinal Cord Ischemia

Spinal cord ischemia is a fatal complication following thoracoabdominal aortic aneurysm surgery. Researchers can investigate the strategies for preventing and treating this complication using experimental models of spinal cord ischemia. The model described here demonstrates varying degrees of paraplegia that relate to the length of occlusion following thoracic aortic occlusion in a rat spinal cord ischemia model.
A 2-Fr. balloon-tipped catheter was advanced through the femoral artery into the descending thoracic aorta until the catheter tip was placed at the left subclavian artery in anesthetized male Sprague-Dawley rats. Spinal cord ischemia was induced by inflating the catheter balloon. After a set period of occlusion (9, 10, or 11 min), the balloon was deflated. Neurologic assessment was performed using the motor deficit index at 24 h after surgery, and the spinal cord was harvested for histopathological examination.
Rats that underwent 9 min of aortic occlusion showed mild and reversible motor impairment in the hind limb. Rats subjected to 10 min of aortic occlusion presented with moderate but reversible motor impairment. Rats subjected to 11 min of aortic occlusion displayed complete and persistent paralysis. The motor neurons in the spinal cord sections were more preserved in rats subjected to shorter duration of aortic occlusion.
Researchers can achieve a reproducible hind limb motor deficit following thoracic aortic occlusion using this spinal cord ischemia model.

This study demonstrates the technique to make a minimally invasive and easily reproducible model of spinal cord ischemia in rats. Various degrees of hind limb motor deficit can be produced by controlling the aortic occlusion time.

Déficit motor reprodutível após oclusão aórtica em um modelo de rato da isquemia da medula espinhal

Spinal cord ischemia is a fatal complication following thoracoabdominal aortic aneurysm surgery. Researchers can investigate the strategies for preventing ...

Two-vessel Occlusion Mouse Model of Cerebral Ischemia-reperfusion

In this study, a middle cerebral artery (MCA) occlusion mouse model is employed to study cerebral ischemia-reperfusion. A reproducible and reliable mouse model is useful for investigating the pathophysiology of cerebral ischemia-reperfusion and determining potential therapeutic strategies for patients with stroke. Variations in the anatomy of the circle of Willis of C57BL/6 mice affects their infarct volume after cerebral-ischemia-induced injury. Studies have indicated that distal MCA occlusion (MCAO) can overcome this problem and result in a stable infarct size. In this study, we establish a two-vessel occlusion mouse model of cerebral ischemia-reperfusion through the interruption of the blood flow to the right MCA. We distally ligate the right MCA and right common carotid artery (CCA) and restore blood flow after a certain period of ischemia. This ischemia-reperfusion injury induces an infarct of stable size and a behavioral deficit. Peripheral immune cells infiltrate the ischemic brain within the 24 h infiltration period. Additionally, the neuronal loss in the cortical area is less for a longer reperfusion duration. Therefore, this two-vessel occlusion model is suitable for investigating the immune response and neuronal recovery during the reperfusion period after cerebral ischemia.

A mouse model of cerebral ischemia-reperfusion is established to investigate the pathophysiology of stroke. We distally ligate the right middle cerebral artery and right common carotid artery and restore blood flow after 10 or 40 min of ischemia.

Modelo de Mouse de dois vasos oclusão de isquémia-reperfusão Cerebral

In this study, a middle cerebral artery (MCA) occlusion mouse model is employed to study cerebral ischemia-reperfusion. A reproducible and reliable mouse ...

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.

Avaliação da reserva de fluxo coronariano após reperfusão de isquemia miocárdica em ratos

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

Murine Surgical Model of Topical Elastase Induced Descending Thoracic Aortic Aneurysm

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. An aneurysm forms as a result of progressive weakening and eventual dilation of the aorta, which can rupture or tear once it reaches a critical diameter. Aneurysms of the descending aorta in the chest, called descending thoracic aortic aneurysms (dTAA), make up a large proportion of aneurysm cases in the United States. Uncontained dTAA rupture is almost universally lethal, and elective repair has a high rate of morbidity and mortality. The purpose of our model is to study dTAA specifically, to elucidate the pathophysiology of dTAA and to search for molecular targets to halt the growth or reduce the size of dTAA. By having a murine model to study thoracic pathology precisely, targeted therapies can be developed to specifically test dTAA. The method is based on the placement of porcine pancreatic elastase (PPE) directly on the outer murine aortic wall after surgical exposure. This creates a destructive and inflammatory reaction, which weakens the aortic wall and allows for aneurysm formation over weeks to months. Though murine models possess limitations, our dTAA model produces robust aneurysms of predictable size. Furthermore, this model can be used to test genetic and pharmaceutical targets which may arrest dTAA growth or prevent rupture. In human patients, interventions such as these could help avoid aneurysm rupture, and difficult surgical intervention.

We describe a surgical protocol to consistently induce robust descending thoracic aortic aneurysms in mice. The procedure involves left thoracotomy, thoracic aorta exposure, and placement of a sponge soaked in porcine pancreatic elastase on the aortic wall.

Modelo cirúrgico murino de elastase tópica induzida por aneurisma de aorta torácica descendente

According to the Center for Disease Control, aortic aneurysms (AAs) were considered a leading cause of death in all races and both sexes from 1999-2016. ...