Los experimentos se realizaron en ratas hembra Sprague-Dawley, con un peso de 250-300 g. Todos los procedimientos con animales cumplían con las normas establecidas en la Guía para el Cuidado y Uso de Animales de Laboratorio (Instituto de Recursos Animales de Laboratorio, Academia Nacional de Ciencias, Bethesda, MD, EE.UU.) y fueron aprobados por la Mayo Clinic College de Medicina Institucional Cuidado de Animales y el empleo Comisión (IACUC). 1. Preparación <ol><li> Autoclave todos los instrumentos quirúrgicos antes de la cirugía. Si se han previsto múltiples cirugías en diferentes ratas en el mismo día, enjuague los instrumentos después de cada procedimiento animal y después esterilizar utilizando un esterilizador de cuentas en caliente. </li><li> Anestesiar la rata con 4% de isoflurano en 1 L / min O 2. </li><li> La transferencia de la rata para una resistencia de calentamiento controlado para conservar la temperatura corporal a 37 ° C. Mantener la anestesia con isoflurano 1-2% en 1 L / min O 2. </li><li> Administrar el fármaco analgésico (buprenorfina liberación sostenida de 0,6 mg / kg) Dobcutaneously. </li><li> Aplique un ungüento para los ojos para evitar que se sequen durante el procedimiento. </li><li> Con el fin de compensar la pérdida de fluidos corporales debido a la laparotomía, es importante para administrar 10 ml / kg de 0,9% por vía subcutánea solución salina normal antes de la operación. </li><li> Afeitar el área abdominal y limpiar la piel con almohadillas de etanol povidona yodada y el 70%. </li></ol> 2. Procedimiento Quirúrgico <ol><li> Asegúrese de que la profundidad de la sedación es adecuada mediante el control de los reflejos físicos, como la retirada de la pizca dedo del pie, reflejo palpebral, el tono de la mandíbula, y la respiración tasa / patrón. </li><li> Realizar una laparotomía a través de una pequeña incisión en la línea media (2-2,5 cm de longitud), utilizando una hoja de bisturí quirúrgico Nº 10. </li><li> Tire del delgado y el colon en el lado derecho del abdomen mediante el uso de bastoncillos de algodón y cubrir con una gasa estéril empapada en solución salina normal al 0,9% para mantener los órganos húmedo. </li><li> retraer con suavidad hacia arriba el bazo, el hígado, el estómago y el páncreas para exponer el AORta y la arteria renal izquierda. </li><li> Con la ayuda de un microscopio quirúrgico, separe con cuidado la aorta abdominal por encima y por debajo del riñón izquierdo y la arteria renal izquierda de las venas, la grasa y el tejido conectivo que rodea con unas pinzas de disección romos curvada e hisopos de algodón estériles. <ol><li> Use las pinzas con un movimiento (disección roma) de apertura y cierre repetidos a lo largo de la longitud de los vasos para extraer el tejido conectivo y los bastoncillos de algodón con un movimiento de balanceo lateral para eliminar la grasa. NOTA: La disección de la región peri-aórtica es una etapa muy delicada ya que los nervios y los vasos linfáticos podrían ser dañados. Asegúrese de mantener las arterias húmedo con solución salina durante el procedimiento de disección. </li></ol></li><li> Colocar una sutura de seda 4-0 por debajo de la aorta. </li><li> El uso de clips microvasculares, sujetar la aorta por encima (justo debajo de la arteria mesentérica superior) y por debajo de la bifurcación de la arteria renal. </li><li> La punción de la aorta a nivel del kidn izquierdabifurcación de la arteria ey con un catéter intravenoso 24 G y avanzar el catéter en la arteria renal. NOTA: Este es un paso crítico como punción a través de la arteria renal puede ocurrir. </li><li> Conectar una jeringa llena con la solución de fármaco o solución salina (hasta 500 l) para el catéter y perfundir el riñón. </li><li> Inmediatamente después de la perfusión, la abrazadera de la vena renal izquierda y el uréter izquierdo con un clip microvascular y retirar el catéter. A continuación, coloque un trozo de esponja de gelatina absorbible pinza hemostática, con una pequeña gota de adhesivo tisular, sobre el área de punción de la aorta y aplicar una suave presión con un hisopo de algodón. </li><li> Al mismo tiempo, liberar la abrazadera de la aorta abdominal, por debajo de la bifurcación de la arteria renal izquierda. Después de 5 min, liberar la pinza de la vena renal y el uréter. </li><li> liberar con cuidado la abrazadera de la aorta, por encima de la bifurcación de la arteria renal izquierda, y permitir la reperfusión del riñón. La isquemia renal total debe durar no más de 7 min. </li><li&gt; que no se produzca una hemorragia activa y observar de cerca a la zona durante 10 minutos más. </li><li> Cerrar la incisión abdominal en dos capas (músculo y piel), utilizando 4-0 suturas absorbibles y un patrón continuo para prevenir la infección. Además de la técnica de patrón de sutura continuo, otra opción sería utilizar una técnica simple, interrumpido, especialmente para el cierre de la pared del cuerpo para evitar la dehiscencia. </li><li> Aplique un ungüento antibiótico tópico sobre el área de la incisión para prevenir las infecciones. </li><li> La transferencia de la rata en una jaula de observación libre de la ropa de cama sobre una almohadilla caliente hasta la recuperación completa con un rango de temperatura entre 35-37 ° C. Ropa de cama suelta debe ser cubierto (por ejemplo con un paño o toalla de papel) o retirado de la jaula hasta los animales que se recuperan para evitar la asfixia o aspiración de ropa de cama. </li><li> Después de la cirugía, observar a los animales de forma continua hasta que respira espontáneamente, después cada hora durante unas horas. Vuelva a la dosis del analgésico Buprenorfina SR 72 hrmás adelante, si se observan signos de malestar, como letargo, encorvados y desaliñado, mueca, no reanudar las actividades normales. </li><li> Después de la terminación de todos los estudios, la eutanasia a los animales con la inhalación de una sobredosis de CO2 y obtención de los tejidos renales para ex vivo tales como los análisis de histología y Western Blot 5. </li></ol>

<ol>
	<li>Dejani, H., Eisen, T. D., Finkelstein, F. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Revascularization+of+renal+artery+stenosis+in+patients+with+renal+insufficiency.">Revascularization of renal artery stenosis in patients with renal insufficiency.</a> Am. J. Kidney Dis. 36 (4), 752-758 (2000).</li><li>Kang, D. H., 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=Impaired+angiogenesis+in+the+remnant+kidney+model:+I.+Potential+role+of+vascular+endothelial+growth+factor+and+thrombospondin-1.">Impaired angiogenesis in the remnant kidney model: I. Potential role of vascular endothelial growth factor and thrombospondin-1.</a> J. Am. Soc. Nephrol. 12 (7), 1434-1447 (2001).</li><li>Kang, D. H., Hughes, J., Mazzali, M., Schreiner, G. F., Johnson, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impaired+angiogenesis+in+the+remnant+kidney+model:+II.+Vascular+endothelial+growth+factor+administration+reduces+renal+fibrosis+and+stabilizes+renal+function.">Impaired angiogenesis in the remnant kidney model: II. Vascular endothelial growth factor administration reduces renal fibrosis and stabilizes renal function.</a> J. Am. Soc. Nephrol. 12 (7), 1448-1457 (2001).</li><li>Kang, D. H., 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=Role+of+the+microvascular+endothelium+in+progressive+renal+disease.">Role of the microvascular endothelium in progressive renal disease.</a> J. Am. Soc. Nephrol. 13 (3), 806-816 (2002).</li><li>Chade, A. R., Kelsen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversal+of+renal+dysfunction+by+targeted+administration+of+VEGF+into+the+stenotic+kidney:+a+novel+potential+therapeutic+approach.">Reversal of renal dysfunction by targeted administration of VEGF into the stenotic kidney: a novel potential therapeutic approach.</a> Am. J. Physiol.- Renal Physiol. 302 (10), F1342-F1350 (2012).</li><li>Eirin, A., 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=Changes+in+Glomerular+Filtration+Rate+After+Renal+Revascularization+Correlate+With+Microvascular+Hemodynamics+and+Inflammation+in+Swine+Renal+Artery+Stenosis.">Changes in Glomerular Filtration Rate After Renal Revascularization Correlate With Microvascular Hemodynamics and Inflammation in Swine Renal Artery Stenosis.</a> Circ.-Cardiovasc. Interv. 5 (5), 720-728 (2012).</li><li>Chade, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+Renal+Injury+in+Early+Atherosclerosis+and+Renovascular+Disease.">Distinct Renal Injury in Early Atherosclerosis and Renovascular Disease.</a> Circulation. 106 (9), 1165-1171 (2002).</li><li>Seddon, M., Saw, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atherosclerotic+renal+artery+stenosis:+review+of+pathophysiology,+clinical+trial+evidence,+and+management+strategies.">Atherosclerotic renal artery stenosis: review of pathophysiology, clinical trial evidence, and management strategies.</a> Can. J. Cardiol. 27 (4), 468-480 (2011).</li><li>Lao, D., Parasher, P. S., Cho, K. C., Yeghiazarians, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atherosclerotic+renal+artery+stenosis--diagnosis+and+treatment.">Atherosclerotic renal artery stenosis--diagnosis and treatment.</a> Mayo Clin Proc. 86 (7), 649-657 (2011).</li><li>Sharfuddin, A. A., Molitoris, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathophysiology+of+ischemic+acute+kidney+injury.">Pathophysiology of ischemic acute kidney injury.</a> Nat. Rev. Nephrol. 7, 189-200 (2011).</li><li>Noiri, E., 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=Oxidative+and+nitrosative+stress+in+acute+renal+ischemia.">Oxidative and nitrosative stress in acute renal ischemia.</a> Am. J. Physiol.- Renal Physiol. 281 (5), F948-F957 (2001).</li><li>Koesters, R., 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=Tubular+Overexpression+of+Transforming+Growth+Factor-&#206;1+Induces+Autophagy+and+Fibrosis+but+Not+Mesenchymal+Transition+of+Renal+Epithelial+Cells.">Tubular Overexpression of Transforming Growth Factor-&#206;1 Induces Autophagy and Fibrosis but Not Mesenchymal Transition of Renal Epithelial Cells.</a> Am. J. Pathol. 177 (2), 632-643 (2010).</li><li>Shanley, P. F., Rosen, M. D., Brezis, M., Silva, P., Epstein, F. H., Rosen, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Topography+of+focal+proximal+tubular+necrosis+after+ischemia+with+reflow+in+the+rat+kidney.">Topography of focal proximal tubular necrosis after ischemia with reflow in the rat kidney.</a> Am. J. Pathol. 122 (3), 462-468 (1986).</li></ol>

Este trabajo es apoyado en parte por una beca de investigación de Astra Zeneca.

The increasing incidence of chronic kidney disease raises the need for novel therapeutic approaches that can promote functional kidney recovery7,8. Traditional therapies include the systemic administration of anti-inflammatory, anti-fibrotic drugs9. However, these strategies are frequently characterized by unwanted side effects due to off-target distribution of the injected drug. Therefore, in this manuscript, we describe a simple procedure for delivering drugs into the renal artery of rats. This pr...

The renal microvasculature is involved in a wide spectrum of kidney diseases. Depending on the pathophysiology of disease, the endothelial cells may present structural or functional impairment, which may play a pivotal role in propagating kidney damage by creating an ischemic microenvironment. This renal microvascular dysfunction may catalyze the onset of a progressive deterioration of renal function over time, leading to chronic kidney disease (CKD), end-stage renal disease, hypertension and cardiorenal syndrome. In fact, untreated hypertension may have implications in renal arterioles, causing nephrosclerosis or glomerulosclerosis with significant reduction in vascular volume fraction, increase in vascular resistance and development of tubulointerstitial fibrosis1.
Loss of renal microvasculature may be due to altered vascular homeostasis induced by local angiogenic/anti-angiogenic factors imbalance. This correlates with attenuated Vascular Endothelial Growth Factor (VEGF) signaling as well as elevated thrombospondin-12-4. Thus, using different animal models (mice, rats and pigs), the therapeutic effect of exogenous administration of VEGF has been recently investigated in some forms of renal disease, showing reduced interstitial fibrosis and stabilized renal and cardiac function3-5. This effect is likely due to actions of VEGF on endothelial cells of the microvascular bed and inflammatory monocyte phenotype switching6.
For some preclinical studies, the use of rodents, the most commonly used laboratory animals, provides a good animal model for high throughput studies due to relatively low costs and ease of handling. Moreover, the use of genetically-altered rats as models of human diseases, such as hypertension, has become more and more frequent in the scientific community. Therefore, the aim of this protocol is to describe a useful intrarenal VEGF delivery technique in rats that is easy to perform and highly reproducible. Moreover, the same method can be used to selectively deliver other drugs.

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			<td height="21" style="height:21px;width:257px;">Surgical Microscope</td>
			<td style="width:176px;">Leica</td>
			<td style="width:119px;">M125</td>
			<td style="width:376px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Isoflurane 100 ml</td>
			<td style="width:176px;">Cardinal Healthcare</td>
			<td style="width:119px;">PI23238</td>
			<td>Anesthetic</td>
		</tr>
		<tr height="133">
			<td height="133" style="height:133px;width:257px;">Buprenorphine HCL SR LAB 1mg/ml, 5 ml</td>
			<td style="width:176px;">ZooPharm Pharmacy</td>
			<td style="width:119px;"></td>
			<td style="width:376px;">Buprenorphine narcotic analgesic formulated in a polymer that slows absorption extending duration of action (72 hours duration of activity).&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Liquid is viscous, warming to room temperature aids in drawing into syringe.&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; Recommended dosage: 1-1.2 mg/kg SC. DO NOT DILUTE.</td>
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			<td height="42" style="height:42px;width:257px;">Puralube Vet Ophthalmic Ointment</td>
			<td style="width:176px;">Dechra</td>
			<td style="width:119px;">NDC17033-211-38</td>
			<td>Sterile ocular lubricant</td>
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		<tr height="56">
			<td height="56" style="height:56px;width:257px;">Lactated Ringer&#39;s Injection, USP, 250 mL VIAFLEX Plastic Container</td>
			<td style="width:176px;">Baxter Healthcare Corp.</td>
			<td style="width:119px;">NDC0338-0117-02</td>
			<td>For body fluids replacement</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Sol Povidone-Iodine&#160; Swabstick, 3&#39;&#160;</td>
			<td style="width:176px;">Cardinal Heatlhcare</td>
			<td style="width:119px;">23405-010B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Sterile cotton tipped applicators</td>
			<td style="width:176px;">Kendall</td>
			<td style="width:119px;">8884541300</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">4-0 silk suture (without needle)&#160;</td>
			<td style="width:176px;">Cardinal Heatlhcare</td>
			<td style="width:119px;">A183H</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">Vessel Clip, Straight, 0.75 x 4mm Jaw</td>
			<td style="width:176px;">World Precision Instruments&#160;</td>
			<td style="width:119px;">501779-G</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">I.V. Catheter, Straight Hub, Radiopaque, 24g x 3/4&#34;, FEP Polymer</td>
			<td style="width:176px;">Jelco</td>
			<td align="right" style="width:119px;">4053</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Phosphate Buffered Saline</td>
			<td style="width:176px;">Life Technologies</td>
			<td align="right" style="width:119px;">10010023</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">SURGIFOAM Absorbable Gelatin Sponge</td>
			<td style="width:176px;">Cardinal Healthcare</td>
			<td align="right" style="width:119px;">179082</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">4-0 VICRYL PLUS (ANTIBACTERIAL) VIOLET 27&#34; RB-1 TAPER</td>
			<td style="width:176px;">Ethicon</td>
			<td style="width:119px;">VCP304H</td>
			<td>For muscle layer suturing</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">4-0 VICRYL PLUS (ANTIBACTERIAL) UNDYED 18&#34; PC-3 CUTTING</td>
			<td style="width:176px;">Ethicon</td>
			<td style="width:119px;">VCP845G</td>
			<td>For skin layer suturing</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">Triple antibiotic ointment</td>
			<td style="width:176px;">Actavis</td>
			<td style="width:119px;">NDC0472-0179-56</td>
			<td>For topical use on the site of the incision</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Recombinant Rat VEGF 164 Protein</td>
			<td style="width:176px;">R&#38;D Sytems</td>
			<td style="width:119px;">564-RV</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Rabbit monoclonal VEGFA</td>
			<td style="width:176px;">Abcam</td>
			<td style="width:119px;">ab46154</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Rabbit monoclonal FLK1</td>
			<td style="width:176px;">Cell Signaling</td>
			<td align="right" style="width:119px;">9698</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:257px;">Rabbit monoclonal AKT</td>
			<td style="width:176px;">Cell Signaling</td>
			<td align="right" style="width:119px;">4691</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">Rabbit monoclonal phosphoAKT (Ser 473)</td>
			<td style="width:176px;">Cell Signaling</td>
			<td align="right" style="width:119px;">4060</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">Rabbit monoclonal p44/42 MAPK (ERK1/2)</td>
			<td style="width:176px;">Cell Signaling</td>
			<td align="right" style="width:119px;">4695</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:257px;">Rabbit monoclonal phospho p44/42 MAPK (Thr202 and Tyr 204)</td>
			<td style="width:176px;">Cell Signaling</td>
			<td align="right" style="width:119px;">4370</td>
			<td></td>
		</tr>
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intravascular delivery of biologics to the rat kidney

The renal microvascular compartment plays an important role in the progression of kidney disease and hypertension, leading to the development of End Stage Renal Disease with high risk of death for cardiovascular events. Moreover, recent clinical studies have shown that renovascular structure and function may have a great impact on functional renal recovery after surgery. Here, we describe a protocol for the delivery of drugs into the renal artery of rats. This procedure offers significant advantages over the frequently used systemic administration as it may allow a more localized therapeutic effect. In addition, the use of rodents in pharmacodynamic analysis of preclinical studies may be cost effective, paving the way for the design of translational experiments in larger animal models. Using this technique, infusion of rat recombinant Vascular Endothelial Growth Factor (VEGF) protein in rats has induced activation of VEGF signaling as shown by increased expression of FLK1, pAKT/AKT, pERK/ERK. In summary, we established a protocol for the intrarenal delivery of drugs in rats, which is simple and highly reproducible.

<html> Hemos inyectado dos dosis diferentes de VEGF recombinante de rata (rrVEGF, 0,17 mg / kg y 5 mg / kg) o PBS. Los animales se sacrificaron 8 horas después de la cirugía para examinar la activación de la vía VEGF. El procedimiento quirúrgico no afectó la morfología del riñón perfundido (Figura 1A) en comparación con el control (Figura 1B), como se muestra por tinción con H &amp; E. Mientras Sirius tinción con rojo no mostró ningún aument...

Watch this Scientific Journal Video about Intravascular Delivery of Biologics to the Rat Kidney at JoVE.com

Intravascular Delivery of Biologics to the Rat Kidney

La administración de fármacos para la recuperación de la función renal requiere el control de la localización y distribución del compuesto terapéutico. A continuación, describimos en detalle una técnica sencilla para la entrega intrarrenal de drogas en ratas. Este procedimiento se puede realizar fácilmente sin mortalidad y alta reproducibilidad.

Intravascular de entrega de los productos biológicos para el riñón de rata

The renal microvascular compartment plays an important role in the progression of kidney disease and hypertension, leading to the development of End Stage ...

intravascular-delivery-of-biologics-to-the-rat-kidney

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Medicine

7.4K vistas.  Mayo Clinic.  La administración de fármacos para la recuperación de la función renal requiere el control de la localización y distribución del compuesto terapéutico. A continuación, describimos en detalle una técnica sencilla para la entrega intrarrenal de drogas en ratas. Este procedimiento se puede realizar fácilmente sin mortalidad y alta reproducibilidad. 

Video: Intravascular Delivery of Biologics to the Rat Kidney

Slow-release Drug Delivery through Elvax 40W to the Rat Retina: Implications for the Treatment of Chronic Conditions

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these diseases. Chronic retinal diseases such as retinal oedema or neovascularization usually require multiple intraocular injections to effectively treat the condition. However, the risks associated with these injections increase with repeated delivery of the drug. Therefore, alternative delivery methods need to be established in order to minimize the risks of reinjection. Several other investigations have developed methods to deliver drugs over extended time, through materials capable of releasing chemicals slowly into the eye. In this investigation, we outline the use of Elvax 40W, a copolymer resin, to act as a vehicle for drug delivery to the adult rat retina. The resin is made and loaded with the drug. The drug-resin complex is then implanted into the vitreous cavity, where it will slowly release the drug over time. This method was tested using 2-amino-4-phosphonobutyrate (APB), a glutamate analogue that blocks the light response of the retina. It was demonstrated that the APB was slowly released from the resin, and was able to block the retinal response by 7 days after implantation. This indicates that slow-release drug delivery using this copolymer resin is effective for treating the retina, and could be used therapeutically with further testing.

This paper details how Elvax 40W can be used as a slow-release method for drug delivery to the adult rat retina. The protocol for preparing, loading, and delivering the drug-resin complex to the eye is described.

De liberación lenta Drug Delivery través Elvax 40W a la Rata Retina: Implicaciones para el tratamiento de condiciones crónicas

Diseases of the retina are difficult to treat as the retina lies deep within the eye. Invasive methods of drug delivery are often needed to treat these ...

Investigación

Medicina

Mouse Kidney Transplantation: Models of Allograft Rejection

Rejection of the transplanted kidney in humans is still a major cause of morbidity and mortality. The mouse model of renal transplantation closely replicates both the technical and pathological processes that occur in human renal transplantation. Although mouse models of allogeneic rejection in organs other than the kidney exist, and are more technically feasible, there is evidence that different organs elicit disparate rejection modes and dynamics, for instance the time course of rejection in cardiac and renal allograft differs significantly in certain strain combinations. This model is an attractive tool for many reasons despite its technical challenges. As inbred mouse strain haplotypes are well characterized it is possible to choose donor and recipient combinations to model acute allograft rejection by transplanting across MHC class I and II loci. Conversely by transplanting between strains with similar haplotypes a chronic process can be elicited were the allograft kidney develops interstitial fibrosis and tubular atrophy. We have modified the surgical technique to reduce operating time and improve ease of surgery, however a learning curve still needs to be overcome in order to faithfully replicate the model. This study will provide key points in the surgical procedure and aid the process of establishing this technique.

Here, we present a protocol to study the immunology of rejection. The surgical model presented reports a short operating time and a concise technique. Depending on the donor-recipient strain combination, the transplanted kidney may develop acute cellular rejection or chronic allograft damage, defined by interstitial fibrosis and tubular atrophy.

Ratón Trasplante de Riñón: Modelos de rechazo del aloinjerto

Rejection of the transplanted kidney in humans is still a major cause of morbidity and mortality. The mouse model of renal transplantation closely ...

Normothermic Ex Vivo Kidney Perfusion for the Preservation of Kidney Grafts prior to Transplantation

Kidney transplantation has become a well-established treatment option for patients with end-stage renal failure. The persisting organ shortage remains a serious problem. Therefore, the acceptance criteria for organ donors have been extended leading to the usage of marginal kidney grafts. These marginal organs tolerate cold storage poorly resulting in increased preservation injury and higher rates of delayed graft function. To overcome the limitations of cold storage, extensive research is focused on alternative normothermic preservation methods.
Ex vivo normothermic organ perfusion is an innovative preservation technique. The first experimental and clinical trials for ex vivo lung, liver, and kidney perfusions demonstrated favorable outcomes.
In addition to the reduction of cold ischemic injury, the method of normothermic kidney storage offers the opportunity for organ assessment and repair. This manuscript provides information about kidney retrieval, organ preservation techniques, and isolated ex vivo normothermic kidney perfusion (NEVKP) in a porcine model. Surgical techniques, set up for the perfusion solution and the circuit, potential assessment options, and representative results are demonstrated.

Normothermic Ex Vivo Kidney Perfusion for the Preservation of Kidney Grafts prior to Transplantation

The severe organ shortage has resulted in increased use of marginal kidney grafts for transplantation. This has triggered interest in alternative storage methods, since marginal grafts especially tolerate cold storage poorly. The technique of normothermic ex vivo kidney perfusion (NEVKP) represents a novel preservation method for kidney grafts prior to &#160;transplantation.

Normotérmica<em&gt; Ex Vivo</em&gt; Perfusión renal para la Preservación de riñón Injertos antes del trasplante

Kidney transplantation has become a well-established treatment option for patients with end-stage renal failure. The persisting organ shortage remains a ...

Intraluminal Drug Delivery to the Mouse Arteriovenous Fistula Endothelium

Delivery of therapeutic agents to enhance arteriovenous fistula (AVF) maturation can be administered either via intraluminal or external routes. The simple murine AVF model was combined with intraluminal administration of drug solution to the venous endothelium at the same time as fistula creation. Technical aspects of this model are discussed. Under general anesthesia, an abdominal incision is made and the aorta and inferior vena cava (IVC) are exposed. The infra-renal aorta and IVC are dissected for clamping. After proximal and distal clamping, the puncture site is exposed and a 25 G needle is used to puncture both walls of the aorta and into the IVC. Immediately after the puncture, a reporter gene-expressing viral vector was infused in the IVC via the same needle, followed by 15 min of incubation. The intraluminal administration method enabled more robust viral gene delivery to the venous endothelium compared to administration by the external route. This novel method of delivery will facilitate studies that explore the role of the endothelium in AVF maturation and enable intraluminal drug delivery at the time of surgical operation.

After puncturing the aorta through the inferior vena cava (IVC) to create an aorto-caval fistula in the mouse, solution containing a drug is infused into the IVC via the same needle, followed by incubation. This method enables more robust drug delivery to the venous endothelium compared to the external route.

Intraluminal entrega de la droga a la fístula arteriovenosa ratón endotelio

Delivery of therapeutic agents to enhance arteriovenous fistula (AVF) maturation can be administered either via intraluminal or external routes. The ...

Method of Direct Segmental Intra-hepatic Delivery Using a Rat Liver Hilar Clamp Model

Major hepatic surgery with inflow occlusion, and liver transplantation, necessitate a period of warm ischemia, and a period of reperfusion leading to ischemia/reperfusion (I/R) injury with myriad negative consequences. Potential I/R injury in marginal organs destined for liver transplantation contributes to the current donor shortage secondary to a decreased organ utilization rate. A significant need exists to explore hepatic I/R injury in order to mediate its impact on graft function in transplantation. Rat liver hilar clamp models are used to investigate the impact of different molecules on hepatic I/R injury. Depending on the model, these molecules have been delivered using inhalation, epidural infusion, intraperitoneal injection, intravenous administration or injection into the peripheral superior mesenteric vein. A rat liver hilar clamp model has been developed for use in studying the impact of pharmacologic molecules in ameliorating I/R injury. The described model for rat liver hilar clamp includes direct cannulation of the portal supply to the ischemic hepatic segment via a side branch of the portal vein, allowing for direct segmental hepatic delivery. Our approach is to induce ischemia in the left lateral and median lobes for 60 min, during which time the substance under study is infused. In this case, pegylated-superoxide dismutase (PEG-SOD), a free radical scavenger, is infused directly into the ischemic segment. This series of experiments demonstrates that infusion of PEG-SOD is protective against hepatic I/R injury. Advantages of this approach include direct injection of the molecule into the ischemic segment with consequent decrease in volume of distribution and reduction in systemic side effects.

A unique rat liver hilar clamp model was developed for studying the impact of pharmacologic molecules in ameliorating ischemia-reperfusion injury. This model includes direct cannulation of the portal supply to the ischemic liver segment via a branch of the portal vein, allowing for direct hepatic delivery.

Método de la entrega directa segmentaria intra-hepática utilizando un modelo de hígado de rata hiliar abrazadera

Major hepatic surgery with inflow occlusion, and liver transplantation, necessitate a period of warm ischemia, and a period of reperfusion leading to ...

Surgical Labyrinthectomy of the Rat to Study the Vestibular System

To study the vestibular system or the vestibular compensation process, a number of methods have been developed to cause vestibular damage, including surgical or chemical labyrinthectomy and vestibular neurectomy. Surgical labyrinthectomy is a relatively simple, reliable, and rapid method. Here, we describe the surgical technique for rat labyrinthectomy. A postauricular incision is made under general anesthesia to expose the external auditory canal and the tympanic membrane, after which the tympanic membrane and the ossicles are removed without the stapes. The stapes artery, which is located between the stapes and the oval window, is a vulnerable structure and must be preserved to obtain a clear surgical field. A hole to fenestrate the vestibule is made with a 2.1-mm drill bur superior to the stapes. Then, 100% ethanol is injected through this hole and aspirated several times. Meticulous dissection under a microscope and careful bleeding control are essential to obtain reliable results. Symptoms of vestibular loss, such as nystagmus, head tilting, and a rolling motion, are seen immediately after surgery. The rotarod or rotation chair test can be used to objectively and quantitatively evaluate the vestibular function.

This protocol describes the surgical labyrinthectomy of a rat, which is a useful method for studying the vestibular system.

Labyrinthectomy quirúrgica de la rata para el estudio del sistema Vestibular

To study the vestibular system or the vestibular compensation process, a number of methods have been developed to cause vestibular damage, including ...

A Clinical Trial Assessing the Safety, Efficacy, and Delivery of Olive-Oil-Based Three-Chamber Bags for Parenteral Nutrition

Limited evidence exists to precisely estimate efficacy and safety differences between parenteral nutrition (PN) prepared using olive-oil-based three-chamber bags (3CBs) and soybean-oil-based compounded bags (CoBs) in hospitalized adult patients. We designed a multicenter, randomized, prospective, open-label, noninferiority protocol to compare the efficacy, safety, and distribution of olive-oil-based 3CBs and soybean-oil-based CoB formulations in adult Chinese patients requiring PN during surgical intervention. Subjects were randomized to receive either one of the study treatments using an interactive voice or web-based recognition system in accordance with the randomization code. Randomization was further stratified based on the study site and surgical category. Both treatment groups received similar amounts of calories and protein. In addition, the two study treatments contained a similar composition of the amino-acid component. The only difference between the two PN formulations was the lipid constitution. The duration of administration of study treatments was a minimum of 5 days up to a maximum of 14 days after the surgical procedure. The primary efficacy endpoint was serum prealbumin levels on day 5 of the study. Noninferiority was proved if the anti-log of the lower bound of the 95% confidence interval (CI) of the treatment difference was at least 0.80. Other efficacy measures included treatment preparation time; duration to achieve tolerability of oral nutrition; associated infectious complications; length of hospitalization; and laboratory assessment of markers of nutrition, inflammation, metabolism, and oxidative stress. A total of 458 patients were enrolled in the study. The results showed that olive-oil-based 3CBs were non-inferior to soybean-based CoBs, besides being well tolerated. The infection rate was found to be significantly lower in the olive-oil-based 3CB group. Thus, this study may be used as a reference for future research on lipid emulsion and 3CBs.

Here, we present a protocol for a study comparing the efficacy, safety, and delivery of olive-oil-based 3CB and soybean-oil-based CoB formulations in adults requiring parenteral nutrition. The results revealed that olive-oil-based 3CBs is non-inferior and well tolerated compared to soybean formulations.

Un ensayo clínico que evalúa la seguridad, eficacia y entrega de bolsas de tres cámaras basadas en aceite de oliva para la nutrición parenteral

Limited evidence exists to precisely estimate efficacy and safety differences between parenteral nutrition (PN) prepared using olive-oil-based ...

An Efficient Sieving Method to Isolate Intact Glomeruli from Adult Rat Kidney

Preservation of glomerular structure and function is pivotal in the prevention of glomerulonephritis, a category of kidney disease characterized by proteinuria which can eventually lead to chronic and end-stage renal disease. The glomerulus is a complex apparatus responsible for the filtration of plasma from the body. In disease, structural integrity is lost and allows for the abnormal leakage of plasma contents into the urine. A method to isolate and examine glomeruli in culture is critical for the study of these diseases. In this protocol, an efficient method of retrieving intact glomeruli from adult rat kidneys while conserving structural and morphological characteristics is described. This process is capable of generating high yields of glomeruli per kidney with minimal contamination from other nephron segments. With these glomeruli, injury conditions can be mimicked by incubating them with a variety of chemical toxins, including protamine sulfate, which causes foot process effacement and proteinuria in animal models. Degree of injury can be assessed using transmission electron microscopy, immunofluorescence staining, and western blotting. Nephrin and Wilms Tumor 1 (WT1) levels can also be assessed from these cultures. Due to the ease and flexibility of this protocol, the isolated glomeruli can be utilized as described or in a way that best suits the needs of the researcher to help better study glomerular health and structure in diseased states.

The main focus of this protocol is to efficiently isolate viable primary glomeruli cultures with minimal contaminants for use in a variety of downstream applications. The isolated glomeruli retain structural relationships between component cell types and can be cultured ex vivo for a short time.

Un método eficiente de tamizado para aislar intactos glomérulos del riñón de rata adulta

Preservation of glomerular structure and function is pivotal in the prevention of glomerulonephritis, a category of kidney disease characterized by ...

Orthotopic Rat Kidney Transplantation: A Novel and Simplified Surgical Approach

Kidney transplantation offers increased survival rates and improved quality of life for patients with end-stage renal disease, as compared to any type of renal replacement therapy. Over the past few decades, the rat kidney transplantation model has been used to study the immunological phenomena of rejection and tolerance. This model has become an indispensable tool to test new immunomodulatory pharmaceuticals and regimens prior to proceeding with expensive preclinical large animal studies.
This protocol provides a detailed overview of how to reliably perform orthotopic kidney transplantation in rats. This protocol includes three distinctive steps that increase the probability of success: perfusion of the donor kidney by flushing through the portal vein and the use of a cuff system to anastomose the renal veins and ureters, thereby decreasing cold and warm ischemia times. Using this technique, we have achieved survival rates beyond 6 months with normal serum creatinine in animals with syngeneic or tolerant kidney transplants. Depending on the aim of the study, this model can be modified by pre- or posttransplant treatments to study the acute, chronic, cellular, or antibody-mediated rejection. It is a reproducible, reliable, and cost-effective animal model to study different aspects of kidney transplantation.

The purpose of this manuscript and protocol is to explain and demonstrate in detail the surgical procedure of orthotopic kidney transplantation in rats. This method is simplified to achieve the correct perfusion of the donor kidney and shorten the reperfusion time by using the venous and ureteral cuff anastomosis technique.

Trasplante de riñón de rata ortotópica: un enfoque quirúrgico novedoso y simplificado

Kidney transplantation offers increased survival rates and improved quality of life for patients with end-stage renal disease, as compared to any type of ...

Intratracheal Administration of Dry Powder Formulation in Mice

In the development of inhalable dry powder formulations, it is essential to evaluate their biological activities in preclinical animal models. This paper introduces a noninvasive method of intratracheal delivery of dry powder formulation in mice. A dry powder loading device that consists of a 200 &#181;L gel loading pipette tip connected to an 1 mL syringe via a three-way stopcock is presented. A small amount of dry powder (1-2 mg) is loaded into the pipette tip and dispersed by 0.6 mL of air in the syringe. Because pipette tips are disposable and inexpensive, different dry powder formulations can be loaded into different tips in advance. Various formulations can be evaluated in the same animal experiment without device cleaning and dose refilling, thereby saving time and eliminating the risk of cross-contamination from residual powder. The extent of powder dispersion can be inspected by the amount of powder remaining in the pipette tip. A protocol of intubation in mouse with a custom-made light source and a guiding cannula is included. Proper intubation is one of the key factors that influences the intratracheal delivery of dry powder formulation to the deep lung region of the mouse.

Dry powder formulations for inhalation have great potential in treating respiratory diseases. Before entering human studies, it is necessary to evaluate the efficacy of the dry powder formulation in preclinical studies. A simple and noninvasive method of the administration of dry powder in mice through the intratracheal route is presented.

Administración Intratraqueal De La Formulación De Polvo Seco En Ratones

In the development of inhalable dry powder formulations, it is essential to evaluate their biological activities in preclinical animal models. This paper ...