Dr. de Caestecker's laboratory is supported by NIH 1RO1 HL093057-01 and 1RC4DK090770-01. Dr. Harris' laboratory is supported by DK38226,DK51265, DK62794 and funding from the Veterans Administration. Support for mouse kidney injury surgeries, serum creatinine, and fibrosis assays also provided by the Vanderbilt O'Brien Kidney Injury Center grant 1P30 DK079341.

<ol>
	<li>Autoclave all surgical instruments before surgery. Note that if one is performing multiple surgeries on different mice, rinse instruments after use and then sterilize using a hot bead sterilizer. It is not sufficient to soak in 70% ethanol.</li>
	<li>Give 0.5 ml S/C sterile normal saline preoperatively and immediately postoperatively to compensate for loss of body fluid during surgery.</li>
	<li>Weigh the mice.</li>
	<li>Anesthetize mouse using IP Xylazine/Ketamine mixture. It usually takes 3-5 min for the mice to reach surgical plane...

<ol>
	<li>Singh, A. P., Junemann, A., Muthuraman, A., Jaggi, A. S., Singh, N., Grover, K., Dhawan, R. <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+acute+renal+failure.">Animal models of acute renal failure.</a> Pharmacological reports: PR. 64, 31-44 (2012).</li><li>Heyman, S. N., Rosenberger, C., 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=Experimental+ischemia-reperfusion:+Biases+and+myths-the+proximal+vs.+Distal+hypoxic+tubular+injury+debate+revisited.">Experimental ischemia-reperfusion: Biases and myths-the proximal vs. Distal hypoxic tubular injury debate revisited.</a> Kidney Int. 77, 9-16 (2010).</li><li>Lieberthal, W., Nigam, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+renal+failure.+II.+Experimental+models+of+acute+renal+failure:+Imperfect+but+indispensable.">Acute renal failure. II. Experimental models of acute renal failure: Imperfect but indispensable.</a> Am. J. Physiol. Renal Physiol. 278, F1-F12 (2000).</li><li>Dunn, S. R., Qi, Z., Bottinger, E. P., Breyer, M. D., Sharma, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utility+of+endogenous+creatinine+clearance+as+a+measure+of+renal+function+in+mice.">Utility of endogenous creatinine clearance as a measure of renal function in mice.</a> Kidney Int. 65, 1959-1967 (2004).</li><li>Yuen, P. S., Dunn, S. R., Miyaji, T., Yasuda, H., Sharma, K., Star, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simplified+method+for+HPLC+determination+of+creatinine+in+mouse+serum.">A simplified method for HPLC determination of creatinine in mouse serum.</a> Am. J. Physiol. Renal Physiol. 286, F1116-F1119 (2004).</li><li>Hetu, P. O., Gingras, M. E., Vinet, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+and+validation+of+a+rapid+liquid+chromatography+isotope+dilution+tandem+mass+spectrometry+(LC-IDMS/MS)+method+for+serum+creatinine.">Development and validation of a rapid liquid chromatography isotope dilution tandem mass spectrometry (LC-IDMS/MS) method for serum creatinine.</a> Clin. Biochem. 43, 1158-1162 (2010).</li><li>Keppler, A., Gretz, N., Schmidt, R., Kloetzer, H. M., Groene, H. J., Lelongt, B., Meyer, M., Sadick, M., Pill, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasma+creatinine+determination+in+mice+and+rats:+An+enzymatic+method+compares+favorably+with+a+high-performance+liquid+chromatography+assay.">Plasma creatinine determination in mice and rats: An enzymatic method compares favorably with a high-performance liquid chromatography assay.</a> Kidney Int. 71, 74-78 (2007).</li><li>Yang, L., Besschetnova, T. Y., Brooks, C. R., Shah, J. V., Bonventre, J. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+cell+cycle+arrest+in+G2/M+mediates+kidney+fibrosis+after+injury.">Epithelial cell cycle arrest in G2/M mediates kidney fibrosis after injury.</a> Nat. Med. 16, 535-543 (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, 462-468 (1986).</li><li>Chawla, L. S., Amdur, R. L., Amodeo, S., Kimmel, P. L., Palant, C. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+severity+of+acute+kidney+injury+predicts+progression+to+chronic+kidney+disease.">The severity of acute kidney injury predicts progression to chronic kidney disease.</a> Kidney Int. 79, 1361-1369 (2012).</li><li>Lo, L. J., Go, A. S., Chertow, G. M., McCulloch, C. E., Fan, D., Ordonez, J. D., Hsu, C. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dialysis-requiring+acute+renal+failure+increases+the+risk+of+progressive+chronic+kidney+disease.">Dialysis-requiring acute renal failure increases the risk of progressive chronic kidney disease.</a> Kidney Int. 76, 893-899 (2009).</li><li>Burne, M. J., Haq, M., Matsuse, H., Mohapatra, S., Rabb, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+susceptibility+to+renal+ischemia+reperfusion+injury+revealed+in+a+murine+model.">Genetic susceptibility to renal ischemia reperfusion injury revealed in a murine model.</a> Transplantation. 69, 1023-1025 (2000).</li><li>Muller, V., Losonczy, G., Heemann, U., Vannay, A., Fekete, A., Reusz, G., Tulassay, T., Szabo, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sexual+dimorphism+in+renal+ischemia-reperfusion+injury+in+rats:+Possible+role+of+endothelin.">Sexual dimorphism in renal ischemia-reperfusion injury in rats: Possible role of endothelin.</a> Kidney Int. 62, 1364-1371 (2002).</li><li>Schmitt, R., Marlier, A., Cantley, 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=Zag+expression+during+aging+suppresses+proliferation+after+kidney+injury.">Zag expression during aging suppresses proliferation after kidney injury.</a> J. Am. Soc. Nephrol. 19, 2375-2383 (2008).</li><li>Oxburgh, L., de Caestecker, M. 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We describe two models of IR-AKI to study the effects of moderate and severe renal injury. These models allow us to induce consistent and predictable injury with low mortality. Our protocol outlines many of the difficulties and pitfalls traditionally associated with this model. Moreover, we have shown that depending on the length of renal pedicle clamping, the model induces a largely reversible mild and moderate AKI, or more severe AKI with incomplete recovery and persistent renal fibrosis. Post-injury fibrosis in the se...

A variety of experimental models of acute kidney injury (AKI) have been developed to match the diversity and complexity of the human condition (see reference for a recent, comprehensive review1). Each of these models has its own strengths and weaknesses, and while each mimics the corresponding human conditions with varied efficiencies, none precisely model the pathophysiology of their human counterparts. Ischemia reperfusion (IR)-induced AKI has been developed as a model of acute ischemia-induced renal injury in rodents. While the severity of renal tubular injury seen in this model is rarely observed in patients with renal hypoperfusion injuries2, despite its limitations and largely because of the relatively reproducible nature of this model, its extensive use has provided and, it is expected, will continue to provide important insights into many of the common basic mechanisms of AKI, repair, and therapy3. IR surgery requires familiarity with the mouse kidney anatomy, which we have illustrated in a simplified form in Figure 1. Renal ischemia-reperfusion (IR) injury surgery can be performed via ventral (laparotomy) or dorsal (retroperitoneal) approaches. We use a dorsal approach since it is less traumatic, allowing faster recovery times and improved survival (particularly when first learning the procedure). Renal IR injury can be performed unilaterally or bilaterally. However, differences between effective clamp pressures (which may result from interposition of perihilar fat between the clamp jaws) and/or differences in renal responses to ischemia between sides leads to more variable results. While this is not an insurmountable problem, it can increase variability between experiments, which is a major issue for this model. Unilateral IR can be performed with contra-lateral nephrectomy. This is our method of choice since it reduces variability in clamping between pedicles, and at the same time allows one to evaluate renal function, which is unaffected with unilateral IR alone. There has been discussion about what is the most practical vs. optimal method to assess renal function in mice. Blood urea nitrogen (BUN) provides a measure of renal function and is a useful "first look" marker in some models of AKI, including IR injury. However, BUN levels can be affected by volume status of the mice which may be affected, particularly following ventral approach IR injury, when delayed recovery reduces oral intake of fluids for a number of days post-surgery. Serum creatinine is less influenced by hydration status but is clearly affected by muscle mass. One of the difficulties with serum creatinine measurements has been problems with detection of non-creatinine chromogens in mouse serum using picric acid based techniques. As an alternative, a number of centers have developed an HPLC-based method to quantify mouse creatinine that is not affected by this artifact4. However, unlike BUN and picric acid creatinine assays, which only require 5-10 &mu;l of serum, HPLC-assays require ~ 25 &mu;l serum per assay, which if performed in duplicate will require ~100 &mu;l of whole blood per assay. This can be limiting for mouse studies. Some centers have developed more sensitive HPLC and Mass Spectrometry-based methods that allow analysis of smaller sample volumes5, 6. However, these technologies are not widely available. An alternative, enzymatic cascade assay (which requires only 5-10 &mu;l of serum) has been evaluated in mouse and rat serum samples and shown to closely parallel HPLC measurements of serum creatinine while picric acid assays always over-estimate creatinine values7 . While this assay is not widely used in the AKI literature, the assay is commercially available, simple to use, and we find gives reliable results with this model of IR-induced AKI in mice.

<table border="1">
	<tbody>
		<tr>
			<td>Drug or solution</td>
			<td>Company</td>
			<td>Catalogue number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Ketamine (anesthetic)</td>
			<td>Webster Veterinary</td>
			<td>07-881-9413 (100 mg/ml)</td>
			<td>Final concentration 30 mg/ml Ketamine with 3 mg/ml Xylazine administered at 3-4 ml/kg (100 mg/kg Ketamine and 10 mg/kg Xylazine)</td>
		</tr>
		<tr>
			<td>Xylazine (analgesic)</td>
			<td>Webster Veterinary</td>
			<td>07-808-1939 (100 mg/ml)</td>
			<td>As above</td>
		</tr>
		<tr>
			<td>Antisedan (anti-Xylazine)</td>
			<td>Webster Veterinary</td>
			<td>07-867-7097 (5 mg/ml)</td>
			<td>Optional: to reverse effects of Xylazine in order to increase the rate of recovery after surgery Use 0.5-0.7 mg/kg</td>
		</tr>
		<tr>
			<td>Buprenorphine (analgesic)</td>
			<td>Bedford Laboratories</td>
			<td>NDC 55390-100-10 (0.3 mg/ml)</td>
			<td>Dose 0.05-0.1 &mu;g/g every 8-12 hr. Make up a 1:5 dilution in sterile normal saline preoperatively and give 2.5-5 &mu;l/g of the diluted solution.</td>
		</tr>
		<tr>
			<td>Ophthalmic ointment</td>
			<td>Dechra</td>
			<td>NDC 17033-211-38</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Betadine swab sticks</td>
			<td>Purdue Products L.P.</td>
			<td>NDC 67618-153-01</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Nolvasan Surgical Scrub</td>
			<td>Pfizer Animal Care</td>
			<td>300253</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Table 2. Drugs and solutions for I/R surgery.</td>
		</tr>
		<tr>
			<td>Iris Scissors</td>
			<td>Integra Miltex</td>
			<td>VWR 21909-404</td>
			<td>For skin and muscle dissection</td>
		</tr>
		<tr>
			<td>Curved iris forceps</td>
			<td>FST</td>
			<td>11065-07</td>
			<td>To hold skin and muscle, to remove peri-nephric fat</td>
		</tr>
		<tr>
			<td>Blunt forceps</td>
			<td>ROBOZ</td>
			<td>RS-5228</td>
			<td>To manipulate kidneys</td>
		</tr>
		<tr>
			<td>Vascular clamp (795 g pressure)</td>
			<td>ROBOZ</td>
			<td>RS-5459</td>
			<td>Good for C57BL/6 and BALB/c mice strains</td>
		</tr>
		<tr>
			<td>Schwartz clip applying forceps</td>
			<td>ROBOZ</td>
			<td>RS-5450</td>
			<td>For RS-5459 clamps</td>
		</tr>
		<tr>
			<td>Vascular clamp (75-85 g pressure)</td>
			<td>FST</td>
			<td>18055-02</td>
			<td>Optimal for CD1 mice strain, but also can be used for C57BL/6 and BALB/c</td>
		</tr>
		<tr>
			<td>Micro-Serrefine Clamp Applicator-14 cm with Lock</td>
			<td>FST</td>
			<td>18056-14</td>
			<td>For FST 18055-02 clamps</td>
		</tr>
		<tr>
			<td>Gayman T/Pump (water-bath heated platform)</td>
			<td>Braintree Scientific</td>
			<td>TP-650</td>
			<td>The water heater is set at 38 &deg;C 1 hr prior surgery</td>
		</tr>
		<tr>
			<td>15" W x 24" Heated platform</td>
			<td>Braintree Scientific</td>
			<td>HHP-2</td>
			<td>Connect to Gayman heated water pump</td>
		</tr>
		<tr>
			<td>Heating pad</td>
			<td>Braintree Scientific</td>
			<td>Model 39DP</td>
			<td>Uses microwave for heating. This is useful for warming during recovery</td>
		</tr>
		<tr>
			<td>Absorbable suture (Vicryl 5-0)</td>
			<td>ETHICON</td>
			<td>VCP834G</td>
			<td>For fascia and muscle</td>
		</tr>
		<tr>
			<td>Non-absorbable suture: monofilament nylon MONOMID 6/0 660B)</td>
			<td>CP Medical</td>
			<td>CP-B660B-03</td>
			<td>For skin</td>
		</tr>
		<tr>
			<td>Halsey needle holder: Tungsten Carbide/13 cm</td>
			<td>FST</td>
			<td>12501-13</td>
			<td>To hold suture needles</td>
		</tr>
		<tr>
			<td>Timer</td>
			<td>FST</td>
			<td>06-662-3</td>
			<td>To quantify ischemia time</td>
		</tr>
		<tr>
			<td>Hot bead sterilizer</td>
			<td>FST</td>
			<td>18000-45</td>
			<td>To sterilize instruments between mice if you are performing multiple surgeries (it is not sufficient to soak instruments in ethanol)</td>
		</tr>
		<tr>
			<td>Electric razor</td>
			<td>Braintree Scientific</td>
			<td>CLP-22965</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Tape</td>
			<td>Durapore</td>
			<td>1538-0</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>1 ml Syringe</td>
			<td>EXELint</td>
			<td>26044</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sterile cotton tipped applicators</td>
			<td>Kendall</td>
			<td>8884541300</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Absorbent BenchPad</td>
			<td>VWR</td>
			<td>56617-014</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Surgical drapes</td>
			<td>VWR</td>
			<td>21902-985</td>
			<td>Need to be autoclaved</td>
		</tr>
		<tr>
			<td>2'' x 2'' Gauze Pads</td>
			<td>Medi-First</td>
			<td>60673</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td>Sterile gloves</td>
			<td>Cardinal Health</td>
			<td>2D7251</td>
			<td>&nbsp;</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>Table 3. Equipment and instruments for I/R surgery.</td>
		</tr>
	</tbody>
</table>

ischemia-reperfusion model of acute kidney injury and post injury fibrosis in mice

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often unreported mortality rates that may confound analyses. Bilateral renal pedicle clamping is commonly used to induce IR-AKI, but differences between effective clamp pressures and/or renal responses to ischemia between kidneys often lead to more variable results. In addition, shorter clamp times are known to induce more variable tubular injury, and while mice undergoing bilateral injury with longer clamp times develop more consistent tubular injury, they often die within the first 3 days after injury due to severe renal insufficiency. To improve post-injury survival and obtain more consistent and predictable results, we have developed two models of unilateral ischemia-reperfusion injury followed by contralateral nephrectomy. Both surgeries are performed using a dorsal approach, reducing surgical stress resulting from ventral laparotomy, commonly used for mouse IR-AKI surgeries. For induction of moderate injury BALB/c mice undergo unilateral clamping of the renal pedicle for 26 min and also undergo simultaneous contralateral nephrectomy. Using this approach, 50-60% of mice develop moderate AKI 24 hr after injury but 90-100% of mice survive. To induce more severe AKI, BALB/c mice undergo renal pedicle clamping for 30 min followed by contralateral nephrectomy 8 days after injury. This allows functional assessment of renal recovery after injury with 90-100% survival. Early post-injury tubular damage as well as post injury fibrosis are highly consistent using this model.

Moderate IR-induced AKI. Unilateral IR with simultaneous contralateral nephrectomy substantially reduces variability in results, but with shorter clamp times necessary for the mice to survive this procedure, we still found that only 50-60% of mice developed the expected renal insufficiency 24 hr after injury (Figure 3A). In practical terms this creates difficulties evaluating data unless the studies involve treatment regimens that can be initiated at least 24 hr after injury, allowing ti...

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Ischemia-reperfusion Model of Acute Kidney Injury and Post Injury Fibrosis in Mice

We describe models of moderate and severe ischemia-reperfusion-induced kidney injury in which the mice undergo unilateral renal pedicle clamping followed by simultaneous or delayed contralateral nephrectomy, respectively. These models consistently give rise to renal dysfunction and post-injury fibrosis, but injury severity and survival are dependent on mouse background, age and surgical equipment.

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often ...

ischemia-reperfusion-model-acute-kidney-injury-post-injury-fibrosis

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39.0K Views.  Vanderbilt University Medical Center. We describe models of moderate and severe ischemia-reperfusion-induced kidney injury in which the mice undergo unilateral renal pedicle clamping followed by simultaneous or delayed contralateral nephrectomy, respectively. These models consistently give rise to renal dysfunction and post-injury fibrosis, but injury severity and survival are dependent on mouse background, age and surgical equipment.