Name: a mouse model of intestinal partial obstruction
Uploaded: 2018-03-05T14:30:00
Description: Watch this Scientific Journal Video about A Mouse Model of Intestinal Partial Obstruction at JoVE.com

The authors would like to thank Benjamin J Weigler, D.V.M., Ph.D. and Walt Mandeville, D.V.M. (Animal Resources &#38; Campus Attending Veterinarian, University of Nevada, Reno) for their excellent animal services provided to the mice as well as their counsel on surgical procedures.

The following protocol has been approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Nevada-Reno (UNR) Animal Resources and complies with all institutional ethical guidelines regarding the use of research animals.
1. Animals.
<ol>
	<li>Obtain mature (4-6 weeks old) C57BL/6 mice weighing between 20-30 g. House the colony of laboratory mice in a centralized animal facility at UNR Animal Resources.</li>
</ol>
2. Partial Obstruction Surge...

<ol>
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D., Notari, L., Sun, R., Zhao, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+smooth+muscle+responses+to+inflammation.">Mechanisms of smooth muscle responses to inflammation.</a> Neurogastroenterol Motil. 24, 802-811 (2012).</li><li>Chen, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Smooth+muscle+hyperplasia/hypertrophy+is+the+most+prominent+histological+change+in+Crohn's+fibrostenosing+bowel+strictures:+A+semiquantitative+analysis+by+using+a+novel+histological+grading+scheme.">Smooth muscle hyperplasia/hypertrophy is the most prominent histological change in Crohn's fibrostenosing bowel strictures: A semiquantitative analysis by using a novel histological grading scheme.</a> J Crohns Colitis. 11, 92-104 (2017).</li><li>Huizinga, J. D., Chen, J. 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We demonstrated that mice receiving the intestinal PO surgery consistently and reproducibly develop intestinal smooth muscle hypertrophy, which mimics human intestinal obstruction. Intestinal obstruction surgeries have been developed for different animals including mice7, rats10, guinea pigs11, dog12 and cats13. The mouse model of intestinal obstruction has time, cost, size, and phenotypic advantages ov...

Intestinal obstructions are a partial or complete blockage in the small or large intestine which prevents digested food, fluids, and gas from moving through the intestines1. Due to the obstruction, the blockage induces the intestinal walls to become thickened, narrowing the lumen2. Intestinal obstruction can occur as a result of abdominal or pelvic surgeries that cause abdominal adhesion tissue formation or from GI disorders such as inflammatory bowel diseases (Crohn&#39;s disease), diverticulitis, hernias, volvulus, stricture, intussusception, constipation, fecal impaction, pseudo-obstruction, cancers and tumors3,4,5. Intestinal obstructions in these cases often lead to the hypertrophy of the tunica muscularis of the intestine6.
PO of the lumen induces intestinal distention, and increases smooth muscle layer thickness around the obstruction in response to the need to continue functional peristalsis7,8,9,10,11,12,13. Animal models of intestinal PO have been developed to study smooth muscle hypertrophy in mice7, rats10, guinea pigs11, dogs12, and cats13 that consistently develop similar hypertrophy within the intestinal muscle layers.
A mouse model of intestinal PO is the most cost effective way to generate and study intestinal obstructions in vivo. Small intestine obstructions are carried out in mice by using a silicone ring surgically placed surrounding the ileum. The PO mice showed an early increase in the number of cells (hyperplasia), and an increase in muscle layer thickness (hypertrophy) after PO surgery8,15. SMC are the primary plastic cells that are growing within smooth muscle layers in response to the hypertrophic conditions14, but other cells such as ICC and PDGFR&#945;+ cells that are closely associated with SMC, are also repopulated. We have previously reported that the PO mice develop hypertrophy in the small intestine, in which SMC are dedifferentiated into PDGFR&#945;+ cells that are highly proliferative7,15,16. Conversely, ICC are degenerated and lost within the hypertrophied smooth muscle layers during the development of intestinal obsruction7. Another major benefit of the PO model is its capacity to induce changes in the enteric nervous system and propagating neurogenic motor patterns. The major propagating neurogenic motor pattern in the mouse small bowel is the migrating motor complex (MMC), which is neurogenic and does not require ICC or electrical slow waves17. The PO model can provide clear insights into how MMCs and enteric nerves are remodeled by partial obstruction.
Here, we propose a murine protocol for intestinal PO surgery using a silicone ring. Mice receiving PO surgery reliably produce hypertrophy in the tunica muscularis of the small intestine. Within hypertrophic muscle, SMC, ICC, PDGFR&#945;+, and neuronal cells are dramatically remodeled.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Surgical drape</td>
			<td>Medical and veterinary supplies</td>
			<td>SMS40</td>
			<td>40&#8221;X100 yards</td>
		</tr>
		<tr>
			<td>Underpad, econ, pro plus</td>
			<td>Medical and veterinary supplies</td>
			<td>MSC281224</td>
			<td>17x24&#8221;</td>
		</tr>
		<tr>
			<td>Iris scissors</td>
			<td>Braintree scientific, Inc</td>
			<td>SC-i-130</td>
			<td></td>
		</tr>
		<tr>
			<td>Iris scissors</td>
			<td>Vantage</td>
			<td>V95-304</td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont electronic &#38; jeweler tweezers</td>
			<td>Dumont</td>
			<td>98-180-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Braided absorbable suture</td>
			<td>Covidien polysorb</td>
			<td>SL-5687G</td>
			<td>5-0, polyglactin</td>
		</tr>
		<tr>
			<td>Nylon non-absorbable mono filament</td>
			<td>AD surgical</td>
			<td>S-N618R13</td>
			<td>6-0, nylon</td>
		</tr>
		<tr>
			<td>Surgical blade</td>
			<td>Dynarex</td>
			<td></td>
			<td>No.15</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>Jacobson microvascular</td>
			<td>36-1342TC</td>
			<td>8.5 inch</td>
		</tr>
		<tr>
			<td>Scalpel handle</td>
			<td>Flinn scientific</td>
			<td>AB1049</td>
			<td></td>
		</tr>
		<tr>
			<td>Microsurgical scissor</td>
			<td>WPI</td>
			<td>503305</td>
			<td></td>
		</tr>
		<tr>
			<td>Petrolatum ophthalmic ointment</td>
			<td>Puralube VET</td>
			<td></td>
			<td>3.5 g</td>
		</tr>
		<tr>
			<td>Fluriso (isoflurane)</td>
			<td>Vetone</td>
			<td>V1 502017</td>
			<td>250 ml</td>
		</tr>
		<tr>
			<td>Steri-strip reinforced skin closure</td>
			<td>3M</td>
			<td>R1547</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical gloves</td>
			<td>Medline</td>
			<td>MSG2270</td>
			<td></td>
		</tr>
		<tr>
			<td>Ear loop face mask</td>
			<td>The safety zone</td>
			<td>RS700</td>
			<td></td>
		</tr>
		<tr>
			<td>Avant gauze non-woven sponges</td>
			<td>Caring</td>
			<td>PRM25444</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical cup</td>
			<td>Admiral&#160; craft OYC-2</td>
			<td>725-A42</td>
			<td>2.5 oz</td>
		</tr>
		<tr>
			<td>Swabstick</td>
			<td>ChloraPrep</td>
			<td>260103</td>
			<td>2% w/v Chlorhexidine&#160; Gluconate (CHG) and 70% v/v Isopropyl Alcohol (IPA)</td>
		</tr>
		<tr>
			<td>Cotton tipped applicator</td>
			<td>Puritan</td>
			<td>806-WC</td>
			<td></td>
		</tr>
		<tr>
			<td>Buprenorphine</td>
			<td>Zoo pharm</td>
			<td>BZ8069317</td>
			<td>1 mg/ml</td>
		</tr>
		<tr>
			<td>Gentamycin sulfate</td>
			<td>Vetone</td>
			<td>G-6336-04</td>
			<td>100 mg/ml</td>
		</tr>
		<tr>
			<td>Fast acting gel cream remover</td>
			<td>Veet</td>
			<td>8111002</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>AHS</td>
			<td>AH01T2516</td>
			<td>1 ml with needle</td>
		</tr>
		<tr>
			<td>Silicon ring</td>
			<td>VWR</td>
			<td>60985-720</td>
			<td>6 mm in length, 4 mm exterior diameter, 3.5 mm interior diameter</td>
		</tr>
		<tr>
			<td>C57BL/6 mice</td>
			<td>The Jackson Laboratory</td>
			<td></td>
			<td>4-6 weeks old</td>
		</tr>
	</tbody>
</table>

a mouse model of intestinal partial obstruction

Intestinal obstructions, that impede or block peristaltic movement, can be caused by abdominal adhesions and most gastrointestinal (GI) diseases including tumorous growths. However, the cellular remodeling mechanisms involved in, and caused by, intestinal obstructions are poorly understood. Several animal models of intestinal obstructions have been developed, but the mouse model is the most cost/time effective. The mouse model uses the surgical implantation of an intestinal partial obstruction (PO) that has a high mortality rate if it is not performed correctly. In addition, mice receiving PO surgery fail to develop hypertrophy if an appropriate blockade is not used or not properly placed. Here, we describe a detailed protocol for PO surgery which produces reliable and reproducible intestinal obstructions with a very low mortality rate. This protocol utilizes a surgically placed silicone ring that surrounds the ileum which partially blocks digestive movement in the small intestine. The partial blockage makes the intestine become dilated due to the halt of digestive movement. The dilation of the intestine induces smooth muscle hypertrophy on the oral side of the ring that progressively develops over 2 weeks until it causes death. The surgical PO mouse model offers an in vivo model of hypertrophic intestinal tissue useful for studying pathological changes of intestinal cells including smooth muscle cells (SMC), interstitial cells of Cajal (ICC), PDGFR&#945;+, and neuronal cells during the development of intestinal obstruction.

Partial obstruction (PO) was surgically induced in one month old mice by placing a silicone ring around the ileum close to the ileocecal sphincter. This ring created a partial blockage in the ileum. Sham operations (SO) were also performed without a ring on age/sex matched mice and these mice did not show any symptoms similar to those found in PO mice. Mice quickly recovered from PO surgery within a few hours. They showed no obvious behavioral changes or weakness within the first week, bu...

Watch this Scientific Journal Video about A Mouse Model of Intestinal Partial Obstruction at JoVE.com

A Mouse Model of Intestinal Partial Obstruction

Intestinal obstructions are a partial or complete blockage of the intestine that can cause severe abdominal pain, nausea, vomiting, and preventing the passage of stool. This procedure for creating intestinal partial obsructions in mice is reliable in studying the mechanisms underlying pathological cell growth and death in the intestine.

Intestinal obstructions, that impede or block peristaltic movement, can be caused by abdominal adhesions and most gastrointestinal (GI) diseases including ...

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