This work was supported by grants from the National Natural Science Foundation of China (81930007, 81625002, 81800307, 81470389, 81500221, 81770238), the Shanghai Outstanding Academic Leaders Program (18XD1402400), the Science and Technology Commission of Shanghai Municipality (201409005200), Shanghai Pujiang Talent Program (2020PJD030), and China Postdoctoral Science Foundation (2020M671161, BX20190216).

The experiments involving animal work are performed with all necessary approvals from the Laboratory Animal Welfare Ethics Committee of Renji Hospital, Shanghai Jiao Tong University, School of Medicine (R52021-0506). Female and male C57BL/6J mice aged between 8-10 weeks were used in the study.
1. Preparation of the simplified anesthesia equipment (OPTIONAL)
NOTE: This is an optional pre-operative set up and can be replaced with titratable anesthesia a...

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The present report demonstrated a easy&#160;protocol for MI induction in mice with readily available materials, which was modified from a method reported by Gao16. Murine MI models are indispensable for mechanistic exploration and drug screen for post-MI dysfunction and remodeling12. Among the existing techniques for MI induction, coronary artery ligation represents the most commonly practiced one. Coronary artery ligation faithfully recapitulates the ischemia nature of myo...

Myocardial infarction (MI) represents one of the significant causes of death and disability worldwide1,2,3,4,5. Despite timely reperfusion, there is currently a lack of effective therapies to treat post-MI cardiac remodeling. Correspondingly, considerable efforts have been made to mechanistic exploration and therapy exploitation for MI6,7,8. Of note, the establishment of MI models is a prerequisite to meet these ends.
Several methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been proposed to induce MI models in small animals. Isoproterenol treatment is a simple method for MI induction, but it cannot induce infarction of the targeted area9. Cryoinjury leads to myocardial necrosis via the generation of ice crystals and disruption of the cell membrane rather than direct ischemia10. By contrast, coronary artery ligation permits precise control of occlusion site and extent of infarct area and faithfully recapitulates remodeling response following infarction11,12. Coronary artery ligation is typically performed following intubation, mechanical ventilation, and thoracotomy, which is technically challenging13,14. Several modified protocols for coronary artery ligation (e.g., ventilation free) were reported and potentiated the induction of MI, but detailed visual demonstrations are lacking15,16,17. These issues pose a significant financial and technical barrier for groups wishing to engage in research using MI models. This report presents an approach for induction of MI in mice. The current method is easy, timesaving, and uses surgical tools and equipment found readily in most laboratories.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2,3,5-Triphenyltetrazolium chloride</td>
			<td>SIGMA</td>
			<td>T8877-25G</td>
			<td>TTC staining</td>
		</tr>
		<tr>
			<td>4-0 silk suture</td>
			<td>YUANKANG</td>
			<td>4-0</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Autoclave</td>
			<td>HIRAYAMA</td>
			<td>HVE-50</td>
			<td>Sterilization for the solid</td>
		</tr>
		<tr>
			<td>Buprenorphine</td>
			<td>Qinghai Pharmaceutical FACTORY Co., Ltd.</td>
			<td>H10940181</td>
			<td>reduce post-operative pain</td>
		</tr>
		<tr>
			<td>Centrifugation tube</td>
			<td>Biological Hope</td>
			<td>1850-K</td>
			<td>15ML</td>
		</tr>
		<tr>
			<td>Depilatory cream</td>
			<td>ZIKER BIOTECHNOLOGY</td>
			<td>ZK-L2701</td>
			<td>Depilation agent for laboratory animals</td>
		</tr>
		<tr>
			<td>Forcep</td>
			<td>RWD</td>
			<td>F12028</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Gas filter</td>
			<td>ZHAOXIN</td>
			<td>SA-493</td>
			<td>Operator protection</td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>RWD</td>
			<td>20071302</td>
			<td>Used for anesthesia</td>
		</tr>
		<tr>
			<td>Light source</td>
			<td>Beijing PDV</td>
			<td>LG-150B</td>
			<td>Operating lamp</td>
		</tr>
		<tr>
			<td>Micro-mosquito hemostat</td>
			<td>FST</td>
			<td>13011-12</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Needle</td>
			<td>BINXIONG</td>
			<td>42180104</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Needle and the 6-0 silk suture</td>
			<td>JIAHE</td>
			<td>SC086</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>ShangHaiJZ</td>
			<td>J32030</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>ShangHaiJZ</td>
			<td>J32010</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Povidone-iodine swabs</td>
			<td>SingleLady</td>
			<td>GB26368-2010</td>
			<td>Skin disinfection</td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td>CNSTRONG</td>
			<td>JYJ1030</td>
			<td>Surgical instrument</td>
		</tr>
		<tr>
			<td>Sterile eye cream</td>
			<td>Shenyang Xingqi Pharmaceutical Co., Ltd.</td>
			<td>H10940177</td>
			<td>prevent corneal dryness</td>
		</tr>
		<tr>
			<td>Ultra-high resolution ultrasound imaging system for small animals</td>
			<td>VisualSonics</td>
			<td>Vevo 2100</td>
			<td>Echocardiographic analysis</td>
		</tr>
	</tbody>
</table>

a modified simple method for induction of myocardial infarction in mice

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI remodeling and evaluation of novel therapeutics. Different methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been used to induce MI. Compared with isoproterenol treatment and cryoinjury, coronary artery ligation may better reflect the ischemic response and chronic remodeling after MI. However, traditional methods for coronary ligation in mice are technically challenging. The current study describes a simple and efficient process for induction of MI in mice with readily available materials. The mouse chest skin was cut open under stable anesthesia. The heart was immediately externalized through the intercostal space after blunt separation of the pectoralis major and pectoralis minor. The left anterior descending branch (LAD) was ligated with a 6-0 suture 3 mm from its origin. Following LAD ligation, staining with 2,3,5-Triphenyltetrazolium chloride (TTC) indicated successful induction of MI and temporal changes of post-MI scar size. Meanwhile, survival analysis results showed overt mortality within 7 days after MI, mainly due to cardiac rupture. Moreover, post-MI echocardiographic assessment demonstrated successful induction of contractile dysfunction and ventricular remodeling. Once mastered, an MI model can be established in mice within 2-3 min with readily available materials.

The experimental protocol and some of the critical steps are shown in Figure 1. The simplified anesthesia equipment induced anesthesia. As shown in Figure 2A, the induced anesthesia was stable, as reflected by the regular breathing rates (varied from 90-107 breaths/min in the tested mice). Following coronary artery ligation, TTC staining analysis indicated successful induction of myocardial infarction and temporal changes of post-MI scar size (<strong class="xfi...

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A Modified Simple Method for Induction of Myocardial Infarction in Mice

Under adequate anesthesia, the mouse heart was externalized through the intercostal space, and myocardial infarction was successfully induced by ligating the left anterior descending artery (LAD) using materials readily available in most laboratories.

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI ...

This report presents a unique approach for the induction of myocardial infarction in mice. The current method is easy, time-saving, and it uses the surgical tubes and equipment found readily in most laboratories. The establishment of myocardial infarction models provides a premise for investigating the past mechanisms of post-MI remodeling, and variation of novel therapeutics.Apply the depilatory cream to the mouse chest, and wait for one minute. Then gently wipe off the depilatory cream and hair with wet gauze. Secure the mouse on a surgery platform in the supine position.Disinfect the surgical area as described in the text. Then place a sterile drape around the disinfected area. Make a 0.5 centimeter skin cut along the line connecting the xiphoid and armpit, and bluntly separate the pectoral major and pectoral minor muscles using forceps.Open the fourth intercostal space using a Micro-Mosquito hemostat. Externalize the heart by pushing it toward the fourth intercostal space with the index finger of the left hand. Secure the heart with the left hand and ligate the left anterior descending branch with a 6/0 suture three millimeters from its origin.Place the heart back into the thoracic cavity quickly. Evacuate the air out of the thoracic cavity by gently pressing on the chest cavity. For post-operative pain management, inject buprenorphine subcutaneously every four to six hours for up to seventy-two hours post-surgery.Place the mouse on a heating pad to recover from the anesthesia. Secure the euthanized mouse on the surgery platform in the supine position. Make a ventral incision of approximately three to four centimeters in the upper abdomen.Cut off the ribs from both sides of the thorax cavity, and then remove the diaphragm. Perfuse the heart with 10 milliliters of cold four degree celsius 1X PBS through intraventricular injection. Then collect the heart by cutting off the aortic root, and immediately storing it at minus 80 degrees Celsius.Slice the frozen heart into one millimeter thick sections on ice using razor blades. Incubate the prepared heart slices in 1%TTC solution dissolved in one 1X PBS at 37 degrees Celsius for 10 to 15 minutes. Then photograph the slices using a digital camera.Following coronary artery ligation, TTC staining analysis indicated successful induction of myocardial infarction, and temporal changes of post-MI scar size. Survival analysis results showed overt mortality within seven days after MI in male and female C57BL/6J mice. Ventricular rupture was a common reason for post-MI death.Post-MI echocardiographic assessment demonstrated successful induction of contractile dysfunction and ventricular remodeling. When attempting to externalize the heart, don't press the chest cavity firstly, and following our resistance, indicates a need to adjust the direction against the weighted praise. Following this procedure, intramyocardial injection of viral vectors or cells can be performed to test the efficacy of gene therapies or cell therapies in heart disease matters.

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3.2K visualizações.  The First Affiliated Hospital of Bengbu Medical College. Este relato apresenta uma abordagem única para a indução de infarto do miocárdio em camundongos. O método atual é fácil, economiza tempo e utiliza tubos cirúrgicos e equipamentos encontrados prontamente na maioria dos laboratórios. O estabelecimento de modelos de infarto do miocárdio fornece uma premissa para investigar os mecanismos passados de remodelação pós-IAM e variação de novas terapêuticas.Aplique o creme depilatório no peito do rato e aguarde um minuto. Em seg...