A Modified Simple Method for Induction of Myocardial Infarction in Mice

Summary

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.

Abstract

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.

Introduction

Myocardial infarction (MI) represents one of the significant causes of death and disability worldwide^1,2,3,4,5. 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 MI^6,7,8. Of note, the establishment of MI models is a prerequisite to meet these en....

Protocol

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.......

Discussion

The present report demonstrated a easy 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.......

Materials

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