Mouse Myocardial Infarction Modeling

Mouse Myocardial Infarction Modeling

Disease Mechanism

      Myocardial Infarction (MI) is a severe cardiovascular disease. Its pathogenesis lies in the partial or complete obstruction of coronary arteries. This obstruction impairs the blood circulation of the heart, causing part of the myocardial tissue to be in a state of ischemia and hypoxia for a long time, which eventually leads to local necrosis and seriously endangers the patient's life and health.

Experimental Animal Information

      Animal Strain: C57

      Animal Sex: Male

      Age: 6 - 8 weeks old

Modeling Procedures

1. Anesthesia and Preoperative Preparation:

       Inhalation anesthesia was performed using isoflurane. A mouse - specific hair clipper was used to carefully shave off the hair on the mouse's chest and armpit areas to fully expose the surgical operation site. Afterwards, in accordance with the standard procedure, the surgical site was strictly disinfected with iodine tincture and 75% ethanol successively.

2. Tracheal Intubation Operation:

       After the mouse was anesthetized, a toe - pinching test was conducted. When it was confirmed that the mouse had no response, the tracheal intubation related to the MI surgery could be carried out. First, turn on the external light source and the microscope switch, then turn on the ventilator and set the respiratory rate parameter to 110 bpm. Subsequently, insert the tracheal tube into the mouse's trachea carefully along the direction of the glottis, and connect the mouse to the ventilator after completion. At this time, closely observe the mouse's breathing state. If the fluctuation rhythm of the mouse's thorax is consistent with the set frequency of the ventilator, it indicates that the tracheal intubation is successful, and the formal MI surgery can be carried out.

3. Thoracotomy and Exposure of the Heart:

      Place the mouse in a right lateral recumbent position, and use ophthalmic scissors to operate at the axillary position of the mouse's left forelimb. With the help of micro - scissors, accurately open the thoracic cavity between the 3rd and 4th intercostal spaces of the mouse's chest to fully expose the mouse's heart. Then, use micro straight forceps to gently clamp a small amount of pericardial tissue, and carefully tear a little of the pericardium below the left atrial appendage, so that the left anterior descending coronary artery (LAD) or its location can be completely exposed.

4. Coronary Artery Ligation:

      With the assistance of a microscope, accurately find the direction of the left anterior descending coronary artery (LAD) or its possible location. Use a needle holder to firmly clamp the 7 - 0 suture with a needle, insert the needle at a position 2 mm below the lower edge of the left atrial appendage, and let the suture pass through the LAD to completely block the blood supply of the LAD.

5. Thoracic Cavity Closure:

      After completing the coronary artery ligation operation, use 6 - 0 suture to carefully suture the opening of the thoracic cavity. During the suture process, it is necessary to ensure that there are no gaps or dislocations in all parts, so as to ensure that the thoracic cavity is completely closed. Then, suture the muscles and skin layer by layer from the inside out.

6. Postoperative Management:

      After the operation, it is necessary to closely monitor the mouse's physical condition, focusing on whether there are abnormal breathing and other conditions. After the mouse wakes up naturally, first remove the mouse from the ventilator, then carefully take off the tracheal tube, and then place the mouse in a normal environment for feeding.

Modeling Success Criteria

      During the operation, if the electrocardiogram shows ST - segment elevation after the ligation operation, the modeling can be determined to be successful.

Modeling Cycle

The total time required for the entire modeling process is 1 day.