Establishment of a modified myocardial ischemia reperfusion model in the SD rat / 医学研究生学报

ABSTRACT

Objective The establishment of the model of myocardial ischemia-reperfusion injury (MIRI) in SD rats involves lengthy time, severe damage, and death of the rats.We aimed at an efficient and rapid method for establishing an MIRI model in rats to ensure a high success rate of modeling and survival of the animals.Methods Using the trachea intubation-assisted breathing machine, we fully exposed the hearts of 80 adult SD rats (8-10 weeks old and weighing 250-300 mg) by mutilating the 2-3 intercostal muscles.Then, we rapidly positioned and ligated the left anterior descending (LAD) coronary artery for an hour, and established the model of MIRI at 48 hours after releasing the slipknot.We performed electrocardiography (ECG) before, during, and at 1 and 48 hours after operation, ligated the same part again at 48 hours postoperatively, and measured the size of the myocardial ischemia and infarction areas using Evans-TTC double staining.Results The survival rate of the 80 rats was 90% and the success rate of MIRI modeling was 86.25%.After ligation of the LAD coronary artery, ECG showed the ST segment and T wave elevation, followed by gradual decrease of the ST segment and R wave voltage, the myocardium and cardiac apex muscle grey or dark grey below the ligation slipknot.The heart rate myocardial motion amplitude were obviously reduced after ligation.Evans-TTC double staining revealed an evident myocardial infarction area at 48 hours after modeling and the ratio of the ischemia area + infarction area to the total myocardial area of the left ventricle was 0.43 to 0.55 (P>0.05) and that of the infarction area to the ischemia area + infarction area was 0.35 to 0.45 (P>0.05).Conclusion The modified rat model of MIRI can be fast and efficiently established, with a high success rate of modeling and a low mortality of the animals.