Establishment and evaluation of rat heart ischemia-reperfusion injury model in vivo

AIM: To establish and evaluate a rat model of heart ischemia-reperfusion injury in vivo.METHODS: Seventy-two male Sprague-Dawley rats weighing(250±50)g were randomly divided into sham operation group(sham),ischemia-reperfusion group(I/R) and normal group.The animals were anesthetized and heparinized.Myocardial ischemia-reperfusion was induced by ligating the left anterior descending coronary artery with "U-shape tube" for 35 min followed by 120 min or 240 min reperfusion in vivo.The heart infarct size was measured by triphenyltetrazolium chloride(TTC) staining.The myocardial cell apoptotic index was determined by the method of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling(TUNEL).Immunohistochemical method was used to detect the expression of Bcl-2 and Bax in rat ischemia myocardium.The blood level of MB isoenzyme of creatine kinase(CK-MB),cardiac troponin I(cTnI),nitric oxide(NO),malondialdehyde(MDA),total superoxide dismutase(T-SOD)and glutathione peroxidase(GSH-Px) were detected after reperfusion for 2 h and 4 h.RESULTS: Compared with normal group and sham group,there were obvious changes of ST-T segment and Q wave in the electrocardiogram of I/R group.The blood level of CK-MB,cTnI,NO,MDA and GSH-Px in I/R group increased(P0.05,P0.01) after reperfusion for 2 h and 4 h,and the blood level of T-SOD in I/R group after reperfusion for 2 h and 4 h also increased(P0.05).The heart infarct size in I/R group was the largest as compared to other groups.Among these groups,the apoptotic index of I/R group was the highest and the Bcl-2/Bax ratio in I/R group decreased(P0.01).CONCLUSION: The rat model of heart ischemia-reperfusion injury in vivo can be successfully established with the "U-shape tube".There are obviously changes of heart infarct size,blood level of CK-MB,cTnI,NO,MDA,T-SOD and GSH-Px,myocardial apoptotic index and Bcl-2/Bax ratio between I/R rats and control animals.