Protective effects of carnitine against myocyte apoptosis following myocardial ischemia/reperfusion in rabbits

    MA Lanª²Xiang, XI Zengª²Qian, ZHANG Hua, YANG Xingª²Chang, YUAN Pingª²Li, DUAN Jiª²Yuan, ZHANG Lei

    1Department of Cardiology, Shaanxi Provincial Corps Hospital, Chinese People¬ðs Armed Police Forces, Xi¬ðan 710054, China, 2Department of Cardiology, Xijing Hospital, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To study the protective effects of carnitine on cardiac myocyte apoptosis following myocardial ischemia/reperfusion (MI/R). METHODS: Rabbits were subjected to 45ª²min myocardial ischemia followed by reperfusion for 3 h. Anesthetized rabbits were randomly divided into 3 group: control group (n=5), in which left anterior descending coronary artery was exposed and a piece of silk thread was placed around the artery but not tied, MI/R group (n=10), in which normal saline 1.5 mL was injected into sublingual vein after MI, and carnitine group (n=10), in which carnitine 1.5 mL/(kg¡¤h) was given intravenously 5 min after MI. The animals were sacrificed and their hearts were harvested. Apoptosis was identified by TUNEL and apoptosis index (AI) was obtained. The expression of Fas and Bclª²2 protein was measured by immunohistochemical technique. RESULTS: MI/R caused significant cardiac dysfunction and myocardial death. Compared with the MI/R group, the carnitine group had better protection against MI/R injury, as shown by marked decrease of AI and the average A value of Fas protein, as well as significantly improved the average A value of Bclª²2 protein. CONCLUSION: Carnitine can protect myocardium from MI/R injury by modulating the expression of Fas and Bclª²2 protein and inhibiting apoptosis following myocardial MI/R. ......