左旋卡尼汀对培养乳鼠心肌细胞模拟缺血再灌注损伤的保护作用

目的: 探讨左旋卡尼汀(L-carnitine)对乳鼠心肌细胞在模拟缺血(缺氧)再灌注(缺氧-复氧)状态下发生损伤的保护作用及其可能的机制. 方法: 培养出生1～3 d的SD乳鼠心肌细胞,建立缺血再灌注损伤(I/R)模型,实验分3组:①正常对照组(Control);② I/R组:缺氧120 min,复氧240 min;③左旋卡尼汀组:I/R之前2 h加入不同浓度左旋卡尼汀,使其终浓度分别为1组20 mg/L, 2组50 mg/L, 3组100 mg/L, 4组200 mg/L. 观察指标包括: ①超氧化物酶(SOD)活性;②丙二醛(MDA)含量;③琥珀酸脱氢酶(SDH)活性;④流式细胞仪(FCM)分析细胞凋亡率. 结果: I/R组心肌细胞内MDA含量明显升高,SOD活性显著下降,琥珀酸脱氢酶(SDH)活性明显变低,而且细胞凋亡率也显著增加,与Control组比较具有显著性差异(P＜0.05);但是在药物治疗组,随给药浓度的增加,MDA含量逐渐恢复正常,SOD活性逐渐回升,SDH活性明显升高,而且细胞凋亡率呈下降趋势,各药物治疗组与I/R组比较各实验指标均具有显著性差异(P＜0.05),表明心肌细胞在经左旋卡尼汀预处理之后,抗损伤能力加强,发生损伤的程度减少. 结论: 左旋卡尼汀对心肌细胞具有保护作用,其作用在一定范围内呈剂量依赖关系.

Protective effects of L-carnitine against simulated ischemia and reperfusion injury in cultured neonatal rat cardiomyocytes

AIM: To study the effects of L carnitine against simulated ischemia/reperfusion injury in cultured neonatal rat cardiomyocytes and its possible mechanism. METHODS: A cell culture model of neonatal rat(born within 3 d)cardiacmyocytes was used.The cultured cardiomyocytes were classied into 3 groups,control group, I/R group(anoxia for 120 min, reoxygenation for 240 min)and L carnitine group (L carnitine, which was classed into four different concentration, was added to the cell 2 h before anoxia.). The activities of superoxide dismutase (SOD) and succinate dehydrogenase (SDH) and the content of malondialdehyde (MDA) and the apoptosis was determined by flow of cytometry (FCM). RESULTS: I/R group showed more decrease of SOD and SDH activities and increase of MDA compared with the control group ( P <0.05), as the same time, the apoptosis rate was increased more sharply ( P <0.05). In L carnitine group, the activities of SOD and SDH were significantly increased but MDA and the apoptosis rate were decreased little by little with the incrase of the concentration of L carnitine. And as compared with I/R group, there was a statistical significance ( P <0.05). CONCLUSION: L carnitine can protect cardiomyocyte from ischemia/reperfusion injury and the protective effect is in a dose related manner within certain concentration.