血浆脂蛋白相关磷脂酶A2浓度对急性心肌梗死大鼠心功能的影响

Effects of plasma concentration of lipoprotein-associated phospholipase A2 on cardiac function in rats with acute myocardial infarction

目的探讨血浆脂蛋白相关磷脂酶A2(lipoprotein-associated phospholipase A2,Lp-PLA2)浓度对急性心肌梗死大鼠心功能影响。方法结扎SD大鼠左冠状动脉前降支建成急性心肌梗死模型,将存活的36只大鼠按电脑随机数字表法随机分为低剂量阿托伐他汀组[5 mg/(kg·d)],高剂量阿托伐他汀组[10 mg/(kg·d)]和对照组(等量0.9%氯化钠溶液),每组12只。假手术组10只给予等量0.9%氯化钠溶液灌胃。实验过程共14 d。分别于大鼠心肌梗死后第1天和干预治疗14 d后,采用超声心动图评估大鼠心功能,以及采用酶联免疫吸附试验法评估大鼠血浆Lp-PLA2浓度。比较各组间上述指标的区别及血浆Lp-PLA2浓度与左心室射血分数的关系。结果(1)急性心肌梗死后,与假手术组相比,心肌梗死模型组大鼠心功能明显受损,差异有统计学意义(P<0.05)。药物干预治疗14 d后,与对照组相比,阿托伐他汀治疗组大鼠心功能明显改善,差异有统计学意义(P<0.05);与低剂量组相比,高剂量阿托伐他汀治疗组大鼠左心室射血分数较高,差异有统计学意义(52.7%±4.8%vs.48.5%±5.8%,P<0.05)。(2)急性心肌梗死后第1天,与假手术组相比,心肌梗死模型组大鼠血浆Lp-PLA2浓度均轻微升高,但差异无统计学意义(P=0.074);药物干预治疗14 d后,与对照组相比,阿托伐他汀治疗组大鼠血浆Lp-PLA2浓度明显降低,差异有统计学意义(P<0.05);高剂量组Lp-PLA2浓度较低剂量低,但差异无统计学意义(P=0.066)。(3)Pearson相关分析提示心肌梗死后大鼠血浆Lp-PLA2浓度与左心室射血分数呈负相关(r=-0.609,P<0.05)。结论急性心肌梗死后血浆Lp-PLA2浓度升高,阿托伐他汀能够下调血浆Lp-PLA2浓度;血浆Lp-PLA2浓度与大鼠左心室射血分数呈负相关,提示血浆Lp-PLA2浓度是预测心肌梗死后心功能一个较好的指标。

Objectives To investigate the effects of plasma concentration of lipoprotein-associated phospholipase A2（LpPLA2） on cardiac function in rats with acute myocardial infarction（AMI）. Methods AMI was induced in SD rats by permanent occlusion of the left anterior descending coronary artery. Totally 36 survival rats were randomly and evenly assigned into low-dose atorvastatin group [5 mg /（kg·d）],high-dose atorvastatin group [10 mg /（kg·d）] and control group（same volume of saline）. Ten rats in sham group were orally given equal volume of saline. The general course was14 days. On the first day and the 14 th day,cardiac function was measured by echocardiography and plasma concentrations of Lp-PLA2 were evaluated by enzyme-linked immunesorbent assay. Differences among groups were compared and the relationship between plasma concentration of Lp-PLA2 and left ventricle ejection fraction（LVEF） was also evaluated.Results（1）One day after AMI,cardiac function significantly decreased in AMI model groups compared with sham group（P〈0.05）. Fourteen days later,cardiac functions in atorvastatin groups significantly improved compared with control group（P〈0.05）. LVEF in high-dose atorvastatin group was significantly higher than that in low-dose atorvastatin group（52.7% ±4.8% vs. 48.5% ±5.8%,P〈0.05）.（2） One day after AMI,plasma concentrations of Lp-PLA2 increased in AMI model group when compared with the sham group,but the difference was not statistically significant（P =0.074）.Fourteen days later,plasma concentration of Lp-PLA2 was significantly higher in atorvastatin group than that in control group（P〈0.05）; and plasma concentration of Lp-PLA2 in high-dose atorvastatin group was lower than that in low-dose atorvastatin group,but the difference was not significant（P=0.066）.（3）Pearson correlation analysis indicated that plasma concentration of Lp-PLA2 after AMI negatively correlated with LVEF（r =-0.609,P〈0.05）. Conclusions Plasma concentration of Lp-PLA2 increases after AMI and atorvastatin can reduce plasma concentration of Lp-PLA2. Plasma concentration of Lp-PLA2 negatively correlates with LVEF,indicating that plasma concentration of Lp-PLA2 might be a good indicator for predicting cardiac function after AMI.