粉防己碱调控炎症因子减轻大鼠心肌缺血/再灌注损伤

Tetrandrine control pro-inflammatory factor to reduce rat myocardial ischemia/ reperfusion injury

摘要:

目的 研究粉防己碱通过对心肌缺血/再灌注（I/R）过程中炎症因子肿瘤坏死因子-α（TNF-α）、白细胞介素（IL）- 1β、IL-6的影响减轻I/R损伤。方法 80只健康雄性SD大鼠随机分为4组: I/R组、假手术组（Sham）、粉防己碱治疗组（Tet）, 辛伐他汀治疗组（Sim）。I/R组结扎大鼠冠状动脉左前降支造成心肌缺血30 min/再灌注24 h后处死大鼠; Sham组只穿针不结扎, 余步骤同I/R组; Tet组在缺血前20 min腹腔注射Tet, Sim组结扎手术前予辛伐他汀 （2 mg/kg）连续灌胃14d, 余步骤同I/R组。抽血检测血清中肌酸激酶（CK）, 乳酸脱氢酶（LDH）。二维（2D）超声评价心脏功能: 检测左心室舒张末期内径（LVDd）、左心室收缩末期内径（LVDs）、左心室短轴缩短率（FS）和射血分数（EF）, 每个指标连续测量三个心动周期, 取其平均值。24h后取心肌标本, 用酶联免疫吸附法（ELISA）检测血清和心肌组织中IL-1β, IL-6, TNF-α表达水平。髓过氧化物酶（MPO）测定心肌组织中性粒细胞的浸润程度。伊文蓝/氯化四唑（EB/TTC）双染色法测量心肌梗死面积（MIS）。结果 （1）各组血清心肌酶水平比较: I/R组、Tet组、Sim组水平显著高于Sham组（P＜0.01）。与I/R组相比, Tet组和Sim组均显著降低（P＜0.01）, Tet组与Sim组比较无显著性差异（P＞0.05）。（2）各组心肌梗死面积比较: 心肌梗死面积、梗死面积/左室面积%、梗死面积/缺血面积% 3项指标, Tet组与Sim组显著低于I/R组, 而Tet组与Sim组之间无显著性差异（P＞0.05）。（3）各组再灌注24h后超声检测心功能比较: 以Sham组术前心功能数据为对照, I/R组、Tet组、Sim组FS、EF值均显著降低（P＜0.01）, Tet组和Sim组显著高于I/R组（P＜0.01）。I/R组、Tet组、Sim组E/A比值均显著降低（P＜0.01）, Tet组和Sim组显著高于I/R组（P＜0.01）。（4）各组缺血心肌局部MPO活性比较: I/R组、Tet组、Sim组均显著高于Sham组（P＜0.01）。Tet组与Sim组无显著性差异（P＞0.05）。（5）各组大鼠血清及心肌组织局部炎症因子TNF-α, IL-1β, IL-6表达水平比较: I/R组、Tet组、Sim组均显著高于Sham组（P＜0.01）, Tet组与Sim组显著高于I/R组（P＜0.01）。Tet组与Sim组无显著性差异（P＞0.05）。结论 炎症因子参与了I/R损伤。粉防己碱可减轻I/R损伤时心肌酶的释放, 保护膜结构, 减少局部中性粒细胞浸润, 改善心功能。

Abstract:

Objective To investigate the effects of tetrandrine(Tet) on expression of pro-inflammatory factors, including TNF-α, IL-1β and IL-6, in rat suffering from cardiac ischemia/reperfusion(I/R) injury, and the mechanism through which Tet attenuates cardiac I/R injury. Methods Totally 80 male Sprague-Dawley(SD) rats were randomly divided into 4 groups: sham group, I/R group, Tet group and simvastatin(Sim) group. The SD rats in I/R group were subjected to 30- min left anterior descending (LAD) coronary occlusion and 24-h reperfusion to make I/R injury model in vivo. The rats in sham group were not subjected to similar procedures except artery occlusion. The rats in Tet group received abdo minal injection of Tet at 20 min before I/R injury. The rats in Sim group received intragastric ad ministration of Sim (2 mg/kg) for 14 days before I/R injury. Cardiac function was assessed using two-dimensional(2-D) ultrasound, including left ventricular end-diastolic dimension(LVDd), left ventricular end-systolic dimension(LVDs), fractional shortening(FS), and left ventricular ejection fraction(LVEF). The serum levels of creatine kinase (CK) and lactate dehydrogenase (LDH) were detected. The expression levels of TNF-α, IL-1β and IL-6 in serum and myocardial tissue were detected by ELISA. The neutrophil infiltration degree in myocardium was deter mined by measuring the activity of myeloperoxidase (MPO) method. Azovan Blue/2,3,5-Tripheny-2H-Tetrazoliam Chloride (EB/TTC) dyeing method was used to measure the infraction size. Results The LDH and CK levels were significantly higher in I/R, Tet and Sim groups than in sham group (P＜0.01), and were much lower in Tet and Sim groups than in I/R group (P＜0.01); there was no difference between Tet and Sim groups (P＞0.05). Myocardial infarction size, ratio of infarction size to left ventricular myocardial size, and ratio of infarction size to ischemia size were lower in Tet and Sim groups than in I/R group (P＜0.01); there was no difference between Tet and Sim groups (P＞0.05). Compared with sham group, FS, LVEF and E/A were decreased significantly in I/R, Tet and Sim groups(P＜0.01), which was higher in Tet and Sim groups than in I/R group(P＜0.01). The activity of MPO was significantly higher in I/R, Tet and Sim groups than in sham group (P＜0.01), and in Tet group than in Sim group (P＞0.05); there was no difference between Tet and Sim groups (P＞0.05). The levels of TNF-α, IL-1β and IL-6 were significantly higher in in I/R, Tet and Sim groups than in sham group (P＜0.01), and in Tet and Sim groups than in I/R group (P＜0.01); there was no difference between Tet and Sim groups (P＞0.05). Conclusion Tet can attenuate myocardial I/R injury. It achieves this pharmacologic action through reducing the levels of harmful cytokines including TNF-α, IL-6 and IL-1β.