Objective: To investigate the mechanism by which Shexiang Tongxin dripping pills (STDP) improves coronary microcirculation disorder (CMD) and cardiac dysfunction in a porcine model of myocardial ischemia-reperfusion injury.
Methods: Fourteen minipigs were randomly selected for interventional balloon occlusion of the middle left anterior descending branch to induce CMD, and another 7 pigs received sham operation. The pig models of CMD were randomized equally into the model group and STDP-treated group. All the animals were fed with common feed for 8 weeks, and in STDP-treated group, the pigs were given STDP at the daily dose of 3 mg/kg (mixed with feed) for 8 weeks. Before and at the 8th week after the operation, the pigs underwent coronary angiography and echocardiography to determine the vessel lumen diameter and TIMI frame count (CTFC). The pathologies of the myocardium and the microvessels were examined with HE staining at the 8th week. Western blotting was used to detect the expression of silencing information regulator (Sirt1), peroxidase proliferator-activated receptor-γ coactivator-1α (PGC-1α), peroxisome proliferator-activated receptor α (PPARα), extracellular signal-regulated kinase1/2 (ERKI/2), Toll-like receptor 4 (TLR4), and uncoupling protein 2 (UCP2) in myocardial tissue.
Results: Before and at the 8th week after the operation, the diameter of the anterior descending vessel in the 3 groups did not differ significantly (P > 0.05). At the 8th week, the number of CTFC frames in the model group increased significantly compared with that in the sham-operated group, but was obviously lowered by treatment with STDP (P < 0.05). Myocardial ischemia-reperfusion injury significantly increased the interventricular septal thickness at end-diastole, left ventricular end-diastole dimension, end-diastole volume, interventricular septal thickness at end-systole and left ventricular mass at 8 weeks after the modeling (P < 0.05), but such changes were significantly alleviated by treatment with STDP (P < 0.05). STDP treatment markedly alleviated myocardial microvascular congestion, thrombosis and peripheral inflammatory cell infiltration induced by myocardial ischemia-reperfusion, but atrophy of the myocardial muscle fiber remained distinct. STDP obviously suppressed the down-regulation of Sirt1, PGC-1α, and PPARα and the up-regulation of ERK1/ 2, TLR4, and UCP2 in the myocardial tissues induced by myocardial ischemia-reperfusion injury.
Conclusions: STDP has anti-inflammatory effects and regulates energy metabolism in the myocardium through modulating Sirt1, PGC-1α, PPARα, ERKI/2, TLR4, and UCP2 to improve CMD and cardiac dysfunction after myocardial ischemia-reperfusion.
目的: 探究麝香通心滴丸（STDP）改善猪心肌缺血再灌注后冠脉微循环障碍（CMD）和心功能障碍的可能作用机制。
方法: 根据随机数字表法，从21只小型猪随机选取14只行介入球囊阻断左前降支中部血流再灌注建立CMD模型，其余7只作为假手术组，仅行冠脉血管造影，不需要实施手术；再根据随机数字表法将14只动物随机分为CMD模型组（n=7）、CMD+STDP治疗组（n=7），3组动物均以普通饲料喂养8周。药物干预：治疗组予将麝香通心滴丸（3 mg· kg-1· d-1）拌入饲料中进行喂养8周。分别于第0周（手术前）、8周行冠脉造影、计算管腔直径和校正TIMI帧数（CTFC）、心脏彩色超声多普勒检查；8周时处死并取出左前降支冠脉远端分布区域心肌，HE染色观察心肌小血管及心肌组织的病理改变；Western blot检测前降支远端供血区心肌组织中沉默信息调节因子（Sirt1）、过氧化物酶增殖激活受体-γ共激活子-1α（PGC-1α）、过氧化物酶体增殖物激活受体α（PPARα）、细胞外信号调节激酶1/2（ERK1/2）、Toll样受体4（TLR4）、解偶联蛋白2（UCP2）的表达。
结果: 实验0周和8周时，3组实验动物的冠脉左前降支血管直径差异无统计学意义（P > 0.05）。实验0周时，各组实验动物CTFC血流帧数值差异无统计学意义（P > 0.05）；第8周时，与假手术组相比，模型组CTFC血流帧数显著增加；与模型组比较，STDP治疗组CTFC血流帧数减少（P < 0.05）。实验0周，3组实验动物心脏彩超各项指标差异无统计学意义（P > 0.05）；实验8周时，相对于假手术组，模型组舒张期室间隔厚度、左室舒张期内径、左室舒张末容积、收缩期室间厚度、左室质量指标值增加（P < 0.05）；与模型组比较，治疗组的上述指标值减小（P < 0.05）。HE染色结果显示，与假手术组相比，模型组心肌组织微血管充血、血栓形成及周边炎症细胞聚集，心肌纤维萎缩，心肌间质炎性细胞浸润；与模型组相比，治疗组未见明显充血，血管周边炎症细胞较少，心肌肌纤维萎缩程度较明显，但心肌间质炎症浸润相对较轻。相对于假手术组，其余各组的心肌组织中Sirt1、PGC-1α、PPARα表达下调，ERK1/2、TLR4、UCP2表达上调；而治疗组与模型组相比，Sirt1、PGC-1α、PPARα表达量更高，ERKI/2、TLR4、UCP2表达量更低。
结论: STDP可能通过Sirt1、PGC-1α、PPARα、ERK1/2、TLR4、UCP2发挥抗炎和调节能量代谢作用，从而改善缺血再灌注后冠脉微循环障碍和心功能障碍。
Keywords: Shexiang Tongxin dripping pills; cardiac dysfunction; coronary microcirculation disorder; ischemia-reperfusion.