Bai Hua, Lu Sheng-Feng, Chen Wan-Ying, Zhong Ze-Hao, Gu Yi-Huang
The Second Clinical Medical College, Nanjing University of Traditional Chinese Medicine, Nanjing 210023, China.
Zhen Ci Yan Jiu. 2017 Dec 25;42(6):471-6. doi: 10.13702/j.1000-0607.2017.06.001.
To observe the effect of moxibustion (Moxi) preconditioning with seed-sized moxa cones on myocardial ischemia-reperfusion injury (MI/RI) at different stages, and to analyze the correlation between this effect and the expression of autophagy related protein Beclin 1.
This study contains two parts: 1) changes of myocardial pathological injury and percentages of myocardial infarcted area at different time-points after modeling and Moxi intervention, and 2) effect of Moxi on contents of serum cardiac troponin T(cTnT) and expression of myocardial Bcl-2, Bax and Beclin 1 proteins. In the first part, 42 SD rats were randomly divided into model group, 1 day (d) Moxi group, 2 d Moxi group, 3 d Moxi group，4 d Moxi group, 5 d Moxi group and 7 d Moxi group. The model of MI/RI was established by ligating the left anterior descending coronary artery (LAD) for 30 min and reperfusion for 240 min. The electrocardiogram (ECG) of standard limb lead Ⅱ was monitored and the heart was taken 4 h after reperfusion for examining myocardial infarcted size with triphenyl tetrazolium chloride (TTC) staining. In the second part, 48 SD rats were randomized into sham-operation, model, moxibustion and autophagy inhibitor (3-MA) groups, with 12 rats in each group. The serum cTnT level was assayed and histopathological changes of the myocardial tissue below the ligation site were examined with HE staining, and the expression levels of Bcl-2, Bax and Beclin 1 proteins in the myocardial tissue below the LAD-ligated site were detected using Western blot.
Compared with the model group, the percentages of myocardial infarcted area were significantly decreased in the 4 d, 5 d and 7 d Moxi groups (<0.05), but without significant differences among the 3 Moxi groups (>0.05). The state of MI-induced breakage and disordered arrangement of myocardial fibers with interstitial edema and inflammatory cell infiltration at the MI stage in the Moxi group and at the reperfusion stage in the autophagy inhibitor group was relatively lighter. The levels of serum cTnT content and Bax/Bcl-2 and Beclin 1 protein expression at the MI and reperfusion stages were significantly higher in the model group than in the sham-operation group (<0.01), and considerably lower in the Moxi and autophagy groups than in the model group (<0.01). The serum cTnT content, ratio of Bax/Bcl-2 expression and Beclin 1 expression levels at the MI and reperfusion stages were significantly lower in the autophagy inhibitor group than in the Moxi group (<0.05).
Moxibustion with seed-sized moxa cones at "Neiguan" (PC 6) can effectively alleviate myocardial ischemia in MI/RI rats, which is probably related to its effect in down-regulating Bax/Bcl-2 and Beclin 1 expression and in inhibiting autophagy.
观察麦粒灸预处理对不同阶段心肌缺血再灌注损伤（MI/RI）的影响，并分析其与自噬相关蛋白Beclin 1表达的相关性。
本研究分为两部分：1）建模及麦粒灸干预后不同时间点心肌病理损伤变化及心肌梗死面积百分比；2）麦粒灸对血清心肌肌钙蛋白T（cTnT）含量及心肌Bcl-2、Bax和Beclin 1蛋白表达的影响。第一部分，将42只SD大鼠随机分为模型组、麦粒灸1天组、麦粒灸2天组、麦粒灸3天组、麦粒灸4天组、麦粒灸5天组和麦粒灸7天组。采用结扎左冠状动脉前降支（LAD）30分钟并再灌注240分钟的方法建立MI/RI模型。监测标准肢体导联Ⅱ的心电图（ECG），再灌注4小时后取心脏，用氯化三苯基四氮唑（TTC）染色检测心肌梗死面积。第二部分，将48只SD大鼠随机分为假手术组、模型组、艾灸组和自噬抑制剂（3-MA）组，每组12只。检测血清cTnT水平，用HE染色观察结扎部位以下心肌组织的组织病理学变化，用Western blot检测LAD结扎部位以下心肌组织中Bcl-2、Bax和Beclin 1蛋白的表达水平。
与模型组相比，麦粒灸4天组、5天组和7天组心肌梗死面积百分比显著降低（<0.05），但3个麦粒灸组之间无显著差异（>0.05）。麦粒灸组MI期和自噬抑制剂组再灌注期心肌纤维断裂、排列紊乱伴间质水肿和炎性细胞浸润的状态相对较轻。模型组MI期和再灌注期血清cTnT含量、Bax/Bcl-2及Beclin 1蛋白表达水平显著高于假手术组（<0.01），麦粒灸组和自噬组显著低于模型组（<0.01）。自噬抑制剂组MI期和再灌注期血清cTnT含量、Bax/Bcl-2表达比值及Beclin 1表达水平显著低于麦粒灸组（<0.05）。
麦粒灸“内关”（PC 6）可有效减轻MI/RI大鼠的心肌缺血，可能与其下调Bax/Bcl-2和Beclin 1表达及抑制自噬有关。
