电针内关穴对心肌缺血再灌注损伤大鼠腺苷A1受体的表达及腺苷含量的影响

Effect of Electroacupuncture at Neiguan( PC6) on Expression of Adenosine A1 Receptors and Content of Adenosine in Rats with Myocardial Ischemia-reperfusion Injury

目的：观察电针预处理＂内关＂穴对心肌缺血再灌注损伤（myocardial ischemia-reperfusion injury,MIRI）大鼠腺苷A1受体的表达及腺苷含量的影响,探讨电针＂内关＂穴抗MIRI可能的作用机制。方法：将40只SPF级雄性SD大鼠随机分为假手术组、心肌缺血再灌注损伤组、电针＂内关＂穴组和电针＂环跳＂穴组,每组10只。电针＂内关＂组和电针＂环跳＂组分别在造模前给予电针刺激,每次20 min,1次/d,共治疗7 d。各组分别于预处理结束当天行冠脉结扎法建立MIRI模型。记录造模前后心电图II导联T波电压值,HE染色及透射电镜检测心肌病理形态学的变化,高效液相法检测血清腺苷的含量,免疫组化法检测心肌腺苷A1受体的表达。结果：造模后各组大鼠II导联心电图T波电压显著上升,与术前比较具有显著的统计学差异（P〈0.01）;电针内关组T波在结扎40 min和再灌注60 min后均明显低于模型组和电针环跳组（P〈0.01）。心肌HE染色及超微结构：与假手术组比较,模型组组心肌损伤较严重,肌纤维紊乱,部分溶解,小血管扩张;与模型组比较,电针内关组心肌损伤较轻微,肌纤维大多正常,心肌有明显改善;电针环跳组心肌损伤严重,细胞结构模糊,肌纤维紊乱,肌丝断裂、溶解,线粒体空泡化。腺苷A1受体的表达：与假手术组比较,模型组的腺苷A1受体的表达明显下降（P〈0.05）;与模型组比较,内关组腺苷A1受体表达显著增强,差异具有显著的统计学意义（P〈0.01）。腺苷含量：与假手术组比较,MIRI组腺苷含量显著下降（P〈0.01）;与模型组比较,内关组腺苷含量显著上升（P〈0.01）;环跳组腺苷A1受体的表达及腺苷含量虽高于模型组,但差异无统计学意义（P〉0.05）。结论：电针内关穴对大鼠MIRI具有预保护作用,可改善MIRI大鼠的心电图T波,减轻心肌的病理损伤,而这种保护效应的产生可能与电针内关穴上调腺苷A1受体的表达及增加血清腺苷的含量有关。

Objective： To observe the effect of electroacupuncture of Neiguan（ PC6） pretreatment on expression of the adenosine A1 receptor and content of adenosine in rats with myocardial ischemic reperfusion injury（ MIRI） and explore the mechanism of electroacupuncture at Neiguan（ PC6） anti MIRI. Methods： Forty male SD SPF rats were randomly divided into sham operation group,ischemia reperfusion injury group,electroacupuncture at Neiguan（ PC6） group and electroacupuncture at Huantiao（ GB30）group,10 rats in each group. Electroacupuncture at Neiguan（ PC6） group and electroacupuncture at Huantiao（ GB30） group were treated with electroacupuncture before modeling,20 minutes for each time,once a day for 7 days. All the groups at the end of the day for pretreatment used coronary artery ligation method to establish MIRI model. We recorded ECG II lead T wave voltage mode before and after HE staining and the transmission electron microscope was used to detect the pathological change in myocardium.The content of serum adenosine was detected by HPLC. The expression of myocardial adenosine A1 receptor was detected by immunohistochemistry. Results： The model rats＇ II ECG T wave voltage increased significantly,and had statistically significant difference compared with preoperative ones（ P〈0. 01）. Electroacupuncture at Neiguan（ PC6） group＇s T waves in the ligation of 40 min and 60 min after reperfusion were significantly lower than those in the model group and the electroacupuncture at Huantiao（ GB30） group（ P〈0. 01）. Compared with the sham operation group,model group＇s myocardial injury was serious,partial dissolution of muscle fiber was disorder and there was small vessel expansion. Compared with the model group,EA at Neiguan（ PC6）group had minor myocardial injury and cardiac muscle fiber was mostly normal and the cardiac muscle had obviously improved.Acupuncture at Huantiao（ GB30） group＇s heart muscle damage was serious,cell structure obscure,muscle fiber disorder,fracture,dissolution and vacuolization of mitochondria. Adenosine A1 receptor expression： Compared with the sham operation group,the model group＇s expression of adenosine A1 receptor was significantly decreased（ P〈0. 05）. Compared with the model group,Neiguan group＇s expression of adenosine A1 receptor was significantly increased and the difference was statistically significant（ P〈0. 01）. The content of adenosine： Compared with sham operation group,the MIRI group significantly decreased the content of adenosine（ P〈0. 01）. Compared with the model group,Neiguan group significantly increased the content of adenosine（ P〈0. 01）. Although the expression of adenosine A1 receptor and content of adenosine of Huantiao group was higher than that of the model group,but the difference had no statistical significance（ P〈0. 05）. Conclusion： Electroacupuncture had preprotective effect on rats MIRI that can improve T wave of ECG and reduce the pathological injury of myocardium,and the expression of this protective effect may be produced with electroacupuncture up-regulation of adenosine A1 receptor and the serum adenosine content increasing.