电针心包经穴对大脑中动脉闭塞大鼠脑组织NMDAR亚单位NR1、钙离子的影响

Effects of electroacupuncture at pericardium meridian acupoints on NMDAR subunits NR1 and intracellular Ca^(2+) in rats with middle cerebral artery occlusion

目的观察电针心包经穴对大脑中动脉闭塞(MCAO)大鼠脑组织NMDAR亚单位NR1表达以及胞内Ca^(2+)含量的影响,探讨脑缺血神经修复的相关作用机制。方法将90只SPF级SD大鼠随机分为正常组、假手术组、模型组、心包经组、肺经组,每组18只。采用颈外动脉插入线栓法制备大鼠左侧MCAO模型。心包经取"天泉""曲泽""内关""大陵"穴;肺经取"天府""尺泽""列缺""太渊"穴。心包经组、肺经组在造模成功后第2天开始行电针治疗,处理3 d,每次30 min,其他组仅捆绑固定30 min。分别运用TTC染色技术、免疫组化法、流式细胞术分别检测梗死脑组织体积、脑组织中NR1及胞内Ca^(2+)的含量,每个指标各30只。结果(1)BWT评分。(1)组间比较。处理前:与正常组、假手术组比较,模型组、肺经组、心包经组评分均降低,差异有统计学意义(P<0.05);与正常组、假手术组、模型组比较,心包经组评分升高,差异有统计学意义(P<0.05),与肺经组差异无统计学意义(P>0.05)。(2)组内比较。肺经组、心包经组评分均升高,差异均有统计学意义(P<0.05)。(2)脑梗死体积比较:与正常组、假手术组比较,模型组、肺经组、心包经组体积均变大,差异有统计学意义(P<0.05),提示MCAO造模成功。模型组、肺经组、心包经组之间差异无统计学意义(P>0.05)。(3)脑组织NR1的表达。与正常组比较,模型组、肺经组、心包经组NR1阳性表达均升高,差异有统计学意义(P<0.05);与假手术组比较,模型组、肺经组NR1阳性表达均升高,差异有统计学意义(P<0.05),心包经组NR1阳性表达差异无统计学意义(P>0.05);与模型组比较,心包经组NR1阳性表达明显降低,差异有统计学意义(P<0.05)。(4)胞内Ca^(2+)含量。与正常组、假手术组比较,模型组、肺经组、心包经组Ca^(2+)含量均上升,差异有统计学意义(P<0.05);与模型组比较,肺经组、心包经组Ca^(2+)含量均降低,差异均有统计学意义(P<0.05)。结论电针心包经穴可改善MCAO大鼠神经损伤程度,可能与降低NR1的过度表达,减少胞内Ca^(2+)含量,减轻兴奋性毒性对神经元的损伤,从而促进神经损伤修复有关。

Objective To observe the effects of electroacupuncture at pericardium meridian acupoints on the expression of N-methylD-aspartate receptor 1(NR1)and the concentration of intracellular Ca^(2+)in rats with middle cerebral artery occlusion(MCAO)and to explore the mechanism of cerebral ischemic nerve repair.Methods Ninty SPF grade SD rats were randomly divided into normal group,sham operation group,model group,pericardium meridian group and lung meridian group,with 18rats in each group.The left MCAO model was prepared by inserting thread into external carotid artery.Acupoints such as"Tianquan(PC 2)","Quze(PC 3)","Neiguan(PC 6)"and"Daling(PC 7)"in the pericardium meridian and"Tianfu(LU 3)","Zhize(LU 5)","Lieqian(LU 7)"and"Taiyuan(LU 9)"in the lung meridian were taken.Electroacupuncture treatment was started in the pericardium meridian and lung meridian groups on the second day after successful modeling,and treatment was conducted for 3 days,30 min each time,while the other groups were only bound and fixed for 30 min.The volume of infarcted brain tissue,NR1 positive expression and intracellular Ca^(2+)content in brain tissues were detected by TTC staining,immunohistochemistry and flow cytometry,respectively,with 30 samples in each group.Results(1)BWT score.(1)Comparison between groups:Before treatment,compared with the normal group and the sham operation group,the scores of the model group,the lung meridian group and the pericardium meridian group decreased significantly(P<0.05);compared with the normal group,the sham operation group and the model group,the score of pericardium meridian group increased significantly(P<0.05),but there was no significant difference between the pericardium meridian group and the lung meridian group(P>0.05).(2)Comparison within groups:the scores of the lung meridian group and the pericardium meridian group increased significantly compared with those before treatment(P<0.05).(2)Comparison of cerebral infarction volume.Compared with the normal group and the sham operation group,the volumes of the model group,the lung meridian group and the pericardium meridian group were larger,and the difference was statistically significant(P<0.05),indicating that the model of MCAO was successful.There was no significant difference among the model group,the lung meridian group and the pericardium meridian group(P>0.05).(3)Expression of NR1 in brain tissue.Compared with the normal group,the positive expression of NR1 in the model group,the lung meridian group and the pericardium meridian group increased significantly(P<0.05).Compared with the sham operation group,the positive expression of NR1 in the model group and the lung meridian group increased significantly(P<0.05),but there was no significant difference in NR1 expression in the pericardium meridian group(P>0.05).Compared with the model group,the positive expression of NR1 in the pericardium meridian group was significantly lower(P<0.05).(4)Intracellular Ca^(2+)content.Compared with the normal group and the sham operation group,Ca^(2+)content in the model group,the lung meridian group and pericardium meridian group increased significantly(P<0.05).Compared with the model group,the content of Ca^(2+)in lung meridian group and pericardium meridian group decreased,and the difference was statistically significant(P<0.05).Conclusion Electroacupuncture of acupoints in pericardium meridian can improve the degree of nerve injury in MCAO rats,which may be related to the reduction of NR1 overexpression,the decrease of intracellular Ca^(2+)concentration,the alleviation of injury on neuron by excitatory toxicity,and the promotion of nerve injury repair.