电针对VD大鼠脑微血管内皮细胞一氧化氮合酶表达的影响

Effect of Electroacupuncture on Nitric Oxide Synthase Expression of Endothelial Cells inside the Brain Micrangium in Vascular Dementia Rats

目的:观察一氧化氮合酶(iNOS)在血管性痴呆(VD)大鼠脑微血管内皮细胞中的表达情况及电针对其的影响。方法:采用夹闭再通大鼠双侧颈总动脉的方法建立缺血再灌注损伤性VD模型,电针组用G-6805电针治疗仪,以疏密波刺激“百会”“大椎”“足三里”“膈俞”,治疗20 min,每日1次,连续治疗7 d。利用SP免疫组织化学染色方法,观察脑微血管内皮细胞iNOS的活性,并与假手术组、模型组做比较。结果:电针组大鼠脑微血管内皮细胞iNOS的活性较模型组减弱,与模型组比较有显著性差异(P<0.01)。结论:电针可抑制VD大鼠脑微血管内皮细胞iNOS的活性,对脑缺血再灌注损伤具有脑保护作用。

Objective： To observe the expression of inducible nitric oxide synthase （iNOS） in the endothelial cells inside the cerebral micrengium and the effect of electroacupuncture （EA） in vascular dementia （VD） rats. Methods： Thirty Wistar rats were evenly randomized into sham-operation （control）, model and EA groups. VD model was established by occlusion of the bilateral common carotid artery and reperfusion plus intraperitoneal injection of sodium nitroprusside （2.5 mg/kg）. In EA group, EA （frequency 5/45 Hz, strength 1.5-3 V） was applied to “Baihui”（GV 20）, “Dazhui”（GV 14）, “Zusanli”（ST 36） and “Geshu”（BL 17） for 20 minutes, once a day, continuously for 7 days. The activity of iNOS in the endothelial cells of right cerebral cortex tissue was assayed with immunohistochemical method. The rat＇s memory-learning ability was detected by using step-down test （passive avoidance reaction, latency and number of errors of step-down）. Results： In comparison with control group, the latency of stepdown from the platform of model group shortened significantly, and the number of errors of model group increased remarkably. While compared with model group, the latency of step-down of EA group increased significantly and the ru＇nber of errors decreased markedly （ P〈0.01 ）. No significant differences were found between control and EA groups in these two indexes （ P 〉 0.05）. Very weak immunoreaction （IR） of iNOS was found only in fewer slices of the brain tissues in control group; while in majority of the slices of model group, moderate IR and stronger IR were found. In comparison with model group, mild IR of iNOS in EA group was predominant while moderate and strong IR were significantly fewer in the number of slices. There was a significant difference between model group and EA group （ P〈 0.01 ）, suggesting that after EA, the activity of iNOS in most endothelial cells in cerebral micrengium reduced obviously. Conclusion： Electroacupuncture can obviously reduce the activity of iNOS in the endothelial cells of cerebral micrengium in VE） rats, and protect the brain from ischernia/reparfusion injury.