电针对全脑缺血再灌注大鼠血中一氧化氮、内皮素含量的影响

目的:研究一氧化氮(NO)、内皮素(ET)在全脑缺血再灌注损伤中的作用及电针的保护作用机理。方法:SD大鼠随机分为假手术组、模型组、电针治疗组(取左侧“肩”“外关”“髀关”“足三里”穴)、穴位对照组(取左侧“清冷渊”“灵道”“箕门”“漏谷”穴)、非穴位对照组(取左侧“天泉”与“曲泽”连线中点、“曲泽”与“郄门”连线中点、“五里”与“阴包”连线中点和“膝关”与“中都”连线中点),电针参数为连续波,频率10Hz,波宽0.6ms,电压1.5-3V(以肌肉轻微抽动为度),时间10min。每天1次,共3d。假手术组和模型组只固定不针刺。三动脉结扎法造成大鼠全脑缺血再灌注损伤模型,硝酸还原酶法测定血清NO含量,放射免疫法测定血浆ET含量,原子吸收分光光度计测定脑组织Ca2+含量,干湿重法测定脑组织含水量。结果:与假手术组比较,模型组结扎颈总动脉30min的血清NO含量明显降低,血浆ET含量无明显变化;再灌注30min,血清NO含量显著降低,血浆ET含量显著增加,再灌注120min,脑组织Ca2+含量和含水量显著增加。电针能显著升高再灌注30min后血清NO含量,降低血浆ET含量、脑组织Ca2+含量和含水量,与模型组比较有显著性差异。结论:脑缺血再灌注急性期存在血液NO含量降低而ET含量升高,电针治疗脑缺血再灌注损伤的机制可能与升高血清NO含量和降低血浆ET含量有关。

Effects of Electroacupuncture on Serum Nitric Oxide and Endothelin Contents in Rats with Cerebral Ischemia-reperfusion Injury

OBJECTIVE: To observe the effect of electroacupuncture (EA) on serum nitric oxide (NO) and plasma endothelin (ET) contents in cerebral ischemia/reperfusion (CI/R) rats. METHODS: Fifty-five SD rats were evenly randomized into sham-operation (sham-op), model, EA, acupoint-control (acu-con) and non-acupoint (non-acu)-con groups. CI/R model was produced by occlusion of the basilar artery and bilateral common carotid arteries and reperfusion. EA (10 Hz, 1.5-3 V, duration of 0.6 ms) was applied to left "Jianyu" (LI 15), "Waiguan" (TE 5), etc. for EA group, left "Qinglengyuan" (TE 11), "Lingdao" (HT 4), etc. for acu-con (being not used for CI in clinic) group, and the mid-points between left "Tianquan" (PC 2) and "Quze" (PC 3), PC3 and "Ximen" (PC 4), etc. for non-acu-con group. Carotid venous blood was collected 30 min after CI and after CI/ R respectively for analyzing serum NO content with nitrate reductase (NR) method and plasma ET content with radioimmunoassay, and the brain was taken for detecting its water content and Ca2+ content with flame atomic absorption method. RESULTS: Compared with sham-op group, serum NO contents of model group 30 min after CI and CI/R, that of EA group 30 min after CI, acu-con group 30 min after CI/R decreased significantly (P < 0.05), and plasma ET content of model group 30 min after CI/R increased considerably (P < 0.05). While compared with model group, serum NO content of EA group 30 min after CI/R increased significantly (P < 0.05) and plasma ET of EA group decreased significantly (P < 0.05). Serum NO level of acu-con group 30 min after CI/R was markedly lower than that of EA group at the same time course. In comparison with sham-op group, Ca2+ contents of model group and acu-con group and water cntent ratio of the brain tissue of model group increased significantly (P < 0.05), while compared with model group, Ca2+ content of EA group decreased remarkably (P < 0.05), and Ca2+ of acu-con group was significantly higher than that of EA group (P < 0.05). No significant differences were found between acu-con and non-acu-con groups in the aforementioned indexes (P > 0.05). CONCLUSION: EA of commonly-used acupoints can revise CI/R induced decrease in serum NO level and increase in plasma ET and cerebral Ca2+ significantly at the early period of CI/R, which may contribute to its favorable effects in the treatment of CI.