[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.