电针对局灶性脑缺血再灌注大鼠大脑皮层一氧化氮的影响

本研究在大鼠脑缺血再灌注的模型上，应用改良镉还原法测定大鼠脑内ＮＯ的代谢产物──亚硝酸盐含量的变化，并应用免疫组织化学方法测定大鼠脑内ｃＮＯＳ及 ｉＮＯＳ的免疫活性变化。研究结果显示：①大鼠一侧大脑中动脉栓塞３０分钟再灌注２４小时后，脑内ＮＯ代谢产物亚硝酸盐含量明显高于对照例，差异显著（ Ｐ＜ ０． ０５），同时免疫组织化学显示 ｉＮＯＳ免疫活性增强；②缺血再灌注大鼠电针处理后，缺血侧亚硝酸盐含量与对照例相比虽有升高，但升幅仅为３３．３％，无显著性差异，其升幅与未电针组大鼠相比低 ３６． ４９％；电针缺血侧ｉＮＯＳ免疫活性细胞数明显减少。结果表明：①大鼠局灶性脑缺血再灌注可使脑内ＮＯ代谢水平升高，在ＮＯ代谢产物含量升高的同时，ｉＮＯＳ的活性也增强；②电针抗脑缺血再灌注损伤的机制之一是通过抑制ＮＯ代谢而实现的。

Effect of Acupuncture on the Metabolism of Nitric Oxide in Cerebral Cortex after Focal Cerebral Ischemia Following Reperfusion in Rats

By using a kinetic cadmium-reduction method for determination of inorganic nitrite and using immunohitochemistry method for observation of NOS immunoactivity in rat brain, we surveyed changes of inorganic nitrite and NOS immunoactivity in middle cerebral artery occlusion (MCAo) group and MCAo+ electroacupuncture (EA) group. The results showed that: ① content of inorganic nitrite in the region of infarction in MCAo group was higher than that of control side (P < 0. 05), rising degree was 95 %; ② iNOS immunoactive neurons were only distributed in cerebral cortex on the ischemic side but not on the control side in MCAo group; ③ after treating with acupuncture, changes differing from MCAo group emerged as below: the content of inorganic nitrite on the ischemia side was remarkably lower than MCAo group (P < 0. 05 ). In comparing with control side, the content of inorganic nitrite on the ischemic side was slightly increased, rising degree was 33. 3 %, no difference was discovered. Above results demonstrate that rise of NO level in rats brain was related to iNOS immunoactive enhancing after MCAo following reperfusion. One of the mechanism of protecting neurons against damage after cerebral ischemia with acupuncture was inhibiting iNOS activity.