电针对高血压大鼠皮层脑梗死延髓与脊髓NgR表达的影响

目的观察电针对易卒中型肾性高血压大鼠（stroke-prone renovascular hypertensive rats,RHRSP）大脑中动脉闭塞（middle cerebral artery occlusion，MCAO）后缺血再灌注（ischemia-reperfu-sion，I/R）不同时间点脑皮层、延髓、脊髓勿动蛋白受体（nogoreceptor，NgR）蛋白表达的影响，探讨电针对急性脑梗死（acute cerebral infarction，ACI）远隔损害的可能机制。方法雄性SPF级SD大鼠行双肾双夹术复制RHRSP，再用线栓法制作MCAO模型，用随机数字表法分为高血压组60只、假手术组60只、脑梗死组60只、电针组60只、假针刺组60只。脑梗死组仅作MCAO缺血再灌注处理；假手术组仪做手术创伤；电针组选取督脉“百会”和“大椎”穴进行电针治疗，每天1次，共28天。假针刺组选“大椎”、“百会”穴处给予针灸针贴肤治疗。治疗后第1、7、14、28天各组分别处死6只大鼠，分离出右侧大脑、延髓和左侧脊髓，用尼氏染色法检测脑梗死体积，用Westernblot法检测NgR表达。结果（1）皮层区：与高血压组比较，MCAO术后第1、7、14、28天，脑梗死组NgR表达升高（P〈0．05）；与脑梗死组比较，MCAO术后第1天，电针组和假针刺组NgR表达与其相当（P〉0．05）；第7、14、28天，电针组NgR表达降低（P〈0．05），假针刺组NgR表达与其相当（P〉0．05）。（2）延髓区：与高血压组比较，MCAO术后第1天，假手术组、脑梗死组、电针组、假针刺组NgR表达与其相当（P〉0．05）；第7、14、28天脑梗死组NgR表达升高（P〈0．05）；与脑梗死组比较，第7、14、28天电针组NgR表达降低（P〈0．05）；假针刺组NgR表达与其相当（P〉0．05）。（3）脊髓区：与高血压组比较，MCAO术后第1、7天，假手术组、脑梗死组、电针组、假针刺组NgR表达与其相当（P〉0．05）；第14、28天脑梗死组NgR表达升高（P〈0．05）。与脑梗死组比较，第14、28天电针组NgR表达降低（P〈0．05）；假针刺组NgR表达与其相当（P〉0．05）。结论大鼠脑梗死后皮层、延髓、脊髓区NgR表达增高是参与ACI远隔损害的一个重要原因，电针对高血压大鼠1／R脑损伤的保护作用可能与其下调中枢神经髓鞘生长抑制介导因子Nogo-A受体NgR蛋白表达等机制密切相关。

Effect of Electric Acupuncture on the Expression of NgR in the Cerebral Cortex,the Medulla Ob-Iongata,and the Spinal Cord of Hypertensive Rats after Cerebral Infarction

Objective To observe the effect of electric acupuncture （EA） on the Nogo receptors （NgR） protein expression in the cerebral cortex, the medulla oblongata, and the spinal cord of cerebral ischemia-reperfusion（I/R） stroke-prone renovascular hypertensive rats （RHRSP） with middle cerebral artery occlusion （MCAO） at different time points, and to investigate its possible mechanisms for remote- organ injury of acute cerebral infarction （ACI）. Methods The RHRSP model was duplicated in male SPF grade SD rats. Then the MCAO model was prepared by a thread stringing method. Rats were divided into the hypertension group,the sham-operation group, point group by random number table method,60 in the MCAO group,the EA group, and the sham-acu- each group. Rats in the MCAO group only receivedMCAO reperfusion treatment. Those in the sham-operation group only received surgical trauma. Baihui （DU20） and Dazhui （DU14） were needled in the EA group, once daily for a total of 28 days. The needles were acupunctured at the skin one cun distant from Baihui （DU20） and Dazhui （DU14） and then the same EA treatment was performed in the sham-acupoint group. At day 1, 7, 14, 28 after treatment,six rats were executed from each group,and their right cortex and medulla oblongata, and the left spinal cord were isolated. The infarct volume was detected by Nissl＇s staining method. The NgR expression was de- tect by Western blot. Results （1）In the cortex area： compared with the hypertension group,the NgR ex- pression increased in the MCAO group at day 1,7,14,and 28 after MCAO （P 〈0.05）. Compared with the MCAO group,the NgR expression of the EA group and the sham-acupoint group were equivalent at 1 day af- ter MCAO （P 〉0.05）. At day 7, 14,and 28 after MCAO,the NgR expression decreased in the EA group （P 〈 0.05）, it was quite similar to that in the sham-acupoint group （P 〉0.05）. （2） In the medulla oblongata area： compared with the hypertension group, the NgR expression was equivalent in the sham-operation group, the MCAO group,the EA group, and the sham-acupoint group at 1 day after MCAO （P 〉0.05）. At day 7,14, and 28 after MCAO,the NgR expression increased in the MCAO group （P 〈0.05）. Compared with the MCAO group,the NgR expression decreased in the EA group at day 7,14,and 28 after MCAO （P 〈0.05）, whereas it was similar in the sham-acupoint group （P 〉0.05）. （3） In the spinal cord area： compared with the hyper- tension group,the NgR expression was equivalent in the sham-operation group,the MCAO group,the EA group, and the sham-acupoint group at day 1 and 7 after MCAO （P 〉0.05）. At day 14 and 28 after MCAO, the NgR expression increased in the MCAO group （P 〈0.05）. Compared with the MCAO group,the NgR ex- pression decreased in the EA group at day 14 and 28 after MCAO （P 〈0.05）, whereas it was equivalent in the sham-acupoint group （P 〉0.05）. Conclusions Increased NgR expression in the cerebral cortex,the medulla oblongata, and the spinal cord of cerebral infarct rats was an important reason for involving re- mote-organ injury of ACI. The protective effect of EA on hypertensive I/R cerebral injury rats might be closely related to down-regulating central nervous system myelin growth inhibition mediated factors Nogo-A receptor NgR protein expression.