针刺对糖尿病合并脑缺血再灌注大鼠学习记忆行为的影响

Effect of Acupuncture on Learning-memory Ability in Diabetic Rats with Concomitant Cerebral Ischemia-reperfusion Injury

目的:建立糖尿病合并脑缺血再灌注导致学习记忆障碍大鼠模型,观察针刺对其学习记忆行为的改善作用。方法:Wistar大鼠87只,分为正常对照组、糖尿病+假手术组、脑缺血组、糖尿病+脑缺血组(模型组)、糖尿病+脑缺血+针刺组。腹腔注射链脲佐菌素建立糖尿病模型,3d后双侧颈总动脉夹闭再灌注2次。术后1个月,用跳台和Morris水迷宫判断其学习记忆能力;取海马组织,HE染色观察CA1区的细胞分布。针刺治疗从术后1周开始,取穴为“百会”、双侧“三阴交”“脾俞”或“百会”、双侧“肾俞”“足三里”,两组穴位交替进行,手针治疗,刺入后提插捻转,以手下有涩紧感为度,留针30min,隔日1次,共治疗15次。结果:电击后15min模型组的被动回避反应下台潜伏期明显缩短(P<0.01),24h后仍小于其它各组(P<0.05);针刺组下台潜伏期明显延长(P<0.05)。模型组学会主动回避反应的训练次数显著多于其它4组(P<0.001);针刺组明显少于模型组(P<0.05)。模型组在目标象限停留的时间最短(P<0.01),游泳的距离也最短(P<0.05)。模型组大鼠海马CA1区呈现明显的神经元缺失,脑缺血组的神经元也有所减少,针刺治疗后神经元缺失有所减轻。结论:糖尿病合并脑缺血再灌注可在短期内造成学习记忆障碍,糖尿病可加重脑缺血造成的脑损伤,针刺可改善糖尿病合并脑缺血再灌注造成的学习记忆障碍。

Objective： To observe the effect of acupuncture on learning and memory ability in rats with cognition impairment due to diabetes mellitus （DM） and cerebral ischemia （CI）/reperfusion injury （CI/RI）. Methods： A total of 87 female Wistar rats were randomly divided into 5 groups： normal control, CI, DM＋ sham-CI, DM＋ CI and DM＋ CI ＋ acupuncture （Acup）. DM model was induced by intraperitoneal injection of streptozotocin （60 mg/kg）, and 3 days later CI/RI was duplicated by occlusion of the bilateral carotid arteries and reperfusion in the same rats. ＂Baihui＂ （GV 20）, bilateral ＂Sanyinjiao＂ （SP 6）, ＂Pishu＂ （BL 20）, or GV20, bilateral ＂Shenshu＂ （BL 23） and ＂Zusanli＂ （ST 36） were punctured alternatively with filiform needles and stimulated manually. On day 10 and 30 after CI, the rats＇ learning-memory ability was detected by using step-down passive and active avoidance tests or Morris water maze test. At the end of the experiments, the animals anesthetized under 12% urethane （1 g/kg） were transcardially perfused with PBS fluid containing 4% paraform for sampling the brain tissue containing hippocampus region which was cut into sections （40 μm） and stained with hematoxylin and eosin （H＆ E） method for observing morphological changes of the hippocampus under light microscope. Results： After electrical shock stimulation, the latencies of step-down passive avoidance in DM ＋ CI group at 15 min and 24 h shortened significantly in comparison with control, CI, DM ＋ sham-CI and DM ＋ CI ＋ Acup groups （P〈0. 05, 0. 01 ）. Compared with DM ＋ CI group, the avoidance latency of DM ＋ CI ＋ Acup increased significantly （P〈0.05）. In active avoidance test, the training times for rats to learn making active avoidance reaction in DM＋CI group were significantly more than those in DM＋sham-CI, CI and DM＋CI＋Acup groups （P〈0.001）, the active avoidance correction rate of DM＋CI group decreased significantly in comparison with the other 4 groups （P〈0.01 ）, while these two indexes of DM＋CI ＋Acup group were markedly superior to those of DM＋CI group （P〈0.05）. In comparison with DM＋CI group, the percentages of swimming time and swimming distance in original platform quadrant vs total time and distance in DM＋CI＋Acup group were significantly higher （P〈0.05）. Microscopic observation showed that the neuronal loss in the CA1 of the hippocampus was milder in DM＋ CI ＋ Acup group than that in DM＋ CI group. These results displayed that in DM＋ CI rats, the cognitive ability declined significantly and neural injury of the brain tissue was definite , and acupuncture had a favorable effect on the animals＇ changes of behavior and cerebral morphology . Conclusion： Acupuncture therapy can ameliorate the learning - memory ability in rats with DM ＋ CI.