Objectives: To observe the effect of simulated repeated transcranial acupuncture (rTAS) on learning and memory abilities and cerebral microvascular flow in vascular dementia (VD) model rats, so as to explore the potential mechanism of rTAS in treating VD.
Methods: Thirty-two Wistar rats were randomly divided into normal, model, acupuncture and rTAS groups (n=8 rats in each group). The VD model was established by permanent ligation of bilateral common carotid arteries. For rats of the acupuncture group, "Baihui" (GV20) and "Shenting" (GV24) were needled, and for rats of the rTAS group, GV20 and GV24 were stimulated by simulated repeated transcranial manipulation (200 r/min, for 5 min). The treatment was conducted once daily for 14 days. After the intervention, learning and memory abilities were evaluated using the Morris water maze test. Laser speckle technology was used to measure the average cerebral microvascular flow. ELISA was performed to measure the contents of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1), nitric oxide (NO), and inducible nitric oxide synthase (iNOS) in the hippocampal tissues.
Results: In comparison with the normal group, the escape latency of rats in the model group was prolonged (P<0.01), and the times of crossing the platform were decreased (P<0.01). The average cerebral microvascular flow and the VEGF content in the hippocampus were significantly decreased, while the contents of NO, iNOS, and ET-1 were significantly increased (P<0.01). In comparison with the model group, the escape latency was significantly shortened (P<0.01), the average cerebral microvascular flow and VEGF content in the hippocampus were significantly increased (P<0.05, P<0.01), while contents of iNOS were significantly decreased (P<0.05, P<0.01) in both acupuncture and rTAS groups；and the times of crossing the platform were increased (P<0.01), the contents of NO and ET-1 in hippocampus were significantly decreased (P<0.01) in the rTAS group. The effects of rTAS were significantly superior to those of acupuncture in up-regulating the average cerebral microvascular flow (P<0.05) and VEGF content (P<0.01), and down-regulating the NO, iNOS and ET-1 contents (P<0.01, P<0.05).
Conclusions: rTAS can increase cerebral microvascular flow, improve spatial cognition and enhance learning and memory abilities of VD rats. The underlying mechanism may be involved in promoting angiogenesis, improving endothelial function and mitigating oxidative stress.
目的: 观察模拟经颅重复针刺（rTAS）手法对血管性痴呆（VD）模型大鼠学习记忆能力及脑微血流的影响，探讨rTAS对VD的治疗作用及潜在机制。方法: Wistar大鼠根据随机数字法随机选择8只大鼠为空白组，其余大鼠采用永久性双侧颈总动脉结扎法制备VD大鼠模型，造模成功的大鼠随机分为模型组、常规针刺组、模拟rTAS组，每组8只。造模成功后第2天行针刺干预，模拟rTAS组给予模拟rTAS手法；常规针刺组给予常规针刺手法；模型组与空白组给予同等条件抓取及固定，不予针刺。干预14 d后，采用Morris水迷宫实验评价各组大鼠学习记忆能力；运用激光散斑技术检测各组大鼠脑血流平均灌注量；ELISA法检测大鼠海马组织血管内皮生长因子（VEGF），内皮素-1（ET-1），一氧化氮（NO），诱导型一氧化氮合酶（iNOS）含量。结果: 与空白组比较，模型组大鼠逃避潜伏时间显著增加（P<0.01）、穿越原平台次数显著减少（P<0.01），脑血流平均灌注量降低（P<0.01），海马VEGF含量显著降低（P<0.01），NO、iNOS、ET-1含量显著升高（P<0.01）。与模型组比较，模拟rTAS组大鼠逃避潜伏时间显著缩短（P<0.01）、穿越原平台次数显著增多（P<0.01），常规针刺组大鼠逃避潜伏时间显著缩短（P<0.01），模拟rTAS组与常规针刺组大鼠脑血流平均灌注量、海马VEGF含量均显著升高（P<0.05，P<0.01），模拟rTAS组海马NO、iNOS、ET-1含量显著降低（P<0.01），常规针刺组海马iNOS含量显著降低（P<0.05）。与常规针刺组比较，模拟rTAS组大鼠脑血流平均灌注量显著提高（P<0.05），海马VEGF含量显著升高（P<0.01），NO、iNOS、ET-1含量降低（P<0.01，P<0.05）。结论: rTAS可增加VD大鼠大脑血流灌注，改善空间认知、学习记忆能力，其作用机制可能与促进血管新生，改善内皮功能，抗氧化应激相关。.
Keywords: Laser speckle; Learning and memory ability; Microvascular flow; Repeated transcranial acupuncture manipulation; Vascular dementia.