Objective: To observe the effect of scalp acupuncture on the expression of argarginine vasopressin receptor-1a(V1aR), phosphorylated calmodulin-dependent protein kinase Ⅱ(p-CaMKⅡ), and aquaporin 4(AQP4) at hypothalamus in middle cerebral artery occlusion (MCAO) rats, so as to explore the molecular mechanisms of scalp acupuncture reducing encepha-ledema in acute ischemic stroke.
Methods: A total of 96 male SD rats were randomly divided into normal， model, inhibitor and scalp acupuncture groups, with 24 rats in each group. The MCAO model was established by thread occlusion method. The inhibitor group was intraperitoneally injected with V1aR inhibitor (30 μg/kg)，once a day for 7 consecutive days. In the scalp acupuncture group, acupuncture was applied to bilateral "parietal and temporal anterior oblique line", with rapid insertion of 2 needles at 15° to 20°, twisting at 100 r/min for 1 min, and retaining the needles for 30 min, once a day for 7 consecutive days. The neurologic deficit score (NDS) and neurological score (NS) were evaluated before and after intervention. The positive expression of p-CaMKⅡ and AQP4 proteins in hypothalamus was detected by immunohistochemistry. The water content of left brain tissue was determined by BIIiot method. The expression of V1aR mRNA in hypothalamus was detected by real-time PCR.
Results: Compared with the normal group, the NDS, NS, hypothalamic V1aR mRNA expression, water content of the brain tissue, and hypothalamic p-CaMKⅡ and AQP4 positive expression levels were significantly increased (P<0.01) in the model group. Compared with the model group, the NDS, NS, hypothalamic V1aR mRNA expression, water content of the brain tissue, and hypothalamic p-CaMKⅡ and AQP4 positive expression levels were significantly decreased (P<0.01) in the inhibitor and scalp acupuncture groups.
Conclusion: Regulating the signaling pathway of V1aR/CaMKⅡ/AQP4 in hypothalamus may be one of the molecular mechanisms of scalp acupuncture reducing encephaledema in acute ischemic stroke.
目的：观察头针对局灶性脑缺血大鼠下丘脑精氨酸加压素受体1a(V1aR)、磷酸化钙调蛋白依赖性蛋白激酶-Ⅱ(p-CaMKⅡ)和水通道蛋白4(AQP4)表达的影响，探讨头针治疗急性缺血性脑卒中脑水肿的机制。方法：雄性SD大鼠随机分为正常组、模型组、抑制剂组、头针组，每组24只。采用线栓法复制大脑中动脉栓塞大鼠模型。抑制剂组给予V1aR抑制剂(30 μg/kg)腹腔注射，1次/d，连续7 d；头针组于双侧“顶颞前斜线”以15°～20°接力式快速刺入2针，100 r/min捻转1 min，留针30 min，1次/d，连续7 d。干预前后评价大鼠神经功能缺损评分和神经行为学评分；real-time PCR法检测大鼠下丘脑V1aR mRNA表达量；BIIiot法测定大鼠左侧脑组织含水量；免疫组织化学法检测大鼠下丘脑p-CaMKⅡ、AQP4蛋白阳性表达水平。结果：与正常组比较，模型组神经功能缺损评分、神经行为学评分、下丘脑V1aR mRNA表达量、脑组织含水量、下丘脑p-CaMKⅡ和AQP4阳性表达水平均明显升高(P<0.01)；与模型组比较，抑制剂组和头针组神经功能缺损评分、神经行为学评分、下丘脑V1aR mRNA表达量、脑组织含水量、下丘脑p-CaMKⅡ和AQP4阳性表达水平均明显降低(P<0.01)。结论：调控脑缺血后下丘脑异常的V1aR/CaMKⅡ/AQP4信号通路可能是头针减轻缺血性脑卒中脑水肿的机制之一。.
Keywords: Aquaporin 4; Argarginine vasopressin receptor-1a; Encephaledema; Ischemic stroke; Phosphorylated calmodulin-dependent protein kinase Ⅱ; Scalp acupuncture.