Jia Wang-Hua, Chi Wen-Ying, Lou Chao, Wang Gui-Zhi
Laboratory of Anesthesiology, Weifang Medical College, Weifang 261053, China.
Zhen Ci Yan Jiu. 2016 Jun 25;41(3):225-9.
To observe the effect of electroacupuncture (EA) intervention on pain thresholds (PT) and contents of β-endorphin (EP) in the hypothalamus and spinal cord, and the expression of 5-HT in the dorsal raphe nucleus(DRN)in rats with pelmatic incisional pain, so as to investigate the underlying mechanisms of acupuncture in reducing post-operative pain.
Wistar rats were randomized into normal control, model, EA and non-acupoint groups (=8/group). The pelmatic pain model was induced by making an incision (about 1 cm in length, to the fascia and muscle layers) from the heel towards the toes. EA (2 Hz, 1.5-2 V) was applied to "Zusanli" (ST 36) and "Kunlun" (BL 60) or non-acupoint (about 3 mm beside the ST 36 and BL 60) on the affected side for 20 min, once daily for three days. The thermal PT and mechanical PT were measured before and after operation and after EA. The contents of β-EP in hypothalamus and L-S spinal cord were detected using enzyme linked immunosorbent assay (ELISA) and the expressions of β-EP in hypothalamus and 5-HT in DRN were measured with immunohistochemistry.
After EA intervention, the markedly decreased mechanical and thermal pain thresholds on day 1 and 3 after paw incision were significantly increased in the EA group (<0.05), but not in the non-acupoint group (>0.05). The hypothalamic β-EP content was significantly higher in the model group than in the normal group (<0.05), and further up-regulated in the EA group (not the non-acupoint group) than in the model group (<0.05). In addition, the hypothalamic β-EP immunoreactive (IR)-positive cell number and 5-HT immunoactivity level in DRN were also considerably up-regulated in the EA group (<0.05) but not in the non-acupoint group (>0.05). No significant changes were found in the lumbar spinal β-EP contents in the model, EA and non-acupoint groups (>0.05).
EA stimulation of "Zusanli"(ST 36) and "Kunlun" (BL 60) has an analgesic effect in pelmatic incision pain rats, which may be related to its effects in raising the level of hypothalamic β-EP and the expression of 5-HT in DRN.
观察电针干预对盆腔切口痛大鼠痛阈及下丘脑和脊髓中β-内啡肽（EP）含量、中缝背核（DRN）中5-羟色胺（5-HT）表达的影响，以探讨针刺减轻术后疼痛的潜在机制。
将Wistar大鼠随机分为正常对照组、模型组、电针组和非穴位组（每组8只）。通过从足跟向足趾作一约1 cm长、深达筋膜和肌肉层的切口诱导盆腔疼痛模型。电针（2 Hz，1.5 - 2 V）刺激患侧“足三里”（ST 36）和“昆仑”（BL 60）或非穴位（ST 36和BL 60旁约3 mm处）20 min，每日1次，共3天。分别于术前、术后及电针后测量热痛阈和机械痛阈。采用酶联免疫吸附测定（ELISA）法检测下丘脑和腰段脊髓中β-EP含量，用免疫组织化学法检测下丘脑β-EP表达及DRN中5-HT表达。
电针干预后，电针组大鼠在 paw 切口后第1天和第3天显著降低的机械和热痛阈明显升高（P<0.05），而非穴位组无明显变化（P>0.05）。模型组下丘脑β-EP含量显著高于正常组（P<0.05），电针组（而非非穴位组）下丘脑β-EP含量较模型组进一步上调（P<0.05）。此外，电针组下丘脑β-EP免疫反应阳性（IR）细胞数和DRN中5-HT免疫活性水平也显著上调（P<0.05），而非穴位组无明显变化（P>0.05）。模型组、电针组和非穴位组腰段脊髓β-EP含量无明显变化（P>0.05）。
电针刺激“足三里”（ST 36）和“昆仑”（BL 60）对盆腔切口痛大鼠具有镇痛作用，其机制可能与其提高下丘脑β-EP水平及DRN中5-HT表达有关。
