| 摘要: | 目的：神經細胞、神經膠細胞、TRPV1離子通道在發炎痛的機制尚有不明之處。利用老鼠足部發炎痛模型，以中醫電針作為介入治療，探討上述物質之變化。
方法：使用C57/B6小鼠與TRPV1基因剔除小鼠。經於小鼠足部注射佛朗氏完全佐劑引發發炎痛，再進行電針治療。分組為控制組、發炎組(注射佛朗氏完全佐劑)、針灸組(注射佛朗氏完全佐劑後加上電針)、TRPV1基因剔除組(注射佛朗氏完全佐劑於TRPV1?/?小鼠)。利用控制組與其餘三組比較，欲證實佛朗氏完全佐劑能成功誘發發炎痛。利用針灸組、TRPV1基因剔除組與發炎組比較，欲證實電針能夠有效緩解發炎痛，並比較電針與TRPV1基因剔除止痛的效益、生化因子的變化。更進一步使用腺?酸及嗎啡之致效劑與結抗劑來證實電針改善發炎痛的路徑。並比較穴位與非穴位之電針療效。
結果：成功誘發發炎痛模型並證實電針組與TRPV1基因剔除組其疼痛行為測試有所改善。西方墨點法與組織染色分析顯示，發炎相關生化因子如離子通道、神經膠細胞皆被電針有效地抑制。電針改善發炎痛路徑，同時與腺?及內生性嗎啡有關。穴道在止痛上有其專一性，優於非穴道處。
結論：電針在穴位上，藉由促進腺?酸及內生性嗎啡生成，可有效降低發炎痛及發炎相關因子。TRPV1基因、神經細胞、神經膠細胞參與其中。
Background: Inflammatory pain is a common clinical syndrome with unclear mechanisms such as the roles of neuron cells, microglial cells, and transient receptor potential cation channel subfamily V member 1 (TRPV1) signaling pathways. Electroacupuncture (EA) is a common Chinese clinical medical technology that might reduce pain. By using a mouse inflammatory pain model, we tried to check how EA can regulate spinal neurons, microglial cells and related molecules.
Methods: By injection of complete Freund’s adjuvant (CFA) on plantar area, inflammatory pain was induced among normal or TRPV1 knockout C57/B6 mice. Four subgroups (n = 10 for all groups) were subdivided to group 1, control group (anesthesia + saline), group 2, Control + CFA (anesthesia + 0.5 mg/ml CFA), group 3, Control + CFA + EA (anesthesia +0.5 mg/ml CFA + 2 Hz EA), and group 4, Control + CFA + TRPV1-/- (anesthesia + 0.5 mg/ml CFA). Von Frey and Hargraves’ test were recorded on baseline, day1 and day2. At L3~L5 spinal level, variations of pain related molecules levels in the dorsal horn (SCDH) and dorsal root ganglion (DRG) were studied at the end of the experimental course with western blotting and immunohistochemical staining. There were other subgroups, namely CFA + EA group, CFA + sham EA group, CFA + endomorphin group, CFA + N6-Cyclopentyladenosine group, CFA + naloxone group, CFA + rolofylline group, and CFA + naloxone + rolofylline group. These agonist and antagonist of mu opioid and adenosine receptor were used among subgroups analysis. The effects of EA and sham EA were compared, too.
Results: We found that injection of CFA significantly caused a mechanical and thermal hyperalgesia, which can be reversed by EA or TRPV1 genetic deletion. Expression levels of S100 calcium-binding protein B (S100B), ionized calcium-binding adapter molecule 1 (Iba-1), phospho-p38 (pp38), receptor for advanced glycation end-products (RAGE), TRPV1, phosphoinositide 3-kinase (pPI3K), serine/threonine protein kinase B(pAKT), mammalian target of rapamycin (pmTOR), C-AMP Response Element-binding protein (pCREB), nuclear factor kappa-light-chain-enhancer of activated B cells (pNF-κB), voltage-gated sodium channel 1.7 (Nav1.7) and Nav1.8 related to signaling pathway were dramatically increased in the DRG and SCDH of inflamed mice, and then reversed by EA and TRPV1 knockout. According to behavior test and variation of Nav1.8, agonist of mu opioid or adenosine receptor caused similar analgesic effect like EA. Only the combination of antagonists of mu opioid and adenosine receptor could block analgesic effect of EA.
Conclusions: In the present study, we found that EA crucially attenuated inflammatory pain. There was a close relationship among EA, neurons and microglia cells. By raising levels of adenosine and endogenous opioids, EA attenuated inflammatory pain. Besides, by using TRPV1 knockout mice to inhibit signal pathway, we proved the important role of TRPV1 in inflammatory pain model again. |
