| Objective: to observe the influence of electro-acupuncture (EA) JIAJI points on ERK(extracellular signal-regulated kinase) , neurokinin-1(NK-1)in dorsal horn neurons of complete Freund's adjuvant(CFA)arthritis rats and research the mechanism of electro-acupuncture analgesia through signal transduction pathway.Methods: 80 male, Wistar rats were randomly divided into normal control group, pure EA group,CFA model group(30min, 24h, 48h) and EA therapy group(30min, 24h, 48h).Each group contained 10 rats.Complete Freund's adjuvant was injected into the plantar surface of the left hindpaw of the Wistar rats to make the model of pain. The dual L3-L5 JIAJI points of the rats were given electro-acupuncture. Pain thresholds and foot swelling degree of each group were measured. Immunohistochemical technique was used to determine the change of phospho-ERK, NK-1 in dorsal horn neurons of all groups.Results: 1.Compared with normal control group and pure EA group, 30min, 24h, 48h after CFA injection in the plantar surface of rat left hind paw, the pain thresholds of CFA model group all declined(p<0.01),while the phospho-ERK in ipsilateral dorsal horn neurons increased significantly (P<0.01) ; Pain thresholds of EA therapy group rised in contrast to the CFA model group(p<0.01) though there were still difference compared with the normal control group.The phospho-ERK in ipsilateral dorsal horn neurons of EA therapy group decreased significantly compared to the CFA model group (P<0.01) . 2.After making models 24h, the NK-1 in the ipsilateral dorsal horn neurons increased significantly in CFA model group Comparedto normal control group and pure EA group (P<0.01) . The NK-1 in EA therapy group also increased Compared to normal control group (0.01 NK-1 are important signal moleculars during electro-acupuncture analgesia. Electro-acupuncture can modulate the phosphorylation of ERK, which contributed to acupuncture analgesia. |
