Objective To observe the effect of electroacupuncture(EA)stimulation of"Futu"(LI 18)

etc.on activities of satellite glial cells(SGCs)in the dorsal root ganglia(DRG)in rats with neck-incision pain so as to explore its mechanism underlying reduction of post-surgical pain of thyroidectomy.Methods Male SD rats were randomly divided into control

model

EA-Futu(LI 18)

EA-Hegu(LI 4)-Neiguan(PC 6)

and EA-Zusanli(ST 36)-Yanglingquan(GB 34)groups

with 20 rats in each group.The neck-incision pain model was established by making a longitudinal incision and repeated mechanical stimulation.In the EA-LI 18

EA-LI 4-PC 6and EA-ST 36-GB 34 groups

EA stimulation was administrated for 30 min

once a day

continuously for 3days.The thermal pain threshold(PT)of the neck-incision region was detected.The immunoactivity of glial fibrillary acidic protein(GFAP

a specific marker for SGCs)and connexin 43(Cx 43)of DRGs(C 2-C 6)was determined by fluorescent immunohistochemistry.The expression levels of GFAP

IL-1β

IL-6

and TNF-αmRNAs were determined by quantitative Real-time PCR

and the contents of IL-1β

IL-6

TNF-αassayed by enzyme linked immunosorbent assay(ELISA)and the expression of Cx 43 protein was detected by Western blot.Results After EA intervention at LI 18 and LI 4-PC 6(but not ST 36-GB 34)

neck incisioninduced reduction of the thermal PT was obviously prolonged in comparison with the model group(P<0.05)

suggesting apain relief.The expression levels of GFAP

IL-1β

IL-6and TNF-αmRNAs and Cx 43 protein

and the contents of IL-1β

IL-6and TNF-αin C 2-C 6DRGs were all significantly up-regulated in the model group relevant to those of the control group(P<0.05).Following EA

modeling induced dramatic increase of expression of GFAP

IL-1β

IL-6and TNF-αmRNAs and Cx 43 protein in both EA-LI 18 and EA-LI 4-PC 6groups

and the contents of IL-1βand TNF-αin the EA-LI 18 group

IL-6in the EA-LI 4-PC 6group was considerably down-regulated(P<0.05).In comparison with the model group

no significant changes were found in all the abovementioned indexes of EA-ST 36-GB 34 group except the down-regulated IL-1βand TNF-αmRNAs

in the contents of IL-1βand TNF-αof the EA-LI 4-PC 6group

and in the IL-6content of the EA-LI 18group(P>0.05).Conclusion EA stimulation of LI 18 and LI 4-PC 6can significantly suppress pain reaction of neck incision in the rat

which is closely associated with its effects in down-regulating the activity of SGCs

decreasing the release of pro-inflammatory cytokines and in weakening the expression of Cx 43 in the cervical DRGs.