[Effects of electroacupuncture at "Futu" (LI 18) on the immunoactivity of substance P, 5-HT 1 AR, etc. of the cervical spinal dorsal horn in rats with neck incision pain].
OBJECTIVE
To observe the effect of electroacupuncture(EA) of bilateral "Futu" (LI 18) on the immunoactivity of substance P (SP), NK-1 receptor (R), cyclooxygenase-1 (COX-1), 5-HT 1 AR and 5-HT2 AR in the cervical spinal dorsal horn of rats with neck incision pain, so as to explore its underlying mechanism in relieving incision pain.


METHODS
A total of 40 Wistar rats were randomly divided into control, model (incision pain), EA-Futu(LI 18), and EA-Zusanli(ST 36)-Yanglingquan (GB 34, EA-ST 36-GB 34) groups (n = 10/group). A 1.5 cm longitudinal incision was made along the middle of the neck in pentobarbital-anesthetized rats. Pain threshold (PT) was measured using radiant heat. EA (1-2 mA, 2 Hz/15 Hz) was applied to bilateral LI 18, ST 36-GB 34 for 30 min. The expression of SP, NK-1 R, COX-1, 5-HT 1 AR and 5-HT2 AR in the spinal cord (C1-C4) tissue were detected with immunohistochemistry.


RESULTS
After the operation, the thermal PT was decreased obviously in markedly after treatment (P < 0.05), and no significant changes were found in PT in EA-ST 36-GB 34 group (P > 0.05). The immunoactivity of SP, NK-1 R, COX-1 in the superficial dorsal horn in model group was increased significantly and that of 5-HT 1 AR and 5-HT 2 AR significantly and mildly, separately compared with control group (P < 0.05). In comparison with model group, the immunoreactivity of SP, NK-1 R and COX-1 was decreased considerably, and that of 5-HT 1 AR and 5-HT 2 AR was upregulated remarkably in EA-LI 18 group (P < 0.05). No significant changes were found in the immunoactivity of SP, NK-1 R, COX-1, 5-HT 1 AR and 5-HT 2 AR in EA-ST 36-GB 34 group (P > 0.05).


CONCLUSIONS
EA-Futu (LI 18) can significantly suppress pain reaction of neck incision in the rat, which is closely associated with its effects in downregulating the expression of SP, NK-1 R, COX-1 and upregulating that of 5-HT 1 AR and 5-HT 2 AR in the spinal dorsal horn.
Qiao
Li-na
LN
Institute of Acu-moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Wang
Jun-ying
JY
Chen
Shu-ping
SP
Gao
Yong-hui
YH
Yang
Yong-sheng
YS
Liu
Jun-ling
JL
D015669:Acupuncture Points; D000818:Animals; D051545:Cyclooxygenase 1 / Q000378:metabolism; D015671:Electroacupuncture; D008297:Male; D023421:Models, Animal; D010149:Postoperative Pain / Q000378:metabolism / Q000628:therapy*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism / Q000601:surgery*; D013373:Substance P / Q000378:metabolism*
D018040:Receptors, Neurokinin-1; D044282:Receptor, Serotonin, 5-HT1A; D013373:Substance P; D051545:Cyclooxygenase 1