Role of ERK signaling pathway in spinal cord in reduction of neuropathic pain by electro-acupuncture at Zusanli and Yanglingquan
10.3760/cma.j.issn.0254-1416.2012.08.011
- VernacularTitle:ERK信号通路在电针刺激足三里穴和阳陵泉穴减轻大鼠神经病理性痛中的作用
- Author:
Cong ZHAO
;
Jianbo YU
- Publication Type:Journal Article
- Keywords:
Mitogen-activated protein kinases;
Electric stimulation therapy;
POINT ST36 (ZUSANLI);
POINT GB34 (YANGLINGQUAN);
Neuralgia
- From:
Chinese Journal of Anesthesiology
2012;32(8):942-946
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the role of ERK signaling pathway in spinal cord in reduction of neuropathic pain (NP) by electro-acupuncture (EA) at Zusanli and Yanglingquan.Methods Fifty male SpragueDawley rats,weighing 180-220 g,in which the intrathecal catheter was successfully placed without complications,were randomly divided into 5 groups (n =10 each):sham operation group (S group),chronic constrictive injury (CCI) group,acupuncture at acupoint group (EA group),acupuncture at non-acupoint group (NA-EA group),and ERK inhibitor U0126 group (U0126 group).NP was induced by CCI in groups CCI,EA,NA-EA and U0126.The animals were anesthetized with intraperitoneal chloral hydrate 300 mg/kg.The right sciatic nerve was exposed and 4 ligatures were placed on the sciatic nerve at 1 mm intervals.EA (intensity ＜ 1.5 mA,frequency 2Hz) of Zusanli and Yanglingquan lasting 30 min was performed once a day for 6 days starting from 4th day after induction of NP in group EA.EA was performed at the points 5 mm lateral to the acupoints of Zusanli and Yanglingquan on the operated side in group NA-EA.Intrathecal U0126 5 μg was started on 4th day after induction of NP twice a day for 6 consecutive days.The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were measured at 1 day before CCI (T0,baseline) and at days 3,5,7 and 9 after CCI (T1-4).The rats were sacrificed on 10th day after induction of NP and the right lumbar segment (L4-6) of the spinal cord was removed for determination of the expression of P2X3 receptor protein and mRNA,ERK1/2 and phosphorylated ERK1/2 (p-ERK1/2) in the spinal cord dorsal horn.Results Compared with group S,MWT was significantly decreased,TWL was significantly shortened,the expression of P2X3 receptor protein and mRNA,and p-ERK1/2 was up-regulated in the other 4 groups (P ＜ 0.01).Compared with CCI group,MWT was significantly increased,TWL was significantly prolenged,the expression of P2X3 receptor protein and mRNA,and p-ERK1/2 was downregulated in EA and U0126 groups (P ＜ 0.01),and no significant change in the parameters mentioned above was found in NA-EA group (P ＞ 0.05).Compared with EA group,MWT was significantly increased,TWL was significantly prolonged,the expression of P2X3 receptor protein and mRNA,and p-ERK1/2 was down-regulated in U0126 group (P ＜ 0.01).Conclusion ERK signaling pathway in spinal cord is involved in reduction of NP by EA at Zusanli and Yanglingquan.
