Role of extracellular signal-regulated kinase in central amygdala on fentanyl-induced hyperalgesia in rats
10.3760/cma.j.issn.0254-1416.2015.10.004
- VernacularTitle:中央杏仁核细胞外信号调节激酶在芬太尼诱发大鼠痛觉过敏中的作用
- Author:
Pingping YIN
;
Shenghui GE
;
Fang LUO
- Publication Type:Journal Article
- Keywords:
Extracellular signal-regulated kinase(ERK);
Fentanyl;
Hyperalgesia;
Amygdala
- From:
Chinese Journal of Anesthesiology
2015;35(10):1186-1188
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the role of extracellular signal-regulated kinase1/2 (ERK1/2) in the central amygdala on fentanyl-induced hyperalgesia in rats.Methods Thirty-two male SpragueDawley rats, weighing 60-100 g, were randomly divided into 4 groups (n =8 each) using a random number table: control group (group C), fentanyl-induced hyperalgesia group (group H), U0124 group (group U1) , and U0126 group (group U2).A catheter was implanted in the central amygdale.In group C, normal saline was injected subcutaneously, and 6.5 h later dimethyl sulfoxide (DMSO) was injected via the catheter.In group H, fentanyl was injected subcutaneously to induce hyperalgesia, and 6.5 h later DMSO was injected via the catheter.In group U1, hyperalgesia was induced, and 6.5 h later ERK1 inhibitor U0124 1.5 nmol was injected via the catheter.In group U2, hyperalgesia was induced, and 6.5 h later ERK1/2 inhibitor U0126 1.5 nmol was injected via the catheter.Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal threshold (TWT) were measured before fentanyl injection, at 6.5 h after injection, and at 30 min after DMSO or U0124/U0126 administration via the catheter (T0-2).After the last measurement of pain threshold, the rats were sacrificed, and the amygdala tissues were sampled for detection of the expression of phosphorylated ERK1/2 (p-ERK1/2) by Western blot in groups C and H.Results Compared with group C, the MWT and TWT were significantly decreased at T1,2in H and U1 groups, and at T1in group U2 (P＜0.05) , the expression of p-ERK2 was up-regulated (P＜0.05) , and no significant change was found in the expression of p-ERK1 in group H (P＞0.05).Compared with group H,the MWT and TWT were significantly increased at T2 in group U2 (P＜0.05) , and no significant change was found in MWT, TWT in group U1 (P＞0.05).Conclusion ERK2 activation in the central amygdala is involved in the development of fentanyl-induced hyperalgesia in rats.
