Fentanyl induced hyperalgesia and upregulation of pro-inflammatory cytokines in dorsal root ganglions in ;rats
CHANG Lu
YE Fang
SHU Hai-hua
YANG Lin
HUANG Wen-qi
Abstract：Objective To investigate the expression of pro-inflammatory cytokines in lumbar dorsal root ganglions (DRG) of rats model of high-dose fentanyl induced hyperalgesia. Methods 64 male SD rats were divided into 2 groups (n = 32), fentanyl group and normal saline (NS) group. The rats were injected with fentanyl (60 μg/kg) or NS 4 times in total subcutaneously with a 15-minute interval. Mechanical and thermal nociception were measured via the tail pressure test (tail flick thresholds, TFT) and paw withdrawal test (paw withdrawal latency, PWL) at 1 day before, at 1, 2, 3 and 4 hour and on 1 ~ 7 day after administration. 4 rats were sacrificed and the lumbar DRG were harvested to analyze the expression of PGE2 , IL-1β, IL-6 and TNF-αvia ELISA. Results There were no significant changes of TFT, PWL and the expression of pro-inflammatory cytokines in DRG compared to baseline of rats in NS group. The value of TFT , PWL in fentanyl group were above the baseline at the 1 ~ 4 hour and below the baseline at 1~3 day after fentanyl injections. PGE2 , IL-1β, TNF-α and IL-6 increased on 1,3,5,7 day after fentanyl injections significantly. Conclusions High-dose fentanyl induced significant hyperalgesia and up-regulation of pro-inflammatory cytokines in DRG. The expression pro-inflammatory cytokines peaked later and were more protracted than the change of behavior test and show no direct relationship between the two.
Keywords：FentanylHyperalgesiaDorsal root ganglionPro-inflammation cytokines
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 1912-1915 )