Pregnancy suppresses neuropathic pain induced by chronic constriction injury in rats through the inhibition of TNF-α.
著者
小野寺, 美子
(Onodera, Yoshiko)
神田, 恵
(Kanao-Kanda, Megumi)
神田, 浩嗣
(Kanda, Hirotsugu)
笹川, 智貴
(Sasakawa, Tomoki)
岩崎, 寛
(Iwasaki, Hiroshi)
国沢, 卓之
(Kunisawa, Takayuki)
上位タイトル
Journal of pain research
Vol.10,
(2017.
3)
,p.567-
574
識別番号
ISSN
1178-7090
DOI
10.2147/JPR.S121810
その他
PMID：28331359
抄録
PURPOSE:
Pregnancy-induced analgesia develops during late pregnancy, but it is unclear whether this analgesia is effective against neuropathic pain. The detailed molecular mechanisms underlying pregnancy-induced analgesia have not been investigated. We examined the antinociceptive effect of pregnancy-induced analgesia in a neuropathic pain model and the expression of tumor necrosis factor (TNF)-α, glial fibrillary acidic protein (GFAP), Iba-1, and c-Fos in the spinal dorsal horn just before parturition.
MATERIALS AND METHODS:
Female Sprague Dawley rats (200-250 g) were randomly assigned to one of four groups (pregnant + chronic constriction injury [CCI]; pregnant + sham injury; not pregnant + CCI; and not pregnant + sham injury). Separate groups were used for the behavioral and tissue analyses. CCI of the left sciatic nerve was surgically induced 3 days after confirming pregnancy in the pregnancy group or on day 3 in the not pregnant group. The spinal cord was extracted 18 days after CCI. TNF-α, GFAP, Iba-1, and c-Fos expression levels in the spinal dorsal horn were measured by Western blot analysis. Mechanical threshold was tested using von Frey filaments.
RESULTS:
The lowered mechanical threshold induced by CCI was significantly attenuated within 1 day before parturition and decreased after delivery. TNF-α expression in CCI rats was decreased within 1 day before parturition. Further, GFAP, Iba-1, and c-Fos expression in the spinal dorsal horn was reduced in the pregnant rats. Serum TNF-α in all groups was below measurable limits.
CONCLUSION:
Our findings indicate that pregnancy-induced analgesia suppresses neuropathic pain through reducing spinal levels of TNF-α, GFAP, Iba-1, and c-Fos in a rat model of CCI.
キーワード
TNF-α
glial cell
neuropathic pain
pregnancy-induced analgesia
注記
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