Estrogen-dependent, sex-specific modulation of mustard oil-induced secondary thermal hyperalgesia by orphanin FQ in the rat

NEUROSCIENCE LETTERS

卷:456

Article

Claiborne, Jomo A.¹  Nag, Subodh¹  Mokha, Sukhbir S.¹ 

[1] Meharry Med Coll, Dept Neurobiol & Neurotoxicol, Nashville, TN 37208 USA

关键词: Sex differences;    Nociception;    Orphanin FQ;    Tail flick;    Mustard oil;    Spinal cord;   

DOI  :  10.1016/j.neulet.2009.03.106

来源: Elsevier

【 摘 要 】

Activation of opioid receptor-like 1 receptor (ORL1) by intrathecal administration of orphanin FQ (OFQ). an endogenous ligand for the ORL1 receptor, has been shown to produce antinociception. In addition, we have recently shown gonadal hormone-dependent, sex-specific modulation of acute spinal nociception such that estrogen attenuated OFQ-induced antinociception in the female whereas testosterone was required for the expression of antinociception in the male. However, sex-related differences in the role of OFQ under hyperalgesic conditions are unknown. Hence, we investigated whether OFQ produces sex-specific modulation of mustard oil-induced secondary thermal hyperalgesia in the rat. Mustard oil application to the hind limb significantly reduced the tail-flick latencies (TFL) in male, and ovariectomized (OVX), estradiol treated ovariectomized (OVX + E), proestrous (ProE) and diestrous (DiE) females, Intrathecal administration of OFQ not only attenuated mustard oil-induced decrease in TFLs, i.e. reversed hyperalgesia, but also led to a significant increase in TFLs above the baseline, i.e. produced antinociception in male, OVX, and diestrous rats. However, OFQ failed to alter TFLs in proestrous or OVX + E females, thus these two groups with elevated estrogen levels remained hyperalgesic following mustard oil treatment. These findings demonstrate that OFQ modulates mustard oil-induced secondary hyperalgesia in an estrogen-dependent, sex-specific manner. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

【 授权许可】

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