Department of Physiology, School of Basic Medicine, Kunming Medical University, Kunming, Yunnan, China.
Department of Colorectal Cancer Surgery, Third Affiliated Hospital, Kunming Medical University, Kunming, Yunnan, China.
Neurosci Lett. 2019 Jul 27;706:93-98. doi: 10.1016/j.neulet.2019.05.016. Epub 2019 May 11.
Galanin and galanin receptors (GalRs) play important roles in the transmission and modulation of nociceptive information. Our previous research has shown that the expression of GalR1 is upregulated and that GalR1 activation in the nucleus accumbens (NAc) of rats with neuropathic pain has an antinociceptive effect. However, the antinociceptive effect of NAc galanin in neuralgia remains unclear. The present study aimed to explore the antinociceptive effect induced by galanin in rats with neuropathic pain and the underlying mechanism. The results showed that the intra-NAc injection of galanin induced a dose-dependent increase in hindpaw withdrawal latency (HWL) to noxious thermal and mechanical stimulation in mononeuropathic rats and that this effect was stronger than that in intact rats. The intra-NAc injection of the non-selective GalR antagonist galantide reduced HWL in the rats with neuropathic pain, but there was no influence of galantide on HWL in intact rats. Moreover, galanin expression in the NAc was upregulated after sciatic nerve ligation. All of these results demonstrate that galanin plays a role in antinociception via binding to GalRs in the NAc of rats and that endogenous galanin is involved in the antinociception after peripheral nerve injury.
甘丙肽和甘丙肽受体（GalRs）在痛觉信息的传递和调制中发挥重要作用。我们之前的研究表明，神经病理性疼痛大鼠伏隔核（NAc）中 GalR1 的表达上调，GalR1 激活具有抗伤害作用。然而，神经痛时 NAc 甘丙肽的抗伤害作用尚不清楚。本研究旨在探讨神经病理性疼痛大鼠 NAc 甘丙肽诱导的抗伤害作用及其机制。结果表明，NAc 内注射甘丙肽可剂量依赖性增加神经损伤大鼠后爪对有害热和机械刺激的退缩潜伏期（HWL），其作用强于完整大鼠。非选择性 GalR 拮抗剂甘丙肽纳对内完整大鼠的 HWL 没有影响，但可降低神经损伤大鼠的 HWL。此外，坐骨神经结扎后 NAc 中甘丙肽的表达上调。所有这些结果表明，甘丙肽通过与大鼠 NAc 中的 GalRs 结合发挥抗伤害作用，内源性甘丙肽参与外周神经损伤后的抗伤害作用。
