侧脑室内连续注射神经肽S对神经病理性疼痛大鼠疼痛及焦虑行为的影响

Effect of Intracerebroventricular Injection of Neuropeptide S on Pain and Anxiety Behaviors in Rats with Neuropathic Pain

目的研究侧脑室内连续注射神经肽S对神经病理性疼痛大鼠疼痛行为及焦虑行为的影响,探讨神经肽S对疼痛和焦虑影响的作用机制。方法 40只雄性Sprague-Dawley大鼠被随机分为假手术对照组(Sham-Veh组)、假手术神经肽S组(Sham-NPS组)、慢性压迫性神经损伤组(CCI组)、神经肽S低剂量组(NPSl组,0.1 nmol/L)和神经肽S高剂量组(NPSh组,1 nmol/L),每组8只。制备CCI动物模型,造模成功后第7天左侧侧脑室置入微透析用导针,自术后第8天起每日侧脑室注射相应药物,在术后第14天检测机械痛缩足阈值和热辐射缩足潜伏期,并通过高架十字迷宫检测焦虑行为的变化。采用免疫组织荧光技术检测左侧杏仁核区神经肽S受体(NPSR)的表达。结果与Sham-Veh组比较,CCI组大鼠术后14 d出现明显疼痛和焦虑行为(P<0.01),NPSh组明显缓解(P<0.01),NPSl组与CCI组比较无显著性差异(P>0.05)。免疫组织荧光结果显示,与CCI组相比,NPSh组杏仁核区NPSR表达明显增加。结论神经肽S可以剂量依赖性地逆转CCI大鼠的疼痛和焦虑行为,其机制可能与杏仁核NPSR上调有关。

Objective To investigate the effects of intracerebroventricular injection of neuropeptide S （NPS） on pain and anxiety behaviors in rats with neuropathic pain, and explore the possible mechanism. Methods 40 male Sprague-Dawley rats were randomly divided into Sham-Vehicle group, Sham-NPS group, chronic constriction injury （CCI） group, Neuropeptide S low-dose group （NPSl group, 0.1 nmol/L） and Neuropeptide S high-dose group （NPSh group, 1 nmol/L）, with 8 rats in each group. Pain-related behaviors, anxiety-related behaviours, and expression of NPS receptor （NPSR） in the left amygdaloid nucleus were measured on the 14th day via intracerebroventricular injection. Results Compared with the Sham-Vehicle group, the CCI group demonstrated significant pain and anxiety behaviors 14 days after operation （P〈0.01）, the NPSh group significantly relieved （P〈0.01）. And there was no significant difference between the NPSl group and the CCI group （P〉0.05）. Compared with the CCI group, NPSR expression in amygdaloid nucleus increased in the NPSh group. Conclusion NPS can dose-dependently relieve the pain and anxiety behaviors in CCI rats, which may be related with the increase of NPSR in amygdaloid nucleus.