侧脑室内注射神经肽S对瑞芬太尼痛觉过敏小鼠镇痛效果的研究

The analgesic effect of intracerebroventricular injection of neuropeptide S on remifentanil induced hyperalgesia in mice

目的研究侧脑室内注射神经肽S对瑞芬太尼痛觉过敏小鼠镇痛效果的影响,探究神经肽S对疼痛影响的作用机制。方法将雄性,体质量为20 g±2 g的56只昆明系雄性小鼠,分为对照组、瑞芬太尼组、切口痛组、切口痛-瑞芬太尼组。然后利用切口痛-瑞芬太尼模型进行实验,分为Saline组、NPS 0.1 nmol/L组、NPS 1 nmol/L组、NPS 10 nmol/L组,每组8只;侧脑室注射不同剂量NPS,利用甩尾实验和热板实验观察NPS对切口痛-瑞芬太尼痛觉过敏小鼠的镇痛效果。做小鼠全脑冠状切片的免疫组化染色,统计分析c-Fos免疫反应在光镜下位于神经元核内蓝黑色颗粒;收集脑组织样本进行蛋白免疫印迹检测Mor和NRSF蛋白的表达水平。结果利用瑞芬太尼联合切口痛成功构建了切口痛-瑞芬太尼痛觉过敏小鼠疼痛模型,在甩尾实验和热板实验中,发现NPS治疗能有效延长小鼠的甩尾潜伏期和热板实验潜伏应答期;c-Fos免疫组化染色发现NPS治疗能显著减少c-Fos阳性细胞的数目;蛋白免疫印迹实验结果证明NPS治疗能够显著下调Mor蛋白水平,而上调NRSF蛋白的水平,说明NPS能够有效地缓解疼痛,且NPS的治疗作用还呈现剂量依赖性,在0.1 nmol/L、1 nmol/L和10 nmol/L 3个剂量当中,随着剂量升高NPS的保护作用越强。结论在切口痛-瑞芬太尼痛觉过敏小鼠疼痛模型中,侧脑室注射NPS能够有效缓解疼痛,对瑞芬太尼引起的痛觉过敏有明显的镇痛效果。

Objective To study the analgesic effect of intracerebroventricular injection of neuropeptide S on remifentanil induced hyperalgesia in mice,and to explore the mechanism of Neuropeptide S on pain. Methods A total of 56 Kunming male mice,weighing 20 g ± 2 g,were divided into control group,remifentanil group,incision pain group and incision pain remifentanil group. Incision pain remifentanil group was conducted for test and divided into Saline group,NPS 0. 1 nmol/L group,NPS group 1 nmol/L group,NPS 10 nmol/L group,with 8 rats in each group; Different doses of NPS were injected into the lateral ventricle,and the analgesic effect of NPS on the incision pain-remifentanil hyperalgesia mice was observed by tail flick experiment and hot plate experiment. Immunohistochemical staining of mouse coronal slices was performed. The c-Fos immunoreactivity was statistically analyzed under light microscopy. Blue-black granules were located within the neuronal nucleus. Brain tissue samples were collected for immunoblotting to detect Mor and NRSF protein levels. Results We used remifentanil combined with incision pain to successfully construct incision pain remifentanil induced hyperalgesia in mice model of pain,and in the tail flick test and hot plate test,we found that NPS treatment can effectively prolong the tail flick latency and response latency in hot plate test period; c-Fos immunohistochemical staining found that NPS treatment can significantly reduce the number of c-Fos positive cells; Western blot results showed that NPS treatment can significantly reduce Mor protein levels,and up-regulate the level of NRSF protein,indicating that NPS can effectively relieve pain The therapeutic effect of NPS was also dose-dependent. Among the three doses（ 0. 1 nmol/L,1 nmol/L,and 10 nmol/L）,the protective effect of NPS was stronger with increasing doses. Conclusion In the incision pain-remifentanil pain model of hyperalgesia mice,injection of NPS into the lateral ventricle can effectively relieve pain,and there is a significant analgesic effect on hyperalgesia caused by remifentanil.