内脏高敏感大鼠脑干降钙素基因相关肽、c-fos基因表达的研究

Study on Expression of Calcitonin Gene-related Peptide and c-fos Gene in Brainstem of Rats with Visceral Hypersensitivity

背景:肠易激综合征(IBS)的发病机制复杂,内脏敏感性增高是其重要的生物学特征。目的:观察内脏高敏感大鼠脑干降钙素基因相关肽(CGRP)、c-fos的表达分布情况,探讨IBS的发病机制。方法:10只雌性Sprague-Dawley(SD)大鼠随机分为模型组和对照组。以腹腔注射鸡卵清蛋白的方法建立内脏高敏感模型。造模成功后4周行免疫组化染色,观察脑干各核团CGRP、c-fos的表达和分布情况。结果:两组大鼠脑干多个核团表达CGRP、c-fos免疫阳性神经元。模型组CGRP的表达在三叉神经感觉主核、臂旁内侧核、中缝背核、孤束核等核团明显高于对照组,差异有统计学意义。模型组c-fos的表达在中缝背核、臂旁核、蓝斑核、三叉神经感觉主核、孤束核等核团明显高于对照组,差异有统计学意义。结论:内脏高敏感大鼠脑干上行转导通路上多个部位的CGRP、c-fos表达增加,提示在IBS的发病过程中,高级神经中枢可通过CGRP、c-fos参与痛觉过敏的形成,并对上传的痛觉刺激信号进行调控。

The pathogenesis of irritable bowel syndrome （IBS） is complicated, and visceral hypersensitivity may be its potential biomarker. Aims： To investigate the expression and distribution of calcitonin gene-related peptide （CGRP） and c-fos gene in brainstem of rats with visceral hypersensitivity, and to explore the pathogenesis of IBS. Methods： Ten female Sprague-Dawley rats were randomly divided into model group and control group. The rat model with visceral hypersensitivity was constructed by injecting chicken egg albumin into the abdominal cavity. After 4 weeks, expression of CGRP and c-fos was detected by immunohistochemical assay. Results： CGRP and c-fos were expressed in many nucleus of brainstem in two groups. The expression of CGRP in nucleus sensorius principalis nervi trigemini, medial parabrachial nucleus, nucleus raphes dorsalis and nucleus solitarius in model group was significantly higher than those in control group. The expression of c-fos in nucleus raphes dorsalis, parabrachial nucleus, nucleus ceruleus, nucleus sensorius principalis nervi trigemini and nucleus solitarius in model group was significantly higher than those in control group. Conclusions： The expression of CGRP and c-fos in brainstem of rats with visceral hypersensitivity is up-regulated, which means the central nervous system may be involved in hyperalgia via CGRP and c-fos, and may modulate the pain stimulus signal in the pathogenesis of IBS.