切断膈肌下迷走神经对应激大鼠延髓、下丘脑Fos表达的影响

Effects of bilateral subdiaphragamatic vagotomy on the expression of Fos in medulla and hypothalamus under stress in rats

目的:探讨在束缚-浸水应激状态下,情绪变化、体温降低、胃肠道的反馈信息三者中哪种因素是诱发延髓、下丘脑神经元Fos表达的主导因素。方法:将雄性Wistar大鼠随机分两组:手术组、对照组。手术组切断双侧膈肌下迷走神经,对照组同样暴露神经但不切断。术后6d进行实验,将大鼠束缚-浸水应激3h后处死,测腹腔温度;取胃,观察胃粘膜损伤程度;取脑,应用免疫组化染色方法观察两组动物延髓、下丘脑神经元的Fos表达。结果:手术组动物延髓迷走神经运动背核、孤束核、下丘脑室旁核Fos表达较对照组减弱(P<0.05),延髓最后区减弱最为显著(P<0.01);腹腔温度低于对照组(P<0.05);胃粘膜损伤程度较对照组减轻(P<0.05)。结论:研究表明,束缚-浸水应激过程中,诱发延髓迷走神经背核、孤束核、最后区、下丘脑室旁核神经元Fos表达的主要因素是胃肠的反馈信息。

Objective：To investigate which is the dominant factor inducing the Fos expression in medulla and hypothalamus among lower body temperature,emotion change and feedback information from the gastrointestinal tract under the restraint water-immersion stress. Methods：Male Wistar rats weighting 180-220 g were randomly divided into two groups：operation group,control group. Bilateral subdiaphragamatic vagotomy was performed in rats of operation group,the vagus nerves were uncovered but were not cut off in control group. Six days after operation,rats were put into death after restraint water-immersion stress for 3 h. The abdominal cavity temperature was measured,the gastric mucosal ulcer index was determined according to guth criteria,and the immuno histochemical methods were used to detect the Fos expression in medulla and hypothalamus. Results：Expression of Fos was decreased significantly in DMV（dorsal motor nucleus of the vagus）,NTS（nucleus of solitary tratct） and PVN（Paraventricular nucleus） after bilateral subdiaphragamatic vagotomy （P〈0.05）,and the decrease in AP（area postrema） was the most prominent （P〈0.01）; the abdominal cavity temperature was lower than that of the control group （P〈0.05）; the gastric mucosal ulcer index was reduced significantly （P〈0.05）. Conclusion：The results suggest that the feedback regulation information from the gastrointestinal tract,rather than lower body temperature and psychological stressor,play a dominant role in inducing the Fos expression in DMV,NTS,AP and PVN.