肠易激综合征大鼠P物质能神经通路的改变

Change of substance P containing neural pathway in rat model of irritable bowel syndrome

目的:应用c-fos作为神经通路的指示物,探讨SP能神经通路在IBS发病机制中的可能作用.方法:应用冰水灌胃法建立便秘型肠易激综合征(c-IBS)大鼠模型,模型组与对照组各10只大鼠.通过免疫组化方法研究两组大鼠直肠球囊扩张后肠道肌间神经丛、腰骶段脊髓背角、下丘脑及前扣带回SP和c-fos表达,对染色切片进行计算机病理图像分析.结果:模型组回盲部及结肠肌间神经丛SP阳性表达的不透光率密度均显著高于对照组(分别为176.6vs155.5,172.3vs152.0,P<0.05),脊髓背角、下丘脑及前扣带回SP阳性表达的面积均显著高于正常对照组(分别为169318vs137655,144728vs114403,145117vs117612,P<0.05),脊髓背角、下丘脑及前扣带回SP阳性表达的不透光率密度均显著高于正常对照组(分别为182.1vs160.2,128.3vs117.9,127.9vs114.5,P<0.05).模型组回盲部及结肠肌间神经丛、脊髓背角、下丘脑及前扣带回c-fos阳性表达的面积均显著高于正常对照组(191712vs154363,73597vs41179,46258vs33238,302369vs204563,708506vs409856,P<0.05),模型组回盲部及结肠肌间神经丛、脊髓背角、下丘脑及前扣带回c-fos阳性表达的不透光率密度均显著高于正常对照组(120.9vs109.0,101.3vs92.2,125.4vs88.7,115.5vs88.6,120.6vs105.1,P<0.05).相关分析显示:模型组肠道、脊髓、下丘脑、前扣带回SP表达与c-fos表达之间密切相关(r=0.594-0.721,P<0.05).结论:SP在中枢及肠道可能参与C-IBS的病理生理过程,而且SP能神经通路可能是参与肠道感觉或运动功能调节的神经传导通路之一.

<Abstrac>AIM: To investigate the expression of substance P (SP) and c-fos in the enteric nervous system (ENS) and central nervous system (CMS) of a rat model of constipation-predominant irritable bowel syndrome (C-IBS), and to explore the possible role of SP-immunoreactive nerve fibers in IBS. METHODS: The rat model was established by intragastrical injection with ice-cold water (0-4癈). The expressions of SP and c-fos in the ENS and CNS of model group (n = 10) and control group (n = 10) were detected by immunohis-tochemistry, and analyzed semi-quantitatively by comput-erized color image analyzer. The statistical differences of the opacity density (OD) and immunoreactive areas (IA) between the two groups were examined by t-test. RESULTS: The expressions of SP in ileocecus, colonic myenteric plexus, spinal dorsal horn, hypothalamus, and the fore part of gyrus cinguli were significantly higher in model group than those in the corresponding regions of control group (OD: 176.6 vs 155.5,172.3 vs 152.0,182.1 vs 160.2, 128.3 VS117.9, 127.9 vs114.5, P<0.05; IA: 169318 vs 137655, 144728 vs 114403, 145117 vs 117612 except in ileocecus and colonic myenteric plexus, P<0.05). The expression of c-fos in the above tissues was significantly higher in model group than that in the corresponding regions in control group (OD: 120.9 vs 109.0, 101.3 vs 92.2,125.4 vs887,115.5 VS88.6,120.6 vs 105.1, P<0.05; IA: 191 712 vs 154 363,73 597 vs 41 179,46 258 vs 33 238, 302 369 vs204 563,708 506 vs409 856, P<0.05). There was a close correlation between the expression of SP and c-fos in the same region (r= 0.594-0.721, P<0.05). CONCLUSION: The abnormal SP immunoreactive nerve fibers may be involved in the pathogenesis of IBS. SP containing neural pathway may play an important role in the regulation of the gastrointestinal function.