Wang Shen-Hao, Dong Lei, Luo Jin-Yan, Gong Jun, Li Lu, Lu Xiao-Lan, Han Shui-Ping
Department of Gastroenterology, Second Hospital of Xi'an Jiaotong University, 157, Xi 5 Road, Xi'an 710004, Shaanxi Province, China.
World J Gastroenterol. 2007 Dec 7;13(45):6041-7. doi: 10.3748/wjg.v13.45.6041.
To investigate if there are changes in serotonin (5-HT) levels, enterochromaffin (EC) cells and mast cells in small intestinal mucosa of patients with irritable bowel syndrome (IBS).
Diarrhea-predominant (IBS-D, n = 20), or constipation-predominant (IBS-C, n = 18) IBS patients and healthy controls (n = 20) underwent colonoscopy and peroral small intestinal endoscopy, and mucosal samples were obtained at the descending part of the duodenum, proximal end of jejunum and terminal ileum. High-performance liquid chromatography-electrochemistry and immunohistochemical methods were used to detect 5-HT content, EC cells and mast cells.
(1) There were no differences in the number and distribution of EC cells between IBS patients and the normal group. (2) The mucosal 5-HT contents at the duodenum, jejunum and ileum in IBS-C patients were 182 +/- 90, 122 +/- 54, 61 +/- 35 ng/mg protein, respectively, which were all lower than those in the normal group (256 +/- 84, 188 +/- 91, and 93 +/- 45 ng/mg protein, respectively), with a significant difference at the jejunum (P < 0.05). There were no differences in the small intestinal mucosal 5-HT contents between IBS-D patients and the normal group. The mucosal 5-HT contents at the duodenum were significantly higher than those at the ileum in the three groups (P < 0.001). (3) The numbers of mast cells in patients with IBS-C and IBS-D at the ileum were 38.7 +/- 9.4 and 35.8 +/- 5.5/high power field (hpf), respectively, which were significantly more than that in the normal group (29.8 +/- 4.4/hpf) (P < 0.001). There was no significant difference in the numbers of mast cells at the other two parts between IBS patients and the normal group. The numbers of mast cells in IBS-C, IBS-D, and normal groups were all significantly higher at the ileum (38.7 +/- 9.4, 35.8 +/- 5.5, 29.8 +/- 4.4/hpf, respectively) than at the duodenum (19.6 +/- 4.7, 18.5 +/- 6.3, 19.2 +/- 3.3/hpf, respectively, P < 0.001).
The changes in the 5-HT signaling pathway at the jejunum of IBS-C patients and the increase in mast cells in patients with IBS at the terminal ileum may offer evidence to explain the pathogenesis of IBS.
探讨肠易激综合征（IBS）患者小肠黏膜中5-羟色胺（5-HT）水平、肠嗜铬（EC）细胞和肥大细胞是否存在变化。
腹泻型（IBS-D，n = 20）或便秘型（IBS-C，n = 18）IBS患者及健康对照者（n = 20）接受结肠镜检查和经口小肠内镜检查，并在十二指肠降部、空肠近端和回肠末端获取黏膜样本。采用高效液相色谱-电化学法和免疫组织化学方法检测5-HT含量、EC细胞和肥大细胞。
（1）IBS患者与正常组之间EC细胞的数量和分布无差异。（2）IBS-C患者十二指肠、空肠和回肠黏膜的5-HT含量分别为182±90、122±54、61±35 ng/mg蛋白，均低于正常组（分别为256±84、188±91和93±45 ng/mg蛋白），空肠处差异有统计学意义（P < 0.05）。IBS-D患者与正常组之间小肠黏膜5-HT含量无差异。三组中十二指肠黏膜5-HT含量均显著高于回肠（P < 0.001）。（3）IBS-C和IBS-D患者回肠肥大细胞数量分别为38.7±9.4和35.8±5.5/高倍视野（hpf），显著多于正常组（29.8±4.4/hpf）（P < 0.001）。IBS患者与正常组在另外两个部位的肥大细胞数量无显著差异。IBS-C组、IBS-D组和正常组回肠肥大细胞数量（分别为38.7±9.4、35.8±5.5、29.8±4.4/hpf）均显著高于十二指肠（分别为19.6±4.7、18.5±6.3、19.2±3.3/hpf，P < 0.001）。
IBS-C患者空肠5-HT信号通路的变化以及IBS患者回肠末端肥大细胞的增加可能为解释IBS的发病机制提供依据。
