肠易激综合征患者内脏高敏感性与肥大细胞的关系

目的：探讨肠易激综合征（IBS）患者肠黏膜肥大细胞（MC）在内脏高敏感机制中的可能作用和临床意义。方法：应用电子气压泵及灌注导管测压仪检测22例腹泻型IBS（D－IBS）患者、20例便秘型IBS（C－IBS）患者和19例正常人肛门直肠压力、直肠对容量刺激的感觉及直肠顺应性。取回肠末端、回盲部、升结肠、乙状结肠黏膜标本，应用特殊组化染色法（甲苯胺蓝改良染色法）对MC染色，并应用彩色病理图像分析软件进行分析。结果：IBS患者肛门直肠括约肌的静息压、收缩压、松弛压与正常人相似（P＞0．05）；感觉阈值、排便阈值、疼痛阈值明显低于正常人（P＜0．01）；直肠顺应性降低（P＜0．01）；向直肠内注气20或40ml后，均可引起直肠肛门抑制性反射。IBS患者回肠末端、回盲部、升结肠MC明显增多（P＜0．01），且D－IBS和C－IBS组间也有明显差异（P＜0．01），而乙状结肠MC在各组间均无明显变化。结论：IBS患者MC存在变异，MC在IBS内脏高敏感的病理生理过程中可能具有重要作用。

Visceral hypersensitivity in irritable bowel syndrome and mast cells

Objective: To investigate the changes of the mast cells(MCs) in colonic mucosa, and to elucidate their possible roles in visceral hypersensitivity of irritable bowel syndrome (IBS). Methods: Rectal visceral perception thresholds to balloon distention, rectal compliance and anorectal manometry were examined in 22 patients with diarrhea predominant IBS, 20 patients with constipation predominant IBS and 19 healthy volunteers by means of electric barastat and perfusion catheter manometer. The biopsies of the terminal ileum, the ileocecal junction(ICJ), the ascending colon, and the sigmoid colon were stained specifically with histochemistry for the MCs. The results were investigated qualitatively and quantitatively by means of color imagine analyzer. Results: In patients with IBS, the anorectal resting pressure, squeeze pressure, and relaxation pressure were similar to those of normal volunteers( P >0.05); Rectal compliance decreased( P <0.01); While the average sensation thresholds, defecation thresholds and discomfort thresholds were much lower than those in normal volunteers( P <0.01). All patients had similar minimum relaxation volume to elicit the anorectal inhibitory reflux. The number of MCs in the terminal ileum, ICJ, and the ascending colon was significantly elevated in IBS ( P < 0.01), and the MCs in IBS had great variations. Conclusion: The MCs of intestinal mucosa may play an important role in the gut hypersensitivity in both motor response and visceral perception in IBS.