Study On Changing Of Brain-gut Peptide, Mast Cell And Shifting Of Th1/Th2Balance Of Large Intestinal Mucosa In Patients With Irritable Bowel Syndrome

Part I Changes of brain-gut peptide and mast cell in irritable bowel-syndromeObjective:To investigate the changes of vasoactive intestinal polypeptide (VIP)、calcitonin gene-related peptide (CGRP) and mast cell (MC) in irritable bowel syndrome (IBS), and to study their possible roles in pathogensis.Methods:In40patients with IBS who fulfilled the Rome Ⅲ criteria and in20non-IBS control subject, biopsy specimens taken from the mucosa of terminal ileum and recto-sigmoid junction at colouscopy were further examined using immunohistochemical staining of VIP, CGRP and MC. The results of immunohistochemisty were investigated qualitatively by color image analyzer.Results:Significant increase of VIP, CGRP and MC were found in IBS of colon compared to the controls (P<0.01), and compared with sigmoid, there were no significantly difference in ileum. But the iluem and sigmoid compared, CGRP and MC were no significantly difference in C-IBS patients (P>0.05).Conclusion:VIP、CGRP and MC are involved in the pathophysiological mechanism of IBS in certain ways, and their possible roles in the colon suggests the further studies may be useful in the understanding of IBS pathophysiology. Part Ⅱ Study on the shifting of Thl/Th2balance of large intestinal mucosa in patients with irritable bowel syndromeObjective:To investigate the expressions of Thl cytokine IFN-γ、 interleukin(IL)-12and Th2cytokine IL-4、IL-10intestinal mucosa in patients with irritable bowel syndrome(IBS). The primary of this study was to demonstrate immune mechanism underlying the activation of Thl/Th2cytokine production in colonic mucosa, so as to provide new idea for IBS in humans.Methods:The patients with IBS were diagnosed according to Rome Ⅲ criteria. Mucosal speciments were harvested from ascending, descending colon and rectum by colonscopy in60patients with IBS and20health controls. The expressions of Thl and Th2cytokine gene expressions and protein secretion were examined by RT-PCR and Western blot respectively.Results:(1) Compared with controls, the gene expressions and protein secretion of Thl cytokine IFN-γ、IL-12and IL-4have no significant difference. However, the expressions of Th2cytokine IL-10in diarrhea-predominant IBS (D-IBS) were decreased significantly compared with controls. In constipation predominant IBS (C-IBS) patients, the expressions of all Th1and Th2cytokine had no statistical difference compared with control.(2) The gene expression and protein secretion of IFN-γ in post infective IBS (PI-IBS) patients were increased significantly increased. The expressions of IL-4and IL-12in PI-IBS no significant difference compared with controls. However, the expressions of IL-10in PI-IBS patients were decreased significantly compared with control. The expressions of Thl and Th2cytokine in non-PI-IBS patients had no statistical difference compared with controls.(3) The expressions of Thl cytokine IFN-γ、IL-12and Th2cytokine IL-4、IL-10had no statistical difference compared with each other in all parts of gut.Conclusion:(1) Because the expressions of Th2IL-10mRNA and protein were decreased significantly, the shift of Thl/Th2balance of colon and rectal mucosa in D-IBS patients was demonstrated along with decreased Th2activity.(2) There are Th1/Th2immune balance in C-IBS patients.(3) Because increased expression of proinflammatory cytokine Thl IFN-γ and decreased expression of anti-inflammatory cytokine Th2IL-10mRNA and protein, the shift of Thl/Th2balance of colon and rectal mucosa in PI-IBS patients was demonstrated along with increased Th1and decreased Th2immune activity.