Analysis on serotonin-related environment of gastrointestinal tissue in canine inflammatory bowel disease.

2013 Fiscal Year Final Research Report

• Project/Area Number: 24780306
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Clinical veterinary science
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Ide Kaori 東京農工大学, (連合)農学研究科(研究院), 講師 (40550281)
• Project Period (FY): 2012-04-01 – 2014-03-31
• Keywords: セロトニン / 犬 / 慢性腸症 / 炎症性腸疾患 / 過敏性腸症候群 / 腸管クロム親和性細胞

Outline of Final Research Achievements

Serotonin (5-HT), a gut hormone produced by enterochromaffin cell (EC cell), is essential key factor responsible for pathophysiology of inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) in humans. This current study focused on intestinal 5-HT environment and analyzed its differences between healthy dogs and dogs with IBD.
Immunohistochemistry with canine duodenum mucosal tissue revealed characteristic cells positively stained with anti-5-HT antibody, which was suspected as canine EC cells. The number of these cells were significantly different between canine IBD group and healthy controls. Realtime RT-PCR analysis for TPH1 and SERT gene mRNA using total RNA from duodenal mucosal tissue were also analyzed and compared in the two groups.
These results correspond to the characteristics seen in human IBS patients and some human IBD patients.

Free Research Field

獣医学

Academic Significance and Societal Importance of the Research Achievements

症状と腸粘膜生検の結果より臨床的に犬のいわゆる炎症性腸疾患（IBD）と診断される症例の中には，特徴が似るものの実際には異なる要因のものが混在していると考えられており，未知の病態を明らかにすることは，各症例に応じたより適切な治療法の開発につなげるために必要である。本研究では，ヒトの過敏性腸症候群との関連で知られる消化管ホルモン・セロトニンに着眼してIBD犬群の病態解析を行った。その結果，IBD犬群では健常群に比べて腸粘膜組織中のセロトニン産生細胞の数が有意に多く，セロトニン再取り込み機構の遺伝子転写量が低かった。犬IBDにおいても腸のセロトニン機構の異常が明らかとなった。