Role of brain orexin in the pathogenesis of irritable bowel syndrome

2017 Fiscal Year Final Research Report

• Project/Area Number: 26460955
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Gastroenterology
• Research Institution: Asahikawa Medical College
• Principal Investigator: Toshikatsu Okumura 旭川医科大学, 医学部, 教授 (60281903)
• Co-Investigator(Kenkyū-buntansha): 粂井 志麻 旭川医科大学, 大学病院, 医員 (00548969) ; 高草木 薫 旭川医科大学, 医学部, 教授 (10206732) ; 野津 司 旭川医科大学, 医学部, 准教授 (30312367)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 内臓知覚 / オレキシン / 中枢神経 / ドパミン / アデノシン / カンナビノイド

Outline of Final Research Achievements

We tried to clarify the brain mechanism to regulate visceral sensation. Visceral sensation was evaluated by colonic distension-induced abdominal withdrawal reflex (AWR) in conscious rats. Intracisternal injection of orexin-A dose-dependently increased the AWR threshold volume, suggesting that orexin acts centrally to induce an visceral antinociceptive action. The orexin-induced visceral antinociception mediate the morphin-, levodopa or brain ghrelin-induced visceral antinociception because orexin 1 receptor antagonist could significantly blocked the morphine-, levodopa- or ghrelin-induced visceral hyposensitivity. The orexin-induced visceral hyposensitivity was potently blocked by either dopamine D1 or D2 antagonist, adenoshine A1 antagonist or cannabinoid CB2 antagonist, suggesting that the dopaminergic, adenoshinergic or cannabinoid signaling may mediate the orexin-induced visceral antinociception.

Free Research Field

消化器内科