| Project/Area Number |
14570480
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Gastroenterology
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| Research Institution | Nagasaki University |
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Principal Investigator |
MIZUTA Yohei Nagasaki University, Graduate School of Biomedical Sciences, Associate Professor, 大学院・医歯薬学総合研究科, 助教授 (40274641)
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| Co-Investigator(Kenkyū-buntansha) |
村瀬 邦彦 長崎大学, 大学院・医歯薬学総合研究科, 助教授 (30274640)
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| Project Period (FY) |
2002 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2005: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2004: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | stress / colonic motility / chronic visceral hypersensitivity / serotonergic pathway / irritable bowel syndrome / セロトニン / 過敏性大腸症候群 |
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| Research Abstract |
Objectives ; Visceral hypersensitivity, intestinal dysmotility and stress play a major role in the pathophysiology of irritable bowel syndrome. However, the significance of visceral hypersensitivity in changes of colorectal motor function by stress is not conclusive. Therefore, the present study was designed to investigate whether defecation or colonic transit are more susceptible to the stress in chronic visceral hypersensitivity, and how 5-hydroxytryptamine and its receptor system is involved in such events.
Methods ; Rat model of chronic visceral hypersensitivity was induced by mechanical colorectal irritation during postnatal development. Abdominal withdrawal reflex was tested by graded colorectal distention. Fecal pellet output and colonic transit studies were performed under baseline and wrap-restraint stress in both rats subjected to neonatal colorectal irritation and controls. The effect of 5-hydroxytryptamine agonist on spontaneous defecation was studied. Additionally, we exami
… More
ned the possible involvement of 5-hydroxytryptamine 3-receptors in the defecative response to stress by employing granisetron in both groups.
Results ; Neonatal colorectal irritation resulted in significant increase of abdominal withdrawal reflex scores. Both defecation and colonic transit were not different between chronic visceral hypersensitivity group and control under baseline condition. The stress and 5-hydroxytryptamine agonist resulted in significant increase of defecation in chronic visceral hypersensitivity group compared to control. The prior administration of granisetron inhibited stress-induced defecation in chronic visceral hypersensitivity group as well as control. Stress-induced acceleration of colonic transit was not significantly different between both groups.
Conclusions ; These results suggest that chronic visceral hypersensitivity can modulate the effect of stress on fecal pellet output via serotonergic pathway. Therefore, chronic visceral hypersensitivity may be related to the important susceptibility of defecative response to stressful events in patients with irritable bowel syndrome. Less
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