| Project/Area Number |
16500216
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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 |
Nerve anatomy/Neuropathology
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| Research Institution | Nagoya University |
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Principal Investigator |
OZAKI Noriyuki Nagoya University, Graduate School of Medicine, Associate Professor, 大学院・医学系研究科, 助教授 (40244371)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIURA Yasuo Nagoya University, Graduate School of Medicine, Trustee, 大学院・医学系研究科, 理事 (50093042)
SHINODA Masamichi Nagoya University, Graduate School of Medicine, Research Associate, 大学院・医学系研究科, 助手 (20362238)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | visceral pain / organic dyspepsia / functional dyspepsia / nerve growth factor / maternal separation / hyperalgesia / ion channels / stomach / 過敏性腸症候群 / 痛覚鈍磨 / 急性ストレス / 迷走神経 / 大内臓神経 |
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| Research Abstract |
Aim_of Investigation : Gastric hyperalgesia may be involved in organic and functional dyspepsia (pain and discomfort). In this study, we investigated the mechanisms of gastric hyperalgesia induced by experimental ulcer by behavioral and immunohistochemical methods. Neonatal maternal separation induces visceral hyperalgesia in colon. This study compares the effects of maternal separation on response sensitivity to gastric and colorectal distension in Long-Evans rats.
Methods : Ulcer was made by acetic acid injection into the stomach wall. The expression of NGF and the innervations of the stomach wall were examined by immunohistochemistry. Expression of NGF receptors, and ion channels in gastric sensory neurons were examined by combination of retrograde tracing and immunohistochemistry. The involvement of NGF in hyperalgesia was behaviorally evaluated by testing an anti-NGF antibody.
Maternal separation was performed in Long Evans rats. Visceral sensitivities were assessed in stomach and c
… More
olon at 10 weeks of age by either gastric or colorectal distension. Somatic pain sensitivities were also assessed.
Results : An increased NGF immunoreactivity with accumulation of polymorphonuclear leucocytes was observed in the ulceration. The number of neurofilament protein- and GAP-43-immunoreactive fibers increased in the gastric mucosa around the ulcer. No changes were observed in the expression of NGF receptors (TrkA, p75) and ion channels (TRPV1, TRPV2, ASIC3) in the gastric sensory neurons. Gastric hyperalgesia was attenuated by systemic administration of neutralizing anti-NGF antibody.
In contrast to the response to colorectal distension, maternal separation induced decreased response to gastric distension, especially in male rats. No difference was found between control and separated rats in somatic pain sensitivities.
Conclusions : NGF contributes to the development of gastric hyperalgesia. Maternal separation differentially modulates visceral pain sensation in stomach and colon. Less
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