2002 Fiscal Year Final Research Report Summary
An investigation of underlying mechanism of delayed inflammatory state and hyperalgesia located in a healed wound-A study of involvement of sympathetic activity and possibility of therapeutical effect of preemptive sympathectomy
| Project/Area Number |
13671503
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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 |
Orthopaedic surgery
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| Research Institution | Nagoya University |
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Principal Investigator |
NAKAMURA Ryogo Nagoya University, Graduate School of Medicine, Professor, 大学院・医学系研究科, 教授 (10115610)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Jun Nagoya University, Research Institute of Environmental Medicine, Associate Professor, 環境医学研究所, 助教授 (00235350)
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| Project Period (FY) |
2001 – 2002
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| Keywords | SYMPATHETIC NERVE / HYPERALGESIA / NORADRENALINE / ATP / CHRONIC PAIN |
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| Research Abstract |
1, Preemptive sympathectomy prevented the development of inflammatory changes (swelling, redness) in the hindpaw, while but not influence the augmenting effects of noradrenaline on the C-fiber nociceptors of chronic inflamed rats. This suggests fundamental differences of underlying mechanism between developments of inflammatory process and adrenergic sensitivity of nociceptors under chronic inflamed condition.
2, There was a clear development of daily change in plasma noradrenaline in rats rendered neuropathic. This suggests that sympathetic activity is not stable through the whole period of CRPS.
3, Low concentration of ATP (a mimic dose of sympathetic transmitter) excited some of the CPRs after heat stimulations, but the subsequent heat responses were decreased. Higher concentration of ATP (a mimic dose of damaged cell) excited some CPRs and increased the heat responses. ATP seems not to have a predominant role in the sympathetically maintained hyperalgesia in CRPS.
4, There were clear differences between the Lewis strain and Sprague-Dawley rate in chronic inflammation induced noradrenaline sensitivity of cutaneous C-fiber nociceptors. This suggests that wide rage of therapeutic effect of sympathectomy is due to difference of sympathetic dependency of each subject.
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