| Project/Area Number |
11470267
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thoracic surgery
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| Research Institution | Tohoku University |
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Principal Investigator |
TABAYASHI Koichi Graduate school of medical science Profess, 大学院・医学系研究科, 教授 (90142942)
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| Co-Investigator(Kenkyū-buntansha) |
YOKOYAMA Hitoshi Graduate School of medical Science, Tohoku University, Lecturer, 医学部・附属病院, 講師 (80282127)
IGUCHI Atsushi Graduate School of medicla Science, Tohoku University, Assciate Proffessor, 大学院・医学系研究科, 助教授 (90222851)
SATO Masaaki Graduate school of mechatronics, Tohoku University, Professor, 大学院・工学研究科, 教授 (30111371)
近江 三喜男 東北大学, 大学院・医学系研究科, 助教授 (00144931)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥8,600,000 (Direct Cost: ¥8,600,000)
Fiscal Year 2000: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1999: ¥5,900,000 (Direct Cost: ¥5,900,000)
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| Keywords | Elastase-induced rat aneurysmal model / pipette aspiration / local wall elastic modulus / Intravascular ultrasound system / Wall motion / Matrix metalloproteinases (MMPs) / elastase-induced aneurysm model / Matrix metalloproteinase(MMP) / rat大動脈瘤モデル / 血管内超音波カテーテル / tissue remodeling |
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| Research Abstract |
Introduction : The first objective of this study is to develop the methodology to estimate aortic aneurysm biomechanically. The second objective is to estimate a significance of matrix metalloproteinase (MMP) compared with biomechanical stress.
Methods : We used the elastase-induced rat aneurysmal model. 1) Measurement of the aneurysmal wall motion and geometry by intravascular ultrasound system. 2) Measurement of the wall stiffness by the pipette aspiration. 3) Histological analysis. 4) Measurement of the MMP activity by gelatin zymography.
Results : Intra-aortic infusion of elastase produced significant aortic dilatation (control, 1.7±0.26mm, ; 7days, 5.46±1.38 mm ; 14days, 6.46±1.45 mm). No cases ruptured, but the daughter aneurysms were produced in a few cases. Aneurysmal wall motion significant decreased. Most aneurysm lumens contained mural thrombus. The elastic modulus of the maximal dilated position decreased once, and increased significantly. The excessive fibrosis occurred in adventitia of aneurysmal wall. The neutrophils mural infiltration occurred early time. MMP-2 activities increased in aneurysmal wall, but not MMP-9.
Conclusions : In this model, instability of aneurysmal wall occur in maximal dilated position at first, and the area move to distal midsection. The balance of wall stress and wall strength is important to aneurysmal dilatation and rupture. MMP-2 needs to vascular remodeling. MMP-9 will destroy wall structure in this model.
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