大動脈瘤破裂診断システムの開発と破裂予防に関する実験的研究

主动脉瘤破裂诊断系统研制及破裂预防实验研究

• 批准号: 11470267
• 负责人: TABAYASHI Koichi
• 金额: $ 5.5万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11470267/
• 关键词: 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

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.

前言：本研究的第一个目的是发展生物力学评估主动脉瘤的方法。第二个目的是估计基质金属蛋白酶（MMP）与生物力学应力比较的意义。方法：采用弹性酶诱导大鼠动脉瘤模型。1)血管内超声系统测量动脉瘤壁运动和几何形状。2)用移液管抽吸法测量壁刚度。3)组织学分析。4)明胶酶谱法测定MMP活性。结果：主动脉内注入弹性蛋白酶可使主动脉扩张显著（对照组，1.7±0.26mm； 7天，5.46±1.38 mm； 14天，6.46±1.45 mm）。没有病例破裂，但有少数病例产生子动脉瘤。动脉瘤壁运动明显减弱。大多数动脉瘤腔内含有附壁血栓。最大扩张位置的弹性模量减小一次，然后显著增大。过度纤维化发生在动脉瘤壁外膜。嗜中性粒细胞壁浸润发生较早。瘤壁上MMP-2活性升高，而MMP-9活性不升高。结论：在该模型中，动脉瘤壁的不稳定首先发生在最大扩张位置，并向远中段移动。壁面应力和壁面强度的平衡对动脉瘤的扩张和破裂至关重要。MMP-2需要血管重塑。在这个模型中，MMP-9会破坏墙体结构。