Significance of myocardial bridge upon atherosclerosis in The LAD coronary artery

心肌桥对LAD冠状动脉粥样硬化的意义

• 批准号: 02807037
• 负责人: ISHII Toshiharu
• 金额: $ 0.96万
• 依托单位: Tokyo Medical College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02807037/
• 关键词: Coronary artery; Myocardial bridge; Atherosclerosis; Endothelial cell; Shear stress; 内皮細胞; ずり応力

A part of the left anterior descending coronary artery running in the epicardial adipose tissue is often covered by myocardial tissue. This condition is designated as myocardial bridge (MB). We have previously noticed that the intima of the LAD covered by MB is never affected by atherosclerotic process. We investigate such protective effect of MB against atherosclerosis by immunohistochemical and electron microscopy. The intimal thickness beneath MB is remarkably thin in comparison with that before the entrance of MB and after the exit of MB. It consists of only few layers of smooth muscle cell with few collagen fibers and little matrix. All of the smooth muscle cells there show contractile form. In addition, not only there is no lipid deposition, but both types of foam cells derived from either macrophage or smooth muscle cells are absent. By scanning electron microscopy, the spindle-shaped endothelial cells are axially and regularly arranged along the course of the coronary artery. This denotes that the blood flow alternates into the condition of high shear stress under the MB.

冠状动脉左前降支在心外膜脂肪组织中走行的一部分常被心肌组织覆盖。这种情况被称为心肌桥（MB）。我们之前已经注意到MB覆盖的LAD内膜从未受到动脉粥样硬化过程的影响。我们通过免疫组化和电镜观察MB对动脉粥样硬化的保护作用。MB下方内膜厚度明显薄于MB入口前和出口后内膜厚度。它仅由几层平滑肌细胞和少量胶原纤维和基质组成。所有的平滑肌细胞都有收缩的形态。此外，不仅没有脂质沉积，而且不存在来自巨噬细胞或平滑肌细胞的两种类型的泡沫细胞。扫描电镜下可见梭形内皮细胞沿冠状动脉的走行沿着轴向规则排列。这表明血流在MB下交替进入高剪切应力状态。

项目成果

Tracy RE,: "Renal microvascular features of hypertension in Japan,Guatemala,and the United States." Arch Pathol Lab Med. 116. 50-55 (1992)

Tracy RE：“日本、危地马拉和美国高血压的肾微血管特征。”

Ishii T: "Variations with age and serum cholesterol levels in topographic distribution of macroscopic aortic atherosclerotic lesions as assessed by image analysis methods." Mod Pathol. 3. 713-719 (1990)

Ishii T：“通过图像分析方法评估宏观主动脉粥样硬化病变的地形分布随年龄和血清胆固醇水平的变化。”

Tracy RE,Malcom GT,Ishii T et al.: "Renal Microvascular Features of Hypertention in Japan,Guatemala,and the United States" Arch Pathol Lab Med. 116. 50-55 (1992)

Tracy RE、Malcom GT、Ishii T 等人：“日本、危地马拉和美国高血压的肾微血管特征”Arch Pathol Lab Med。

Ishii T: "Atherosclerosis suppression in the left anterior descending coronary artery by the Presence of myocardial brige:An ultrastructural study." Mod Pathol. 4. 424-431 (1991)

Ishii T：“心肌桥的存在抑制左冠状动脉前降支的动脉粥样硬化：一项超微结构研究。”

Ishikawa Y,Ishii T,Masuda S,Asuwa N,Kiguchi H: "Multiple regenersting colonic ulcers in secondary amyloidosis caused by rheumatoid avthritis" Acta Pathol Jpn. 43. 59-64 (1993)

Ishikawa Y、Ishii T、Masuda S、Asuwa N、Kiguchi H：“类风湿性关节炎引起的继发性淀粉样变性中的多发性再生结肠溃疡”Acta Pathol Jpn。