Effects of shear stress on the intimal hyperplasia of autogenous Vein grafts

剪切应力对自体静脉移植物内膜增生的影响

基本信息

批准号：
05807107
负责人：
KOMORI Kimihiro
金额：
$ 1.28万
依托单位：
Second Department of Surgery, Faculty of Medicine, Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05807107/
关键词：
vein graft intimal thickening shear stress prostacyclin nitric oxide eicosapentanoic acid Shear stress 自家動脈グラフト自家静脈グラフト

项目摘要

Late graft failure is still a significant problem particularly in cases with poor runoff (low shear stress) vessels. We have already reported that the intimal thickening of the autogenous vein graft in the poor runoff model was significantly thicker than that in normal flow group. Endothelium modulates the responsiveness of the underlying vascular smooth muscles by releasing prostacyclin or endothelium-derived relaxing factor <Nitric Oxide (NO) >. These factor are not only vasodilators but also potent inhibitors of platelet aggregation. The present experiments were desingned to examine whether the production of prostacyclin or NO were altered in poor runoff conditions of canine autogenous vein grafts by using a poor runoff model. Under abnormal flow conditions characterized by low shear stress, the production of prostacyclin in the canine vein graft was lower than that in normal flow conditions. In addition, the production of NO in canine vein grafts are also impaired under poor runoff conditions.Marine oils and high levels of eicosapentanoic acid (EPA) prevents intimal thickening in vein grafts. However, the precise mechanism by which EPA prevents intimal thickening is still unknown. The present experiments was designed toexamine whether EPA supplementation would alter the NO production in reversed vein grafts of dogs. The presents results demonstrated that EPA supplementation reduces intimal thickening of the autogenous vein graft, which may be due to an improved release of NO.These results suggest that the dysfunction of the endothelium in terms of the decreased production of prostacyclin or NO under abnormal flow conditions may thus increase platelet aggregation and eventually facilitate the development of peripheral arterial occlusive disease and thus the occurrence of late graft failure. The preserved or enhanced endothelial function may be important role for preventing the late graft failure.

晚期移植失败仍然是一个重大问题，特别是在径流（低剪切应力）血管较差的情况下。我们已经报道，差径流模型中自体静脉移植物的内膜增厚明显厚于正常流量组。内皮通过释放前列环素或内皮衍生的松弛因子<一氧化氮（NO）>来调节底层血管平滑肌的反应性。这些因子不仅是血管扩张剂，也是血小板聚集的有效抑制剂。本实验旨在通过使用不良径流模型来检查在犬自体静脉移植物的不良径流条件下前列环素或NO的产生是否发生改变。在以低剪切应力为特征的异常流动条件下，犬静脉移植物中前列环素的产生低于正常流动条件下。此外，在较差的径流条件下，犬静脉移植物中一氧化氮的产生也会受到损害。海洋油和高含量的二十碳五烯酸（EPA）可防止静脉移植物中的内膜增厚。然而，EPA 防止内膜增厚的确切机制仍不清楚。本实验旨在检验补充 EPA 是否会改变狗反向静脉移植物中 NO 的产生。目前的结果表明，补充 EPA 可以减少自体静脉移植物的内膜增厚，这可能是由于 NO 释放的改善。这些结果表明，在异常血流条件下，前列环素或 NO 的产生减少，从而导致内皮功能障碍。因此可能会增加血小板聚集，最终促进外周动脉闭塞性疾病的发展，从而导致晚期移植失败的发生。保留或增强的内皮功能可能对于预防晚期移植失败具有重要作用。