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.

晚期移植物失败仍然是一个重大问题，尤其是在径流较差（低剪应力）血管的情况下。我们已经报道说，在较差的径流模型中自体静脉移植物的内膜增厚比正常流动组中的厚度明显厚。内皮通过释放前列环蛋白或内皮衍生的松弛因子<一氧化氮（NO）>来调节潜在的血管平滑肌的反应性。这些因素不仅是血管扩张剂，而且是血小板聚集的有效抑制剂。目前的实验是为了检查前列环蛋白或没有的生产是否在犬自动静脉移植物的径流条件下通过使用较差的径流模型改变了。在以低剪切应力为特征的异常流条件下，在犬静脉移植物中的前列环蛋白的产生低于正常流量条件下的前列环蛋白。另外，在径流状况较差的情况下，犬静脉移植物中无需产生NO。海洋油和高水平的Eicosapentanoic Acid（EPA）可防止静脉移植物中的内膜增厚。但是，EPA防止内膜增厚的确切机制仍然未知。目前的实验被设计为征胺是否补充EPA是否会改变反向狗的静脉移植物的NO产生。礼物的结果表明，EPA补充减少了自脉静脉移植的直接增厚，这可能是由于这些结果的释放的改善，这些结果的释放改善，表明内皮的功能障碍是在前列环蛋白下降或没有异常的流动条件下降低的产生，因此可能会增加血小板聚集的最终，并最终会导致血小板聚集的发生，并最终会出现periperal的发展。失败。保存或增强的内皮功能可能是防止晚期移植失败的重要作用。