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Fundamental study of occurence mechanism and therapy for myocardial lesions with the mitral insufficiency.

二尖瓣关闭不全心肌病变发生机制及治疗的基础研究。

基本信息

批准号：
07456143
负责人：
YAMANE Yoshihisa
金额：
$ 4.35万
依托单位：
Tokyo University of Agriculture and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07456143/
关键词：
dog mitral insufficiency myocardial fibrosis platelet aggregation microembolus activated clotting time 家兎

项目摘要

Recently, acquired heart disease of companion animals is increasing in aged animals, especially the mitral valve disease is a social problem in clients. The mitral valve disease, that is myxomatous degeneration of mitral valve is seen in aged dogs. Myxomatous degeneration effects primarily the chordae tendinea and leaflets, and the chordae elongate and may eventually rupture leading to acute worsening of the mitral regurgitation. The mitral leaflets thicken and become redundant with billowing into the left atrium. Degeneration and abnormal collagen synthesis occur in the central zona fibrosa area of the cusps near the chordal insertions. In one view, the myocardium in the mitral valve disease dogs is most commonly thrown into the fibrosis. It had been described that the etiology of the myocardial fibrosis may be peripheral arterial microembolization or idiopathic. But, the etiology was uncertainly.The purpose of this study is to clear up of the occurence mechanism and to establish of t … More he therapy for myocardial lesions with the mitral insufficiency.If the myocardial fibrosis was caused by the coronary arterial microembolus in the mitral valve disease, alterations in platelet function is suggested, and activated platelets might relate to peripheral microembolization in heart muscle. In order to evaluate relationship between fibrosis and microembolus in myocardium, following research was operated. To bigin with, platelet aggregation in dogs with heart disease was mesured using ADP (adenosin 5'-diphosphate) as stimulator, and was compared with in dogs without heart disease.New evaluation method called EPS (Enhancement of Platelet Sensitivity) was compared with usual Max aggregation rate method. Against our expectations, ADP induced lower level of platelet aggregation in many dogs with heart disease. This results indicates that, in heart diseasies such as mitral regurgitation and aortic valve stenosis, platelets unrelentingly suffer from stimulation with regurgitation and turbulent flow, and due to this stimulation lifespan of platelets was shorten and platelets showed lower aggregation.Nextly, we done the experimentally study the same as above-mentioned in the mitral valve diseases. But, the results completely was similar to it.Furthermore, the same data was obtained in the dogs with mitral regurgitation which ws prepared experimentaly.Finally, We refered the canine myocardium with the fibrosis pathomorphologically.The result, fibrosis of the myocardium not be caused by microembolus in peripheral coronary arteries. It was found that they were myocardial fibrosis of the circumvascular/interstitial rather than displacemental fibrosis or fibrosis due to microembolus. Less

近年来，伴侣动物获得性心脏病在老年动物中日益增多，尤其是二尖瓣疾病已成为一个社会问题。二尖瓣病变，即二尖瓣粘液瘤样变性，多见于老年犬。粘液瘤变性主要影响腱索和瓣叶，腱索延长并可能最终破裂，导致二尖瓣返流急性恶化。二尖瓣瓣叶扩张并变得多余，并向左心房内翻滚。在靠近腱索止点的瓣尖中央纤维区发生变性和异常胶原合成。在一个视图中，二尖瓣疾病犬的心肌最常见的是纤维化。已有文献报道，心肌纤维化的病因可能是外周动脉微栓塞或特发性。本研究的目的是阐明其发生机制，建立其临床诊断标准， ...更多信息二尖瓣关闭不全心肌病变的治疗，如果二尖瓣病变的心肌纤维化是由冠状动脉微栓子引起的，则提示血小板功能改变，激活的血小板可能与心肌外周微栓子有关。为探讨心肌纤维化与心肌微栓子的关系，进行了以下研究。为探讨血小板聚集功能，以ADP（adenosin 5 '-diphosphate）为刺激剂，测定了心脏病犬的血小板聚集功能，并与正常犬进行了比较，同时对一种新的评价方法EPS（Enhancement of Platelet Sensitivity）与常用的最大聚集率（Max aggregation rate）进行了比较。与我们的预期相反，ADP在许多心脏病犬中诱导了较低水平的血小板聚集。这一结果表明，在二尖瓣关闭不全和主动脉瓣狭窄等心脏病中，血小板不可避免地受到回流和湍流的刺激，血小板寿命缩短，聚集性降低。结果表明，心肌纤维化并非由冠状动脉微栓子引起，而是由冠状动脉微栓子引起的。结果发现，它们是血管周围/间质性心肌纤维化，而不是移位性纤维化或微栓子引起的纤维化。少