权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

STRUCTURE FUNCTION OF LINKS AMONG HEART MUSCLE CELLS

心肌细胞间连接的结构功能

基本信息

批准号：
3337606
负责人：
THOMAS F ROBINSON
金额：
$ 12.93万
依托单位：
MICHAEL REESE HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
1988
资助国家：
美国
起止时间：
1988-08-01 至 1989-03-31
项目状态：
已结题

项目摘要

During the cardiac cycle up to 70% of the end diastolic volume of blood is ejected with each stroke. As the contraction and subsequent recoil occur, the muscular walls undergo profound changes in shape characterized by variations in wall thickness and volume-filling by shortened, thickened papillary muscles and infoldings of the walls. These effects are accompanied by large changes in ventricular stiffness, with a diastolic to systolic compliance ratio of 50 to 1. Extremely rapid filling during the initial phase of diastolic recoil then occurs without the benefit of any antagonistic muscles. This striking range of dynamic versatility is produced by the geometrical interplay of a large population of variously oriented muscle cells that undergo cyclical relative motions. The rapid and continuous relative sliding of heart muscle cells implies that they must be interconnected in a precise manner, with constraints on extreme displacements. Return to diastolic configuration is rapid and must be promoted by release of energy elastically stored during systole. Furthermore, the maintenance of patency of the myocytes throughout many contractile cycles and the efficiency of transduction of energy to the motion of cells depends critically on the viscosity, and thus on the level of hydration of the extracellular matrix. We propose to further develop and apply specific methods for visualizing and identifying connective tissue structures in heart muscle by means of antibody stains and histological stains for light microscopy and scanning, transmission, and high voltage transmission E.M. We will determine the dispositions of extracellular substances relative to myocytes, in various regions of the heart, for elastin, microfibrils, collagen types, fibronectin, and laminin. Our goals also include the determination of changes in orientation of large collagen and elastin fibers in isolated heart muscles in states of stretch and contraction relative to relaxed state in correlated structural-mechanical studies. The roles of connective tissue relative to myocytes in elastic recoil will be explored in correlated structural-kinematic studies of muscles and enzymatically isolated myocytes. Several models are proposed as working hypotheses to aid in organizing information, designing experiments, and interpreting and evaluating results.

在心动周期期间，高达70%的舒张末期血液体积是每一次撞击都会弹出。当收缩和随后的反冲发生时，肌肉壁的形状发生了深刻的变化，壁厚和体积填充的变化，乳头肌和肌壁内折。这些影响是伴随心室僵硬度的巨大变化，舒张至收缩压顺应性比为50：1 灌装过程中非常快速舒张期回缩的初始阶段然后发生，而没有任何益处。拮抗肌这一惊人的动态多功能性范围，由大量人口的几何相互作用产生，进行周期性相对运动的定向肌肉细胞。快速心肌细胞的持续相对滑动意味着它们必须以精确的方式相互连接，位移。恢复到舒张构型是迅速的，通过在心脏收缩期间弹性储存的能量的释放来促进。此外，在许多情况下，收缩周期和能量向血管的传导效率细胞的运动关键取决于粘度，因此取决于细胞外基质的水合作用。我们建议进一步发展并应用特定的方法来可视化和识别连接词通过抗体染色的心肌组织结构，用于光学显微镜和扫描、透射和高压输电电磁铁我们将决定细胞外物质相对于肌细胞，在不同的区域，心脏，弹性蛋白，微纤维，胶原类型，纤连蛋白，和层粘连蛋白。我们的目标还包括确定离体心肌中大的胶原和弹性蛋白纤维的定向在相对于松弛状态的拉伸和收缩状态中，相关的结构力学研究。结缔组织的作用相对于肌细胞的弹性回缩，肌肉的结构-运动学研究和酶促分离肌细胞提出了几种模型作为工作假设，以帮助组织信息，设计实验，解释和评价结果。