DEVELOPMENT OF CARDIAC EXCITATION/CONTRACTION COUPLING

心脏兴奋/收缩耦合的发展

• 批准号: 2759123
• 负责人: Tony L Creazzo
• 金额: $ 26.27万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2002-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2759123
• 关键词: calcium flux; confocal scanning microscopy; developmental neurobiology; embryo /fetus; heart; histogenesis; laboratory mouse; mammalian embryology; myogenesis; neuromuscular junction; neuromuscular transmission; sarcoplasmic reticulum; voltage /patch clamp; western blottings

Despite many recent advances in the general understanding of Ca2+ handling during cardiac excitation-contraction (EC) coupling, little is known regarding the functional assembly of the various molecular components of EC coupling during the course of embryological development. This is critical information considering that many drugs used in the treatment of heart disease affect Ca2+ handling in some way and, in the pregnant mother, these are likely to affect the fetus differently. Secondly, it is likely that the normal development of these mechanisms is altered in congenital heart disease. In this proposal, the experiments are designed to test how functional aspects of cardiac EC coupling develop in parallel with cardiac junctional complexes and expression of specific proteins in embryonic heart. Junctional complexes are the structural manifestations of EC coupling which have recently been reported in detail in the chick embryo with electron and confocal microscopy. It is anticipated that the time course of development of EC coupling will parallel the appearance and expression of the key protein components. The approaches that will be used include patch clamping, measurements of Ca2+ transients, fluorescence confocal microscopy, and Western blotting. These studies will be carried out in the chick embryo which is the most studied model for embryological development of most cellular systems including EC coupling. Parallel experiments will be conducted in the developing mouse heart for comparison with a mammalian species. The Specific Aims are: 1) to determine the normal development of Ca-induced-Ca-release from the sarcoplasmic reticulum; 2) to determine the normal development of the mechanisms which remove Ca2+ from the cytoplasm; and 3) to determine the relative expression and assembly of the key proteins in cardiac EC coupling. The long term objective of this work is to understand the development of the critical mechanisms which regulate cytosolic Ca2+ on a beat-to-beat basis from the earliest heart tube to the mature four- chambered heart.

尽管最近对 Ca2+ 的一般理解取得了许多进展 心脏兴奋-收缩（EC）耦合过程中的处理，很少有 已知关于各种分子的功能组装 胚胎学过程中EC耦合的组成部分 发展。 考虑到许多药物 用于治疗心脏病会以某种方式影响 Ca2+ 处理 而且，对于怀孕的妈妈来说，这些都可能会影响胎儿 不同。其次，这些可能是正常发展的。 先天性心脏病的机制发生了改变。 在这个提案中， 这些实验旨在测试心脏的功能方面如何 EC 耦合与心脏连接复合物同时发展 胚胎心脏中特定蛋白质的表达。 交界处 配合物是EC偶联的结构表现，其具有 最近在鸡胚中详细报道了电子和 共焦显微镜。 预计时间进程 EC耦合的发展将与外观和表达并行 的关键蛋白质成分。 将使用的方法包括 膜片钳、Ca2+瞬变测量、荧光共焦 显微镜检查和蛋白质印迹法。 这些研究将在 鸡胚胎是胚胎学研究最多的模型 大多数细胞系统的开发，包括 EC 耦合。 平行线 实验将在发育中的小鼠心脏中进行 与哺乳动物物种的比较。 具体目标是： 1) 确定 Ca 诱导的 Ca 释放的正常发育 肌浆网； 2）确定正常发育 从细胞质中去除 Ca2+ 的机制； 3) 确定 心脏EC中关键蛋白的相对表达和组装 耦合。 这项工作的长期目标是了解 调节细胞质 Ca2+ 的关键机制的发展 从最早的心管到成熟的四心管的逐搏基础 心室。