ULTRASTRUCTURE OF THE MYOCARDIAL SARCOLEMMA

这是对心肌肌膜和细胞外基质的研究。 本项目试图了解 心肌肌膜成分的超微结构分析 双层中的细胞表面(糖基化)，它们之间的关系 其他，到细胞外基质和膜运输。该方法 是研究双层的大分子结构和 具有冷冻断裂状态的糖萼/细胞外基质和 免疫电子显微镜。总体目标是确定(1)是否有任何 冷冻断裂和冷冻蚀刻中发现的膜内颗粒 膜与离子转运有关以及(2)哪些特定的大分子 在糖萼内有一个重要的结构和功能 与双层和细胞外基质成分的关系。 方法是(1)检查糖萼的细丝和 细胞外基质在未经处理的组织中确定其构型 和身份。这将在发育过程中的正常心脏中进行 和短暂的缺血后，(2)确定分布和 两种主要转运蛋白Na，K-双分子膜的定位 ATPase和Na-Ca交换器。以下技术的组合将 用于分离的成人心肌细胞、培养的心肌细胞和心脏组织： 超速冷冻、冷冻干燥、冷冻替代、低温 包埋、冷冻骨折和蚀刻、抗体和免疫金标记 贴上骨折标签。 拟议的研究具有双重意义，(1)通过确定 糖萼/细胞外基质的结构成分和 膜内颗粒位于双层之间，具有特定的膜功能 解决了所有细胞生物学的一个基本问题，以及(2)它 利用最先进的超微结构专注于结构功能 肌膜和肌膜的关系(生理和病理) 细胞外基质，在心脏中几乎没有信息。

This is a study of the myocardial sarcolemma and the extracellular matrix. This project attempts to gain an understanding of the function of the myocardial sarcolemma from an ultrastructural analysis of the components of the cell surface (glycocalyx) in the bilayer, their relationship to each other, to the extracellular matrix and to membrane transport. The approach is to study the macromolecular architecture of the bilayer and glycocalyx/extracellular matrix with state-of-the-are freeze-fracture and immunoelectron microscopy. The overall aims are to determine (1) if any of the intramembrane particles as revealed in freeze-fracture and freeze-etch membrane are related to ion transport and (2) which specific macromolecules within the glycocalyx have an important structural and functional relationship to the bilayer and to components of he extracellular matrix. The methodology is to (1) examine the filament of the glycocalyx and extracellular matrix to determine in untreated tissue their configuration and identity. This will be performed in normal hearts, during development and after brief periods of ischemia, (2) to determine the distribution and localization in the bilayer of two major transport proteins, i.e. Na,K- ATPase and Na-Ca exchanger. A combination of the following techniques will be used on isolated adult myocytes, cultured myocytes and heart tissue: ultra-rapid freezing, freeze-drying, freeze-substitution, low temperature embedding, freeze-fracture and etch, antibody and immunogold labeling and label fracture. The proposed research has a two-fold significance, (1) by identifying structural components of the glycocalyx/extracellular matrix and intramembrane particles int he bilayer, with specific membrane function it addresses a question fundamental to the biology of all cells and (2) it utilizes stat-of-the-art ultrastructure to focus on structure-function relationships (both physiological and pathological) of the sarcolemma and extracellular matrix, where in the heart there is little information.