ULTRASTRUCTURE OF THE MYOCARDIAL SARCOLEMMA

这是对心肌肌膜和细胞外基质的研究。 该项目试图了解 从超微结构分析的成分，心肌肌膜 双层中的细胞表面（糖萼），它们与每个 其他的，细胞外基质和膜运输。 的方法 是研究双层的大分子结构， 糖萼/细胞外基质与状态的-the-are冷冻断裂， 免疫电镜 总体目标是确定（1）是否存在以下情况 冷冻断裂和冷冻蚀刻显示的膜内颗粒 膜与离子转运有关;（2）哪些特定的大分子 在糖萼内具有重要的结构和功能 与细胞外基质的双层和组分的关系。 方法是（1）检查糖萼的细丝， 细胞外基质，以确定在未处理的组织中它们的构型 和身份。 这将在发育期间在正常心脏中进行 短暂缺血后，（2）确定分布， 两种主要转运蛋白，即Na，K- ATP酶和钠钙交换器。 以下技术的组合将 用于分离的成体肌细胞、培养的肌细胞和心脏组织： 超快速冷冻，冷冻干燥，冷冻置换，低温 包埋、冷冻断裂和蚀刻、抗体和免疫金标记， 标记骨折。 该研究具有双重意义，（1）通过识别 糖萼/细胞外基质的结构成分， 双分子层中的膜内颗粒，具有特定的膜功能， 解决了所有细胞生物学的基本问题，（2）它 利用最先进的超微结构，专注于结构-功能 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.