ULTRASTRUCTURE OF THE MYOCARDIAL SARCOLEMMA

这是对心肌肌膜的研究。它的方法是分析 用细胞化学和免疫组织化学方法观察糖萼和双层的超微结构 冷冻骨折技术。具体目标是确定，1)如果 双层中的糖萼和膜内颗粒(IMP)是 与膜通透性有关，以及2)这些成分是如何 膜是相互联系的。 方法是在受到扰动后检查它们的形态 在成熟的过程中改变膜的通透性或运输 肌膜，在肌膜特化内和改变后 在双层内的阴离子磷脂中。中国经济结构的变化 IMP‘s和细胞表面会与发病有关，程度和 以防止膜功能的改变。 为此，将使用以下扰动：1)钙耗竭和 补充，2)缺血，3)洋地黄毒性，4)磷脂酶D治疗 以及暴露在两亲分子中。发展研究将比较 新生儿和成人心脏肌膜成分的结构。 糖萼与肌萎缩侧索硬化症的关系探讨 包括诱导IMP的群集并确定是否存在 细胞表面细胞化学标记物平行分布。反过来说， 细胞表面成分(阳离子铁蛋白和ConA受体)将 并监测断裂的肌膜是否平行分布。 IMP的。 传统的冷冻压裂技术加上诸如 超快速冻结、旋转阴影将用于描述和 量化IMP(数量、分布、大小、子结构)。薄片 显微镜下将使用胶体氢氧化铁、阳离子铁蛋白、ConA 和单宁酸的固定。这项拟议的研究有两个方面 意义：1)通过测试糖萼和IMP是否相关 对于膜的通透性，它解决了一个基本的问题 所有细胞的生物学，2)它侧重于结构-功能 关系(生理和病理生理学)的“大 在心脏中几乎没有信息的地方，使用状态 艺术技巧。

This is a study of the myocardial sarcolemma. Its approach is to analyze the ultrastructure of the glycocalyx and the bilayer with cytochemical and freeze-fracture techniques. The specific aims are to determine, 1) if the glycocalyx and the intramembrane particles (IMP's) in the bilayer are related to membrane permeability, and 2) how these components of the membrane are related to each other. The methodology is to examine their morphology after perturbations which alters membrane permeability or transport, during maturation of the sarcolemma, within specializations of the sarcolemma and after alterations in the anionic phospholipids within the bilayer. Structural changes in the IMP's and the cell surface will be related to the onset, to the degree and to the prevention of altered membrane function. To this end the following perturbations will be used: 1) Ca depletion and repletion, 2) ischemia, 3) digitalis toxicity, 4) phospholipase D treatment and exposure to amphiphiles. The developmental studies will compare the structure of the sarcolemmal components in the neonate and adult hearts. Investigation of the relationship between the glycocalyx and IMP's will involve induction of clustering of the IMP's and determining if there is a parallel distribution of cell surface cytochemical markers. In reverse, cell surface components (cationized ferritin and Con A receptors) will be capped and the fractured sarcolemma monitored for a parallel distribution of IMP's. Conventional freeze-fracturing techniques plus refinements such as ultra-rapid freezing, rotary shadowing will be used to describe and quantify IMP's (number, distribution, size, substructure). Thin-section microscopy will use colloidal iron hydroxide, cationized ferritin, Con A and tannic acid fixation. The proposed research has a two-fold significance: 1) by testing whether the glycocalyx and IMP's are related to permeability of the membrane it addresses a question fundamental to the biology of all cells, and 2) it focuses on the structure-function relationships (physiological and pathophysiological) of the "greater membrane," where in the heart there is little information, using state of the art techniques.