ULTRASTRUCTURE OF MYOCARDIAL SARCOLEMMA

这是一项关于心肌肌膜的研究。它的方法是分析 1)糖萼超微结构的电子显微镜观察 细胞化学技术和2)冷冻断裂的双层 技巧。具体的目标是确定1)糖基化反应和 在冷冻破裂的膜中看到的膜内颗粒(IMP)是 与膜的通透性有关以及2)膜的这些成分如何 Ar是相互关联的。方法论是检查它们的形态 在改变膜透性的扰动之后和在成熟过程中 在肌膜上。双分子层的结构变化(尤其是IMP) 而细胞表面将与发病、程度和 防止膜功能改变。为此目的，以下是 在灌流的兔鼻中隔中使用微扰法：“1)钙耗竭 2)缺血和缺氧；3)药物干预。 维拉帕米，洋地黄，麻醉药。发展中金属研究将比较 新生和成年大鼠肌膜成分的结构 心。糖萼与肌萎缩侧索硬化关系的研究 将涉及覆盖细胞表面的成分(唾液酸，Con A) 并监测断裂的肌膜是否平行分布 小鬼粒子。相反，IMP的聚集将被诱导，并且 细胞表面细胞化学标记物的分布情况。传统型 冷冻断裂技术加上超快速冷冻等精细化技术， 旋转跟踪将被用来描述和量化IMP“S(数字， 分布、大小、亚结构)。薄片显微镜将使用 胶体氢氧化铁、阳离子铁蛋白、ConA和单宁酸 定格。拟议的研究具有两重意义：1)通过 检测糖萼和IMP是否与血管通透性有关 它解决了所有细胞生物学的一个基本问题 2)关注结构与功能的关系(生理学 和病理生理学)的“大膜”，在心脏那里 是很少的信息，使用最先进的技术。

This is a study on the myocardial sarcolemma. Its approach is to analyze the ultrastructure of 1) the glycocalyx with electron microscope cytochemical techniques and 2) the bilayer with freeze-fracture techniques. The specific aims are to determine 1) if the glycocalyx and th intramembrane particles (IMP's) seen in freeze-fractured membranes are related to membrane permeability and 2) how these components of themembrane ar related to each other. The methodology is to examine their morphology after perturbations which alter membrane permeability and during maturation of the sarcolemma. Structural changes in the bilayer (especially 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 in the perfused rabbit septum:" 1) Ca depletion and repletion, 2) ischemia and anoxia and 3) drug interventions, i.e. verapamil, digitalis, anesthetics. The developmetal studies will compare the structure of the sarcolemmal components in the neonate and adult rat heart. Investigation of the relationship between the glycocalyx and IMP's will involve capping components of the cell surface (sialic acid, Con A) and monitoring the fractured sarcolemma for parallel distribution of the iMP particles. In reverse, clustering of the IMP's will be induced and the cell surface distribution of cytochemical markers noted. Conventional freeze-fracture 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 (physiologicala nd pathophysiological) of the "greater membrane," where in the heart there is little information, using state of the art techniques.