ULTRASTRUCTURE OF MYOCARDIAL SARCOLEMMA

这是一项关于心肌肌膜的研究。 其方法是分析 电镜观察糖萼的超微结构 细胞化学技术和2）冷冻断裂的双层 技术. 具体的目的是确定1）如果糖萼和 在冷冻断裂的膜中看到的膜内颗粒（IMP）是 与膜的渗透性有关; 2）膜的这些成分 彼此相关。 方法学是检查它们的形态学 在改变膜渗透性的扰动之后和在成熟期间， 的肌膜。 双层结构变化（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， 将在灌注的兔隔膜中使用扰动：“1）Ca耗尽 和饱食，2）缺血和缺氧和3）药物干预， 维拉帕米洋地黄麻醉剂 发展金属研究将比较 新生和成年大鼠肌膜成分的结构 心 糖萼与IMP关系的探讨 将涉及覆盖细胞表面的成分（唾液酸，Con A） 并监测断裂肌膜的平行分布， iMP颗粒。 相反，将诱导IMP的聚集， 观察细胞化学标记物的细胞表面分布。 常规 冷冻断裂技术加上诸如超快速冷冻的改进， 旋转阴影将用于描述和量化IMP“S（数量， 分布、大小、子结构）。 薄切片显微镜将使用 胶体氢氧化铁、阳离子化铁蛋白、Con A和单宁酸 固定 拟议的研究具有双重意义： 1)通过 测试糖萼和IMP是否与细胞的渗透性有关， 它解决了所有细胞生物学的一个基本问题 2）关注结构-功能关系（生理学 和病理生理学）的“大膜”，在心脏有 信息很少，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.