MYOCARDIAL CALCIUM LOCALIZATION BY X-RAY MICROANALYSIS

拟议项目的目标是： 1. 利用能量色散X射线光谱（EDS）技术， 定量钙和其他生物学上重要的元素， 哺乳动物心肌中已知结合或螯合钙的区域 （末端池、线粒体、I带）。 2. 测量钙和其他元素浓度的变化 在这些地点，假设条件下， 影响心肌中钙的储存或释放。 特别是要 研究a）咖啡因，B）变化的细胞外钙， 和c）在静止和强直（在存在下）时肌节长度变化 咖啡因）心室肌。 3. 采用相对较新的冷冻方法（丙烷喷射冷冻）， 研究完整的心肌组织，最终目的是研究 亚细胞元素分布的逐拍变化。

The objectives of the proposed project are: 1. To use the technique of Energy Dispersive X-ray Spectroscopy (EDS) to quantify calcium and other biologically important elements in subcellular regions of mammalian myocardium known to bind or sequester calcium (terminal cisternae, mitochondria, I-band). 2. To measure changes in the concentrations of calcium and other elements at these sites under conditions which have been hypothesized to directly affect storage or release of calcium in myocardium. In particular, we will investigate the effects of a) caffeine, b) varying extracellular calcium, and c) varying sarcomere length on resting and tetanized (in the presence of caffeine) ventricular muscle. 3. To adapt a relatively new freezing method (propane jet freezing) for the study of intact myocardial tissue, with the ultimate goal of studying beat-to-beat variations in subcellular elemental distributions.