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 量化亚细胞中的钙和其他生物学重要元素 已知结合或隔离钙的哺乳动物心肌区域 （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，在假设的条件下直接 影响心肌钙的储存或释放。 特别是，我们将 研究 a) 咖啡因、b) 不同细胞外钙的影响， c) 静息和强直状态下肌节长度不同（在存在的情况下） 咖啡因）心室肌。 3.采用相对较新的冷冻方法（丙烷喷射冷冻） 对完整心肌组织的研究，最终目标是研究 亚细胞元素分布的逐次变化。

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.