MYOCARDIAL CALCIUM LOCALIZATION BY X-RAY MICROANALYSIS

拟议项目的目标是： 1.利用能量色散X射线能谱(EDS)技术 亚细胞中钙和其他生物重要元素的定量 哺乳动物心肌中已知的结合或隔离钙的区域 (终池、线粒体、I带)。 2.测量钙和其他元素浓度的变化 在这些地点的情况下，假设直接 影响心肌中钙的储存或释放。特别是，我们将 研究a)咖啡因，b)改变细胞外钙， 以及c)静息和破伤风(在存在的情况下)改变肌节长度 (指咖啡因)心室肌。 3.采用一种较新的冻结方法(丙烷喷射冻结) 对完整心肌组织的研究，最终目的是研究 亚细胞元素分布的节拍变化。

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.