应用电子显微镜X射线显微分析法研究缺血骨骼肌细胞内钙的分布

在暂时性和持续性缺血组家兔背阔肌切片中,可见不同程度的细胞变性坏死,线粒体中出现中度深染的绒球样结构。在暂时性缺血组还见肌原纤维间有另外两种电子致密颗粒。根据颗粒的分布,大小和结构特征,可认为大颗粒是变性的线粒体,小颗粒是变性的肌质网。X射线显微分析的结果证明,这两种颗粒都含有较高浓度的钙,而绒球样结构仅含微量的钙。这说明光镜下在交性坏死肌细胞中所见的钙沉着,系发生于暂时性缺血肌肉的线粒体和肌质网中。本文结合实验结果对钙沉积的条件作了讨论。     

KF-80快速冷冻技术制备生物样品用于电镜X射线元素分析

新鲜生物样品经快速冷冻固定、冷冻超薄切片后进行电镜下形态观察和在位元素分析，以研究细胞生命活动某个瞬间的形态及元素组成和分布。KF－80快速冷冻仪用液氮使氟时昂－22保持在－160℃，将生物样品快速射入其中以达到快速冷冻固定的目的，在组织样品－大鼠胸主动脉平滑肌细胞和悬滴样品－兔红细胞的观察中证实两者的超微结构保存较好，虽有直径约0．1μm的小冰晶存在，但不影响形态观察和元素分析，平滑肌细胞X射线元素分析结果显示，胞质中钾含量高，钠含量低，核中磷含量高而硫含量低，说明此项技术术能保持胞质与核间元素分布的差异。     

X-RAY MICROANALYSIS OF CALCIUM IN ISCHEMIC SKELETAL MUSCLE CELLS

Tissue sections of both transiently and persistently ischemic musculus latissimus dorsi of rabbitsshow degenerated and necrotic cells in varying degrees. Degenerated mitochondria appearing in the cellscontain moderate electron-dense fluffy intramatrical deposits. However, only in the transient ischemia sam-ple can other two kinds of electron-dense granules be seen between myofibrils. According to their ultra-structure, size and distribution, the larger granules are considered the degenerated mitochondria, and thesmaller ones the degenerated sarcoplasmic reticulum. X-ray microanalysis proves that these two kinds ofgranules contain high concentration of calcium, while the fluffy deposits contain little calcium. The find-ings suggest that the calcium deposits in the degenerated and necrotic cell seen under light microscopeoccur in mitochondria and sarcoplasmic reticulum of the transiently ischemic muscle cell. The conditionsof calcium accumulation in ischemic muscle cells are discussed.