Blaineau S, Julliard A K, Amsellem J, Nicaise G
Laboratoire de Physiologie des Elements Excitables, Université Claude Bernard, Villeurbanne, France.
Histochemistry. 1987;87(6):545-55. doi: 10.1007/BF00492469.
The relevance of the continuum method for a quantitative X-ray microanalysis of epon embedded tissue sections in the particular conditions offered by the Camebax-TEM system was tested and an improved model of specimen holder is proposed. The absolute calcium concentration [Ca] of membrane-bound intracellular glio-interstitial granules was determined by X-ray microanalysis in transmission electron microscopy of Mytilus retractor muscle. The Ca peak and background values were measured by the wavelength-dispersive spectrometer of the Camebax; the mass thickness of the section was recorded simultaneously with an added energy-dispersive detector. The tissue was frozen at approximately equal to 77 K in a mixture of liquid propane and butane, freeze-substituted in the presence of oxalic acid and embedded in epoxy resin. The calcium concentration of glio-interstitial granules can be as high as 180 mmol.kg-1 of epoxy-embedded tissue, with an average of 40 mmol.kg-1. The sampling of the data through repeated experiments is discussed and it is proposed that the cell would be the main level of variation. The Ca content of glio-interstitial granules is significantly lower in the tissues of animals submitted to high-potassium artificial sea-water for 10 min. This finding was predicted by the hypothesis that glio-interstitial tissue is a regulator of calcium concentration in extracellular spaces.
在Camebax - TEM系统所提供的特定条件下，测试了连续体方法对环氧树脂包埋组织切片进行定量X射线微分析的相关性，并提出了一种改进的样品架模型。通过贻贝牵缩肌透射电子显微镜下的X射线微分析，测定了膜结合的细胞内神经胶质 - 间质颗粒的绝对钙浓度[Ca]。Ca峰和背景值由Camebax的波长色散光谱仪测量；切片的质量厚度由附加的能量色散探测器同时记录。组织在丙烷和丁烷的混合液中于约77K冷冻，在草酸存在下进行冷冻置换，然后包埋在环氧树脂中。神经胶质 - 间质颗粒的钙浓度在环氧树脂包埋组织中可高达180 mmol·kg-1，平均为40 mmol·kg-1。讨论了通过重复实验进行数据采样的问题，并提出细胞将是主要的变异水平。在置于高钾人工海水中10分钟的动物组织中，神经胶质 - 间质颗粒的Ca含量显著降低。这一发现由神经胶质 - 间质组织是细胞外空间钙浓度调节剂这一假说来预测。
