The application of synchrotron radiation induced X-ray emission in the measurement of zinc and lead in Wistar rat ameloblasts
The application of synchrotron radiation induced X-ray emission in the measurement of zinc and lead in Wistar rat ameloblasts
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DOI：
10.1016/j.archoralbio.2007.04.003
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发表时间：
2007-10-01
影响因子：
3
通讯作者：
Chan, Sheena W. Y.
中科院分区：
文献类型：
--
作者：
Arora, Manish;Kennedy, Brendan J.;Chan, Sheena W. Y.
The development of analytical techniques for the measurement of trace elements in cellular compartments of developing teeth remains an important methodological issue in dental research. Recent advances in third generation synchrotron facilities have provided high brilliance X-ray sources that can be effectively used to study trace element distributions in small spatial regions with low detection limits. The present study describes for the first time the application of synchrotron radiation induced X-ray emission (SRIXE) in measuring the distribution of zinc and lead in the ameloblasts of developing Wistar rat teeth. Wistar rats were fed a standard rat diet, containing the normal dietary requirements of zinc, ad libitum and exposed to 100 ppm of lead in drinking water. Resin embedded sections of first mandibular molars were analysed using a 13.3 keV incident monochromatic X-ray beam focussed to a 0.2 mu m spot. Characteristic X-rays arising from the entire thickness of the sample were measured using an energy dispersive detector for quantitative analysis of elemental concentrations. The results showed that intranuclear concentrations of zinc were greater than levels in the cytoplasm. Furthermore, nuclear and cytoplasmic concentrations of zinc in the maturation stage (742 27 and 424 25 ppm, respectively) were significantly higher than the zinc levels observed in the nucleus and cytoplasm of presecretory stage ameloblasts (132 10 and 109 10 ppm, respectively) (p < 0.05). A clear lead signal above the background was not detected in the ameloblasts and lead concentrations could only be reliably measured in the developing enamel. Overall, SRIXE was an effective method of studying the spatial distribution of zinc in the cells of developing teeth and offered a unique combination of sub-micron spatial resolution and parts -per- million detection limits (0.8-1 and 0.6-1 ppm for zinc and lead, respectively). (C) 2007 Elsevier Ltd. All rights reserved.
