目的研究锌离子在APP/PS1转基因小鼠嗅球内的定位,为锌离子参与阿尔茨海默病发病的相关性研究提供重要的形态学依据。方法应用浸入式金属自显影技术(AMG)检测锌离子在野生型小鼠和APP/PS1转基因小鼠嗅球内的分布。结果在野生型小鼠和APP/PS1转基因小鼠嗅球内,AMG反应产物呈棕黑色,嗅球的5层结构清晰可见,其中颗粒层锌离子含量最高。在APP/PS1转基因小鼠嗅球内,还可见锌离子聚集在老年斑内,AMG阳性的老年斑主要分布于含锌量较高的颗粒层,其它各层仅见散在分布。野生型小鼠嗅球内未见AMG阳性的老年斑。结论APP/PS1转基因小鼠嗅球的老年斑内含有大量的锌离子,提示锌离子在嗅球Aβ老年斑的形成过程中发挥重要作用,参与AD的发病和进展。
Objective To investigate the localization of free zinc ions in the olfactory bulb of APP/PS1 transgenic mouse brain and to provide a morphological evidence for zinc involving in the pathological process of Alzheimer's disease. Method Immersion autometallography was used to detect the distribution of free zinc ions in the wild-type and APP/PSI transgenic mouse olfactory bulb. Results In the olfactory bulb of wild-type and APP/PS1 transgenic mice , dark brown AMG products were found in all five layers and predominately in the granule cell layer. In the olfactory bulb of APP/PSI transgenic mouse, zinc ions were accumulated in the senile plaques which were mainly distributed in the granule cell layer with few plaques in other layers and no AMG-positive plaques in the wild-type mouse olfactory bulb. Conclusion The accumulation of zinc ions in the senile plaques of the APP/PS1 transgenic mouse suggests that zinc ions might play a role in the formation of senile plaques in Alzheimer disease.