Division of Vascular Surgery, Department of Surgery, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA.
Metallomics. 2011 Aug;3(8):823-8. doi: 10.1039/c1mt00033k. Epub 2011 May 18.
Copper, an essential trace metal in humans, plays an important role in elastic formation. However, little is known about the spatial association between copper, elastin, and elastin producing cells. The aorta is the largest artery; the aortic media is primarily composed of the elastic lamellae and vascular smooth muscle cells, which makes it a good model to address this issue. Synchrotron radiation X-ray fluorescence microscopy (SRXRF) is a new generation technique to investigate the spatial topography of trace metals in biological samples. Recently, we utilized this technique to determine the topography of copper as well as other trace elements in aortic media of Sprague Dawley rats. A standard rat diet was used to feed Sprague Dawley rats, which contains the normal dietary requirements of copper and zinc. Paraffin embedded segments (4 μm of thickness) of thoracic aorta were analyzed using a 10 keV incident monochromatic X-ray beam focusing on a spot size of 0.3 μm × 0.2 μm (horizontal × vertical). The X-ray spectrum was measured using an energy-dispersive silicon drift detector for elemental topography. Our results showed that phosphorus, sulfur, and zinc are predominately distributed in the vascular smooth muscle cells, whereas copper is dramatically accumulated in elastic laminae, indicating a preferential spatial association of copper on elastic laminae in aortic media. This finding sheds new light on the role of copper in elastic formation. Our studies also demonstrate that SRXRF allows for the visualization of trace elements in tissues and cells of rodent aorta with high spatial resolution and provides an opportunity to study the role of trace elements in vasculature.
铜是人体必需的微量元素，在弹性形成中发挥着重要作用。然而，人们对铜、弹性蛋白和产生弹性蛋白的细胞之间的空间关联知之甚少。主动脉是人体最大的动脉；主动脉中层主要由弹性板层和血管平滑肌细胞组成，这使其成为解决这个问题的良好模型。同步辐射 X 射线荧光显微镜（SRXRF）是一种新一代技术，可用于研究生物样本中痕量金属的空间拓扑结构。最近，我们利用这项技术来确定铜以及其他微量元素在 Sprague Dawley 大鼠主动脉中层中的空间分布。使用标准的大鼠饮食来喂养 Sprague Dawley 大鼠，其中包含铜和锌的正常饮食需求。使用 10 keV 入射单色 X 射线束聚焦在 0.3 μm×0.2 μm（水平×垂直）的光斑尺寸上，对胸主动脉的石蜡包埋段（4 μm 厚）进行分析。使用能量色散硅漂移探测器测量 X 射线光谱以进行元素拓扑分析。我们的结果表明，磷、硫和锌主要分布在血管平滑肌细胞中，而铜则大量积聚在弹性板层中，这表明铜在主动脉中层的弹性板层中存在优先的空间关联。这一发现为铜在弹性形成中的作用提供了新的视角。我们的研究还表明，SRXRF 允许以高空间分辨率可视化啮齿动物主动脉组织和细胞中的痕量元素，并为研究微量元素在血管中的作用提供了机会。
