Wills N K, Kalariya N, Sadagopa Ramanujam V M, Lewis J R, Haji Abdollahi S, Husain A, van Kuijk F J G M
Department of Neuroscience & Cell Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.
Exp Eye Res. 2009 Jun 15;89(1):79-87. doi: 10.1016/j.exer.2009.02.014. Epub 2009 Feb 28.
Cadmium is a naturally occurring, highly toxic, metallic element. It pollutes the environment as a result of industrial activity and accumulates in human tissues with a long biological half-life. Cadmium content has been demonstrated to increase in human retinal tissues as a function of age and tobacco smokers have approximately twice as much cadmium in retinal tissues than non-smokers. Smoking is also a key environmental risk factor for the retinal disease age-related macular degeneration (AMD). Recent studies have shown that urinary cadmium levels (a measure of Cd body burden) are higher in smokers who have AMD. We now report the Cd measurements in human retinal tissues from eyes afflicted with AMD compared to non-diseased eyes (controls) from age-matched donors. Human donor eyes frozen under argon gas were assessed for AMD severity using color stereoscopic fundus photographs and the Minnesota Grading System. Cadmium, zinc and, copper levels were measured in retinal tissues (neural retina, retinal pigment epithelium and choroid) using inductively coupled plasma mass spectrometry and graphite furnace spectrophotometry and values were normalized to tissue protein levels. Higher Cd levels were found in the neural retina and RPE for eyes afflicted with AMD compared to controls in males, differences were not statistically significant in females. The results indicate that higher retinal cadmium burdens are associated with the presence of AMD at least in males and suggest possible gender differences in the metabolism of metals in the human retina.
镉是一种天然存在的、剧毒的金属元素。它因工业活动而污染环境，并以较长的生物半衰期在人体组织中蓄积。研究表明，人体视网膜组织中的镉含量会随着年龄的增长而增加，吸烟者视网膜组织中的镉含量约是非吸烟者的两倍。吸烟也是视网膜疾病年龄相关性黄斑变性（AMD）的一个关键环境风险因素。最近的研究表明，患有AMD的吸烟者尿镉水平（衡量镉身体负担的指标）更高。我们现在报告与年龄匹配的供体的非病变眼睛（对照）相比，患有AMD的眼睛的人体视网膜组织中的镉测量结果。使用彩色立体眼底照片和明尼苏达分级系统对在氩气下冷冻的人类供体眼睛进行AMD严重程度评估。使用电感耦合等离子体质谱法和石墨炉分光光度法测量视网膜组织（神经视网膜、视网膜色素上皮和脉络膜）中的镉、锌和铜水平，并将数值标准化为组织蛋白水平。与对照组相比，患有AMD的男性眼睛的神经视网膜和视网膜色素上皮中的镉水平更高，女性差异无统计学意义。结果表明，至少在男性中，较高的视网膜镉负荷与AMD的存在有关，并提示人类视网膜中金属代谢可能存在性别差异。
