Neurochemical changes in welders revealed by proton magnetic resonance spectroscopy
Neurochemical changes in welders revealed by proton magnetic resonance spectroscopy
复制标题
DOI：
10.1016/j.neuro.2009.07.008
复制
发表时间：
2009-11-01
期刊：
影响因子：
3.4
通讯作者：
Kim, Yangho
中科院分区：
文献类型：
--
作者：
Chang, Yongmin;Woo, Seung-Tae;Kim, Yangho
背景：职业和环境锰暴露与多种神经行为和运动功能障碍有关。然而，很少有研究系统地研究了锰暴露的神经化学效应。目的：我们研究了与对照个体相比，长期暴露于锰的焊工脑代谢物比率的典型变化，使用质子磁共振波谱（MRS），研究了脑代谢异常是否与神经行为变化相关，并评估了慢性锰暴露的可能影响。方法：35名长期暴露于锰的焊工和20名年龄匹配的健康受试者在短回波时间内进行单体素MRS，以评估N-乙酰天冬氨酸（NAA）、肌醇（mI）、总胆碱（tCho）和谷氨酰胺加谷氨酸（Glx）水平，每种水平均表示为与总肌酸（tCr）的比值。神经行为测试也进行了定义cognitive status.Results：NAA/tCr，Glx/tCr，和tCho/tCr比值在额叶灰质（前扣带皮层; ACC）和顶叶白色物质之间没有显着差异焊工和对照组。这些代谢物的比例与血锰浓度或神经行为参数没有显着相关性。然而，与对照组相比，焊工ACC中的mI水平显著降低，而顶叶白色物质中的mI水平则无显著性差异（P < 0.01）。此外，在大脑额叶，mI/tCr比值与文字记忆分数以及血锰浓度显著相关（P < 0.05）。结论：在接触锰的焊工中观察到的认知能力下降与ACC中mI/tCr比值的降低有关。焊工中mI的耗竭可能反映了与长时间的脑缺血相关的可能的神经胶质细胞肿胀和/或解毒过程。长期暴露于Mn。(C)2009 Elsevier Inc. All rights reserved.
Background: Occupational and environmental exposure to manganese (Mn) is associated with various neurobehavioral and movement dysfunctions. However, few studies have systemically examined the neurochemical effects of Mn exposure.Objectives: We examined typical changes in cerebral metabolite ratios in welders chronically exposed to Mn, compared with control individuals, using proton magnetic resonance spectroscopy (MRS), investigated whether an abnormality in brain metabolism is associated with neurobehavioral changes, and assessed possible implications of chronic Mn exposure.Methods: Thirty-five welders chronically exposed to Mn and 20 age-matched healthy subjects underwent single-voxel MRS at short echo time to assess the N-acetylaspartate (NAA), myoinositol (mI), total choline (tCho), and glutamine plus glutamate (Glx) levels, each of which was expressed as a ratio to total creatine (tCr). Neurobehavioral tests were also performed to define cognitive status.Results: NAA/tCr, Glx/tCr, and tCho/tCr ratios in the frontal gray matter (anterior cingulate cortex; ACC) and parietal white matter did not differ significantly between welders and control subjects. These metabolite ratios did not correlate significantly with blood Mn concentration or neurobehavioral parameters. However, mI levels in the ACC, but not in the parietal white matter, were significantly reduced in welders compared with control individuals (P < 0.01). Furthermore, in the frontal lobe of the brain, the mI/tCr ratio was significantly correlated with verbal memory scores as well as blood Mn concentration (P < 0.05).Conclusions: The cognitive decline observed in welders exposed to Mn was associated with a decreased mI/tCr ratio in the ACC. The depletion of mI in welders may reflect possible glial cell swelling and/or detoxification processes associated with long-term exposure to Mn. (C) 2009 Elsevier Inc. All rights reserved.