Dietary selenium protects against selected signs of aging and methylmercury exposure.
Dietary selenium protects against selected signs of aging and methylmercury exposure.
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DOI：
10.1016/j.neuro.2010.01.003
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发表时间：
2010-03
期刊：
影响因子：
3.4
通讯作者：
Newland MC
中科院分区：
文献类型：
--
作者：
Heath JC;Banna KM;Reed MN;Pesek EF;Cole N;Li J;Newland MC
急性或短期暴露于高剂量的甲基汞（MeHg）会引起一种特征明确的综合征，包括感觉和运动缺陷。然而，甲基汞对环境的威胁来自长期、低水平的接触，其后果尚不清楚。硒（Se）是一种必需的营养素，既能增加汞（Hg）在神经元中的沉积，又能在短期内减轻甲基汞的神经毒性，但目前还不清楚这种沉积是否会产生长期的不良后果。为了研究这些问题，成年Long Evans大鼠被喂食含有0.06或0.6 ppm硒的亚硒酸钠饮食。在这些饮食100天后，受试者开始在16个月的饮用水中摄入0.0、0.5、5.0或15 ppm的氯化甲基汞。躯体感觉灵敏度、握力、后肢交叉（抱握反射）、屈曲和夜间自愿轮跑是检查的指标。甲基汞在所有测量中引起剂量和时间依赖性损害，在摄入0或0.5 ppm汞的大鼠中没有出现任何影响。躯体感觉功能、握力和屈曲是暴露的最早迹象。硒显着延迟或钝化甲基汞的影响。硒还增加了未暴露的动物随着年龄的增长而奔跑，这是一项可能具有重要临床意义的新发现。神经病理学研究表明，轴突萎缩或轻度变性的周围神经纤维，这是符合异常的感觉运动功能在慢性甲基汞神经毒性。利多卡因刺激再现了躯体感觉障碍，但不再现后肢交叉或屈曲。总之，这些结果量化了长期接触甲基汞的神经毒性，支持硒在改善甲基汞神经毒性方面的安全性和有效性，并证明了硒在衰老过程中的潜在益处。
Acute or short-term exposure to high doses of methylmercury (MeHg) causes a well-characterized syndrome that includes sensory and motor deficits. The environmental threat from MeHg, however, comes from chronic, low-level exposure, the consequences of which are poorly understood. Selenium (Se), an essential nutrient, both increases deposition of mercury (Hg) in neurons and mitigates some of MeHg's neurotoxicity in the short term, but it is unclear whether this deposition produces long-term adverse consequences. To investigate these issues, adult Long Evans rats were fed a diet containing 0.06 or 0.6 ppm of Se as sodium selenite. After 100 days on these diets, the subjects began consuming 0.0, 0.5, 5.0, or 15 ppm of Hg as methylmercuric chloride in their drinking water for 16 months. Somatosensory sensitivity, grip strength, hind-limb cross (clasping reflex), flexion, and voluntary wheel-running in overnight sessions were among the measures examined. MeHg caused a dose- and time-dependent impairment in all measures, No effects appeared in rats consuming 0 or 0.5 ppm of Hg. Somatosensory function, grip strength, and flexion were among the earliest signs of exposure. Selenium significantly delayed or blunted MeHgs effects. Selenium also increased running in unexposed animals as they aged, a novel finding that may have important clinical implications. Nerve pathology studies revealed axonal atrophy or mild degeneration in peripheral nerve fibers, which is consistent with abnormal sensorimotor function in chronic MeHg neurotoxicity. Lidocaine challenge reproduced the somatosensory deficits but not hind-limb cross or flexion. Together, these results quantify the neurotoxicity of long-term MeHg exposure, support the safety and efficacy of Se in ameliorating MeHg's neurotoxicity, and demonstrate the potential benefits of Se during aging.
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影响因子：
5.3
作者：
Lin, YW;Tseng, TJ;Hsieh, ST
通讯作者：
Hsieh, ST
影响因子：
8.8
作者：
Nakamura, T;Popitz-Bergez, F;Strichartz, GR
通讯作者：
Strichartz, GR
影响因子：
5.1
作者：
BAKIR, F;TIKRITI, S;SHIHRISTANI, H
通讯作者：
SHIHRISTANI, H
影响因子：
3.4
作者：
Newland, M. Christopher;Paletz, Elliott M.;Reed, Miranda N.
通讯作者：
Reed, Miranda N.
DOI：
10.1152/ajpregu.00396.2005
发表时间：
2005-12-01
影响因子：
2.8
作者：
Judge, S;Jang, YM;Leeuwenburgh, C
通讯作者：
Leeuwenburgh, C