Behavioral, morphological, and biochemical changes after in ovo exposure to methylmercury in chicks
Behavioral, morphological, and biochemical changes after in ovo exposure to methylmercury in chicks
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DOI：
10.1093/toxsci/kfn158
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发表时间：
2008-11-01
影响因子：
3.8
通讯作者：
Muller, Yara M. R.
中科院分区：
文献类型：
--
作者：
Carvalho, Marcia C.;Nazari, Evelise M.;Muller, Yara M. R.
甲基汞（MeHg）是一种环境污染物，已知会引起包括人类在内的多种动物的神经毒性。然而，侧重于甲基汞中毒对雏鸡影响的研究是基于现象学方法，没有深入研究分子机制。本研究的目的是评估出生后的后果卵内接触甲基汞的行为，形态和生化参数的鸡。在胚胎第5天（E5），将鸡卵单次注射0.1 μ g MeHg/0.05 ml盐水。处理后，将卵放回孵育器中直至孵化（E21）。从出生后第一天到第五天（PN 1-PN 5），甲基汞处理的小鸡表现出较低的频率探索运动和显着较高的频率的翅膀和异常运动。小脑谷胱甘肽（GSH）水平和GSH相关酶GSH还原酶和GSH过氧化物酶的活性显着较高（70，72，和80%，分别）在甲基汞暴露小鸡相比，控制。汞浸渍dennalized在颗粒层，其次是浦肯野和分子层的处理小鸡。甲基汞组的浦肯野细胞数量明显减少，细胞间距增大。我们的研究结果表明，在孵化前暴露于甲基汞引起的运动障碍，这是相关的组织学损害和改变小脑GSH系统的发展，从PN 1到PN 5。
Methylmercury (MeHg) is an environmental pollutant known to induce neurotoxicity in several animal species, including humans. However, studies focusing the effects of MeHg poisoning in chicks were based on phenomenological approaches and did not delve into the molecular mechanisms. The purpose of this study was to evaluate the postnatal consequences of the in ovo exposure to MeHg on behavioral, morphological and biochemical parameters in chicks. At the fifth embryonic day (E5), Gallus domesticus eggs were submitted to a single injection of 0.1 mu g MeHg/0.05 ml saline. After treatment, the eggs returned to the incubator until hatching (E21). From first to fifth postnatal days (PN 1-PN 5), the MeHg-treated chicks showed lower frequency of exploratory movements and a significantly higher frequency of wing and anomalous movements. Cerebellar glutathione (GSH) levels and the activities of the GSH-related enzymes GSH reductase and GSH peroxidase were significantly higher (70, 72, and 80%, respectively) in MeHg exposed chicks in comparison to controls. Mercury impregnation was densest in the granular layer, followed by the Purkinje and molecular layers of treated chicks. A significant reduction of the number of Purkinje cells, as well as a greater distance between these cells were observed in chicks of MeHg group. Our results disclose that the prehatching exposure to MeHg induced motor impairments, which were correlated to histological damage and alterations on the cerebellar GSH system's development from PN 1 to PN 5.