铜在日本青鳉体内的累积特征及其对肝脏组织结构的影响

为了解水体铜(Cu(Ⅱ))在日本青鳉(Oryzias latipes)脑、鳃、肝脏、性腺和肌肉组织中的累积特征,以及Cu(Ⅱ)对肝脏组织结构的影响,本文采用生态学单因子梯度实验,进行20 d的日本青鳉毒性暴露试验。结果显示,日本青鳉各个组织对Cu(Ⅱ)的累积量随着浓度的升高而增多,但不同组织对Cu(Ⅱ)的累积量有较大的差异,铜累积量由大到小依次为:肝脏脑鳃性腺肌肉。铜暴露后的日本青鳉肝细胞出现肿大、大小不一、排列混乱,静脉扩张淤血,部分肝细胞固缩和坏疽等现象。肝脏是日本青鳉蓄积铜的主要器官之一,实验发现高浓度的Cu(Ⅱ)对肝脏组织结构造成了明显的损伤,进而严重影响日本青鳉的存活率。

Accumulation Characteristic of Cu(II) in Oryzias latipes and Its Effect on Liver Histology Structure

In the present study, we investigate the accumulation characteristic of Cu(II) in various tissues of Oryzias latipes, as well as to explore the effects of Cu(II) on liver. Oryzias latipes were exposed to Cu(II) solutions for 20 days using singe gradient factor experiments. We found that the accumulation of Cu(II) in vivo enhances significantly in a concentration dependent manner with the increase of Cu(II) concentration. In addition, the accumulations of Cu(II) varied sharply in different tissues, and the accumulations presented an order as following: liver > brain > gill > gonad > muscle. Light microscopic observation showed that the histology structure of liver changed greatly after Cu(II) exposure, such as the enlargement, chaotical arrangement and size variation of the hepatocytes, and the congestion of the central vein with blood cells and focal necrosis of hepatytes. The liver was one of the main tissues of accumulation of Cu(II). In this study, we found exposure to high concentrations of Cu(II) could bring severe damage to the liver tissue structure, which maybe ultimately affect the survival and growth of Oryzias latipes.