摘要全氟化合物(perfluorinatedcompounds,PFCs)指的是烷基化合物碳原子上连接的氢原子全部被氟原子取代的化合物,是一类具有重要应用价值的含氟有机化合物,但同时是一种具有持久性、化学稳定性和生物蓄积性的新型有机污染物,且因其广泛存在于全球范围内,故对全球生物的安全构成威胁,已成为严重的全球性问题。本文挑选其中三种化合物:全氟辛酸、全氟十二酸和全氟十四酸,探讨其对鲫鱼淋巴细胞产生的凋亡效应并进行比较,同时表明三种化合物对鲫鱼的免疫毒性以及致毒机理。我们选用的是鲫鱼的头肾,将鲫鱼解剖取出肾脏后提取淋巴细胞,将其暴露在1μg/L、10μg/L、100μg/L、1000μg/L和10000μg/L的PFOA、十二酸及十四酸中12小时,通过测定淋巴细胞的凋亡率、活性氧簇(ROS)、丙二醛(MDA)以及还原型谷胱甘肽(GSH)含量来确定其致毒机理。实验结果显示,低剂量的三种全氟化合物暴露就会引起ROS水平和MDA含量明显的升高与GSH含量明显的下降,说明鲫鱼细胞内发生了氧化应激反应和脂质过氧化反应。随着PFOA、十二酸及十四酸暴露浓度的上升,ROS含量和MDA水平都随之上升,GSH含量也随之下降,呈现明显的剂量效应。从实验数据来看,相同浓度的三种全氟化合物所导致的细胞凋亡率相似,十二酸略高但不明显;但是通过对比研究四个指标可以看出,暴露在同一浓度不同种类的全氟化合物中的淋巴细胞内发生反应的剧烈程度不同,这也就间接说明了三种全氟化合物虽然毒性相似但是其致毒机理可能稍有不同。综上所述:PFOA、十二酸和十四酸均能诱导鲫鱼淋巴细胞发生氧化应激反应,产生脂质过氧化,最后导致细胞凋亡,从而使鲫鱼的免疫系统受到了损害。61299
Abstract Perfluorinated compound, which refer to all hydrogen atoms attached to carbon atoms of alkyl compounds substituted by fluorine atom, is a kind of fluorinated organic compounds with important application value. However, it is also a new type of organic pollutant with persistence, chemical stability and biological accumulation. On account of its widespread in the global scope, it poses a threat to the safety of global biological, and has become a serious global problem. In this paper, we selected three kinds of compounds, perfluorooctanoic acid (PFOA), perfluorinated dodecanoic acid and perfluorinated myristic acid, to study and compare the toxic effects of them to Carassius auratus lymphocytes expoundthe immune toxicity.We extracted lymphocytes from the kidney of crucian carp after dissection. The exposure concentrations of PFOA, PFDoA and PFTeDA are 1μg/L, 10μg/L, 100μg/L, 1000μg/L and 10000μg/L, respectively, and the exposure time is 12h. The apoptosis percentages of lymphocytes, reactive oxygen species (ROS), malondialdehyde (MDA) and reduced glutathione (GSH) were determined to demonstrate the mechanism of toxicity. Experimental results showed that low dose exposure of three perfluorinated compounds can significantly increase ROS levels and MDA contents, significantly decrease GSH contents, which indicates that oxidative stress and lipid peroxidation happened in fish lymphocytes. With the increase of exposure concentrations of PFOA, PFDoA and PFTeDA, both ROS and MDA levels increased, but GSH contents decreased. Under the same exposure concentrations, all the three perfluorinated compounds can induce apoptosis of lymphocytes of crucian carp. Compared to four detected indicators, the apoptosis status in lymphocytes exposed to the same concentration of perfluorinated compounds is significantly different. All these results showed that PFOA, PFDoA and PFTeDA can induce oxidative stress, produce lipid peroxidation in carp lymphocytes, and finally lead to apoptosis of cells, so that the immune system of crucian carp was damaged.
毕业论文关键词:全氟辛酸; 全氟十二酸; 全氟十四酸; 鲫鱼淋巴细胞