| 题名 | 得克隆类阻燃剂在野生青蛙和家禽体内富集及组织间特异性分布的研究 |
| 作者 | 李龙 |
| 学位类别 | 硕士 |
| 答辩日期 | 2013-11 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 李兴红 |
| 关键词 | 得克隆类阻燃剂 生物富集 组织特异性分布 青蛙 家禽 dechlorane plus bioaccumulation tissue-specific distribution frog poultry |
| 其他题名 | Bioaccumulation and tissue-specific enrichment of Dechloranes in wild Frog and Poultry |
| 学位专业 | 环境工程 |
| 中文摘要 | 已有研究初步表明，得克隆类化合物在水生生物体的累积、放大、转化等具有与陆生生物体不同的特征。不过，陆生生物体的较少研究结果，不能为其和水生生物体中得克隆类化合物不同的累积特征提供充分的数据支持，更不能解释导致这些差异性的原因。考虑到生物体生活环境和生活习性对污染物富集水平及累积模式可能产生的重要作用，我们选取电子垃圾拆解区泽蛙和家养鸡鸭为研究对象，探讨了得克隆类阻燃剂在这些生物体中的富集、迁移、转化特征；利用研究结果和文献数据，我们进一步对得克隆类污染物在水生、两栖（泽蛙）和陆生生物体中（鸡鸭）的累积特征进行了探讨。 台州电子垃圾循环周边区域采集的泽蛙肝脏、肌肉、脑和卵组织中都普遍检出了得克隆类阻燃剂。DP、Mirex、Dec 602和anti-Cl11-DP的浓度分别为2.01-291 ng/g lw、0.650-179 ng/g lw、0.26-12.4 ng/g lw和未检出（nd）-8.76 ng/g lw。与肝脏、肌肉相比，泽蛙的脑组织的浓度水平最低，说明血脑屏障效应的阻止了污染物进入泽蛙脑组织，化合物分子量和肝脏/脑组织浓度（L/B）比值的正相关性提示，分子量是控制得克隆类化合物穿透血脑屏障的一个重要因素；蛙卵中得克隆类化合物的检出，标志着DPs在泽蛙种群中母系传递过程的发生；化合物在母体肝脏和卵组织间的分配没有显著差异。泽蛙肝脏组织中的fanti值明显小于肌肉和脑组织，说明肝脏组织选择性富集syn-DP，而脑组织选择性富集anti-DP。fCl11-DP值（anti-Cl11-DP/anti-DP）在泽蛙肝脏和肌肉组织中没有差别（p = 0.08），说明泽蛙体内的脱氯产物主要来源于外部环境的贡献。 得克隆类化合物在家养鸡/鸭各组织中（血液、肝脏、肌肉、脂肪、脑和卵组织）也频繁检出，DP、Dec 602、syn-Cl11-DP和anti-Cl11-DP浓度分别为0.498-1222 ng/g lw、nd-5.49 ng/g lw、nd-13.0 ng/g lw和nd-28 ng/g lw。DPs类化合物检出浓度与各组织脂肪含量正相关，说明其在家禽组织间的分配主要是由各组织脂肪含量决定；与肝脏、肌肉相比，鸡/鸭的脑组织中也检测出相对更低的污染物浓度水平，提示血脑屏障产生了阻碍DP类污染物进入及鸡/鸭脑部器官的保护性作用；DP类化合物在卵组织中的检出，说明其在鸡/鸭中可通过母体进行代际传递，且传递效率与肝脏化合物浓度存在明显的相关性（p<0.05）。DP异构体特征（fanti值）分析发现，鸡/鸭卵组织发生了对syn-DP的选择性富集，而脑组织中发生了对anti-DP的选择性透过。fCl11-DP值（ΣCl11-DP/ΣDP）在鸡/鸭肝脏和肌肉组织中并没有差别, 说明鸡/鸭体内得克隆脱单氯产物主要来源于环境的累积。 通过以上的研究，我们总结了得克隆类化合物在水生生物体（基于文献数据）、家禽和泽蛙中的选择性富集、代际传递、脱氯代谢的部分异同。首先，三类生物体血脑屏障对DPs具有较为明显的阻碍作用；血脑屏障对得克隆两种异构体具有不同的穿透效应，脑组织易于表现出对anti-DP的优先富集；其次，DPs可通过母体进行代际传递，母系传递效率具有物种差异性，母系传递过程易于发生对syn-DP的选择性累积；第三，三类生物体肝脏对得克隆的脱单氯代谢能力不突出，生物体体内的脱单氯产物主要来源于外部环境的累积。 虽然目前的研究已经发现了得克隆类阻燃剂在水生、陆生和两栖动物组织中富集和分布存在一定的规律，但对于它在生物体内的迁移转化机制，比如，脑组织和卵组织分别表现出对anti-DP和syn-DP的优先富集机制，还不是特别清楚。进一步的研究亟需开展来阐明DP在生物体内的富集、代谢、转运机制。同时对得克隆类阻燃剂及其脱氯产物的毒性评价也亟待开展。 |
| 英文摘要 | Previous researches have preliminarily revealed certain different characteristics on bioaccumulation, biomagnification and transformation of dechloranes (DPs, including dechlorane plus and its analogs) between aquatic and terrestrial biota. However, conclusions could be not drawn due to the limited researches on DP from the terrestrial biota. Considered the possibly important role of the habitation and living habits of biota, we investigated the DPs levels and tissue distribution in wild frog (Rana limnocharis), and domestic poultry (Gallus domesticus and Anas platyrhynchos domesticus), and further explored the diversity of bioaccumulation and transformation among aquatic (based on literature), terrestrial and amphibious biota. Four compounds, including DP, Mirex, Dec 602 and anti-Cl11-DP, were frequently detected in liver, muscle, brain and egg tissues of frogs, which were collected from the e-waste recyclying area. Their concentrations varied from 2.01-291 ng/g lw, 0.650-179 ng/g lw, 0.26-12.4 ng/g lw and not detected (nd) -8.76 ng/g lw, respectively. Compared with the liver and muscle tissues, the lowest levels of DPs were observed in the brain tissues, indicating the blood-brain barrier worked efficiently to suppress these compounds entering brain tissues in this species. Furthermore, the significant association between molecular mass and L/B ratios revealed that the molecular weight likely had an important effect when DPs crossed the blood-brain barrier. The distribution of DPs between maternal liver and egg tissues was similar, and the detection of DPs in eggs indicated the occurrence of maternal transfer in frogs. fanti values [anti-DP/(anti-DP+syn-DP)] in the liver tissues, were predominantly lower than those in the muscle and brain tissues. The results indicated the preferential enrichment of syn-DP in the liver tissues, while the preferential enrichment of anti-DP in the brain tissues. No difference was found for fCl11-DP (anti-Cl11-DP/anti-DP) value between the liver and muscle tissues, suggesting the anti-Cl11-DP in frog was mainly accumulated from the exterior environment. Four compounds, including DP, Dec 602, syn-Cl11-DP and anti-Cl11-DP, were frequently detected in various tissues of the poultry, which were collected from the e-waste recyclying area. The concentrations of four compounds ranged from 0.498-1222 ng/g lw, nd-5.49 ng/g lw, nd-13.0 ng/g lw and nd-28 ng/g lw, respectively. The concentrations of DPs (wet weight, ww) were significantly related to tissue lipid content (p<0.05), indicating that the lipid content of various tissue predominantly impacted the distribution of DPs in poultry. The relatively lower levels of DPs in the brain tissue with comparsion to liver and muscle tissues, suggested the important protective role of the brain-blood barrier from DPs in poultry. DPs were also frequently detected in poutry eggs, and the maternal transfer efficiency (liver/egg ratio) seemed to be dose-dependent on the liver concentrations. It was worth noting that the selective accumulation of syn-DP was observed in the egg tissues, while the selective enrichment of anti-DP was found in the brain tissues. There were no significantly different for fCl11-DP（ΣCl11-DP/ΣDP）between the liver and muscle tissues, indicating that the anti-Cl11-DP in tissues mainly originated from the exterior environment. In all, the diversities of DPs characteristics, including tissue-specific enrichment, maternal transfer and mono-dechlorinated metabolic capacities among aquatic, terrestrial and amphibious biota, were summarized below. Firstly, the blood-brain barrier can work efficiently to suppress DPs entering the brain tissue with the preferential enrichment of anti-DP in all the biota mentioned above. Secondly, DPs could be transferred through the maternal body, and syn-DP had a prior maternal transfer. However, the maternal transfer efficiency of DPs was species-specific. Thirdly, the monodechlorinated analogs of DP in biota were mainly from the exterior environment, likely ascribed to the low biometabolic capacity of liver to DPs. Our studies, combined with the previous published literature, have revealed the diversities of the tissue distribution, maternal transfer and mono-dechlorinated metabolic capacities on DPs in biota. For example, selective enrichment anti-DP occurred in the brain tissue, while syn-DP in egg. Further studies should be required to clarify the cause resulting in the diversities. DP toxicity data was scarce, and the health effects of DP on biota have not been confirmed. Researches on toxic effects are also needed to evaluate the exposure risk of biota to DPs. |
| 公开日期 | 2015-07-07 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/15616]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 李龙. 得克隆类阻燃剂在野生青蛙和家禽体内富集及组织间特异性分布的研究[D]. 北京. 中国科学院研究生院. 2013. |
| 个性服务 |
| 查看访问统计 |
| 相关权益政策 |
| 暂无数据 |
| 收藏/分享 |
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。
修改评论