- 學位論文
台灣擱淺鯨豚組織銀濃度與奈米銀對鯨豚免疫細胞影響的活體外研究
Silver Tissue Contamination in Taiwanese Stranded Cetaceans and Effects of Silver Nanoparticles on Cetacean Immune Cells in Vitro
摘要
奈米銀因其光學性質，電子性質，良好的抗微生物活性，催化活性和磁性活性而被廣泛應用於各類商品，也成為環境銀汙染的重要來源。在齧齒類及魚類等實驗動物的研究顯示，奈米銀可由呼吸道及消化道進入血液循環並沉積在各臟器中 (特別是腦組織和睪丸)。奈米銀已經被證實可以在上述這些動物模式引起細胞氧化壓力上升、去氧核苷核酸的損傷和細胞凋亡，並對藻類、海洋無脊椎動物和魚類具有毒性。鯨豚是海洋高階掠食者，也是最可能因奈米銀汙染而受到影響的動物之一。但目前卻沒有任何鯨豚相關的奈米銀毒性研究被發表，因此，評估奈米銀對鯨豚的健康影響是亟需進行。本研究開發輔助方法以定位銀在次器官 (suborgan) 層級的位置 (第二章)，藉由鯨豚組織學銀濃度分析技術 (cetacean histological Ag assay; CHAA)，估算鯨豚組織的銀濃度 (第二章和第三章)，並藉上述方法進行研究，建立鯨豚可能的銀代謝途徑之假說，並證明銀可能對鯨豚健康引起系統性而非器官特定性的負面影響 (第三章)。此外，本研究也揭示奈米銀對鯨豚白血球的細胞毒性和免疫毒性（第四章和第五章）。以上結果皆證實銀/銀化合物和奈米銀對鯨豚健康的負面影響，也顯示其在海洋環境中的潛在生態毒性。
並列摘要
Silver nanoparticles (AgNPs), an important source of silver contamination, have been widely used in many commercial products due to their optical properties, electronic properties, antimicrobial activity, catalytic activity, and magnetic activity. The AgNPs are released into the environment, gradually accumulate in the ocean, and may affect the animals of high trophic level via food-web chain, such as cetaceans and humans. Several rodent and fish studies have demonstrated AgNPs can enter the blood circulation via alimentary/respiratory tracts and deposit in multiple organs especially brain and testis. AgNPs have been reported to induce cellular oxidative stress, DNA damage and apoptosis in these animal models, and cause toxic effects on algae, marine invertebrates, and fishes. Cetaceans, as the top predators of ocean, may have been negatively affected by AgNPs, but no toxicity study of AgNPs in cetaceans has been reported. Therefore, it is urgent to investigate the possible negative effects of AgNPs on the health of cetacean. The current study presented an adjuvant method to localize the Ag distribution at suborgan levels (Chapter II), estimated the Ag concentrations of various tissues by cetacean histological Ag assay (CHAA) (Chapters II and III), provided a presumptive metabolic pathway of Ag in cetaceans, demonstrated the possible systemic rather than organ-targeting negative health effects caused by Ag in cetaceans (Chapter III), and revealed the cytotoxicity and immunotoxicity caused by AgNPs on the leukocytes of cetaceans (Chapters IV and V). All the data have demonstrated the negative effects of Ag/Ag compounds and AgNPs on the health of cetaceans and their potential ecotoxicity in marine environment.