碩士 / 國立東華大學 / 海洋生物多樣性及演化研究所 / 98 / Zinc oxide nanoparticles (ZnO NPs) are extensively used in various consumer products such as sunscreens and cosmetics, with high potential of being released into aquatic environments. However, very limited information is available on sublethal effects of ZnO NPs on developing fish. In this study, fertilized zebrafish (Danio rerio) eggs were exposed to various concentrations of ZnO NPs (control, 0.1, 0.5, 1, 5, and 10 mg/L) or zinc ions (Zn2+) (control, 0.08, 0.4, 0.8, 4, and 8 mg/L) until reaching free swimming stage. Hatchability, mortality, and deformities were recorded every 12 hours. Larval swimming behavior was analyzed using a video-based animal movement analysis system. After the behavioral analysis, the larvae were subjected to an apoptosis assay using the acridine orange staining technique. Our results showed that exposure to ZnO NPs or Zn2+ caused hatch delay, but had no significant effect on survival, malformation or apoptosis level. Increased swimming velocity and activity level were observed in the groups exposed to high concentrations of ZnO NPs (5 and 10 mg/L) or Zn2+ (4 and 8 mg/L). To evaluate possible mechanism of observed effects, we also manipulated the antioxidant environment by co-exposure to an antioxidant compound (N-acetylcysteine, NAC) or an antioxidant molecule suppressor (buthionine sulfoximine, BSO) with 5 mg/L ZnO NPs. Co-exposure to NAC did not alter the effects of ZnO NPs on hatchability and swimming behavior. However, co-exposure to BSO caused further hatching delay and decreased maximum velocity of larvae. Our data indicated that toxicity of ZnO NPs cannot be solely explained by dissolved Zn2+, and oxidative stress may be one of the mechanisms of ZnO NPs toxicity.
| Identifer | oai:union.ndltd.org:TW/098NDHU5270014 |
| Date | January 2010 |
| Creators | Chia-Chih Lin, 林嘉智 |
| Contributors | Te-Hao Chen, 陳德豪 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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