碩士 / 國立嘉義大學 / 水生生物科學系研究所 / 101 / Metallothionein (MT) has been shown on the heavy metal detoxification. In addition, it will be induced by variety of chemical substances in organisms. In the past studies, it well knows that the physiological roles of MT-2 of zebrafish exposed to cadmium environment, and it may be associated with the cadmium-detoxification, but the physiological roles of similar to metallothionein B (sMT-B) was still unclear. Therefore, the present study will explore the physiological role of MT-2 and sMT-B of zebrafish upon cadmium exposure, and it induced oxidative stresses. Zebrafish exposed to 0.44 μM, 0.89 μM and 1.78 μM Cd for 0-6 h. The reactive oxygen species (ROS) in the brain tissue was increased, while liver and gill tissue increased upon 0.89 μM and 1.78 μM exposure. The phenomenon also appears in the reaction of lipid peroxidation (LPO). Therefore, the mRNA expression of three antioxidant enzymes (SOD, CAT, GPx) were up-regulated, 1 h later, the highest dose of Cd exposure in the gill tissue was significantly increased and return to control after 6 hs; liver and brain tissue appears the up-regulation mostly exposed to 1.09 μM after 3 hs. MT-2 and sMT-B gene expression are increased significantly with a dose-response in different concentrations of Cd exposure, especially showed the highest expression after 3 hs of Cd exposure. However, MT-2 transcripts expression decreased and sMT-B transcripts were not significantly difference as compare to the control group after 6 hs of Cd-exposure. Finally, the transcripts levels of both genes were decreased upon treatment with RU486, but the sMT-B mRNA was less affected by RU486. Depend on the results that we suggested that the MT-2 and sMT-B play some physiological functions upon cadmium exposure, but the inducion pathway seems to be different. In addition, MT-2 also showed a function on the anti-oxidation and cadmium detoxification but sMT-B seems to play one role on the anti-oxidateive reaction.
| Identifer | oai:union.ndltd.org:TW/101NCYU5061004 |
| Creators | Li-Hsin Shu, 舒立欣 |
| Contributors | Su-Mei Wu, 吳淑美 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 99 |
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