The Study of UVB Induced Oxidative Stress in Earthworms
| Autor: | Po-Chen Chen, 陳泊辰 |
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| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 UVB is harmful to most organisms in the earth. Some animals evolutionally use pigment, mucus or antioxidant to reduce the damage caused by UVB radiation. Earthworms live underground and they have known to be quite sensitive to UVB, but different species of earthworms have different tolerance to UVB. The goal of this study was to find out the possible mechanisms that provide different tolerance for different species of earthworms to avoid UVB damage. Pontoscolex corethrurus can resist high dose of UVB but its mucus has no UVB absorbing function. So the antioxidant in earthworm might be the reasonable mechinisms. The concentration of hydrogen peroxide in P. corethrurus was significantly increased after UVB treatment in 30 minutes, and it decreased back to control in 60 minutes. The activities of catalase and superoxide dismutase (SOD) also had a significant increase in 30 minutes after UVB exposure. When the catalase activity was inhibited by catalase inhibitor, the moratlity of the UVB-treated P. corethrurus was increased. The other kind of earthworm (Eisenia andrei) had a high mortality after UVB irradiation, and the concentration of hydrogen peroxide had significant increase in 30 minutes and had a trend of increasing in 60 minutes. But the activities of antioxidative enzymes didn’t have significant change in an hour after UVB exposure. On the other hand, when the UVB-treated E. andrei incubated with antioxidants, such as curcumin and EUK-134, the additional antioxidants could reduce the mortality caused by UVB. So those results suggested that the quick response of antioxidative enzymatics system in P. corethrurus could handle the oxidative stress caused by UVB in a short time, and quickly remove the oxidative stress in the tissue. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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