Modulation of antioxidant defences in digestive gland of Perna viridis (L.), on mercury exposures
DRS at CSIR-National Institute of Oceanography
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Title |
Modulation of antioxidant defences in digestive gland of Perna viridis (L.), on mercury exposures
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Creator |
Verlecar, X.N.
Jena, K.B. Chainy, G.B.N. |
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Subject |
Perna viridis
Antioxidant defence system Biomarker DNA damage |
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Description |
Sub-lethal effects of mercury exposure (1/10 th of LC sub(50), i.e. 0.045 mg l sup(-1)) for 5, 10 and 15 d was investigated on oxidative stress parameters and antioxidant defences in digestive gland of Perna viridis. In addition to this an in vitro effect of mercury single and supplemented with reduced glutathione on lipid peroxidation was studied. Increased lipid peroxidation (during first 10 days and also during in vitro exposures), protein carbonyl and hydrogen peroxides (from 5 th till last day of exposure) indicate the resultant oxidative stress in the mercury-exposed specimen. DNA damage (F-value) response although less distinct on 5th and 15th d, its low values on 10 th d and significant correlation with hydrogen peroxide suggests the toxic role of free radicals towards DNA integrity. Superoxide dismutase, which remains low initially (5th d) and increases later suggests its immediate response against superoxide radical. Higher activities of catalase, glutathione peroxidase and glutathione reductase on 15th d and glutathione-S-tranferase from 10 th d onwards suggests the adaptive behaviour of the tissue against oxyradicals. Increasing levels of non-enzymatic antioxidant molecules, such as reduced glutathione and ascorbic acid indicated its involvement in counteracting oxidative damage. Further role of reduced glutathione in reducing Hg toxicity is evident in in vitro experiments where lipid peroxidation remains low in mercury concentrations supplemented with reduced glutathione. The elevated levels of metallothionein from 5 th to 10 th d suggest involvement of this protein in detoxification of reactive oxygen species and toxic metal. The above results suggest that both enzymatic and non-enzymatic antioxidants play an important role in protecting cell against Hg toxicity, which can be used as a biomarker of metal contamination in aquatic environment.
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Date |
2008-05-02T12:13:41Z
2008-05-02T12:13:41Z 2008 |
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Type |
Journal Article
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Identifier |
Chemosphere, vol.71(10); 1977-1985p.
http://drs.nio.org/drs/handle/2264/1077 |
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Language |
en
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Rights |
Copyright Elsevier [2008]. It is tried to respect the copyright. If it is brought to our notice that the rights are violated then the item would be withdrawn.
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Publisher |
Elsevier
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