Biochemical markers of oxidative stress in Perna viridis exposed to mercury and temperature.
Oxidative damage and antioxidant properties have been studied in Perna viridis subjected to short-term exposure to Hg along with temperature (72h) and long-term temperature exposures (14 days) as pollution biomarkers. The elevated thiobarbituric acid reactive substances (TBA-RS) levels observed in gills and digestive gland under exposure to Hg, individually and combined with temperature, as also long-term temperature stress have been assigned to the oxidative damage resulting in lipid peroxidation (LPX). Increased activities of antioxidants such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione-S-transferase (GST) both in gills and digestive glands under long-term exposures to temperatures are more prominent to heat rather than cold stress suggesting activation of physiological mechanism to scavenge the ROS produced during heat stress. Also decreased values of reduced glutathione (GSH) on long exposures to temperature stress indicate utilisation of this antioxidant, either to scavenge oxiradicals or act in combination with other enzymes, was more than its production capacity under heat stress. The results suggest that temperature variation does alter the active oxygen metabolism by modulating antioxidant enzyme activities, which can be used as biomarker to detect sublethal effects of pollution.
Verlecar
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National Institute of Oceanography, Dona-Paula, Goa, India. verlecar@nio.org
Jena
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Chainy
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D000818:Animals; D015415:Biomarkers / Q000737:chemistry / Q000378:metabolism*; D002374:Catalase / Q000187:drug effects / Q000378:metabolism; D004064:Digestive System / Q000187:drug effects; D005880:Gills / Q000187:drug effects / Q000201:enzymology; D005978:Glutathione / Q000187:drug effects / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000187:drug effects / Q000378:metabolism; D005980:Glutathione Reductase / Q000187:drug effects / Q000378:metabolism; D005982:Glutathione Transferase / Q000187:drug effects / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008628:Mercury / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D049883:Perna / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000187:drug effects / Q000378:metabolism; D013696:Temperature; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors
D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D008628:Mercury; D005978:Glutathione