MEPS 143:141-150 (1996)  -  doi:10.3354/meps143141

Aspects of antioxidant status in the polychaete Arenicola marina: tissue and subcellular distribution, and reaction to environmental hydrogen peroxide and elevated temperatures

Buchner T, Abele-Oeschger D, Theede H

Solar radiation leads to hydrogen peroxide (H2O2) accumulation in shallow intertidal surface waters during daytime tidal emersion periods. The lugworm Arenicola marina irrigates its sedimentary tubes with surface water containing variable H2O2 concentrations. We studied aspects of the antioxidant status of the intertidal polychaete A. marina in response to seasonal variations of oxidative stress in its environment. Antioxidant enzyme activities [superoxide dismutase (SOD), glutathione reductase (GR) and catalase] and vitamin E were concentrated chiefly in the chloragog and to a lesser extent in body wall tissue. Response to experimental H2O2 exposure (5 µmol l-1) was confined to the chloragog tissue and consisted of elevated catalase activity. On a subcellular level, the major part of enzymatic antioxidants examined was found in the cytosolic (77% of SOD activity, 60% of GR activity, 41% of catalase activity, 87% of total glutathione) and the peroxisomal (56% of catalase activity) fractions, whereas the same antioxidants were virtually absent in mitochondria. Gradual acclimation of winter A. marina (5°C) to higher ambient temperatures (20°C) over 20 d resulted in a doubling of chloragog SOD activities, while catalase activity was not affected. Elevated in situ concentrations of photoproduced H2O2 during summer (1.7 µmol l-1) coincided with a significant increase of chloragog catalase activities in young (winter: 317.97 ± 78.3 U mg-1 protein, summer: 783.41 ± 192.7 U mg-1 protein, means ± SD) and in adult (winter: 480.09 ± 160.1 U mg-1 protein, summer: 1165.5 ± 207.5 U mg-1 protein) lugworms. Seasonal differences in the SOD activities of adult worms (winter: 16.06 ± 4.69 SOD units mg-1 protein; summer: 23.29 ± 3.31 SOD units mg-1 protein) were attributed to the elevated sediment temperatures in intertidal areas during summer.

Arenicola marina · Hydrogen peroxide · Enzymatic antioxidants

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