Oxidative stress and antioxidative defense in cephalopods: a function of metabolic rate or age?

Activities of the antioxidative enzymes superoxide dismutase (SOD). catalas e, glutathione peroxidase (GPX) and glutathione reductase (GR) were measure d in the cephalopods Sepia officinalis and Lolliguncula brevis,is. Maximal enzyme activities were higher in gill tissue than in the mantle musculature of both species. Activities were generally lower in tissues of L. brevis t han in S. officinalis. Comparison with other ectothermic animals showed bot h cephalopod species to have a low enzymatic antioxidative status despite t heir high metabolic rate. Furthermore, changes in antioxidative enzyme acti vities were measured in the cuttlefish S. officinalis with increasing age. The concentrations of malondialdehyde (MDA) and lipofuscin were determined as indicators of lipid peroxidation. Investigated animals were between 1.5 months and over 12 months old. Changes of antioxidative enzyme activities w ith age were not uniform. SOD and GPX activities increased with age, while catalase activity declined. In contrast, GR activity remained almost unchan ged in all age groups. The low level of antioxidative defense might allow f or the significant age-induced rise in MDA levels in gills and mantle muscu lature and for the increase in lipofuscin levels in mantle and brain tissue . It might thereby contribute to increased oxidative damage and a short lif e span in these cephalopods. (C) 2000 Elsevier Science Inc. All rights rese rved.