title: Antioxidant enzyme activity in endemic Baikalean versus Palaearctic amphipods: tagma- and size-related changes.
abstract: The activities of key antioxidant enzymes in two endemic Baikalean amphipod species: Pallasea cancelloides (Gerstf), Eulimnogammarus verrucosus (Gerstf) and the widely distributed Palearctic species Gammarus lacustris (Sars) were studied. This work was done to prove or disprove the hypothesis that Baikalean endemics have specifics in antioxidants system different from Palearctic species. The activities of antioxidant enzymes peroxidase, catalase and glutathione-S-transferase were measured in different sections (tagmata) of the amphipods' bodies as well as in different size groups. Well expressed tagma-related differences in peroxidase activity as well as smaller differences in catalase activity were shown in all studied species. There were no measured differences in glutathione-S-transferase activity among body sections. The existence of size-related changes in some antioxidant enzymes and the difference in such changes between Baikalean and Palearctic amphipods were noted. A significant increase in peroxidase activity with the size was found in both Baikalean species while a significant decrease in peroxidase activity was observed in the Palearctic G. lacustris. In Baikalean P. cancelloides, a significant decrease of catalase activity with the increase in age of crustaceans was noted, while in E. verrucosus no such relationship was found. In the Palearctic G. lacustris, a significant increase in catalase activity with the increase in size was noted. All species are shown to have no size-related differences in glutathione-S-transferase activity. The differences between species as well as between both different tagmata and size-classes within a particular species were estimated. It was assumed that the estimated differences in enzymes activity most likely depend on interspecific variation, rather than on conditional specifics in Lake Baikal.
authors.affiliation: Irkutsk State University, Karl-Marx 1, 664003, Irkutsk, Russia. mtim@irk.ru
authors.forename: M A
authors.initials: MA
authors.lastname: Timofeyev
mesh_terms: D033304:Amphipoda / Q000033:anatomy & histology* / Q000201:enzymology*; D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D049628:Body Size; D005982:Glutathione Transferase / Q000032:analysis*; D010544:Peroxidases / Q000032:analysis*; D012426:Russia; D012800:Siberia
chemical_list: D000975:Antioxidants; D010544:Peroxidases; D005982:Glutathione Transferase