Effect of ambient oxygen concentration on activities of enzymatic antioxidant defences and aerobic metabolism in the hydrothermal vent worm, Paralvinella grasslei |
| |
Authors: | Benjamin Marie Bertrand Genard Jean-François Rees Franck Zal |
| |
Institution: | (1) Equipe Ecophysiologie : Adaptation et Evolution Moléculaires, UPMC – CNRS UMR 7144, Station Biologique, BP 74, 29682 Roscoff cedex, France;(2) Institut des Sciences de la Vie, Université Catholique de Louvain, Animal Biology Unit, Croix du Sud 5, 1348 Louvain-la-Neuve, Belgium |
| |
Abstract: | The alvinellid Paralvinella grasslei is a common endemic polychaete from the deep-sea hydrothermal vent communities located on the East Pacific Rise (EPR). These organisms colonise a large range of microhabitats around active sites where physico-chemical conditions are thought to generate reactive oxygen species (ROS). Furthermore, in this aerobic organism, ROS could also be generated by the activity of the mitochondrial respiratory chain. In this paper, we investigated the effect of ambient oxygen concentration on the activities of three essential antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPX) and their relationships with the activity of enzymes involved in aerobic metabolism (cytochrome c oxidase, COX; citrate synthase, CS). Results of incubation of P. grasslei in a high-pressure vessel with circulating seawater at different oxygen partial pressures indicate that this worm regulates COX and CS activities differently in gills and body wall. CAT and GPX activities increase in these tissues when animals are maintained in filtered surface seawater. Moreover, levels of malondialdehyde increase in gills, testifying that oxidative damage occurs under these conditions. CAT and GPX activities are positively related to COX and CS activities, but no correlation was detected between SOD and the metabolic enzyme activities. In comparison with littoral annelids, SOD activities are very high whereas CAT activities are very low or absent in P. grasslei. The possible reasons for the occurrence of such differences are discussed. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|