Oxygen radical formation in anoxic transgression and anoxia-reoxygenation: Foe or phantom? Experiments with a hypoxia tolerant bivalve


Contact
Doris.Abele [ at ] awi.de

Abstract

Intertidal blue mussels, Mytilus edulis, experience hypoxia reoxygenation during tidal emersion and resubmersion cycles, and this is often suggested to represent a major stress for the animals, especially for their respiratory tissues, the gills. We exposed mussels to experimental short and prolonged anoxia and subsequent reoxygenation and analyzed the respiratory response in excised gill tissue and the effects of treatment on reactive oxygen species (mainly ROS: superoxide anion, O2•- and hydrogen peroxide, H2O2), formation using live imaging techniques and confocal microscopy. Our aim was to understand if this “natural stress” would indeed produce oxidative damage and whether antioxidant defenses are induced under anoxia, to prevent oxidative damage during reoxygenation. Exposure to declining pO2 in the respiration chamber caused an increase of gill metabolic rate between 21 and 10 kPa, a pO2 range in which whole animal respiration is reported to be oxyregulating. Exposure of the animals to severe anoxia caused an onset of anaerobiosis (succinate accumulation) and shifted high and low critical pc values (pc1: onset of oxyregulation in gills, pc2: switch from oxyregulation to oxyconformity) to higher pO2. Concentrations of both ROS decreased strongly during anoxic exposure of the mussels and increased upon reoxygenation. This ROS burst induced lipid peroxidation in the mantle, but neither were protein carbonyl levels increased (oxidative damage in the protein fraction), nor did the tissue glutathione concentration change in the gills. Further, analysis of apoptosis markers indicated no induction of cell death in the gills. To our knowledge, this is the first paper that directly measures ROS formation during anoxia reoxygenation in mussels. We conclude that hypoxia tolerant intertidal mussels do not suffer major oxidative stress in gill and mantle tissues under these experimental conditions. Keywords: blue mussel, oxidative stress, reoxygenation, live imaging



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Scopus/ISI peer-reviewed
Publication Status
Published
Eprint ID
34013
DOI 10.1016/j.marenvres.2013.09.007

Cite as
Rivera-Ingraham, G. A. , Rocchetta, I. , Meyer, S. and Abele, D. (2013): Oxygen radical formation in anoxic transgression and anoxia-reoxygenation: Foe or phantom? Experiments with a hypoxia tolerant bivalve , Marine Environmental Research, 92 , pp. 110-119 . doi: 10.1016/j.marenvres.2013.09.007


Share


Citation

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item