Oxidative stress during stressful heat exposure and recovery in the North Sea eelpout (Zoarces viviparus.


Contact
dabele [ at ] awi-bremerhaven.de

Abstract

The interplay between antioxidants, heat shock proteins and hypoxic signaling is supposed to be important for passive survival of critical temperature stress, e.g. during unfavorable conditions in hot summers. We investigated the effect of mild (18°C), critical (22°C) and severe (26°C) experimental heat stress, assumed to induce different degrees of functional hypoxia, as well as the effect of recovery following heat stress on these parameters in liver samples of the common eelpout Zoarces viviparus.Upon heat exposure to critical and higher temperatures we found an increase in oxidative damage markers such as TBARS (thiobarbituric reactive substances) and a more oxidized cellular redox potential, combined with reduced activities of the antioxidant enzyme SOD at 26°C. Together, this points to higher oxidative stress levels during stressful hyperthermia. In a recovery-time series, heat induced hypoxia and subsequent reoxygenation upon return of the fishes to 12°C led to increased protein oxidation and chemiluminescence rates within the first 12 hours upon recovery, therein resembling ischemia/reperfusion injury in mammals.HSP70 levels were found only slightly elevated after recovery from sub-lethal heat stress, indicating minor importance of the heat shock response in this species. The DNA binding activity of the hypoxia inducible transcription factor (HIF-1) was elevated only during mild heat exposure (18°C), but appeared impaired at more severe heat stress. We suppose that the more oxidized redox state during extreme heat may interfere with the hypoxic signaling response.



Item Type
Article
Authors
Divisions
Programs
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
13868
DOI 10.1242/jeb.01977

Cite as
Heise, K. , Puntarulo, S. , Nikinmaa, M. , Abele, D. and Pörtner, H. O. (2006): Oxidative stress during stressful heat exposure and recovery in the North Sea eelpout (Zoarces viviparus. , Journal of experimental biology, 209 , pp. 353-363 . doi: 10.1242/jeb.01977


Share


Citation

Research Platforms
N/A

Campaigns


Actions
Edit Item Edit Item