Revisiting redox-active antioxidant defenses in response to hypoxic challenge in both hypoxia-tolerant and hypoxia-sensitive fish species

: Leveelahti L., Rytkönen K., Renshaw G., Nikinmaa M.

: 2014

: Fish Physiology and Biochemistry

: 40

: 1

: 183

: 191

: 9

: 0920-1742

DOI: https://doi.org/10.1007/s10695-013-9835-1

: http://api.elsevier.com/content/abstract/scopus_id:84880730791

It is not known whether changes in antioxidant levels always occur in fish in response to the oxidative stress that usually accompanies a hypoxic challenge. The studies of antioxidant responses to hypoxia in fish have mostly focused on very anoxia-tolerant species and indicate that there is an enhancement of antioxidant defenses. Here we present new data on redox-active antioxidants from three species, which range in their tolerance to hypoxia: the epaulette shark, threespine stickleback, and rainbow trout, together with a compilation of results from other studies that have measured oxidative stress parameters in hypoxia-exposed fish. The results suggest that in general, fish do not show an increase in redox-active antioxidant defense in response to oxidative stress associated with hypoxia. Rather, the changes in antioxidant defenses during hypoxia are very much species- and tissue-specific and are not linked to the level of hypoxia tolerance of the fish species. © 2013 Springer Science+Business Media Dordrecht.