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Does exhaustive exercise result in oxidative stress and associated DNA damage in the chub ( Leuciscus cephalus )?
Author(s) -
Aniagu Stanley O.,
Day Norman,
Chipman J. Kevin,
Taylor Edwin W.,
Butler Patrick J.,
Winter Matthew J.
Publication year - 2006
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.20247
Subject(s) - comet assay , oxidative stress , glutathione , dna damage , superoxide dismutase , antioxidant , biology , andrology , oxidative phosphorylation , leuciscus , biochemistry , dna , toxicology , chemistry , fish <actinopterygii> , fishery , enzyme , medicine
DNA strand breaks [as determined by the conventional and formamidopyrimidine glycosylase (FPG)‐modified Comet assay] and antioxidant defense status [as indicated by superoxide dismutase (SOD) activity and reduced glutathione (GSH) concentration] were evaluated in healthy adult chub ( Leuciscus cephalus ) after exhaustive exercise [swimming to their critical swimming speed ( U crit ), twice in succession with a 40 min rest period between] vs. confined (unexercised) control fish. The conventional Comet assay revealed significantly higher DNA strand breaks in all the tissues (blood, liver, and gill), with the highest increase over background evident in the epithelial gill cells of swum fish compared to the controls. Moreover, when the FPG‐modified Comet assay was conducted to reveal specific oxidative lesions, the gill cells of exercised fish sustained the highest level of oxidative DNA damage in comparison to the control. Data on tissue antioxidant defense mechanism were less conclusive, with no significant differences in the tissue levels of SOD or GSH. This suggests that either the degree of oxidative stress was not great enough to evoke a response in terms of defense mechanisms or the timescale of antioxidant defense response was somewhat different from the time between the application of stress and subsequent tissue sampling. From the swimming data, U crit was significantly lower on the second assessment compared to the first (repeat ratio: 0.76), suggesting that the fish were exercised to a level which was not sustainable. Overall, these findings support the theory that acute extreme exercise could result in oxidative stress and associated DNA damage in fish. These observations suggest that fish living in fast flowing and polluted rivers are at increased risk of DNA damage. Environ. Mol. Mutagen., 2006. © 2006 Wiley‐Liss, Inc.