Ischemia and reperfusion of skeletal muscle lead to the appearance of a stable lipid free radical in the circulation
1 Department of Medicine, University of Liverpool, Liverpool L69 3GA; and 2 Department of Sports Science, De Montfort University, Bedford MK40 2BZ, United Kingdom Both ischemia and reperfusion injury and contractile activity are associated with the generation of reactive oxygen species and free ra...
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Published in | American journal of physiology. Heart and circulatory physiology Vol. 284; no. 6; pp. H2400 - H2404 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
United States
01.06.2003
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Subjects | |
Online Access | Get full text |
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Summary: | 1 Department of Medicine, University of Liverpool,
Liverpool L69 3GA; and 2 Department of Sports
Science, De Montfort University, Bedford MK40 2BZ, United
Kingdom
Both
ischemia and reperfusion injury and contractile activity are
associated with the generation of reactive oxygen species and free
radicals by skeletal muscle. In addition, exercise has been reported to
lead to the formation of a circulating free radical species that is
detectable in the blood by spin trapping before analysis by
electron-spin resonance (ESR) techniques. Previous analysis of the ESR
signal indicated that the circulating species is either a carbon- or
oxygen-centered lipid-derived free radical. The current data indicate
that this species is present in the blood of anesthetized rats after
4-h ischemia and 1 h of reperfusion of a single hindlimb. During
4 h of ischemia, the species was also present in
microdialysates from the tibialis anterior muscle but was unchanged in
magnitude compared with control tissue. During 1 h of reperfusion,
the signal intensity increased by a mean of 420% ( P < 0.05, n = 4). Hydroxyl radical activity in the
interstitial fluid also significantly increased during ischemia
and further increased by a mean of 210% ( P < 0.05, n = 4) during reperfusion. No changes in interstitial
superoxide levels were seen, but interstitial PGE 2 content
also increased during reperfusion. A significant positive correlation
was found between the magnitude of the ESR signal and both the hydroxyl
radical activity and PGE 2 content of microdialysis fluids.
These data support the hypothesis that the circulating free radical
species is formed in the interstitial fluid by hydroxyl radical
interaction with a lipid that may be released from reperfused tissue
with a similar pattern to prostanoids.
microdialysis; electron-spin resonance; prostanoids |
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ISSN: | 0363-6135 1522-1539 |
DOI: | 10.1152/ajpheart.00931.2002 |