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First published online December 14, 2007
Journal of Experimental Biology 211, 114-120 (2008)
Published by The Company of Biologists 2008
doi: 10.1242/jeb.012674
Antioxidative defence alterations in skeletal muscle during prolonged acclimation to cold: role of L-arginine/NO-producing pathway
1
i
1
2
1
1
unovi
2
1,*
1 Department of Physiology, Institute for Biological Research `Sini
a
Stankovi
', University of Belgrade, Bulevar Despota Stefana 142, 11060
Belgrade, Serbia
2 Institute of Zoology, Faculty of Biology, University of Belgrade, Studentski
trg 16, 11000 Belgrade, Serbia
* Author for correspondence (e-mail: koracb{at}ibiss.bg.ac.yu)
Accepted 18 October 2007
Early in cold acclimation (1–7 days), heat is produced by shivering,
while late in cold acclimation (12–45 days), skeletal muscle contributes
to thermogenesis by tissue metabolism other than contractions. Given that both
thermogenic phases augment skeletal muscle aerobic power and reactive species
production, we aimed in this study to examine possible changes in skeletal
muscle antioxidative defence (AD) during early and late cold acclimation with
special emphasis on the influence of the L-arginine/nitric oxide
(NO)-producing pathway on the modulation of AD in this tissue. Adult Mill Hill
hybrid hooded rat males were divided into two main groups: a control group,
which was kept at room temperature (22±1°C), and a group maintained
at 4±1°C for 45 days. The cold-acclimated group was divided into
three subgroups: untreated, L-arginine treated and
N
-nitro-L-arginine methyl ester
(L-NAME) treated. The AD parameters were determined in the
gastrocnemius muscle on day 1, 3, 7, 12, 21 and 45 of cold acclimation. The
results showed an improvement of skeletal muscle AD in both early and late
cold acclimation. Clear phase-dependent changes were seen only in copper, zinc
superoxide dismutase activity, which was increased in early cold acclimation
but returned to the control level in late acclimation. In contrast, there were
no phase-dependent changes in manganese superoxide dismutase, catalase,
glutathione peroxidase, glutathione reductase and glutathione S-transferase,
the activities of which were increased during the whole cold exposure,
indicating their engagement in both thermogenic phases. L-Arginine
in early cold acclimation accelerated the cold-induced AD response, while in
the late phase it sustained increases achieved in the early period.
L-NAME affected both early and late acclimation through attenuation
and a decrease in the AD response. These data strongly suggest the involvement
of the L-arginine/NO pathway in the modulation of skeletal muscle
AD.
Key words: skeletal muscle, antioxidative defence, nitric oxide, cold