ISSN 1063-0740, Russian Journal of Marine Biology, 2008, Vol. 34, No. 2, pp. 135–138. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © S.A. Aleshko, O.N. Lukyanova, 2008, published in Biologiya Morya.
Molecular biomarkers of the condition of water
organisms have been widely used in recent decades as
indicators of pollution effects [4, 21]. When estimating
the functional condition of organisms, the important
parameters are activity of antioxidant system enzymes
and intensity of toxicant biotransformations processes
. However, to use the biomarkers correctly we have
to know the limitations of their natural variability in the
populations of surveyed species .
The coastal area of the Sea of Japan in the Russian
Primorye is characterized by pronounced differentia-
tion of seasons, which requires physiological adapta-
tions of organisms. The activities of biochemical pro-
cesses can vary signiﬁcantly throughout the year
depending on environmental temperature, food avail-
ability, stages of the reproductive cycle, and the growth
rates of organisms. The observed ﬂuctuations can be a
part of the annual physiological cycle of an organism
and are not always determined by the effects of pollu-
Fishes are widely used in programs for monitoring
of anthropogenic pollution for integral estimations of
the condition of water areas. Species performing no sig-
niﬁcant migrations are preferred, as well as near-bot-
tom species that are in contact with bottom substrates,
where pollutants are accumulated. In many countries
different species of ﬂounders are used as species-indi-
cators [9, 16]. However, there are only a few data about
the seasonal dynamics of molecular biomarkers in ﬁsh
[14, 19]. The Far-Eastern smooth ﬂounder
is conﬁned to coastal shallows and makes
up stable local aggregations in Peter the Great Bay .
This species spawns in January–February . In recent
has been actively used in ecolog-
ical studies . Moreover, the smooth ﬂounder is also
an object of commercial ﬁshery; therefore, the studies
of pollution effects on the metabolism in this ﬁsh spe-
cies are also of certain practical value.
The target of this project was to study the seasonal
dynamics in the activities of several antioxidant
enzymes and parameters of biotransformation in a
regional species-indicator, the smooth ﬂounder from
Amurskii Bay, Sea of Japan.
MATERIAL AND METHODS
In 2005–2006, in the central part of Amurskii Bay,
we sampled 6 males and 6 females of the smooth ﬂoun-
der every month. In the period of navigation the ﬁsh
were caught with a bottom trawl; in the winter we used
stand nets. The liver was isolated immediately after the
sampling, rinsed with a physiological solution and
delivered to the laboratory at a temperature of zero
degrees. All analyses were performed within one day
from the moment of sampling. Samples of organs,
about 1 g in weight, were homogenized in cooled
0.05 M tris–HCl buffer (pH 7.5), in an ice bath. The
homogenates were centrifuged for 20 min at 10000 rpm.
The concentration of proteins was then determined in
the supernatant using the method of Greenberg .
The concentration of reduced glutathione was mea-
sured in tests with Ellman’s reagent . The intensity
of peroxide oxidation processes of lipids was analyzed
Seasonal Variations of Biotransformation and Antioxidant
Parameters in Liver of the Smooth Flounder
from Amursky Bay (Sea of Japan)
S. A. Aleshko and O. N. Lukyanova
Paciﬁc Fisheries Research Center, TINRO-Center, Vladivostok, 690950 Russia
Accepted November 13, 2007
—This study examines the seasonal dynamics of the activity of some antioxidant enzymes, the
biotransformation enzyme glutathione-S-transferase, and levels of reduced glutathione and malondialdehyde in
the liver of the ﬂounder
from Amurskii Bay, Sea of Japan. The individual variability of
biomarkers was fairly low. Signiﬁcant sex differences were only found for superoxide dismutase.
, biomarkers, antioxidant system, Amurskii Bay.