This study was conducted to determine the
single and combined effects of cadmium (Cd) exposure at
different concentrations and durations on biological
responses in
Gammarus pulex
. The animals were exposed to
4, 8, 16 or 32 μg l
-1 of CdCl
2 for 24, 48, 72 or 96 h,
respectively. Cd accumulation, protein content, malondialdehyde
content (MDA) and three antioxidant enzymes
superoxide dismutase (SOD), catalase (CAT) and glutathione
peroxidase (GPx) were studied. The results were analyzed
with two-way analysis of variance (two-way
ANOVA) to assess the significance of the effects of exposure
concentration and duration and their combined effects.
The highest accumulation of Cd was found as 15.07 μg g
-1
at 32 μg l
-1 and 96-h Cd exposure. There was a significant
correlation between accumulated Cd concentration and
MDA and protein content and GPx activity. Although there
was no significant synergistic effect of duration and concentration
on Cd accumulation, a significant synergy of
duration and concentration was observed in all other studied
parameters. Interestingly, with the exception of GPx
activity, the effect of concentration was greater than the
effect of duration for all studied parameters. GPx activity
showed that duration had a greater effect than concentration.
Additionally, both SOD and GPx are more effective
than CAT during Cd stress. The results of this study may be
useful for understanding the relationship between organisms
and environmental toxins.
