Søren Achim Nielsen, Jørgen Clausen and Søren Toft
In order to compare the detoxification capacities of two species of spiders, Linyphia triangularis and Pardosa prativaga were exposed to a commonly used pesticide, cypermethrin (a chlorinated pyrethroid). Two detoxification enzyme systems — glutathione Stransferase (GST) and glutathione peroxidase (GSH-Px) — were assayed as biomarkers. The two species of spiders have different life-styles and eat different food, and in our experiment were at different stages of their life-cycle. Therefore, differences in detoxification strategies could be expected. From our results, we suggest two different strategies. L. triangularis had a generally high basal level of GST, which could be further induced by exposure to cypermethrin. The basal activity of GSH-Px was relatively low, and no response to toxic exposure could be traced. Thus, this enzyme plays only a minor role in the detoxification process of cypermethrin in L. triangularis. In P. prativaga, a low basal GST activity was found. However, the basal level of GSH-Px was comparable to that of L. triangularis. A significant rise in GSH-Px activity (with t-butyl-hydroxyperoxide as substrate) was apparent 12 hours after exposure. This may indicate that P450 enzyme systems are involved in the cypermethrin metabolising process in P. prativaga. In addition, GSH-Px activity (with H2O2 as substrate) could be traced in P. prativaga but not in L. triangularis, indicating that a true peroxidase system is active in P. prativaga.
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