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Lipid from cuticle and viscera sequestered 35 and 40%, respectively, of the diflubenzuron taken up by larvae of Aedes aegypti. The rate of toxicant uptake was linear for the first 2 days of exposure. Following treatment of larvae with a mixture of MON 0585 and diflubenzuron, tanning agents and pigments were discharged into the rearing medium during pupation. In the course of poisoning, body fluids and cuticle accumulated soluble arylated peptides and tanning agents at the expense of the sclerotized mucoprotein complex. Changes in protein composition of the integument were indicated by decreased titers of bound phenylalanine and serine in both the immature and pupal stages, however, visual symptoms of poisoning were absent in larvae. Three amino acids linked to citric acid cycle oxidations, namely, aspartic and glutamic acids and proline, declined sharply in body fluids of poisoned animals while a conjugate resembling N-acetyldopamine-O-glucoside was retained. These biochemical lesions suggest the action of MON 0585 was due to (a) loss of benzenoid precursors of the crosslink to the rearing medium; (b) faulty active transport of tanning agents; and (c) unavailability of receptor sites for arylating groups on side chains destined for bridging. 相似文献
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Regina Coimbra Rola Luis Fernando Marins Luiz Eduardo Maia Nery Carlos Eduardo da Rosa Juliana Zomer Sandrini 《Fish physiology and biochemistry》2014,40(6):1817-1825
Fish are commonly exposed to environmental pollutants, which in turns could induce an oxidative stress. So, it is important to understand the effects and the responses elicited by these toxicants in fish species, being fish cell lines important tools for this purpose. Thus, the aim of the present study was to compare the effects of copper and UV-B radiation exposure on zebrafish hepatocytes (ZFL lineage) in terms of reactive oxygen species (ROS) levels, sulfhydril groups content and mRNA levels of important genes related to cellular response to toxic agents. Exposure of ZFL cells to UV-B radiation (23.3 mJ/cm2) significantly increased levels of intracellular ROS and mRNA of both superoxide dismutase isoforms (sod1 and sod2), three glutathione S-transferase isoforms (gstα, gstµ and gstπ) and a heat shock protein (hsp70). However, no changes in nonprotein sulfhydryl groups (NP-SH) content, as well as in the mRNA levels of genes related to glutathione (GSH) synthesis and recycling, were observed. Contrary to this, copper exposure (20 mg/L) diminished NP-SH content and increased the levels of mRNA of genes related to GSH synthesis (gclc and gs). Moreover, copper exposure increases the mRNA levels of some genes related to antioxidant defenses (gpx and gstπ), biotransformation reactions (cyp1a1) and protein repair (hsp70). In conclusion, these results demonstrated that both toxicants could increase ROS levels in ZFL cell line, but the responses are different, which could be related to activation of different signaling pathways. 相似文献
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