title: Hormonal enhancement of insecticide efficacy in Tribolium castaneum: oxidative stress and metabolic aspects.
abstract: Insect anti-stress responses, including those induced by insecticides, are controlled by adipokinetic hormones (AKHs). We examined the physiological consequences of Pyrap-AKH application on Tribolium castaneum adults (AKH-normal and AKH-deficient prepared by the RNAi technique) treated by two insecticides, pirimiphos-methyl and deltamethrin. Co-application of pirimiphos-methyl and/or deltamethrin with AKH significantly increased beetle mortality compared with application of the insecticides alone. This co-treatment was accompanied by substantial stimulation of general metabolism, as monitored by carbon dioxide production. Further, the insecticide treatment alone affected some basic markers of oxidative stress: it lowered total antioxidative capacity as well as the activity of superoxide dismutase in the beetle body; in addition, it enhanced the activity of catalase and glutathione-S-transferase. However, these discrepancies in oxidative stress markers were eliminated/reduced by co-application with Pyrap-AKH. We suggest that the elevation of metabolism, which is probably accompanied with faster turnover of toxins, might be responsible for the higher mortality that results after AKH and insecticide co-application. Changes in oxidative stress markers are probably not included in the mechanisms responsible for increased mortality.
authors: Institute of Entomology, Biology Centre, Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic; Department of Biology, Josip Juraj Strossmayer University of Osijek, Ulica cara Hadrijana 8/A, 31000 Osijek, Croatia.
authors: Ivana
authors: I
authors: Plavšin
authors: Institute of Entomology, Biology Centre, Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors: Tereza
authors: T
authors: Stašková
authors: Institute of Entomology, Biology Centre, Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Education, University of South Bohemia, Jeronýmova 10, 371 15 České Budějovice, Czech Republic.
authors: Michal
authors: M
authors: Šerý
authors: Institute of Entomology, Biology Centre, Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic.
authors: Vlastimil
authors: V
authors: Smýkal
authors: Department of Biology, Josip Juraj Strossmayer University of Osijek, Ulica cara Hadrijana 8/A, 31000 Osijek, Croatia.
authors: Branimir K
authors: BK
authors: Hackenberger
authors: Institute of Entomology, Biology Centre, Academy of Sciences, Branišovská 31, 370 05 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic. Electronic address: kodrik@entu.cas.cz.
authors: Dalibor
authors: D
authors: Kodrík
mesh_terms: D000818:Animals; D004734:Energy Metabolism / Q000187:drug effects* / Q000502:physiology; D007301:Insect Hormones / Q000008:administration & dosage* / Q000633:toxicity; D007306:Insecticides / Q000008:administration & dosage* / Q000633:toxicity; D009479:Neuropeptides / Q000008:administration & dosage* / Q000633:toxicity; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D011761:Pyrrolidonecarboxylic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity; D014231:Tribolium / Q000187:drug effects* / Q000378:metabolism
chemical_list: D007301:Insect Hormones; D007306:Insecticides; D009479:Neuropeptides; C069011:adipokinetic hormone, beetle; D011761:Pyrrolidonecarboxylic Acid
keywords: Adipokinetic hormone; Insecticide; Metabolism; Mortality; Oxidative stress; RNA interference