title: Adipokinetic hormone-induced enhancement of antioxidant capacity of Pyrrhocoris apterus hemolymph in response to oxidative stress.
abstract: The in vivo effects of oxidative stress on adipokinetic hormone (AKH) titer in short-winged (brachypterous) males of the firebug Pyrrhocoris apterus were tested using paraquat (PQ), a bipyridilium herbicide. PQ undergoes a cyclic redox reaction with oxygen during microsomal and electron transfer reactions forming free radicals in the insect body. Oxidative insult (40 pmol PQ) resulted in enhanced protein carbonylation (a biomarker for oxidative stress) and a depletion of glutathione (GSH) pool in the hemolymph. Interestingly, AKH titer was significantly enhanced in hemolymph at 4 h post inoculation of PQ, while its content in CNS (brain with corpora cardiaca) showed non-specific changes in comparable period. Co-injection of AKH with PQ (40 pmol each) reversed these effects by decreasing protein carbonyl formation, increasing reduced GSH levels, and enhancing the total antioxidant capacity of cell free plasma. Our results indicate that there is a positive feedback regulation between an oxidative stressor action and the level of AKH in insect body, and that AKHs might be involved in the activation of antioxidant protection mechanism.
authors.affiliation: Institute of Entomology, Academy of Sciences, Branisovská 31, CZ-370 05 Ceské Budejovice, Czech Republic.
authors.forename: Josef
authors.initials: J
authors.lastname: Vecera
authors.forename: Natraj
authors.initials: N
authors.lastname: Krishnan
authors.forename: Glenda
authors.initials: G
authors.lastname: Alquicer
authors.forename: Dalibor
authors.initials: D
authors.lastname: Kodrík
authors.forename: Radomír
authors.initials: R
authors.lastname: Socha
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D004359:Drug Therapy, Combination; D005978:Glutathione / Q000378:metabolism; D006458:Hemolymph / Q000187:drug effects / Q000378:metabolism*; D006540:Herbicides / Q000494:pharmacology; D020062:Heteroptera / Q000187:drug effects / Q000378:metabolism*; D007301:Insect Hormones / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D009842:Oligopeptides / Q000378:metabolism* / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D010269:Paraquat / Q000494:pharmacology; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D006540:Herbicides; D007301:Insect Hormones; D009842:Oligopeptides; C044833:adipokinetic hormone; D005978:Glutathione; D010269:Paraquat; D011761:Pyrrolidonecarboxylic Acid