title: Effect of temperature and pirimiphos methyl on biochemical biomarkers in Chironomus riparius Meigen.
abstract: Fourth-instar Chironomus riparius Meigen larvae were exposed to the organophosphate (OP) insecticide pirimiphos methyl (0, 0.1, 1.0, and 10 microg/L) for 48, 72, or 96 h at three temperatures (3, 12, or 22 degrees C). Two biochemical biomarkers, acetylcholinesterase (AChE) and glutathione S-transferase (GST), were measured in individual larvae from each treatment. AChE activity was inhibited by the OP in a dose-responsive fashion. This response remained similar at all three temperatures, demonstrating that AChE is a robust and specific biomarker. Exposure duration had little effect on AChE activity. In contrast, GST activity was induced at the highest OP insecticide concentration, but induction was also evident at 3 degrees C. There was a significant effect of exposure duration, with an overall decline in GST activity over time. This result agrees with previous work suggesting that GSTs are not particularly suitable for use as a biomarker of pesticide exposure or effect in Chironomus.
authors.affiliation: Division of Zoology, School of Animal and Microbial Sciences, The University of Reading, Whiteknights, Reading, Berkshire RG6 6AJ, UK. a.callaghan@reading.ac.uk
authors.forename: Amanda
authors.initials: A
authors.lastname: Callaghan
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Fisher
authors.forename: Albania
authors.initials: A
authors.lastname: Grosso
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Holloway
authors.forename: Mark
authors.initials: M
authors.lastname: Crane
mesh_terms: D000110:Acetylcholinesterase / Q000032:analysis* / Q000187:drug effects / Q000494:pharmacology; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002683:Chironomidae / Q000502:physiology*; D004781:Environmental Exposure; D005982:Glutathione Transferase / Q000032:analysis* / Q000187:drug effects / Q000494:pharmacology; D007306:Insecticides / Q000009:adverse effects*; D007814:Larva / Q000254:growth & development; D009946:Organothiophosphorus Compounds / Q000009:adverse effects*; D012680:Sensitivity and Specificity; D013696:Temperature
chemical_list: D015415:Biomarkers; D007306:Insecticides; D009946:Organothiophosphorus Compounds; C014153:pirimiphos methyl; D005982:Glutathione Transferase; D000110:Acetylcholinesterase