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Inhibition of avian esterases by organophosphorus insecticides: Problems of reactivation and storage

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Brain and serum esterase activities were measured in starlings (Sturnus vulgaris) dosed with corn oil, demeton-S-methyl (S-[2-(ethyl thio)ethyl]O,O-dimethyl phosphorothioate), chlorpyrifos (O,O-diethylO-(3,5,6-trichloro-2-pyridinyl) phosphorothioate) or triazophos (O,O-diethylO-(1-phenyl-1H-1,2,4-triazol-3-yl) phosphorothioate). Activity was assayed before and after (1) storage at 20°C and (2) chemical reactivation by pyridine-2-aldoxime methiodide (P2AM). During storage, significant spontaneous reactivation occurred in samples from birds dosed with chlorpyrifos or triazophos but not in the birds dosed with demeton-S-methyl or corn oil. The degree of chemical reactivation of samples was dependent on the compound administered, the type of esterase and the time after dosing. Brain acetylcholinesterase appeared to be more readily reactivated than serum esterases by P2AM. Following dosing with the diethyl organophosphorus compounds, spontaneous or chemical reactivation sometimes resulted in levels of esterase activity above those measured before dosing. This indicates that release and/orde novo synthesis had occurred. It is important to take into account spontaneous reactivation during storage when assessing the inhibition of esterase activity.

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  1. Aldridge WN (1953) Serum esterases. Biochem J 53:110–124

  2. Aldridge WN, Reiner E (1972) Enzyme inhibitors as substrates. Interactions of esterases with esters of organophosphorus and carbamic acids. Neuberger A, Tatum EL (eds) Frontiers of biology, Vol 26, North Holland Publishing Co, Amsterdam

  3. Bunyan PJ, Jennings DM, Taylor A (1968) Organophosphate poisoning: Some properties of avian esterases. J Agric Food Chem 16:326–331

  4. Busby DG, Holmes SB, Pearce PA, Fleming RA (1987) The effect of aerial application of Zectran on brain cholinesterase activity in forest songbirds. Arch Environ Contam Toxicol 16:623–629

  5. Ellman GL, Courtney KD, Andreas Jr V, Featherstone RM (1961) A new and rapid colorimetric determination of AChE activity. Biochem Pharmac 7:88–95

  6. Felton CL, Brown PM, Fletcher MR, Stanley PI, Quick MP, Machin AF (1981) Bird poisoning following the use of warble fly treatments containing famphur. Vet Rec 108:440

  7. Fleming WJ, Bradbury SP (1981) Recovery of ChE activity in mallard ducklings administered organophosphorus pesticides. J Toxicol Environ Health 8:885–897

  8. Gomori G (1953) Human esterases. J Lab Clin Med 42:445–453

  9. Hill EF (1989a) Divergent effects of post-mortem ambient temperature on organophosphorus- and carbamate-inhibited brain cholinesterase activity in birds. Pest Biochem Physiol 33:264–275

  10. — (1989b) Sex and storage affect cholinesterase activity in blood plasma of Japanese quail. J Wildl Diseases 25:580–585

  11. Hill EF, Fleming WJ (1982) Anti-ChE poisoning of birds: Field monitoring and diagnosis of acute poisoning. Environ Toxicol Chem 1:27–38

  12. Ludke JL, Hill EF, Dicker MP (1975) ChE response and related mortality among birds fed ChE inhibitors. Arch Environ Contam Toxicol 3:1–21

  13. Mackness MI, Thompson HM, Hardy AR, Walker CH (1988) Distinction between ‘A’ esterases and arylesterases-implications for esterase classification. Biochem J 245:293–296

  14. Martin AD, Norman G, Stanley PI, Westlake GE (1981) Use of reactivation techniques for the differential diagnosis of organophosphate and carbamate pesticide poisoning in birds. Bull Environ Contam Toxicol 26:775–782

  15. Thompson HM, Walker CH, Hardy AR (1988) Esterases as indicators of avian exposure to insecticides. Greaves MP, Smith BD, Greig-Smith PW (eds) BCPC Mono No. 40, Field methods for the study of environmental effects of pesticides. BCPC, Croydon, pp 39–45

  16. Thompson HM, Tarrant KA, Hart ADM (1991) Exposure of starlings, house sparrows and skylarks to pesticides. In: Greig-Smith PW, Frampton GK, Hardy AR (eds) The Boxworth Project: Pesticides, cereal farming and the environment. HMSO, London. In press

  17. Wallace KB, Herzberg U (1988) Reactivation and aging of phosphorylated brain acetylcholinesterase from fish and rodents. Toxicol Appl Pharmacol 92:307–314

  18. Westlake GE, Blunden CA, Brown PM, Bunyan PJ, Martin AD, Sayers PE, Stanley PI, Tarrant KA (1980) Residues and enzyme changes in wood mice from the use of chlorfenvinphos and an organomercurial fungicide on winter wheat seed. Ecotoxicol Environ Safety 4:1–16

  19. Zinkl JG, Roberts RB, Henny CJ, Lenhart DJ (1980) Inhibition of brain ChE activity in forest birds and squirrels exposed to aerially applied acephate. Bull Environ Contam Toxicol 24:676–683

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Thompson, H.M., Walker, C.H. & Hardy, A.R. Inhibition of avian esterases by organophosphorus insecticides: Problems of reactivation and storage. Arch. Environ. Contam. Toxicol. 20, 509–513 (1991).

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  • Ethyl
  • Diethyl
  • Acetylcholinesterase
  • Chemical Reactivation
  • Thio