Accession Number:

ADA058683

Title:

Reactions of Methamidophos with Mammalian Cholinesterase,

Descriptive Note:

Corporate Author:

FEDERAL AVIATION ADMINISTRATION WASHINGTON D C OFFICE OF AVIATION MEDICINE

Report Date:

1978-07-01

Pagination or Media Count:

10.0

Abstract:

The lethality of methamidophos, a phosphoramidothioate, to rats i.p. LD50, 15 mgkg, is similar to that of such potent organophosphate compounds as parathion and paraoxon. Certain distinctive features of its chemical structure, and reported failure of cholinesterase inhibited with methamiodophos to reactivate spontaneously in insects, prompted this study of its reactions with mammalian cholinesterase to determine if the treatment of poisoning requires modification. Atropine 10 mgkg or pralidoxime 60 mgkg afforded significant protection against lethality from methamidophos LD50s, 60 or - 0.4 and 52 or - 4.9 mgkg, respectively. Partial spontaneous recovery of inhibited cholinesterase activity was observed. However, a single dose of pralidoxime, given essentially simultaneously with methamidophos, did not hasten the recovery of cholinesterase activity. Author

Subject Categories:

  • Biochemistry
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE