Archives of Toxicology

, Volume 68, Issue 10, pp 648–655 | Cite as

In vitro oxime-induced reactivation of various molecular forms of soman-inhibited acetylcholinesterase in striated muscle from rat, monkey and human

  • John G. Clement
  • Nancy Erhardt


The purpose of this study was to compare the in vitro reactivation of the various molecular forms of soman-inhibited acetylcholinesterase by oximes such as HI-6, toxogonin and PAM, in striated muscle tissue from three species-rat, monkey and human. To simulate the various in vivo conditions the oxime was present either 5 min before and after (Pre-Post) or 5 min after (Post) exposure to the nerve agent soman. In the Pre-Post mode the oxime effects would result from a combination of not only shielding of acetylcholinesterase from soman inhibition but also from immediate reactivation of soman-inhibited acetylcholinesterase. In the Post experimental group the increase in soman-inhibited acetylcholinesterase activity was due to reactivation. HI-6 (Pre-Post) increased significantly the activity of soman-inhibited acetylcholinesterase in the rat, human and monkey muscle. HI-6 (Post) was a highly effective reactivator of soman-inhibited acetylcholinesterase in the rat muscle and moderately so in the human and monkey muscle. Toxogonin (Pre-Post) and toxogonin (Post) were effective in increasing soman-inhibited acetylcholinesterase activity in rat muscle but were relatively ineffective in the human and monkey muscle. PAM (Pre-Post) and PAM (Post) were ineffective in increasing soman-inhibited acetylcholinesterase activity in muscle from all species examined. Effectiveness of oxime-induced reactivation of soman-inhibited acetylcholinesterase could be estimated from the total acetylcholinesterase activity which appears to reflect the results found with the individual molecular forms of acetylcholinesterase. In addition, SAD-128, a non-oxime bispyridinium compound, appeared to enhance significantly the HI-6 induced reactivation of soman-inhibited acetylcholinesterase in human but not rat striated muscle.

Key words

Oxime Soman Acetylcholinesterase Striated muscle Rat Human Monkey 


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  1. Berends F (1987) Mechanisms of ageing of organophosphate-inhibited esterases. In: De Matteis F, Lock EA (eds) Structure molecular mechanisms toxicity, McMillan Press, UK, pp 125–152Google Scholar
  2. Boskovic B (1981) The treatment of soman poisoning and its perspectives. Fundam Appl Toxicol 1: 203–213CrossRefPubMedGoogle Scholar
  3. Clement JG (1979) Efficacy of PRO-PAM (Af-methyl-l,6-dihydropyridine-2-carbaldoxime hydrochloride) as a prophylaxis against organophosphate poisoning. Toxicol Appl Pharmacol 47: 305–311CrossRefPubMedGoogle Scholar
  4. Clement JG (1981) Toxicology and pharmacology of bispyridinium oximes — insight into the mechanism of action vs soman poisoning in vivo. Fundam Appl Toxicol 1: s193-s202CrossRefGoogle Scholar
  5. Clement JG (1983) Efficacy of mono- and bis-pyridinium oximes versus soman, sarin and tabun poisoning in mice. Fundam Appl Toxicol 3: 533–535CrossRefPubMedGoogle Scholar
  6. Clement JG (1991) Variability of sarin-induced hypothermia in mice: investigation into incidence and mechanism. Biochem Pharmacol 42: 1316–1318CrossRefPubMedGoogle Scholar
  7. Clement JG, Lee MJ, Simons KJ, Briggs CJ (1990) Pharmacokinetics of the acetylcholinesterase oxime reactivator, HI-6, in rhesus monkeys (Macaca mulatto): effect of atropine, diazepam and methoxyflurane anesthesia. Biopharm Drug Dispos 11: 227–232CrossRefPubMedGoogle Scholar
  8. Clement JG, Pierce CH, Houle J-M (1992) Ascending dose tolerance study of the oxime, HI-6, in man. Proc 4th International Symposium, Protection Against Chemical Warfare Agents, June 8-12, 1992 Stockholm, SwedenGoogle Scholar
  9. Clement JG, Madill HD, Bailey DG, Spence JD (1993) Clinical study of a new therapy for nerve agent poisoning: ascending dose tolerance study of HI-6 + atropine in man. United States Army 1993 Medical Defense Bioscience Review. May 10-13,1993 Baltimore, Md.Google Scholar
  10. Clement JG, Rosario S, Bessette E, Erhardt N (1991) Soman and sarin inhibition of molecular forms of acetylcholinesterase in mice: time course of recovery and reactivation by the oxime HI-6. Biochem Pharmacol 42: 329–335CrossRefPubMedGoogle Scholar
  11. DeJong LPA, Wolring GZ (1980) Reactivation of acetylcholinesterase inhibited by l,2,2'-trimethylpropyl methylphosphonofluoridate (soman) with HI-6 and related oximes. Biochem Pharmacol 29: 2379–2387CrossRefGoogle Scholar
  12. DeJong LPA, Wolring GZ (1984) Stereospecific reactivation by some Hagedorn-oximes of acetylcholinesterases from various species including man, inhibited by soman. Biochem Pharmacol 33: 1119–1125CrossRefGoogle Scholar
  13. Ellman GL, Courtney KD, Andres V, Featherstone RM (1961) A new and rapid colorimetric determination of acetylcholinesterase activity. Biochem Pharmacol 7: 88–95CrossRefPubMedGoogle Scholar
  14. Ferguson G (1971) Statistical analysis in psychology and education, McGraw-Hill, New YorkGoogle Scholar
  15. Grubic Z, Tomazic A (1989) Mechanism of action of HI-6 on soman inhibition of acetylcholinesterase in preparations of rat and human skeletal muscle; comparison to SAD-128 and PAM-2. Arch Toxicol 63: 68–71CrossRefPubMedGoogle Scholar
  16. Hamilton MG, Lundy PM (1989) HI-6 therapy of soman and tabun poisoning in primates and rodents. Arch Toxicol 63: 144–149CrossRefPubMedGoogle Scholar
  17. Harris LW, Heyl WC, Stitcher DL, Broomfield CA (1978) Effects of 1,1-oxydimethylene bis-(4-tert-butylpyridinium chloride) (SAD-128) and decamethonium on reactivation of soman and sarin-inhibited Cholinesterase by oximes. Biochem Pharmacol 27: 757–761CrossRefPubMedGoogle Scholar
  18. Heffron PF, Hobbiger F (1979) Relationship between inhibition of acetylcholinesterase and response of the rat phrenic nerve-diaphragm preparation to indirect stimulation at higher frequencies. Br J Pharmacol 66: 323–329PubMedGoogle Scholar
  19. Inestrosa NC, Perelman A (1989) Distribution and anchoring of molecular forms of acetylcholinesterase. Trends Pharmacol Sei 10: 325–329CrossRefGoogle Scholar
  20. Koelle GB, Gilman A (1946) The chronic toxicity of di-isopropyl fluorophosphate (DFP) in dogs, monkeys and rats. J Pharmacol Exp Ther 87: 435–448PubMedGoogle Scholar
  21. Kusic R, Boskovic B, Vqjvodic V, Jovanovic D (1985) HI-6 in man: blood levels, urinary excretion and tolerance after intramuscular administration of the oxime to healthy volunteers. Fundam Appl Toxicol 5: S89-S97CrossRefPubMedGoogle Scholar
  22. Lipp J, Dola T (1980) Comparison of the efficacy of HS-6 versus HI-6 when combined atropine, pyridostigmine and clonazepam for soman poisoning in the monkey. Arch Int Pharmacodyn Ther 246: 138–148PubMedGoogle Scholar
  23. Lomax P, Kokka N, Lee R (1986) Acetylcholinesterase inhibitors and thermoregulation. In: Cooper K, Lomax P, Schonbaum G (eds) Homeostasis thermal stress. 6th International Symposium, Karger, Basel, pp 108–112Google Scholar
  24. Massoulie J, Bon S (1982) The molecular forms of Cholinesterase and acetylcholinesterase in vertebrates. Annu Rev Neurobiol 5: 57–106CrossRefGoogle Scholar
  25. Meeter E, Wolthuis OL (1968) The spontaneous recovery of respiration and neuromuscular transmission in the rat after anticholinesterase poisoning. Eur J Pharmacol 2: 377–386CrossRefPubMedGoogle Scholar
  26. Puu G, Artursson E, Bucht G (1986) Reactivation of nerve agent inhibited human acetylcholinesterases by HI-6 and obidoxime. Biochem Pharmacol 35: 1505–1510CrossRefPubMedGoogle Scholar
  27. Schoene K (1978) Aging of soman-inhibited acetylcholinesterase: inhibitors and accelerators. Biochim Biophys Acta 525: 468–471PubMedGoogle Scholar
  28. Shih TM (1993) Comparison of several oximes on reactivation of soman-inhibited blood, brain and tissue Cholinesterase activity in rats. Arch Toxicol 67: 637–646CrossRefPubMedGoogle Scholar
  29. Stale A, Sentjurc M (1990) A contribution to the mechanism of action of SAD-128. Biochem Pharmacol 40: 2511–2517CrossRefGoogle Scholar
  30. Tattersall JEH (1993) Ion channel blockade by oximes and recovery of diaphragm muscle from soman poisoning in vitro. Br J Pharmacol 108: 1006–1015PubMedGoogle Scholar
  31. Van Helden HPM, Van der Weil HJ, DeLange J, Busker RW, MelchersBPC, Wolthuis OL (1992) Therapeutic efficacy of HI-6 in soman poisoned marmoset monkeys. Toxicol Appl Pharmacol 115: 50–56CrossRefPubMedGoogle Scholar
  32. Wolthuis OL, Kepner LA (1978) Successful oxime therapy one hour after soman intoxication in the rat. Eur J Pharmacol 49: 415–425CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • John G. Clement
    • 1
  • Nancy Erhardt
    • 1
  1. 1.Biomedical Defence SectionDefence Research Establishment SuffieldRalstonCanada

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