Role of soluble guanylate cyclase in reactivation of choline esterase inhibited by phosphoorganic compounds

• Published in: Biochemistry (Moscow) Vol. 64; no. 1; pp. 91 - 94
• Main Authors: Pyatakova, N V, Grigoryev, N B, Severina, I S
• Format: Journal Article
• Language: English
• Published: United States 01.01.1999
• Subjects: Blood Platelets - enzymology; Cholinesterase Reactivators - pharmacology; Cholinesterases - metabolism; Guanylate Cyclase - physiology; Humans; Hydroxylamine - pharmacology; In Vitro Techniques; Nitric Oxide - metabolism; Organophosphorus Compounds - pharmacology; Oximes - pharmacology; Pralidoxime Compounds - pharmacology; Trimedoxime - pharmacology
• ISSN: 0006-2979

The effects of possible activators of soluble guanylate cyclase were studied. Hydroxylamine and some oxime derivatives such as pyridinium aldoximes and bispyridinium dioxime (dipyroxime) were tested as possible guanylate cyclase activators. These compounds are known to be reactivators of choline esterase which has been preinhibited with phosphoorganic compounds. All the tested compounds were found to activate human platelet guanylate cyclase in the concentration range 10-6-10-3 M. The highest stimulatory affect was achieved at 10-4 M with hydroxylamine and dipyroxime: 210 +/- 10 and 320 +/- 15%, respectively. Potassium ferricyanide oxidation of these compounds under mild conditions formed nitroprusside ion, as registered by the electrochemical (polarographic) method; this is evidence that these compounds are NO donors. It is concluded that the activation of guanylate cyclase by the tested compounds is associated with their ability to generate NO during their biotransformation. The possible role of guanylate cyclase activation by oxime derivatives in the mechanism underlying the reactivation of inhibited choline esterase at the cell level is discussed.