In Vitro Cysteine Reactivates Organophosphate Insecticide Dichlorvos-Inhibited Human Cholinesterases.
Sultan Qaboos Univ Med J
; 17(3): e293-e300, 2017 Aug.
Article
en En
| MEDLINE
| ID: mdl-29062551
ABSTRACT
OBJECTIVES:
Organophosphate (OP) pesticides inhibit both red blood cell (RBC) and plasma cholinesterases (ChEs). Oximes, especially pralidoxime (2-PAM), are widely used as antidotes to treat OP poisoning. In addition, N-acetylcysteine (NAC) is sometimes used as an adjuvant antidote. The current study aimed to assess the feasibility of using NAC as a single therapeutic agent for OP poisoning in comparison to in vitro 2-PAM.METHODS:
This study was carried out at the Razi Drug Research Center of Iran University of Medical Sciences, Tehran, Iran, between April and September 2014. A total of 22 healthy human subjects were recruited and 8 mL citrated blood samples were drawn from each subject. Dichlorvos-inhibited blood samples were separately exposed to low and high doses (final concentrations of 300 and 600 µmol.L-1, respectively) of 2-PAM, NAC and cysteine. Plasma and RBCs were then separated by centrifugation and their ChE activity was measured using spectrophotometry.RESULTS:
Although cysteine-and not NAC-increased the ChE activity of both plasma and RBCs over those of dichlorvos, it did not increase them over those of a high dose of 2-PAM.CONCLUSION:
These results suggest that the direct reactions of 2-PAM and cysteine with dichlorvos and the reactivation of phosphorylated ChEs occurr via an associative stepwise addition-elimination process. High therapeutic blood concentrations of cysteine are needed for the elevation of ChE activity in plasma and RBCs; however, both this agent and NAC may still be effective in the reactivation of plasma and RBC ChEs.Palabras clave
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Acetilcisteína
/
Inhibidores de la Colinesterasa
/
Reactivadores de la Colinesterasa
/
Colinesterasas
/
Cisteína
/
Activación Enzimática
/
Intoxicación por Organofosfatos
País/Región como asunto:
Asia
Idioma:
En
Revista:
Sultan Qaboos Univ Med J
Año:
2017
Tipo del documento:
Article