ИСТИНА

Neuropathy target esterase (NTE) of vertebrates is a specific target for neuropathic organophosphates (OPs). This neuronal enzyme is used as a biochemical marker for screening of OPs with respect to their ability to result in organophosphate-induced delayed neuropathy (OPIDN). The inhibition/aging of neuronal NTE within hours of exposure to OP predicts potential for the development of OPIDN after a delay of 1-3 weeks as it was demonstrated for experimental animals. Inaccessibility of human neuronal NTE restricts its practical use as a marker of human neuropathic OP exposure as a result from occupational, environmental, accidental or others OP contacts). The inhibition of NTE activity in circulating lymphocytes and/or platelets could be practically used. However blood cells isolation its time-consuming process providing relatively low yield of cells for NTE assay. This restricts the use of lymphocytes/platelets to monitor routinely NTE activity among individuals exposed to OPs in field and factory conditions. Bioelectrochemical analysis of neuropathy target esterase (NTE) and its inhibitors is based on the combination of the NTE-catalyzed hydrolysis of phenyl valerate and phenol detection by a tyrosinase biosensor. The use of the tyrosinase electrode remarkably improves the sensitivity of NTE detection. The tyrosinase biosensor was found to be suitable for measurements in whole blood where spectrophotometric detection is considerably restricted. Only short homogenation was used as a pretreatment of blood. The specificity of NTE in blood for neuropathic OP was close to that for neuronal and lymphocyte NTE. In order to use blood NTE as a mirror of brain NTE,the correlation between the inhibition of the enzyme in brain and blood should be known. The inhibition of NTE in brain, lymphocytes, and blood of experimental animals was studied in 24 hr after accute i.m. treatment with increasing doses of neuropathic OP o,o-dipropyldichlorvinylphosphate (C3H7O)2P(O)CH=CCl2(PrDClVP). PrDClVP inhibited NTE in a dose-responsive manner and a good agreement was found between brain, lymphocyte and blood NTE inhibition. The obtained results look promising for the development of monitoring system that could be routinely used for individuals exposed to neuropathic OPs.