بررسي تداخل احتمالي پراليدوكسايم در سنجش فعاليت كولين استرازها به روش طيف سنجي در خون محيطي انسان

Evaluation of probable interaction of Pralidoxime in cholinesterase activity assay by colorimetric method in human peripheral blood

AIMS. Evaluation of probable interaction between Pralidoxime and thiocholine substrates by colorimetric Ellmanʹs method and its effect on cholinesterase activity assay in human peripheral blood. METHODS, 10 human peripheral blood samples were collected, We compared effect of Pralidoxime (PRX) and enzymes (ENZ) on Acetyl-thiocholine (ATC) and Butyryl-thiocholine (ETC) by Ellmanʹs method at 37"C. For each enzyme, absorbance of two experiment groups (Enzyme group [Enz(50~I+Sub(2mM)] and PRX group [PRX( IOO~M)+Sub(2mM)]) were read at 410nm against suitable control (all substances in test tube except enzyme and Pralidoxime) and used in enzyme activity calculation. Data analyzed by KruskalWallis test by Prism 5 software. We repeated PRX group with 3, 10,30. 100 and 30n ~M of pralidoxime in I up to 5 minute and calculated relation between false activity (without any enzyme) and PRX concentration or reaction times by correlation analysis. RESULTS. False activity due to PRX and ATC interaction in Ellmanʹs method was 19.4±3.736o/r of AChE activity. False activity due to PRX and BTC interaction in Ellmanʹs method was 8.2±1.474o/r of BehE activity. False activity had direct correlation with PRX concentration (r>0.89) and reverse correlation with reaction time (r<-0.9). CONCLUSION. Pralidoxime ability to dose and time dependent hydrolysis of thiochohnc substrates. seems to increases cholinesterase activity falsely. So Ellmanʹs method test has some limitation for cholinesterase activity assay in presence of Pralidoxime and usage of this test for concentrations more than 200J1M of Pralidoxime is not recommended.