Confirming suspected pesticides poisoning and monitoring the efficacy of treatment by measuring the plasma enzyme activity

ABSTRACT

The inhibitors of plasma cholinesterase include many diverse biologically active substances, the inhibitors which most frequently cause toxicological problems are the nerve gases and the systemic insecticides [parathion and malathion]. Most of these substances inhibit both acetylcholinesterase and plasma cholinesterase, in general the plasma enzyme is more susceptible to inhibition than the red cell enzyme, in consequence plasma cholinesterase activity has been used as a biochemical indicator for the presence of some types of inhibitors and to assess subsequent recovery. Measurement of plasma cholinesterase activity and determination of phenotypes by using fluoride and dibucaine as inhibitors has also shown to be a sensitive method for monitoring and controlling exposure to organophosphate [OP] compounds in medicolegal cases. The Organophosphate compounds are covalently bounded to the catalytic active site of cholinesterase enzyme which produces irreversible inhibition, a normal plasma cholinesterase activity excludes systemic poisoning by organophosphate. The classical method for phenotyping requires a good resolution of spectrophotometer to monitor at 240nm wave length, the rare of hydrolysis of benzolycholine by plasma cholinesterase in phosphate buffer pH 7.4 at 26°C, is observed and recorded on printer