Cholinesterase B

912

Enzymes

Cholinesterase (CHE)

Serum or plasma

R1: 4 x 50 mL;
R2: 4 x 9 mL,
Ready for use

Instructions for Use  |  Safety Data Sheet

For professional use only.

The Cholinesterase enzyme is synthesised in the liver. It is present in the pancreas, myocardium and serum. Cholinesterase activity in the serum is the result of the activity of 13 isoenzymes. It is an index of liver function, although it is seen to be altered only in cases of very advanced hepatitis or cirrhosis. Other clinical situations in which an alteration in the cholinesterase concentration can be seen are poisoning by organic compounds (anticryptogamic substances) and some forms of anaemia. The activity of this enzyme is also determined before subjecting patients to treatment with musclerelaxants containing succinylcholine. In 1949 G.B. Koele (1) used acetylthiocholine in the histochemical localisation of cholinesterase activity, making use of the enzyme’s capacity to hydrolyse C-S bonds as well as C-O bonds. In 1961 G.L. Ellman et al. (2) developed a method for the determination of cholinesterase using as substrate acetylthiocholine and 5-5’ dithio-bis-2-nitrobenzoic acid (DTNB) as revealer of the thiocholine which was freed enzymatically. Subsequently other authors (3,4) used butyrilthiocholine as substrate. The Cholinesterase B method is based on the optimisation of the reagents proposed by Szasz, and they are presented in stabilised liquid form.

Pseudocholinesterase (acylcholine acylhydrolase, EC 3.1.1.8) hydrolyses butyrylthiocoline to butyric acid and thiocholine which in turn reacts with DTNB. This reaction releases 5-thio-2-nitrobenzoic acid intensely coloured yellow.
Butyrilthiocholine + H2O --(Cholinesterase)--> Butyrate + Thiocholine
Thiocholine + DNTB --> 5-thio-2 nitrobenzoate (yellow colour)
The rate of colour appearance is directly proportional to cholinesterase activity.

Store at 2 - 8°C and protect from direct light. When correctly stored, the reagents are stable up the expiry date reported on the label. A slight variation in the composition of the reagent may occur between batches, but this has no effect on the test results. After opening, the vial R1 and R2 are stable 30 days if recapped immediately and protected from contamination, evaporation, direct light and stored at correct temperature.

Multicalibrator (R0300000006)
Normal control serum (R0400000006)
Pathological control serum (R0400000106)