An alternative approach to the prevention of succinyldicholine-induced apnoea.
Succinyldithiocholine was utilized as a substrate analogue of succinyldicholine to study normal and atypical serum pseudocholinesterase (EC 3.1.1.8). In the method, the enzyme acts on succinyldithiocholine to release thiocholine, which reacts with 5,5'-dithio-bis-(2-nitrobenzoic acid) to produce a coloured compound with maximal absorbance at 410 nm. The procedure appears to be precise (between-day analysis gives a coefficient of variation between 1.1 and 3.7%) and amenable to automation, permitting routine use in any laboratory. The reference interval for 300 healthy adults with "usual" cholinesterase genotype was estimated to be 34-77 U/l, with a significant difference between males and females (40-78 U/l for men and 33-76 U/l for women, p less than 0.01). The median activity in 105 individuals with "heterozygous" cholinesterase genotype was 22 U/l (range 5-35 U/l), and for 14 "atypical" homozygotes 1.5 U/l (range 1-4 U/l). The assay with succinyldithiocholine may offer a direct procedure for preoperative screening of individuals with an abnormal response to the muscle relaxant succinyldicholine, thus avoiding the determination of genotype by measurement of inhibitor numbers.
Panteghini
M
M
1. Laboratorio Analisi Chimico-Cliniche, Spedali Civili, Brescia, Italy.
Bonora
R
R
Pagani
F
F
D001049:Apnea / Q000139:chemically induced / Q000517:prevention & control*; D002091:Butyrylcholinesterase / Q000097:blood*; D002802:Cholinesterases / Q000097:blood*; D006801:Humans; D008722:Methods; D013390:Succinylcholine / Q000009:adverse effects*
D002091:Butyrylcholinesterase; D002802:Cholinesterases; D013390:Succinylcholine