Studies on serum cholinesterase isoenzymes in laboratory animals: Serum cholinesterase isoenzyme patterns and cholinesterase activities animal species.

We analyzed cholinesterase (ChE) isoenzyme patterns of various laboratory animal species using electrophoresis to explore possible species-related variations and also to determine if there is a relationship between the ChE activity and the ChE isoenzyme pattern.<br>The laboratory animals that we used were Standard Wistar and Spraque-Dawley rats, Djungarian hamsters, Hartley guinea pigs, Japanese white rabbits (JW-NIBS strain), Beagle dogs, Japanese monkeys, Yorkshire pigs, Thoroughbred horses and Japanese quail. The ChE isoenzyme patterns were determined using polyacrylamide gradient gel electrophoresis (PAG-EP). The activity of serum ChE was measured using Ellman's method. The ChE isoenzymes of Wistar and Sprague-Dawley rats consisted of six separate fractions and sex- and/or age-related differences in the number of fractions were not observed. However, a sex-related variation was observed in the proportions of individual ChE isoenzyme bands for both rat strains. Also a sex-related difference was demonstrated in the serum ChE activity. The number of fractions of the ChE isoenzyme exhibited a species-related variations in the other animals. Hamsters, guinea pigs, rabbits, dogs, monkeys, pigs, horses and quails had 4, 3, 4, 3-5, 3, 3, 4 and 3 ChE isoenzyme bands, respectively. However, with the exception of the rats, the hamsters, guinea pigs, rabbits, dogs, monkeys, pigs, horses and quail did not show any sex-related difference in the proportions of their ChE isoenzyme bands or in the ChE activities.<br>Therefore, it appears that there is a relationship between the serum ChE activity and the proportion of ChE isoenzyme bands. These results suggest a possible species-related variation in the mode of polymerization of serum ChE subunits that constitute the ChE isoenzymes.