Serum cholinesterase isoenzyme pattern and serum cholinesterase activity in wistar rats of different sex and age.

Abstract

Our analysis of serum cholinesterase (ChE) isoenzyme pattern and serum cholinesterase activity using Wistar rats disclosed the following sex- and age-related differences:1. The ChE isoenzymes of the Wistar rats were found to consist of six distinct fractions. There were no detectable sex- or age-related variation in the number of ChE fractions.2. In the female rats, band 6 was present in the highest proportion, 73% (relative concentration) of the sum of six bands, followed by band 5 that accounted for 19%. Bands 6 and 5 were regarded as the main bands and bands 3, 2, 1, and 4 (in descending order) were considered as sub-bands. In the male rats, the proportion of band 5 was almost equal to that of band 6 for the six week old group. The proportion of band 5 (70%) was much higher than that of band 6 (17%) for the twelve week old group. Thus, a sex-related difference was detected in the proportion of the bands, as well as an agerelated difference.For the determination of the rat serum ChE activity, Ellman's method, which utilizes acetylthiocholine (AcSCh) as a substrate, proved to be more suitable than the method which uses acetylcholine (ACh), because the ChE activity determined using the latter method can be less than that determined by the former method, particularly for female rats during their growth phase.