Comparative analysis of esterase activities of human, mouse, and rat blood.

Acetylcholinesterase, butyrylcholinesterase, carboxylesterase, and paraoxonase activities in human, mouse, and rat blood were measured. The proportions of these enzymes activities differed significantly. In humans, the most significant were cholinesterase activities, while in rats and mice the contribution of carboxylesterase activity was the greatest. High arylesterase activity of paraoxonase was observed in all cases. Species-specific differences should be taken into consideration when carrying out preclinical trials on rodents for optimization of the pharmacokinetic characteristics of drugs containing complex ester groups.