[Comparative studies on multiple forms of serum cholinesterase in various species]

Multiple forms of serum cholinesterase (ChE) were compared in 8 species by electrophoretic technique and the following characteristics were noted. The first moving fraction markedly hydrolyzed butyrylthiocholine and the activity was not inhibited by 10(-5)M eserine in the serum of some rabbits tested. Electrophoretic patterns of the ChE were obtained by use of two thiocholines as substrate, and the number of fractions against acetylthiocholine were more than against butyrylthiocholine in dogs, miniature pigs, rabbits, and hamsters. The activities of ChE fractions of dogs (C3), miniature pigs (C1, C2), rabbits (C1), and hamsters (C3) were inhibited by 6.1 X 10(-2)M caffein but not by 10(-4)M ethopropazine, which suggests that the fractions are all true-ChE.