Use of ethopropazine and BW 284C51 as selective inhibitors for cholinesterases from various species.

ABSTRACT

Both inhibitors tested were still able to depress the cholinesterase (ChE) for which it is not selective (BW 284C51 for pseudo ChE, ethopropazine for the true ChE) provided the concentration was high (greater than 10(-2) M). BW 284C51 totally depressed the true ChE activity from bovine erythrocytes at a concentration of 10(-6) M. This inhibitor concentration gave no depression of pseudo ChE activity from horse serum. Ethopropazine totally depressed the pseudo ChE activity from horse serum at a concentration of 5 X 10(-5) M. The true ChE was not inhibited at this concentration. For true ChE from bovine erythrocytes and pseudo ChE from horse serum BW 284C51 and ethopropazine therefore certainly have a potential as selective ChE inhibitors. Ethopropazine at a concentration of 5 X 10(-6) M completely inhibited the pseudo ChE activity in rat plasma and cortex without affecting true ChE activity. BW 284C51 at a concentration of 10(-6) M gave a total depression of the true ChE activity in these preparations. In rat plasma, however, a considerable part of the pseudo ChE activity was depressed at this concentration.