The hydrolysis of indoxyl esters by rat esterases

Abstract

Unsubstituted indoxyl esters are hydrolyzed by rat-erythrocyte preparations, plasma and liver homo-genates at a considerably greater rate than any of the corresponding choline esters. The enzymes chiefly responsible for the hydrolysis of the indoxyl esters are organophosphate-sensitive esterases. Under the experimental conditions described, cholinesterases of erythrocyte preparations and plasma contributed only a fraction of the total hydrolysis, and any contribution by liver cholinesterase was too small to be detected. An organophosphate-resistant esterase may contribute to an extent of not more than 10% in each case. The organophosphate Ro 3-0422 is a more selective anticholinesterase than eserine and was successfully used as such with all three enzyme preparations.