Studies on aspirin esterase of human serum.

Abstract We studied the aspirin-hydrolyzing activity in human serum and found a difference between the sexes in the aspirin-hydrolyzing activity expressed in mU salicylic acid released from ml of serum. However, aspirin-hydrolyzing activity expressed in mU salicylic acid per ml albumin showed no such difference. In cases of chronic hepatitis, liver cirrhosis and nephrosis, the aspirin-hydrolyzing activity was much lower than that seen healthy persons. In disc electrophoretic experiments, the aspirinhydrolyzing activity was found to be located in pseudocholinesterase and albumin and this activity in the cholinesterase region was inhibited by eserine sulfate. When the albumin from human serum was purified by chromatography on DEAE-cellulose and Sephadex G-100, the purified albumin hydrolyzed aspirin and this aspirin-hydrolyzing activity of purified albumin, although not inhibited by eserine sulfate and diisopropyl fluorophosphate, was inhibited by treatment with acetic anhydride. These results suggest that the aspirin-hydrolyzing activity from human serum included the pseudocholinesterase activity and acetylation effect of aspirin.