Comparative Hydrolysis of Certain Dental Local Anesthetics by Human Serum and Plasma

¹ American Dental Association, Chicago, Illinois

The results of comparative experiments with human serum show that acetylcholine is hydrolyzed about 138 to 179, metabutethamine 30 to 35, meprylcaine 15 to 21, piperocaine 5 to 8, and butethamine 0.5 to 0.6 times faster than procaine. An apparent over-all parallelism exists between the rate of hydrolysis of acetylcholine and of the ester-type local anesthetics. In addition, divergent results obtained with respect to the effect of anticoagulants and of time suggest the existence of several cholinesterases having variable activity in regard to the hydrolysis of the ester-type local anesthetics.