RAT LIVER D-BETA-HYDROXYBUTYRATE DEHYDROGENASE .3. INHIBITION BY TOPICAL ANESTHETICS

A series of topical anesthetic agents of quite diverse structure was found to inhibit a solubilizedand partially purified preparation of the phosphatidylcholine- requiring enzyme, o-β-hydroxybutyrate dehydrogenase. Except for the tertiary amines, dibucaine, tetracaine, and quinine, the enzyme inhibitory potency of the various agents correlated well with their anesthetic potency. The same results were obtained whether the enzym was activated with purified phosphatidylcholine or a mixture of mitochondrial lipids. The inhibition was competitive with respect to β-hydroxybutyrate or acetoacetate, but not with respect to nicotinamide-adenine dinucleotide. The inhibition by tetracaine was completely reversible; the inhibition by propanol was only partially reversible. © 1969, American Chemical Society. All rights reserved.