Application of Assay of Platelet Monoamine Oxidase Type-B (MAO-B) Activity to the Discrimination of Selegiline Use from Methamphetamine Abuse

Munehiro Katagi, Hiroe Tsutsumi, Michiaki Tatsuno, Tohru Kamata, Hiroshi Nishioka, Akihiro Miki, Kunio Nakajima, Hitoshi Tsuchihashi
2003 Journal of health science  
An assay of platelet monoamine oxidase type-B (MAO-B) activity has been explored in the search for a reliable method of discriminating selegiline (SG) use from methamphetamine (MA) abuse. MAO-B activity was measured by fluorimetry of 4-hydroxyquinoline (4HOQ) produced by oxidative deamination of kynuramine, the substrate for MAO-B. MA and most of its related compounds including its precursors produced no platelet MAO-B inhibition in vitro even at their lethal levels, though SG, its specific
more » ... G, its specific metabolites selegiline N-oxide (SGO) and N-desmethylselegiline (DM-SG), as well as its enantiomer d-deprenyl exhibited high platelet MAO-B inhibitory potency. In vivo, remarkable inhibition of MAO-B occurred even within an hour after drug administration, and the inhibition apparently lasted approximately 6-8 days after both 2.5 and 7.5 mg oral doses of SG hydrochloride. The present study suggests that the decrease of platelet MAO-B activity would be a significant marker to discriminate SG use from MA abuse, even a week after drug use.
doi:10.1248/jhs.49.189 fatcat:xs5xprsp75fqnmds2vtehhcfnu