Detection of N-monomethyl-lysine generated by metabolic transmethylation.
Administration of radiolabelled deprenyl to rats resulted in the urinary elimination of a (14)C-labelled N(epsilon)-monomethyl-lysine. An increased level of N(epsilon)-monomethyl-lysine was found following an oral dose of another drug, also containing an N-methyl group. The urine sample was treated with 9-fluorenylmethoxycarbonyl chloride and then subjected to high-performance liquid chromatography (HPLC); the radioactive fraction was identified as N(epsilon)-monomethyl-lysine by using HPLC-MS in electrospray mode. Identification of N(epsilon)-monomethyl-lysine in the radioactive fraction gives experimental proof of transmethylation from a well-known drug to an endogenous compound.
Kalász
Huba
H
Department of Pharmacology and Pharmacotherapy, Semmelweis University, 1089 Budapest, Nagyvárad tér 4, Hungary. Huba@kalasz.com
Klebovich
Imre
I
Balogh-Nemes
Katalin
K
Szilágyi
Agnes
A
Tihanyi
Mária
M
Szarvas
Tibor
T
Lengyel
József
J
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005449:Fluorenes / Q000737:chemistry; D008239:Lysine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000652:urine; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D012642:Selegiline / Q000008:administration & dosage; D012680:Sensitivity and Specificity
D005449:Fluorenes; C005205:epsilon-N-methyllysine; D012642:Selegiline; C054007:1-(9-fluorenyl)methyl chloroformate; D008239:Lysine