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Quantitative analysis of eight testosterone metabolites using column switching and liquid chromatography/tandem mass spectrometry
Author(s) -
Magnusson Mats O.,
Sandström Rikard
Publication year - 2004
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.1450
Subject(s) - chemistry , chromatography , androstenedione , tandem mass spectrometry , liquid chromatography–mass spectrometry , electrospray , mass spectrometry , substrate (aquarium) , enzyme , metabolism , quantitative analysis (chemistry) , androgen , biochemistry , hormone , oceanography , geology
The rate at which testosterone is metabolized to different singly hydroxylated metabolites has been widely used as an in vitro marker for activity of different CYP450 enzymes. The interest in extra‐hepatic metabolism, e.g. due to metabolism in the gut wall, has increased during the last decade. Measurement of extra‐hepatic enzyme activity using testosterone as a substrate requires a highly sensitive analytical method. A new liquid chromatography/electrospray tandem mass spectrometry (LC/MS/MS) method, using column switching for online cleaning and desalting of samples, was developed and validated for analysis of 2 α ‐, 2 β ‐, 6 α ‐, 6 β ‐, 7 α ‐, 16 α ‐, and 16 β ‐hydroxytestosterone and androstenedione. The samples were injected on a SB‐CN column and detection was performed using MS/MS. The limits of quantification ranged from 0.3 to 3.33 nM for the different metabolites. The validated method was used to quantify the enzyme activity in rat intestine mucosa. The formation rates of 16 α ‐, 16 β ‐hydroxytestosterone and androstenedione were quantified, and 2 β ‐and 6 β ‐hydroxytestosterone were formed above the limits of detection. Copyright © 2004 John Wiley & Sons, Ltd.