Analysis of testosterone-hydroxylated metabolites in human urine by ultra high performance liquid chromatography-Mass Spectrometry.

Testosterone regulates the male reproductive system and acts directly or indirectly on nearly all systems during fetal, pubertal and adult life. Testosterone homeostasis depends on its synthesis and degradation. The major biotransformation reactions are hydroxylation by different cytochrome P450 (CYP) isoforms. There are no described methods to determine the profile of testosterone-hydroxylated metabolites in human urine. The aim of this study was to develop an analytical method to determine testosterone-hydroxylated metabolites in human urine using UPLC-MS. Seven testosterone-hydroxylated metabolites, androstenedione, and testosterone, were identified by comparison of their t and positive electrospray ionization (ESI) data, with those of analytical standards. The method developed is sensitive, specific, repeatable, and precise. Limits of detection and quantitation for all compounds ranged from 1.360 to 13.054 ng/ml and 4.234-39.679 ng/ml, respectively. The percentages of recovery were between 81.2 and 128.8%. The applicability of the analytical method was confirmed by analysis of urine samples obtained from two groups of healthy men (25-30 and 50-75 years old). All analytes were identified with slightly different metabolites profiles in both groups. In conclusion, the UPLC-MS method developed here was validated for the analysis of testosterone-hydroxylated metabolites in human urine.