The combined ratio of Phase II metabolites of Testosterone in males and females after various application forms

Code: 20C09GG

Today, the steroid profiling mainly relies on the analysis of glucuronide metabolites. After the selective hydrolysis of the glucuronide moiety, the corresponding free steroid is analyzed by gas chromatography – mass spectrometry (GC-MS) subsequent to silylation of hydroxyl - and keto-groups. The inclusion of sulfate metabolites has previously been difficult due to a non-efficient hydrolysis to the corresponding phase I metabolites. Consequently, an important piece of information about alterations in the steroid metabolism after testosterone doping is not monitored so far. During the last years, the direct analysis of phase II steroid metabolites by liquid chromatography – mass spectrometry (LC-MS) has been described.

 In a previous study, conducted by the current research team, the implementation of sulfate androgen metabolites in the steroid profile was investigated after the intramuscular administration of a single dose of testosterone esters to six healthy volunteers. For this purpose, a LC-MS method was developed and validated which allowed for the quantification of eight conjugated steroids within the same run. As an outcome of this study, a promising potential marker for the intake of exogenous testosterone, the ratio of [testosterone glucuronide/testosterone sulfate]/[epitestosterone glucuronide /epitestosterone sulfate] = (TG/TS/EG/ES). This ratio is further called “combined ratio”. 

The hereby proposed study represents a follow up project aiming at the investigation of the impact of endogenous sulfate steroid metabolites on the steroid profile after additional routes of administration – oral and transdermal, in addition to the already examined one - intramuscular. Also, as an additional element, the current study will be expanded to include male and female subjects. Furthermore, the already existing analytical data for the Phase II metabolites of Testosterone will be enriched. The proposed study is expected to increase knowledge of the usefulness of the combined ratio as a complementary biomarker for testosterone abuse