Abstract
We present a method for the analysis of urinary 16(5α)-androsten-3α-ol together with 5β-pregnane-3α,20α-diol and four testosterone metabolites: androsterone (Andro), etiocholanolone (Etio), 5α-androstane-3α,17β-diol (5αA), 5β-androstane-3α,17β-diol (5βA) by means of gas chromatography/combustion/isotopic ratio mass spectrometry (GC/C/IRMS). The within-assay and between-assay precision S.D.s of the investigated steroids were lower than 0.3 and 0.6‰, respectively. A comparative study on a population composed of 20 subjects has shown that the differences of the intra-individual δ 13C-values for 16(5α)-androsten-3α-ol and 5β-pregnane-3α,20α-diol are less than 0.9‰. Thereafter, the method has been applied in the frame of an excretion study following oral ingestion of 50 mg DHEA initially and oral ingestion of 50 mg pregnenolone 48 h later. Our findings show that administration of DHEA does not affect the isotopic ratio values of 16(5α)-androsten-3α-ol and 5β-pregnane-3α,20α-diol, whereas the isotopic ratio values of 5β-pregnane-3α,20α-diol vary by more 5‰ upon ingestion of pregnenolone. We have observed δ 13C-value changes lower than 1‰ for 16(5α)-androsten-3α-ol, though pregnenolone is a precursor of the 16-ene steroids. In contrast to 5β-pregnane-3α,20α-diol, the 16-ene steroid may be used as an endogenous reference compound when pregnenolone is administered.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
