Home About us MoEF Contact us Sitemap Tamil Website  
About Envis
Whats New
Microorganisms
Research on Microbes
Database
Bibliography
Publications
Library
E-Resources
Microbiology Experts
Events
Online Submission
Access Statistics

Site Visitors

blog tracking


 
The Journal of Steroid Biochemistry and Molecular Biology
Vol.
129, No. (1-2), 2012; Pages: 54 - 60

Investigations of the microbial transformation of cortisol to prednisolone in urine samples

Michael Bredehöft, Rainer Baginski, Maria-Kristina Parr, Mario Thevis, Wilhelm Schänzer

Institute of Biochemistry, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933 Cologne, Germany.

Abstract

Doping control samples are normally collected under non-sterile conditions and sometimes, storage and transportation are influenced by parameters such as the temperature. Therefore, microbial contamination and subsequent alteration of a sample's composition are possible. Studies regarding sample collection in cattle breeding have already shown enzymatic transformation of endogenous testosterone to boldenone causing false-positive findings. The aim of the present study was to investigate whether positive doping cases with the synthetic corticosteroids prednisolone and prednisone may result from microbial transformation of the endogenous corticosteroids cortisol and cortisone, respectively. A method comprising parameters such as pH values and screening results for synthetic glucocorticosteroids as well as incubation experiments followed by liquid chromatographic and mass spectrometric analysis was employed to test for contaminating germs with Δ1-dehydrogenase activity. Over 700 urine samples comprising inpatient and doping control specimens were investigated. In none of them, 1,2-dehydrogenating activity was confirmed. These findings are in accordance with other studies. However, the problem of microbial alteration of doping control specimens with special respect to 1,2-dehydrogenation must not be underestimated.

Keywords: Corticosteroids; Dehydrogenation; Biotransformation; Cortisol; Prednisolone; Bacteria; Doping analysis


 

 

 
Copyright © 2005 ENVIS Centre ! All rights reserved
This site is optimized for 1024 x 768 screen resolution