Screening for the illegal use of clostebol acetate in cattle by identification of its urinary metabolites
Hendriks, L.; Gielen, B.; Leyssens, L.; Raus, J.
Veterinary Record 134(8): 192-193
1994
ISSN/ISBN: 0042-4900 PMID: 8171795 Document Number: 430251
The results of screening for anabolic steroids in slaughtered cattle has shown an increased incidence of the abuse of clostebol acetate (4-chlorotestosterone acetate, 4-chloro-17 beta -hydroxyandrost-4-ene-3-one acetate) when injection sites were examined; all urine samples were negative and the percentage of positive fat samples was lower than the percentage of positive infection site samples. To evaluate the metabolic pathway of clostebol acetate, an 18-month-old heifer and a 10 -month-old steer were treated with a single dose of clostebol acetate; urine samples collected before and at intervals after the injection were analysed by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC). Metabolites of clostebol acetate were still present in the urine 21 days after the injection. Gas chromatography, and mass spectrometry and chemical synthesis identified 7 metabolites. Two of the metabolites (4-chloro-epitestosterone and 4-chloro- Delta 4-androstene-3, 17-dione) were easily identified by HPLC and TLC. Chromatograms of 18 urine samples examined by routine methods detected 2 typical spots which were confirmed to be 4-chloro-epitestosterone and 4-chloro- delta 4-androstene-3,17-dione. Since no endogenous chlorinated steroids are present in cattle, samples can be considered clostebol acetate-positive if at least one of the metabolites is identified. Urine samples from other animals with injection sites positive for clostebol acetate were also found to be positive for the 2 metabolites.