Metabolism of methyltestosterone, norethandrolone and methylboldenone in a heifer Original Research Article

In this study, metabolism and excretion of 17α-methyltestosterone, norethandrolone, methylboldenone and metabolites in a heifer were studied. The heifer was treated with these steroids by intra-muscular injection. Samples of urine were collected and analysed using gas-chromatography coupled to a mass-spectrometer. It was concluded that 17α-methyltestosterone, norethandrolone and methylboldenone show similar metabolic pathways. The main route was hydroxylation of the parent compound. The formation of oxygenated products was observed, but this was a minor pathway. The sequential treatment of the heifer possibly caused the formation of different metabolites after treatment with methylboldenone. The concentration of the metabolites in urine was higher than the concentration of the parent compound. The use of the marker metabolites in routine control programs increase the possibility of tracking bovine animals treated with 17α-methyl or ethyl substituted anabolic steroids.