In vivo Administration of Testosterone Propionate in Cattle Analyzed by High Performance Liquid Chromatography-Tandem Mass Spectrometry: An Enzymatic Hydrolysis Study and Drug Abuse Issues

Abstract

This study involved an animal experiment in which testosterone propionate was intramuscularly injected into four steers, and the ensuing urine samples were analyzed using high-performance liquid chromatography-tandem mass spectrometry. The enzymatic hydrolysis conditions were analyzed using analysis of variance (ANOVA) and response surface methodology employing a 33 Box-Behnken design. A survey study was performed in which 48 urine samples were collected from eight untreated steers to estimate the endogenous levels of testosterone metabolites, and it was found that 17β-testosterone was not detected in the majority of the samples, whereas 17a-testosterone was present in 43 of the 48. Drug abuse was identified within 11 days of 17β-testosterone administration. The ratio between both isomers was also assessed; however, a cut-off limit based on an untreated population could not be estimated due to the absence of the beta isomer. Therefore, there may be a correlation between the exogenous use of testosterone in castrate animals and high levels of 17β-testosterone, although confirmation through further investigation would be required.