Ultra high performance liquid chromatography/tandem mass spectrometry based identification of steroid esters in serum and plasma: an efficient strategy to detect natural steroids abuse in breeding and racing animals.

This research presents an analytical method for detecting natural steroids administered to animals in an attempt to improve performance, a practice known as doping. The method uses ultra high performance liquid chromatography and tandem mass spectrometry to identify over 20 steroid esters in animal serum and plasma, proving useful in anti-doping efforts in the breeding and racing industries. The method was tested on bovine and equine subjects, with promising results.

Background

• The article opens by acknowledging the prevalence of doping in racing and food producing animals, where natural steroids (endogenous or exogenous) are administered to enhance performance. These substances are typically given intramuscularly in ester form for increased bioavailability and lasting effect.
• Detecting steroid esters effectively confirms exogenous administration of these steroids, hence aiding in anti-doping efforts.

Method Development

• The researchers developed a quick analytical method capable of detecting a large panel of over 20 steroid esters at trace levels (below 50 pg/mL) in serum and plasma, potentially used for doping in bovine and equine animals.
• The method involves pretreating the sample, then subjecting it to solid phase extraction (SPE) before analysis via ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS).

Validation of the Method

• To prove the method’s efficiency, the researchers conducted three different in vivo experiments involving the administration of various steroids to heifers, a bull, and a stallion.
• The first experiment involved administering testosterone propionate intramuscularly to three heifers. The second experiment administered 17-estradiol benzoate intramuscularly to a bull and a heifer. The third experiment administered nandrolone laurate intramuscularly to a stallion.
• The results successfully detected the respective steroids in each animal. Testosterone propionate and 17-estradiol benzoate were detected 2 and 17 days, respectively, post-administration in bovine, and nandrolone laurate was detected up to 14 days post-administration in equine.

Conclusion

• The researchers were able to establish elimination profiles for these substances in bovine serum and equine plasma.
• The detected concentrations varied among the experiments, with the highest testosterone propionate concentration recorded at 400 pg/mL in a heifer serum, 17-estradiol benzoate concentration of 480 pg/mL in bovine serum, and nandrolone laurate concentration of 440 pg/mL in horse plasma.
• Overall, these findings affirm the effectiveness of the proposed method in detecting animal doping practices, potentially aiding in regulatory and anti-doping efforts in the breeding and racing industries.