Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Feb;16(2):112-126.
doi: 10.1002/dta.3521. Epub 2023 Jun 1.

Detection of boldenone in the urine of female horses-ex vivo formation versus administration

Marjaana Viljanto  1 , Zied Kaabia  2 , Polly Taylor  1 , Pamela Hincks  1 , Tessa Muir  3 , Jocelyn Habershon-Butcher  3 , Ludovic Bailly-Chouriberry  2 , James Scarth  1
Affiliations

Detection of boldenone in the urine of female horses-ex vivo formation versus administration

Marjaana Viljanto et al. Drug Test Anal. 2024 Feb.

Abstract

Boldenone is an anabolic-androgenic steroid (AAS) that is prohibited in equine sports. However, in certain situations, it is endogenous, potentially formed by the microbes in urine. An approach to the differentiation based on the detection of the biomarkers Δ1-progesterone, 20(S)-hydroxy-Δ1-progesterone and 20(S)-hydroxyprogesterone was assessed, and their concentrations were monitored in the urine of untreated female horses (n = 291) alongside boldenone, boldienone, testosterone and androstenedione. Using an ultra-sensitive analytical method, boldenone (256 ± 236 pg/mL, n = 290) and the biomarkers (Δ1-progesterone up to 57.6 pg/mL, n = 8; 20(S)-hydroxy-Δ1-progesterone 85.3 ± 181 pg/mL, n = 130; 20(S)-hydroxyprogesterone 43.5 ± 92.1 pg/mL, n = 158) were detected at low concentrations. The ex vivo production of Δ1-steroids was artificially induced following the storage of urine samples at room temperature for 7 days in order to assess the concentrations and ratios of the monitored steroids. The administration of inappropriately stored feed source also resulted in an increase in 20(S)-hydroxy-Δ1-progesterone concentrations and the biomarker ratios. Using the results from different datasets, an approach to differentiation was developed. In situations where the presence of boldenone exceeds a proposed action limit of 5 ng/mL, the presence of the biomarkers would be investigated. If Δ1-progesterone is above 50 pg/mL or if 20(S)-hydroxy-Δ1-progesterone is above 100 pg/mL with the ratio of 20(S)-hydroxy-Δ1-progesterone:20(S)-hydroxyprogesterone greater than 5:1, then this would indicate ex vivo transformation or consumption of altered feed rather than steroid administration. There remains a (small) possibility of a false negative result, but the model increases confidence that adverse analytical findings reported in female horses are caused by AAS administrations.

Keywords: biomarker; boldenone; female horse; microbial; urine.

PubMed Disclaimer

Similar articles

See all similar articles

References

REFERENCES

    1. International Federation of horseracing Authorities. 2022 International Agreement on breeding, racing and wagering. https://ifhaonline.org/resources/ifAgreement.pdf. Accessed on 17 October 2022.
    1. Viljanto M, Scarth J, Hincks P, et al. Application of testosterone to epitestosterone ratio to horse urine - a complementary approach to detect the administration of testosterone and its pro-drugs in thoroughbred geldings. Drug Test Anal. 2017;9(9):1328-1336. doi:10.1002/dta.2109
    1. Houghton E, Ginn A. Nandrolone in the colt: a review of the science relating to the threshold value. In: Auer DE, Houghton E, eds. Proceedings of the 13th international conference of racing analysts and veterinarians. R&W Publications; 2000:29-33.
    1. Gray BP, Teale P, Pearce CM. Analysis of methyloxime derivatives of intact esters of testosterone and boldenone in equine plasma using ultra high performance liquid chromatography tandem mass spectrometry. Drug Test Anal. 2011;3(4):206-213. doi:10.1002/dta.237
    1. Kaabia Z, Dervilly-Pinel G, Hanganu F, et al. 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. J Chromatogr a. 2013;1284:126-140. doi:10.1016/j.chroma.2013.02.010

LinkOut - more resources

-