Metabolic studies of mesterolone in horses

Doping detection in animals: A review of analytical methodologies published from 1990 to 2019

Despite the impressive innate physical abilities of horses, camels, greyhounds, or pigeons, doping agents might be administered to these animals to improve their performance. To control these illegal practices, anti-doping analytical methodologies have been developed. This review compiles the analytical methods that have been published for the detection of prohibited substances administered to animals involved in sports over 30 years. Relevant papers meeting the search criteria that discussed analytical methods aiming to detect and/or quantify doping substances in animal biological matrices published from 1990 to 2019 were considered. A total of 317 studies were included, of which 298 were related to horses, demonstrating significant advances toward the development of doping detection methods for equine sports. However, analytical methods for the detection of doping agents in sports involving other species are lacking. Due to enhanced accuracy and specificity, chromatographic analysis coupled to mass spectrometry detection is preferred over immunoassays. Regarding biological matrices, blood and urine remain the first choice, although alternative biological matrices, such as hair and feces, have been considered. With the increasing number and type of drugs used as doping agents, the analytes addressed in the published papers are diverse. It is very important to continue to detect and quantify these drugs, recognizing those that are most frequently used, in order to punish the abusers, protect animals' health, and ensure a healthier and genuine competition.

Serial-omics characterization of equine urine

Horse urine is easily collected and contains molecules readily measurable using mass spectrometry that can be used as biomarkers representative of health, disease or drug tampering. This study aimed at analyzing microliter levels of horse urine to purify, identify and quantify proteins, polar metabolites and non-polar lipids. Urine from a healthy 12 year old quarter horse mare on a diet of grass hay and vitamin/mineral supplements with limited pasture access was collected for serial-omics characterization. The urine was treated with methyl tert-butyl ether (MTBE) and methanol to partition into three distinct layers for protein, non-polar lipid and polar metabolite content from a single liquid-liquid extraction and was repeated two times. Each layer was analyzed by high performance liquid chromatography—high resolution tandem mass spectrometry (LC-MS/MS) to obtain protein sequence and relative protein levels as well as identify and quantify small polar metabolites and lipids. The results show 46 urine proteins, many related to normal kidney function, structural and circulatory proteins as well as 474 small polar metabolites but only 10 lipid molecules. Metabolites were mostly related to urea cycle and ammonia recycling as well as amino acid related pathways, plant diet specific molecules, etc. The few lipids represented triglycerides and phospholipids. These data show a complete mass spectrometry based—omics characterization of equine urine from a single 333 μL mid-stream urine aliquot. These omics data help serve as a baseline for healthy mare urine composition and the analyses can be used to monitor disease progression, health status, monitor drug use, etc.

New potential biomarkers for mesterolone misuse in human urine by liquid chromatography quadrupole time-of-flight mass spectrometry

In this paper, mesterolone metabolic profiles were investigated carefully. Mesterolone was administered to one healthy male volunteer. Urinary extracts were analyzed by liquid chromatography quadruple time-of-flight mass spectrometry (LC-QTOFMS) for the first time. Liquid-liquid extraction was applied to processing urine samples, and dilute-shoot analyses of intact metabolites were also presented. In LC-QTOFMS analysis, chromatographic peaks for potential metabolites were hunt down by using the theoretical [M-H](-) as target ions in full scan experiment, and their actual deprotonated ions were analyzed in targeted MS/MS mode. Ten metabolites including seven new sulfate and three glucuronide conjugates were found for mesterolone. Because of no useful fragment ion for structural elucidation, gas chromatography-mass spectrometry instrumentation was employed to obtain structural details of the trimethylsilylated phase I metabolite released after solvolysis. Thus, their potential structures were proposed particularly by a combined MS approach. All the metabolites were also evaluated in terms of how long they could be detected, and S1 (1α-methyl-5α-androst-3-one-17β-sulfate) together with S2 (1α-methyl-5α-androst-17-one-3β-sulfate) was detected up to 9 days after oral administration, which could be the new potential biomarkers for mesterolone misuse.

The metabolism of anabolic-androgenic steroids in the greyhound

BACKGROUND

Effective control of the use of anabolic-androgenic steroids (AASs) in animal sports is essential in order to ensure both animal welfare and integrity. In order to better police their use in Australian and New Zealand greyhound racing, thorough metabolic studies have been carried out on a range of registered human and veterinary AASs available in the region.

RESULTS

Canine metabolic data are presented for the AASs boldenone, danazol, ethylestrenol, mesterolone, methandriol, nandrolone and norethandrolone. The principal Phase I metabolic processes observed were the reduction of A-ring unsaturations and/or 3-ketones with either 3α,5β- or 3β,5α-stereochemistry, the oxidation of secondary 17β-hydroxyl groups and 16α-hydroxylation. The Phase II β-glucuronylation of sterol metabolites was extensive.

CONCLUSION

The presented data have enabled the effective analysis of AASs and their metabolites in competition greyhound urine samples.

Impact of the emergence of designer drugs upon sports doping testing

Historically, dope-testing methods have been developed to target specific and known threats to the integrity of sport. Traditionally, the source of new analytical targets for which testing was required were derived almost exclusively from the pharmaceutical industry. More recently, the emergence of designer drugs, such as tetrahydrogestrinone that are specifically intended to evade detection, or novel chemicals intended to circumvent laws controlling the sale and distribution of recreational drugs, such as anabolic steroids, stimulants and cannabinoids, have become a significant issue. In this review, we shall consider the emergence of designer drugs and the response of dope-testing laboratories to these new threats, in particular developments in analytical methods, instrumentation and research intended to detect their abuse, and we consider the likely future impact of these approaches.

Metabolism of anabolic steroids and their relevance to drug detection in horseracing

The fight against doping in sport using analytical chemistry is a mature area with a history of approximately 100 years in horseracing. In common with human sport, anabolic/androgenic steroids (AASs) are an important group of potential doping agents. Particular issues with their detection are extensive metabolism including both phase I and phase II. A number of the common AASs are also endogenous to the equine. A further issue is the large number of synthetic steroids produced as pharmaceutical products or as 'designer' drugs intended to avoid detection or for the human supplement market. An understanding of the metabolism of AASs is vital to the development of effective detection methods for equine sport. The aim of this paper is to review current knowledge of the metabolism of appropriate steroids, the current approaches to their detection in equine sport and future trends that may affect equine dope testing.

Some aspects of doping and medication control in equine sports

This chapter reviews drug and medication control in equestrian sports and addresses the rules of racing, the technological advances that have been made in drug detection and the importance of metabolism studies in the development of effective drug surveillance programmes. Typical approaches to screening and confirmatory analysis are discussed, as are the quality processes that underpin these procedures. The chapter also addresses four specific topics relevant to equestrian sports: substances controlled by threshold values, the approach adopted recently by European racing authorities to control some therapeutic substances, anabolic steroids in the horse and LC-MS analysis in drug testing in animal sports and metabolism studies. The purpose of discussing these specific topics is to emphasise the importance of research and development and collaboration to further global harmonisation and the development and support of international rules.

Modern techniques for the determination of anabolic–androgenic steroid doping in the horse

Control of the use of performance-affecting substances in the horse is critical to the integrity of a wide range of equine sports, with major implications for both animal welfare and revenue streams. One class of medications enjoying particular public notoriety is the anabolic–androgenic steroid group, as highlighted by the recent ‘Big Brown’ affair and Congressional inquiries into the use of steroids in professional sports, including horse racing, in the USA. This review examines the latest developments pertaining to the analytical detection of these substances in equine biological samples and the supporting regulatory environment. Consideration is given to the full variety of sample matrices available, together with modern sample preparative approaches and instrumental techniques. Issues concerning the regulation of endogenous steroids, including thresholds where applicable, are also discussed.