Metabolites are small molecules involved in the metabolic processes within a horse's body. They are the intermediates and products of metabolism, encompassing a wide range of compounds, such as amino acids, lipids, carbohydrates, and nucleotides. These molecules play roles in energy production, growth, and cellular repair. The study of equine metabolites, often conducted through metabolomics, provides insights into the physiological and pathological states of horses. Changes in metabolite levels can indicate alterations in metabolic pathways, potentially reflecting health conditions or responses to environmental factors. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, function, and diagnostic potential of metabolites in equine health.
Hamamoto-Hardman BD, Steffey EP, Weiner D, McKemie DS, Kass P, Knych HK.The objective of the current study was to describe and characterize the pharmacokinetics and selected pharmacodynamic effects of morphine and its two major metabolites in horses following several doses of morphine. A total of ten horses were administered a single intravenous dose of morphine: 0.05, 0.1, 0.2, or 0.5 mg/kg, or saline control. Blood samples were collected up to 72 hr, analyzed for morphine, and metabolites by LC/MS/MS, and pharmacokinetic parameters were determined. Step count, heart rate and rhythm, gastrointestinal borborygmi, fecal output, packed cell volume, and total prote...
Subhahar MB, Singh J, Albert PH, Kadry AM.Celecoxib, a nonsteroidal anti-inflammatory drug, is frequently used to treat arthritis in humans with minimal gastrointestinal side effect compared to traditional NSAIDs. The primary aim of this study was to determine the pharmacokinetic profile of celecoxib-a selective cyclooxygenase-2 (COX-2) inhibitor in horses. Six horses were administered a single oral dose of celecoxib at 2 mg/kg (body weight). After oral dosing, the drug reached a maximum concentration (mean ± SD) in blood of 1,088 ± 324 ng/ml in 4.58 hr. The elimination half-life was 13.60 ± 3.18 hr, and the area under th...
Bochnia M, Sander J, Ziegler J, Terhardt M, Sander S, Janzen N, Cavalleri JV, Zuraw A, Wensch-Dorendorf M, Zeyner A.Atypical myopathy (AM) in horses is caused by ingestion of seeds of the Acer species (Sapindaceae family). Methylenecyclopropylacetyl-CoA (MCPA-CoA), derived from hypoglycin A (HGA), is currently the only active toxin in Acer pseudoplatanus or Acer negundo seeds related to AM outbreaks. However, seeds or arils of various Sapindaceae (e.g., ackee, lychee, mamoncillo, longan fruit) also contain methylenecyclopropylglycine (MCPG), which is a structural analogue of HGA that can cause hypoglycaemic encephalopathy in humans. The active poison formed from MCPG is methylenecyclopropylformyl-CoA (MCPF-...
Rudolph W, Remane D, Wissenbach DK, Peters FT.1. Ergopeptine alkaloids like ergovaline and ergotamine are suspected to be associated with fescue toxicosis and ergotism in horses. Information on the metabolism of ergot alkaloids is scarce, especially in horses, but needed for toxicological analysis of these drugs in urine/feces of affected horses. The aim of this study was to investigate the metabolism of ergovaline, ergotamine, ergocristine, and ergocryptine in horses and comparison to humans. 2. Supernatants of alkaloid incubations with equine and human liver S9 fractions were analyzed by reversed-phase liquid-chromatography coupled to h...
Knych HK, Arthur RM, McKemie DS, Seminoff K, Hamamoto-Hardman B, Kass PH.Phenylbutazone (PBZ) is a potent mon-steroidal anti-inflammatory drug used commonly in performance horses. The objectives of the current study were to describe blood and urine concentrations and the pharmacokinetics of PBZ and its metabolites following intravenous (IV) and oral administration and to describe the duration of pharmacodynamic effect. To that end, 17 horses received an IV administration and 18 horses an oral administration of 2 g of PBZ. Blood and urine samples were collected prior to and for up to 96 hours post drug administration. Whole blood samples were collected at various t...
Kusano K, Minamijima Y, Mashita S, Kunii H, Yamashita S, Nagata S.Repeated topical application of indomethacin is common in Japanese racehorses, despite the lack of pharmacokinetic data. Objective: To determine the concentrations of indomethacin and its metabolite, desmethylindomethacin, in plasma and urine of Thoroughbreds topically treated repeatedly with indomethacin. Methods: In vivo experimental. Methods: Seven female Thoroughbreds were topically treated with 50 g of 1% indomethacin cream per horse to the back and hips (500 mg of indomethacin/head/2400 cm , 0.21 g/cm ) for 3 consecutive days. Samples were pretreated by protein precipitation for plas...
Czub MP, Venkataramany BS, Majorek KA, Handing KB, Porebski PJ, Beeram SR, Suh K, Woolfork AG, Hage DS, Shabalin IG, Minor W.Serum albumin is the most abundant protein in mammalian blood plasma and is responsible for the transport of metals, drugs, and various metabolites, including hormones. We report the first albumin structure in complex with testosterone, the primary male sex hormone. Testosterone is bound in two sites, neither of which overlaps with the previously suggested Sudlow site I. We determined the binding constant of testosterone to equine and human albumins by two different methods: tryptophan fluorescence quenching and ultrafast affinity extraction. The binding studies and similarities between residu...
You Y, Proctor RM, Vasilko ED, Robinson MA.JWH-250 is a synthetic cannabinoid. Its use is prohibited in equine sport according to the Association of Racing Commissioners International (ARCI) and the Fédération Équestre Internationale (FEI). A doping control method to confirm the presence of four JWH-250 metabolites (JWH-250 4-OH-pentyl, JWH-250 5-OH-pentyl, JWH-250 5-OH-indole, and JWH-250 N-pentanoic acid) in equine urine was developed and validated. Urine samples were treated with acetonitrile and evaporated to concentrate the analytes prior to the analysis by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The chromat...
Stanley S, Van den Berg K, Foo HC, Deng D.The metabolism of the masking agent tolcapone in the horse has been investigated. This substance was found to have undergone various chemical transformations that produced a large variety of phase I metabolites, as well as glucuronide and sulfate conjugation. Confirmation of the presence of tolcapone and the 3-O-methylated metabolite in the blood samples collected up to 240 minutes and in urine obtained up to 24 hours, was successfully conducted using both gas chromatography- and liquid chromatography-tandem mass spectrometry techniques. The 3-O-methyl tolcapone is the better marker to use i...
Bazzano M, Laghi L, Zhu C, Magi GE, Serri E, Spaterna A, Tesei B, Laus F.The present work characterized the metabolomic profile of tracheal wash (TW) and exhaled breath condensate (EBC) in healthy horses and horses with respiratory disease. Six asthma-affected horses (group A) and six healthy controls (group H) underwent clinical, endoscopic and cytologic examinations of upper airways to confirm the active phase of asthma. TW and EBC samples were collected from each animal and investigated by proton nuclear magnetic resonance (H-NMR) metabolomic analysis. A total of ten out of 38 metabolites found in the TW were significantly different between the groups (p < ...
Karlíková R, Široká J, Mech M, Friedecký D, Janečková H, Mádrová L, Hrdinová F, Drábková Z, Dobešová O, Adam T, Jahn P.The case of atypical myopathy (AM) in newborn Haflinger foal with clinical signs of depression and weakness appearing 6 hours after birth resulting in recumbency 12 hours after birth is described. The foal's dam was diagnosed with AM in the 6th month of gestation based on clinical signs of a myopathy, elevated serum activity of creatine kinase, metabolomic analysis and the presence of methylenecyclopropyl acetyl carnitine (MCPA-carnitine) in the blood. At the time of delivery, the mare was grazing on a pasture near sycamore trees but was free of clinical signs of AM. Metabolomic analysis of th...
Lee W, Ko BJ, Sim YE, Suh S, Yoon D, Kim S.Urine was most commonly used biological sample in drug test. To create a false-negative test result, some drug abusers were reported to submit animal urine instead of their own. So, the purpose of this study was to compare and differentiate human from animal urine (Rat 370, Pig 12, Horse 10, Cat 8, Dog 13, Cow 10, Monkey 10) samples through the uses of quantitative 1H-NMR and to find biomarkers that can be used for the discrimination of human urine from animal urine. The 1H-NMR spectroscopy was employed and metabolomic analysis with multivariate statistics was carried out. Human urine samples ...
Waraksa E, Woźniak MK, Kłodzińska E, Wrzesień R, Bobrowska-Korczak B, Namieśnik J.Ibuprofen is widely used in human and veterinary medicine for the treatment of chronic pain as well as rheumatic and musculoskeletal disorders. However, the analgesic and anti-inflammatory properties of Ibuprofen have contributed to frequent drug abuse in equestrian sports. A sensitive and rapid gas chromatography with tandem mass spectrometry based method with a simple liquid-liquid extraction and derivatization requiring 200 μL volume of sample and 2 mL of extraction solvent for the simultaneous determination of ibuprofen and its metabolites was developed. The proposed procedure was optim...
Zhu C, Faillace V, Laus F, Bazzano M, Laghi L.Metabolomics has been recognized as a powerful approach for disease screening. In order to highlight potential health issues in subjects, a key factor is the possibility to compare quantitatively the metabolome of their biofluids with reference values from healthy individuals. Such efforts towards the systematic characterization of the metabolome of biofluids in perfect health conditions, far from concluded for humans, have barely begun on horses. The present work attempts, for the first time, to give reference quantitative values for the molecules mostly represented in the urine metabolome of...
Soma LR, You Y, Robinson MA, Boston RC.Intravenous (iv), subcutaneous (sq), and topical (tp) lidocaine was administered to six horses in a cross-over, randomized design study. Samples were collected for up to 72 hr. Compartmental models were used to investigate the pharmacokinetics of (LD) and its metabolites 3-hydroxylidocaine (3-OH), 4-hydroxylidocaine (4-OH), and monoethylglycinexylidide (MEGX). Metabolites 3-OH and 4-OH were present in conjugated forms, whereas LD and metabolite MEXG were present primarily in the un-conjugated form. Plasma concentrations of LD after iv administration (100 mg) were described by three-compartme...
Anderson JR, Phelan MM, Clegg PD, Peffers MJ, Rubio-Martinez LM.Osteoarthritis (OA), osteochondrosis (OC), and synovial sepsis in horses cause loss of function and pain. Reliable biomarkers are required to achieve accurate and rapid diagnosis, with synovial fluid (SF) holding a unique source of biochemical information. Nuclear magnetic resonance (NMR) spectroscopy allows global metabolite analysis of a small volume of SF, with minimal sample preprocessing using a noninvasive and nondestructive method. Equine SF metabolic profiles from both nonseptic joints (OA and OC) and septic joints were analyzed using 1D H NMR spectroscopy. Univariate and multivariate ...
Knych HK, McKemie DS, Seminoff K, Hartmann P, Hovda L, Benson D.Ethylphenidate is a psychostimulant and analog of the commonly prescribed compound, methylphenidate (Ritalin®). There are a limited number of studies describing the disposition and pharmacologic/toxicological effects of ethylphenidate in any species. The abuse potential in equine athletes along with the limited data available regarding administration in horses necessitates further study. The objectives of the current study were to describe drug concentrations, develop an analytical method that could be used to regulate its use, and describe the pharmacodynamic effects of ethylphenidate in hor...
Pakkanen SAE, de Vries A, Raekallio MR, Mykkänen AK, Palviainen MJ, Sankari SM, Vainio OM.Romifidine, an α-2 adrenoceptor agonist, is a widely-used sedative in equine medicine. Besides the desired sedative and analgesic actions, α-2 adrenoceptor agonists have side effects like alterations of plasma concentrations of glucose and certain stress-related hormones and metabolites in various species. Vatinoxan (previously known as MK-467), in turn, is an antagonist of α-2 adrenoceptors. Because vatinoxan does not cross the blood brain barrier in significant amounts, it has only minor effect on sedation induced by α-2 adrenoceptor agonists. Previously, vatinoxan is shown to prevent th...
Wenzel R, Major D, Hesp K, Doble P.Regulating authorities in the racing industry have restricted the administration of potentially performance enhancing cobalt salts to horses. There are severe penalties for trainers presenting horses with elevated urine cobalt concentrations, and compliance is ensured via analysis of total urinary cobalt at thresholds of 100 μg/L. When cobalt is present as part of the cobalamin molecule it is not considered performance enhancing. This paper demonstrates that a horse can excrete a significant proportion of a commercially available vitamin B12 injection in urine without metabolic modification...
Kenéz Á, Warnken T, Feige K, Huber K.Insulin dysregulation in horses is a metabolic condition defined by high insulin concentrations in the blood and peripheral insulin resistance. This hyperinsulinemia is often associated with severe damage in the hooves, resulting in laminitis. However, we currently lack detailed information regarding the potential involvement of particular metabolic pathways in pathophysiological causes and consequences of equine insulin dysregulation. This study aimed to assess the dynamic metabolic responses given to an oral glucose test (OGT) in insulin-sensitive and insulin-dysregulated horses by a targete...
The attention of sports community toward probiotic supplementation as a way to promote exercise and training performance, together with good health, has increased in recent years. This has applied also to horses, with promising results. Here, for the first time, we tested a probiotic mix of several strains of live bacteria typically employed for humans to improve the training performance of Standardbred horses in athletic activity. To evaluate its effects on the horse performance, we measured lactate concentration in blood, a translational outcome largely employed for the purpose, combined wit...
Jacob SI, Murray KJ, Rendahl AK, Geor RJ, Schultz NE, McCue ME.Metabolomics, the study of small-molecule metabolites, has increased understanding of human metabolic diseases, but has not been used to study equine metabolic syndrome (EMS). Objective: (1) To examine the serum metabolome of Welsh Ponies with and without insulin dysregulation before and during an oral sugar test (OST). (2) To identify differences in metabolites in ponies with insulin dysregulation, obesity, or history of laminitis. Methods: Twenty Welsh Ponies (mean ± SD; 13.8 ± 9.0 years) classified as non-insulin dysregulated [CON] (n = 10, insulin 60 mU/L) at 75 minutes ...
Liu Y, Siard M, Adams A, Keowen ML, Miller TK, Garza F, Andrews FM, Seeram NP.The human health benefits attributed to turmeric/curcumin spice has resulted in its wide utilization as a dietary supplement for companion pets and other animals including horses. While the quantification of free curcuminoids (curcumin, demethoxycurcumin, bisdemethoxycurcumin) and their phase-2 metabolites (curcumin-O-sulfate, curcumin-O-glucuronide) have been extensively investigated in human and rodent biological samples (primarily plasma and serum), there is lack of similar data for horses. Herein, we report a validated LC-ESI-MS/MS method for the simultaneous quantification of the aforemen...
Choi TLS, Wong JKY, Kwok WH, Curl P, Mechie S, Wan TSM.Methylstenbolone (2,17α-dimethyl-5α-androst-1-en-17β-ol-3-one) is a synthetic anabolic and androgenic steroid (AAS) sold as an oral 'nutritional supplement' under the brand names 'Ultradrol', 'M-Sten' and 'Methyl-Sten'. Like other AASs, methylstenbolone is a prohibited substance in both human and equine sports. This paper describes the studies of the in vitro and in vivo metabolism of methylstenbolone in horses using LC/HRMS, GC/MS and GC/MS/MS. Phase I in vitro metabolic study of methylstenbolone was performed using homogenised horse liver. Hydroxylation was the only biotransformation obse...
Waraksa E, Wójtowicz-Zawadka M, Kwiatkowska D, Jarek A, Małkowska A, Wrzesień R, Namieśnik J.A novel assay for the simultaneous determination of ibuprofen (IBU) and its four probable metabolites, 1-hydroxyibuprofen (1-OH IBU), 2-hydroxyibuprofen (2-OH IBU), 3-hydroxyibuprofen (3-OH IBU) and carboxyibuprofen (CBX IBU) in equine urine samples with the application of Gas Chromatography-Electron Ionization-Mass Spectrometry (GC-EI-MS) has been developed and elaborated. The new approach for sample preparation including minimizing matrix effects by the application of weak cation exchange solid-phase extraction together with strong cation exchange solid-phase extraction has been applied. The...
Leng J, Proudman C, Darby A, Blow F, Townsend N, Miller A, Swann J.Equine grass sickness (EGS) is a frequently fatal disease of horses, responsible for the death of 1 to 2% of the U.K. horse population annually. The etiology of this disease is currently uncharacterized, although there is evidence it is associated with Clostridium botulinum neurotoxin in the gut. Prevention is currently not possible, and ileal biopsy diagnosis is invasive. The aim of this study was to characterize the fecal microbiota and biofluid metabolic profiles of EGS horses, to further understand the mechanisms underlying this disease, and to identify metabolic biomarkers to aid in diagn...
Hansson A, Knych H, Stanley S, Berndtson E, Jackson L, Bondesson U, Thevis M, Hedeland M.LGD-4033 has been found in human doping control samples and has the potential for illicit use in racehorses as well. It belongs to the pharmacological class of selective androgen receptor modulators (SARMs) and can stimulate muscle growth, much like anabolic steroids. However, SARMs have shown superior side effect profiles compared to anabolic steroids, which arguably makes them attractive for use by individuals seeking an unfair advantage over their competitors. The purpose of this study was to investigate the metabolites formed from LGD-4033 in the horse in order to find suitable analytical ...
Yuan M, Breitkopf SB, Asara JM.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...
Knych HK, Mama KR, Steffey EP, Stanley SD, Kass PH.OBJECTIVE To measure concentrations of trazodone and its major metabolite in plasma and urine after administration to healthy horses and concurrently assess selected physiologic and behavioral effects of the drug. ANIMALS 11 Thoroughbred horses enrolled in a fitness training program. PROCEDURES In a pilot investigation, 4 horses received trazodone IV (n = 2) or orally (2) to select a dose for the full study; 1 horse received a vehicle control treatment IV. For the full study, trazodone was initially administered IV (1.5 mg/kg) to 6 horses and subsequently given orally (4 mg/kg), with a 5-week ...
Joré C, Loup B, Garcia P, Paris AC, Popot MA, Audran M, Bonnaire Y, Varlet-Marie E, Bailly-Chouriberry L.Erythropoiesis Stimulating Agents (ESAs) were developed for therapeutic purposes to stimulate red blood cell (RBC) production. Consequently, tissue oxygenation is enhanced as athlete's endurance and ESAs misuse now benefits doping. Our hypothesis is that most of ESAs should have similar mechanisms and thus have the same effects on metabolism. Studying the metabolome variations could allow suspecting the use of any ESAs with a single method by targeting their effects. In this objective, a metabolomic study was carried out on 3 thoroughbred horses with a single administration of 4.2μg/kg of Mir...
Fenwick SJ, Scarth JP.Within horseracing, the detection of prohibited substance doping often requires urine analysis; hence, it is necessary to understand the metabolism of the drugs in question. Here, the previously unknown equine metabolism of eight sedatives is reported in order to provide information on target metabolites for use in doping control. Phase I metabolite information was provided by incubation with equine liver S9 fraction. In vitro techniques were chosen in order to reduce the ethical and financial issues surrounding the study of so many compounds, none of which are licensed for use in horses in th...
Jedziniak P, Szprengier-Juszkiewicz T, Olejnik M, Zmudzki J.A confirmatory method for the determination of residues of nine non-steroidal anti-inflammatory drugs and one metabolite in animal muscles has been developed. After enzymatic hydrolysis samples were extracted with acetonitrile and cleaned up using alumina and C(18) SPE cartridges. Liquid chromatography-tandem mass spectrometry was used for the separation and determination of analytes. The method was validated in bovine muscles, according to the Commission Decision 2002/657/EC criteria. Applicability of the method in the analysis of swine, horse and chicken muscles was checked by precision and ...
Mutlib AE, Chui YC, Young LM, Abbott FS.The metabolic fate of xylazine, 2-(2,6-dimethylphenylamino)-5,6-dihydro-4H-1,3-thiazine, in horses is described. The major metabolites identified in the hydrolyzed horse urine were 2-(4'-hydroxy-2',6'-dimethylphenylamino)-5,6-dihydro-4H-1,3-thiazi ne, 2-(3'-hydroxy-2',6'-dimethylphenylamino)-5,6-dihydro-4H-1,3-thiazi ne, N-(2,6-dimethylphenyl)thiourea, and 2-(2',6'-dimethylphenylamino)-4-oxo-5,6-dihydro-1,3-thiazine. These metabolites were also produced by incubating xylazine with rat liver microsomes. The major metabolite produced in vitro by rat liver preparations was found to be the ring op...
Krueger K, Marr I, Dobler A, Palme R.Non-invasive methods enable stress evaluation through measuring fecal glucocorticoid metabolites (FGMs), and immunoglobulin A (IgA) in the feces avoiding stressful blood drawing or stressful restraining of animals in the field. However, FGMs and IgA are mostly analysed in freshly frozen samples, which is difficult when fresh samples cannot be frozen immediately or frozen samples cannot be stored or transported. Good results were also derived from air-dried fecal samples, which are hampered by unstable air humidity in the field. These difficulties may be overcome, when drying of samples could b...
Albornoz A, Morales N, Uberti B, Henriquez C, Burgos RA, Alarcon P, Moran G.Neutrophils participate in innate immunity as the first line of host defence against microorganisms. However, persistent neutrophil activity and delayed apoptosis can be harmful to surrounding tissues; this problem occurs in diverse inflammatory diseases, including asthma-affected horses. Previous studies in horses with acute lung inflammation indicated that treatment with tamoxifen (TX), a selective oestrogen receptor modulator, produces a significant decrease in bronchoalveolar lavage fluid (BALF) neutrophil content. The aim of this study was to investigate the effect of tamoxifen and its me...
Sykes BW, Underwood C, McGowan CM, Mills PC.The objectives of this study were to investigate the impact of formulation (enteric coated and buffered) and feeding on pharmacokinetic variables associated with the oral administration of omeprazole in the horse. Six thoroughbred racehorses were studied in a crossover design. Each received 2 g of an enteric coated or buffered formulation in both the fed and fasted state. Plasma omeprazole concentrations were determined by UHPLC-MS. The effects of feeding or formulation on AUC0-inf_obs, half-life, Tmax or Cmax were not statistically significant. However, a wider-than-expected degree of variati...
Thevis M, Opfermann G, Schänzer W.Electrospray ionization (ESI) mass spectra of 19 common beta(2)-agonists were investigated in terms of fragmentation pattern and dissociation behavior of the analytes, proving the origin of fragment ions and indicating mechanisms of charge-driven and charge-remote fragmentation. Based on these data, liquid chromatographic/ESI tandem mass spectrometric (LC/ESI-MS/MS) screening and confirmation methods were developed for doping control purposes. These procedures employ established sample preparation steps including either acidic or enzymatic hydrolysis, alkaline extraction and, in the case of eq...
Kagan IA, Goodman JP, Seman DH, Lawrence LM, Smith SR.Grasses are a source of nutrients for grazing horses. However, water-soluble carbohydrates (WSCs) of grasses have been implicated in some equine health issues. Grasses also contain phenolic compounds, whose sensory and antimicrobial properties may affect forage intake by horses and horse health. The goals of this study were to assess factors affecting phenolic and WSC concentrations in selected cultivars of cool-season grasses and profile the phenolic compounds. Total phenolics and WSC were quantified in "Linn" and "Calibra" perennial ryegrass (PRG), "Cajun II" tall fescue (Cajun TF), "Persist...
Higgins AJ, Lees P.The presence of cyclooxygenase products of arachidonic acid metabolism in carrageenin-induced inflammatory exudate was investigated in ponies using two models. In the first model, an inflammatory response was stimulated by injecting carrageenin into subcutaneously implanted polypropylene tissue cages and exudates were collected at five predetermined times between 3 and 48 h. In the second model, exudates were harvested at 6, 12 and 24 h from carrageenin-impregnated polyester sponges which had also been inserted beneath the skin. Prostaglandin (PG) E2, thromboxane (TX) B2 and the stable breakdo...
Guan F, You Y, Fay S, Li X, Robinson MA.To address the limitations of current targeted analytical methods that can only detect known doping agents, a novel methodology that permits untargeted drug detection (UDD) has been developed to help in the fight against doping in sports. Fifty-seven drugs were spiked into blank equine plasma and were treated as unknowns since their exact masses and chromatographic retention times were not utilized for detection. The spiked drugs were extracted from the plasma samples and were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). The acquired LC-HRMS raw ...
Harding C, Viljanto M, Habershon-Butcher J, Taylor P, Scarth J.YK-11 is a steroidal selective androgen receptor modulator, a compound class prohibited in both equine racing and human sports because of their potentially performance enhancing properties. YK-11 is easily accessible via internet-based supplement vendors making this compound a possible candidate for doping; however, its phases I and II metabolism has not yet been reported in the horse. The purpose of this study was to investigate the in vivo metabolites of YK-11 in urine and plasma following oral administration with three daily doses of 50 mg to two Thoroughbred horses. In vitro incubations ...
Ruoff WW, Sams RA.The pharmacokinetics and bioavailability of cephalothin given to 6 horse mares at a dosage level of 11 mg/kg of body weight IV or IM were investigated. The disposition of cephalothin given IV was characterized by a rapid disposition phase with a mean half-life of 2.89 minutes and a subsequent slower elimination phase with a mean half-life of only 14.7 minutes. The mean residence time of cephalothin was 10.6 +/- 2.11 minutes. The total plasma clearance of cephalothin averaged 13.6 ml/min/kg and was caused by metabolism and renal elimination. Renal clearance of cephalothin averaged 1.32 ml/min/k...
Yarnell K, Purcell RS, Walker SL.Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, corticotrophin releasing hormone (CRH) is released from the hypothalamus in the brain. This stimulates the release of adrenocorticotrophic hormone (ACTH) from the pituitary gland, which in turn stimulates release of glucocorticoids from the adrenal gland. In horses the glucocorticoid corticosterone is responsible for several adaptations needed to support equine flight behaviour and subsequent removal from the aversive situation. Corticosterone met...
Ishii H, Leung GN, Yamashita S, Nagata SI, Kushiro A, Sakai S, Toju K, Okada J, Kawasaki K, Kusano K, Kijima-Suda I.The use of nicotine stimulants in horses is generally banned in horse racing and equestrian sports-accidental consumption of tobacco products is one of the possible causes of nicotine exposure in horses. The authors recently reported a comprehensive metabolic study of nicotine in equines, differentiating between nicotine exposure and sample contamination by means of a nicotine biomarker trans-3'-hydroxycotinine. To identify potential biomarkers for the differentiation of genuine nicotine administration and consumption of tobacco products, tobacco leaves (equivalent to 250 mg of nicotine) wer...
Hansson A, Knych H, Stanley S, Thevis M, Bondesson U, Hedeland M.Selective androgen receptor modulators (SARMs) are prohibited in sports due to their performance enhancing ability. It is important to investigate the metabolism to determine appropriate targets for doping control. This is the first study where the equine metabolites of SARMs S1, S4 (Andarine) and S22 (Ostarine) have been studied in plasma. Methods: Each SARM was administered to three horses as an intravenous bolus dose and plasma samples were collected. The samples were pretreated with protein precipitation using cold acetonitrile before separation by liquid chromatography. The mass spectrome...
Ishii H, Leung GN, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ agonist in the class of hormones and metabolic modulators. The use of GW1516 is banned in both horseracing and equestrian competitions. To the best of our knowledge, this is the first metabolic study of GW1516 in horses. Methods: After protein precipitation of pre- and post-administration plasma GW1516 samples, the supernatants were analyzed using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry to detect GW1516 and its metabolites. Monoisotopic ions of GW1516 and its metabolites were monitored ...
Lampinen-Salomonsson M, Beckman E, Bondesson U, Hedeland M.Altrenogest (17alpha-allyl-17beta-hydroxyestra-4,9,11-trien-3-one) is a steroid used for the control of estrus in horses. This drug can potentially be abused in racehorses as the occurrence of estrus can alter their performance. This work describes an analytical method based on liquid chromatography-tandem mass spectrometry for the detection of altrenogest in horse urine down to a concentration of 13 pg/mL (0.042 nM). Furthermore, the qualitative aspect of metabolism of altrenogest in the horse has been studied. The main transformations that were found for this species were conjugation with gl...
Mück WM, Henion JD.A screening procedure for the anabolic steroid stanozolol in human and equine urine was developed based on enzymatic hydrolysis, liquid-liquid extraction and reversed-phase liquid chromatography combined on-line with tandem mass spectrometry. The column effluent was introduced into the atmospheric pressure ionization source of a triple-quadrupole mass spectrometer via a heated pneumatic nebulizer liquid chromatograph/mass spectrometer interface. Abundant protonated molecular ions were generated by corona discharge ionization. Confirmation of stanozolol and several of its hydroxylated and dihyd...
Roig M, Segura J, Ventura R.A method to quantify metabolites of 17beta-nandrolone (17betaN) in boar and horse urine has been optimized and validated. Metabolites excreted in free form were extracted at pH 9.5 with tert-butylmethylether. The aqueous phases were applied to Sep Pak C18 cartridges and conjugated steroids were eluted with methanol. After evaporation to dryness, either enzymatic hydrolysis with beta-glucuronidase from Escherichia coli or solvolysis with a mixture of ethylacetate:methanol:concentrated sulphuric acid were applied to the extract. Deconjugated steroids were then extracted at alkaline pH with tert-...
Delcourt V, Garcia P, Pottier I, Mansoibou N, Bache N, Glavieux Y, Chabot B, Perot I, André F, Loup B, Barnabé A, Popot MA, Bailly-Chouriberry L.Synthetic androgenic anabolic steroids (AAS) are banned compounds and considered as major threats by both racing and sports international authorities. Hence, doping control laboratories are continually looking into analytical improvements to increase their detection capabilities, notably by means of emerging technologies. To enhance analytical performances for the detection of synthetic AAS such as stanozolol, specific chromatographic procedures have been developed using recent quaternary liquid chromatography technology originally designed for high-throughput standardized proteomics connected...
So YM, Wong JKY, Choi TLS, Prabhu A, Stewart B, Farrington AF, Robinson P, Wan TSM, Ho ENM.This paper describes the studies of the in vitro biotransformation of two selective androgen receptor modulators (SARMs), namely, RAD140 and S-23, and the in vivo metabolism of RAD140 in horses using ultra-high performance liquid chromatography-high resolution mass spectrometry. in vitro metabolic studies of RAD140 and S-23 were performed using homogenised horse liver. The more prominent in vitro biotransformation pathways for RAD140 included hydrolysis, hydroxylation, glucuronidation and sulfation. Metabolic pathways for S-23 were similar to those for other arylpropionamide-based SARMs. The a...
Porter JK, Voss KA, Bacon CW, Norred WP.Fusarium moniliforme (FM) is associated with equine leukoencephalomalacia (ELEM) and hepatotoxicities in horses and rats. The neurochemical effects of ELEM-associated corn naturally infected with FM and FM strain MRC 826 were studied in rats. Increases in brain 5-hydroxyindoleacetic acid (5-HIAA, major metabolite of serotonin, 5-HT) and 5-HIAA/5-HT ratios were observed in rats fed the ELEM-FM corn. These rats had reduced body weights (17%, P less than 0.01) and increased brain weight/body weight ratios (14%, P less than 0.01) as compared with controls that were fed commercial corn. Rats fed a ...
Silberzahn P, Almahbobi G, Dehennin L, Merouane A.Equine follicular fluid was aspirated at various developmental stages (viable, preovulatory and atretic) determined by ultrastructural study. Estrogens and progestins were analyzed by gas chromatography-mass spectrometry associated with stable isotope dilution. Progesterone and 17-hydroxyprogesterone were the principal progestins of the preovulatory and viable follicles. Among the catechol estrogens, 2-hydroxy-estradiol was particularly abundant in the preovulatory follicle and its definitive identification was made by the scan of a full mass spectrum.
Potter KA, Leid RW, Kolattukudy PE, Espelie KE.Lipoxygenase products of arachidonic acid are important mediators of inflammation, affecting several aspects of cell function. Monohydroxyeicosatetraenoic acid (mono-HETE) and 5,12-dihydroxyeicosatetraenoic acid (LTB4) enhance migration of both neutrophils and eosinophils in several species. The relative ability of positional isomers of HETE and of LTB4 to affect migration of equine eosinophils was studied. The 5, 8, 9, 11, 12, and 15 isomers of HETE were prepared by autooxidation of arachidonic acid, separated by sequential normal phase and reverse phase high performance liquid chromatography...
Harkins JD, Mundy GD, Woods WE, Lehner A, Karpiesiuk W, Rees WA, Dirikolu L, Bass S, Carter WG, Boyles J, Tobin T.Lidocaine is a local anaesthetic agent that is widely used in equine medicine. It is also an Association of Racing Commissioners International (ARCI) Class 2 foreign substance that may cause regulators to impose substantial penalties if residues are identified in post race urine samples. Therefore, an analytical/pharmacological database was developed for this drug. Using our abaxial sesamoid local anaesthetic model, the highest no-effect dose (HNED) for the local anaesthetic effect of lidocaine was determined to be 4 mg. Using enzyme-linked immunosorbent assay (ELISA) screening, administration...
Yuan X, Yao X, Zeng Y, Wang J, Ren W, Wang T, Li X, Yang L, Yang X, Meng J.Horse racing may cause stress-induced physiological changes and tissue damage in horses, but the changes in miRNA expression, protein expression, and metabolic substances in the plasma exosomes of the horse after racing are still unclear. This study detected miRNA, protein expression, and metabolic substances in the plasma exosomes of horses before and after competition, providing new insights for post-race recovery and care of horses. Methods: Eight three-year-old horses that had undergone training were selected as the research subjects, with four horses that had not competed as the contr...
Wang J, Ren W, Li Z, Li L, Wang R, Ma S, Zeng Y, Meng J, Yao X.Equine endurance exercise induces physiological changes that alter metabolism and molecular pathways to maintain balance after intense physical activity. However, the specific regulatory mechanisms remain under debate. Identifying differentially expressed genes (DEGs) and differential metabolites (DMs) associated with equine endurance is essential for elucidating these regulatory mechanisms. This study collected blood samples from six Yili horses before and after an 80 km race and conducted transcriptomics and metabolomics analyses, yielding 722 DEGs and 256 DMs. These DEGs were primarily enri...
Ishii H, Shibuya M, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Yamada M, Leung GN.Daprodustat is a hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) inhibitor and is used as an erythropoiesis stimulant for the treatment of anemia in humans. In general, administering daprodustat to horses will result in a lifetime ban from both equestrian sports and horseracing by the International Federation of Horseracing Authorities and the Fédération Équestre Internationale, respectively. To control the misuse/abuse of daprodustat, we conducted nasoesophageal administration of daprodustat (100 mg/day for 3 days) to three thoroughbred mares and the post-administration hair ...
Subhahar MB, Karakka Kal AK, Philip M, K Karatt T, N I, Vazhat RA, M P MA.ACP-105 is a novel nonsteroidal selective androgen receptor modulator (SARM) with a tissue-specific agonist effect and does not have side effects associated with the use of common androgens. This research reports a comprehensive study for the detection of ACP-105 and its metabolites in racehorses after oral administration (in vivo) and postulating its structures using mass spectrometric techniques. To obtain the metabolic profile of ACP-105, a selective and reliable LC-MS/MS method was developed. The chemical structures of the metabolites were determined based on their fragmentation pattern, a...
