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.
Viljanto M, Kicman AT, Walker CJ, Wolff K, Muir T, Hincks P, Biddle S, Scarth J.Boldenone (1-dehydrotestosterone) is an exogenous anabolic-androgenic steroid (AAS) but is also known to be endogenous in the entire male horse and potentially formed by microbes in voided urine, the gastrointestinal tract, or feed resulting in its detection in urine samples. In this study, equine fecal and urine samples were incubated in the presence of selected stable isotope labeled AAS precursors to investigate whether microbial activity could result in 1-dehydrogenation, in particular the formation of boldenone. Fecal matter was initially selected for investigation because of its high mic...
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...
Habershon-Butcher J, Cutler C, Viljanto M, Hincks PR, Biddle S, Paine SW.Xylazine is widely used worldwide as a short-acting sedative in general equine and racing practice. In the UK, although it has a legitimate use during training, equine anti-doping rules state it is a prohibited substance on race day. The aim of the study was to produce a detection time (DT) to better inform European veterinary surgeons so that xylazine can be used appropriately under regulatory rules. Previous publications have various limitations pertaining to analysis method, particularly for plasma and limited length of time of sample collection. In this study, pharmacokinetic data were pro...
Ueda T, Tozaki T, Nozawa S, Kinoshita K, Gawahara H.Recently, the illegal use of novel technologies, such as gene and cell therapies, has become a great concern for the horseracing industry. As a potential way to control this, metabolomics approaches that comprehensively analyze metabolites in biological samples have been gaining attention. However, it may be difficult to identify metabolic biomarkers for doping because physiological conditions generally differ between resting and exercise states in horses. To understand the metabolic differences in horse plasma between the resting state at training centres and the sample collection stage after...
Knych HK, Weiner D, Steinmetz S, Flynn K, McKemie DS.Hydroxyzine is a first-generation antihistamine and cetirizine, a second-generation antihistamine and active metabolite of hydroxyzine. Hydroxyzine is commonly used in performance horses and as such its use in closely regulated; however, there are no published studies suitable for establishing appropriate regulatory recommendations. In the current study, 12 exercised Thoroughbred research horses received a single oral administration of 500 mg of hydroxyzine. Blood and urine samples were collected prior to and up to 96 hr postdrug administration and concentrations of hydroxyzine and cetirizin...
Sander J, Terhardt M, Sander S, Aboling S, Janzen N.Up to now quantification of hypoglycin A in serum and urine in the range of nmols to μmols per liter plus the measurement of accumulated acyl conjugates have been used for the diagnosis of poisoning by fruits or seeds of in humans and animals. A second poison, methylenecyclopropylglycine, however, is known to occur in this material. The objective of our study was to develop and evaluate a method for the quantification of this compound suitable for test materials obtained from animals and man. Methods: Methylenecyclopropylglycine was extracted from serum and urine of a volunteer by a methanoli...
Guan F, You Y, Li X, Robinson MA.Bioactive peptides possess pharmacological effects and can be illicitly used in sports. To deter such misuse, an untargeted method using high resolution mass spectrometry (HRMS) has been developed for comprehensive detection of multitudinous exogenous peptides in equine plasma and urine. Forty-four peptides were extracted using mixed-mode solid-phase extraction (SPE) from plasma and urine, separated with a hydrophilic interaction liquid chromatography (HILIC) column, and detected on an HRMS instrument. Ammonium formate as a mobile phase additive had effects on HILIC retention and charge state ...
Walter J, Huwiler F, Fortes C, Grossmann J, Roschitzki B, Hu J, Naegeli H, Laczko E, Bleul U.Maturation of oocytes under in vitro conditions (IVM) results in impaired developmental competence compared to oocytes matured in vivo. As oocytes are closely coupled to their cumulus complex, elucidating aberrations in cumulus metabolism in vitro is important to bridge the gap towards more physiological maturation conditions. The aim of this study was to analyze the equine "cumulome" in a novel combination of proteomic (nano-HPLC MS/MS) and metabolomic (UPLC-nanoESI-MS) profiling of single cumulus complexes of metaphase II oocytes matured either in vivo (n = 8) or in vitro (n = 7). Re...
Knych HK, Baden RW, Gretler SR, McKemie DS.Despite their widespread popularity as sport and companion animals and published and anecdotal reports of vast difference in drug disposition and pharmacokinetics between individuals, studies describing equine drug metabolism are limited. It has been theorized that similar to humans, members of the CYP2D family in horses may be polymorphic in nature leading to differences in metabolism of substrates. This study aims to build on the limited current knowledge regarding P450 mediated metabolism in horses by describing the metabolism of the polymorphic CYP2D6 probe drug codeine in vitro. Codeine, ...
Satué K, Fazio E, Ferlazzo A, Medica P.The aim of this study was to verify the existence of possible cross-talk between biochemical contents of follicular fluid (FF) and systemic concentrations according to the follicular development of the metabolites: glucose (GLU), lactate (LACT), cholesterol (CHOL), triglycerides (TG), total bilirubin (T BIL), blood urea nitrogen (BUN), and creatinine (CREAT); enzymatic activities: gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and aspartate aminotransferase (AST); electrolytes: calcium (Ca), phosphorus (P), sodium (Na), chloride (Cl), potassium (K), ...
Gajardo G, López-Muñoz R, Plaza A, Uberti B, Sarmiento J, Morán G, Henríquez C.Tamoxifen (TAM), a selective modulator of estrogen receptors (SERMs) has been recently explored as a therapeutic option for the oral treatment of airway inflammation in the horse. The objective of this work was to establish pharmacokinetic parameters of TAM and its main metabolites in equines, as well as to determine its clinical safety in short-term treatments. Results: We determined TAM and its three main metabolites (4-OH tamoxifen, endoxifen, and N-desmethyl tamoxifen) in plasma after single administration of 0.25 mg/kg in healthy adult horses ( = 12). A maximum concentration of TAM w...
Le Moyec L, Robert C, Triba MN, Bouchemal N, Mach N, Rivière J, Zalachas-Rebours E, Barrey E.Endurance racing places high demands on energy metabolism pathways. Metabolomics can be used to investigate biochemical responses to endurance exercise in humans, laboratory animals, and horses. Although endurance horses have previously been assessed in the field (i.e., during races) using broad-window Nuclear Magnetic Resonance metabolomics, these studies included several different race locations, race distances, age classes, and race statuses (finisher or elimination). The present NMR metabolomics study focused on 40 endurance horses racing in three race categories over 90, 120, or 160 km. T...
Stojiljkovic N, Leroux F, Bubanj S, Popot MA, Paris A, Tabet JC, Junot C.There is an urgent need to implement holistic and untargeted doping control protocols with improved discriminatory power, compared to conventional methods that only target doping agents. Metabolomics, which aims to characterize all metabolites present in biological matrices, could fulfill this need. In this context, the aim of this study was to evaluate the impact of environmental factors on the ability to obtain a metabolic signature of stanozolol administration in horse doping situation. Urine samples from 16 horses breeded in two different places were collected over a one-year period, befor...
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...
Coleman MC, Whitfield-Cargile CM, Madrigal RG, Cohen ND.Metabolic diseases such as obesity and type 2 diabetes in humans have been linked to alterations in the gastrointestinal microbiota and metabolome. Knowledge of these associations has improved our understanding of the pathophysiology of these diseases and guided development of diagnostic biomarkers and therapeutic interventions. The cellular and molecular pathophysiology of equine metabolic syndrome (EMS) and obesity in horses, however, remain ill-defined. Thus, the objectives of this study were to characterize the fecal microbiome, fecal metabolome, and circulating lipidome in obese and non-o...
Genangeli M, Caprioli G, Cortese M, Laus F, Petrelli R, Ricciutelli M, Sagratini G, Sartori S, Vittori S.A new fast and easy analytical procedure for the simultaneous detection and quantification of 9 anabolic steroids (deslorelin, dexamethasone sodium phosphate, prednisolone, methylprednisolone, stanozolol, boldenone, nandrolone, dexamethasone isonicotinate and altrenogest) in horse urine for doping control have been developed by using the ultra-high-performance liquid chromatography coupled with tandem mass spectrometry technique (UHPLC-MS/MS). A total amount of 400 μl of sample was evaporated, restored and injected in the UHPLC-MS/MS. The proposed method was fully validated showing a recove...
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...
Zielinski J, Mevissen M.Testosterone hydroxylation was investigated in human, canine and equine liver microsomes and in human and canine single CYPs. The contribution of the CYP families 1, 2 and 3 was studied using chemical inhibitors. Testosterone metabolites were analyzed by HPLC. The metabolites androstenedione, 6β- and 11β-hydroxytestosterone were found in microsomes of all species, but the pattern of metabolites varied within species. Androstenedione was more prominent in the animal species, and an increase over time was seen in equines. Testosterone hydroxylation was predominantly catalyzed by the CYP3A subf...
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...
Calamari L, Abeni F, Bertin G.This study was conducted to determine the effects of dietary Se source and dose on metabolic and hematological profiles, and their relationships with oxidative status in horses. Twenty-five mature horses were blocked by BW and randomly allocated to 1 of 5 dietary treatments: negative control (CTRL: 0.085 mg of Se/kg of DM), 3 different dietary concentrations of organic Se provided by Se yeast (SY02, SY03, and SY04 containing 0.2, 0.3, and 0.4 mg of total Se/kg of DM, respectively), and 1 positive control provided by sodium selenite (SS03 containing 0.3 mg of total Se/kg of DM). Horses were fed...
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 ...
De Leo M, Giorgi M, Saccomanni G, Manera C, Braca A.Tramadol is a centrally acting analgesic drug that has been used clinically for the last two decades to treat pain in humans. The clinical response of tramadol is strictly correlated to its metabolism, because of the different analgesic activity of its metabolites. O-Desmethyltramadol (M1), its major active metabolite, is 200 times more potent at the micro-receptor than the parent drug. In recent years tramadol has been widely introduced in veterinary medicine but its use has been questioned in some species. The aim of the present study was to develop a new sensible method to detect the whole ...
Acri G, Testagrossa B, Piccione G, Arfuso F, Giudice E, Giannetto C.The evaluation of the performance levels in athletic horses is of major importance to prevent sports injuries. Raman spectroscopy is an innovative technique that allows for a rapid evaluation of biomolecules in biological fluids. It also permits qualitative and quantitative sample analyses, which lead to the simultaneous determination of the components of the examined biological fluids. On the basis of this, the Raman spectroscopy technique was applied on serum samples collected from five Italian Saddle horses subjected to a standardized obstacle course preceded by a warm-up to evaluate the ap...
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...
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 ...
Peck K, Mealey KL, Matthews NS, Taylor TS.To determine whether clearance of capacity-limited drugs in horses differs from that in donkeys by comparing the serum disposition of caffeine and its metabolites, theophylline, theobromine, and paraxanthine after i.v. administration of caffeine to horses and donkeys. Methods: 4 healthy horses and 5 healthy donkeys. Methods: Blood samples were collected from each animal at time 0 (before) and 5, 10, 15, 20, 30, and 45 minutes, and 1, 2, 3, 4, 6, 8, 12, 24, 30, 36, 48, 54, 60, 72, and 96 hours after IV administration of a bolus of caffeine. Serum was analyzed in triplicate by high-performance l...
Knych HK, Corado CR, McKemie DS, Steffey EP.Both the potential analgesic effect and the conflicting reports describing tramadol disposition in the horse warrant further study of the pharmacokinetics of tramadol in this species. Objective: To describe the pharmacokinetics of tramadol and its metabolites, O-desmethyltramadol and N-desmethyltramadol, following i.v. administration of 3 doses to the horse. Methods: Nine adult horses received a single i.v. dose of 0.5, 1.5 and 3 mg/kg bwt tramadol. Blood samples were collected prior to and at various times up to 72 h post administration. Plasma samples were analysed using liquid chromatograph...
Bickhardt K, Deegen E, Espelage W.Investigations of renal function have been done on the basis of renal clearance (Clr) and excretion (E) of endogenous creatinine in healthy horses of different body weight (23 female, 7 male). Creatinine was measured by enzymatic PAP-method. Creatinine-E of female horses was poor positively correlated with body weight. The creatinine-Clr was highly correlated with the inulin-Clr (r = 0,896, p < 0,001). The excretion of creatinine was 35% higher than the filtration of creatinine, determined by inulin-Clr. That demonstrate a tubular net secretion of 26% of the total creatinine excretion. However...
Kollias-Baker C, Maxwell L, Stanley S, Boone T.Cocaine is a naturally occurring alkaloid that is commonly abused by human-beings for its psychostimulatory effects. Occasionally, very small concentrations (i.e. <100 ng/mL) of the primary cocaine metabolite, benzoylecgonine (BZE) have been detected in urine collected from horses competing in athletic events. In this study urine samples, collected from four horses following the administration of 2.5 and 20 mg of cocaine sublingually and 50 mg of cocaine intravenously, were analyzed for the presence of cocaine and/or its metabolites by enzyme-linked immunosorbent assay (ELISA) and gas chrom...
Spyridaki MH, Lyris E, Georgoulakis I, Kouretas D, Konstantinidou M, Georgakopoulos CG.Xylazine and its main metabolites were detected in equine urine after a single-dose intravenous administration of 0.98 and 1.01 mg/kg body weight xylazine, respectively, in two horses, in order to be used for equine doping control routine analysis. The urine levels of the parent drug and its metabolites were determined using gas chromatography-mass spectrometry (GC-MS). Xylazine is metabolised rapidly, down to a concentration level of about 1.0 microg/ml after 1-3h administration. Seven metabolites were identified in urine. 4-Hydroxy-xylazine, the major metabolite, could be traced for 25 h and...
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 ...
Trevisiol S, Moulard Y, Delcourt V, Jaubert M, Boyer S, Tendon S, Haryouli H, Taleb W, Caroff M, Chabot B, Drif L, André F, Garcia P, Loup B....According to international sport institutions, the use of peroxisome proliferator activated receptor (PPAR)-δ agonists is forbidden at any time in athlete career due to their capabilities to increase physical and endurance performances. The (PPAR)-δ agonist GW501516 is prohibited for sale but is easily available on internet and can be used by cheaters. In the context of doping control, urine is the preferred matrix because of the non-invasive nature of sampling and providing broader exposure detection times to forbidden molecules but often not detected under its native form due to the organi...
Popot MA, Garcia P, Hubert C, Bolopion A, Bailly-Chouriberry L, Bonnaire Y, Thibaud D, Guyonnet J.Tiludronate is a non-nitrogen-containing biphosphonate drug approved in equine veterinary medicine for the treatment of navicular disease and bone sparvin in horse. Its hydrophilic properties and its strong affinity for the bone have made the control of its use quite difficult. After an initial step of method development in plasma and urine, due to a strong matrix effect and erratic detection in urine, the final method development was conducted in plasma. After addition of (3-trifluoromethylphenyl) thiomethylene biphosphonic acid as internal standard, automated sample preparation consisted of ...
Ohnuma K, Uchida T, Leung GN, Ueda T, Obara T, Ishii H.In the context of doping control, conventional direct chemical testing detects only a limited scope of target substances in equine biological samples. To expand the ability to detect doping agents and their detection windows, metabolomics has recently become a common approach for monitoring alteration of biomarkers caused by doping agents in relevant metabolic pathways. In horse racing, remarkable changes in metabolic profiles between the rest state and racing are likely to affect the identification of doping biomarkers. Previously, we reported a limited number of significantly upregulated met...
Montesissa C, Stracciari JM, Fadini L, Beretta C.A comparison has been made of the in vitro metabolism of febantel (FBT) with that of one of its pharmacologically active metabolites fenbendazole (FBZ) using microsomal preparations from liver of sheep, calf, horse, pig, rat, chicken and trout. The oxidation of FBT to the corresponding sulphoxide appeared to be far more rapid with the exception of the trout, than a similar reaction with FBZ. Indeed FBT was further metabolized in several species by cyclization and further oxidation. This observation could have toxicological significance in view of the greater tetratogenic effects of the metabol...
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...
Furr M, Kennedy T.Toltrazuril 5% suspension (Baycox, Bayer Canada, Ontario, Canada) was administered to six adult horses followed by blood collection and assay to determine the concentration of toltrazuril and its principal metabolites, toltrazuril sulfone and toltrazuril sulfoxide. From this data, the maximum concentration (C(max)), elimination half-life (T 1/2), and mean residence times of the plasma were determined from standard pharmacokinetic formulas. After a single oral dose of 10 mg/kg body weight a rapid absorption was found, with a mean peak serum concentration of 11.17 mg/L at 18 hours. Elimination w...
Miller-Graber P, Lawrence L, Fisher M, Bump K, Foreman J, Kurcz E.The relationship between elevated plasma ammonia (NH3) levels, fatigue development and muscle metabolism were examined in horses during a submaximal fatigue test. Eight Quarter Horse mares were intravenously infused prior to exercise with either sodium acetate (control) or ammonium acetate (AMINF), and exercised to fatigue on an 11% grade treadmill, carrying 27 kg of lead. Time to fatigue was not different (P greater than 0.05) between groups. Intramuscular NH3 and lactate increased (P less than 0.001) during exercise; however, the treatment did not (P greater than 0.05) affect either. A treat...
Ishii H, Shibuya M, Leung GN, Nozawa S, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ (PPAR-δ) agonist that is banned in horseracing and equestrian sports. Long-term detection and longitudinal distribution of GW1516 in the mane of a horse are reported for the first time and this hair analysis could prolong the detection window of GW1516 for doping control. Methods: Mane hairs were divided into three segments (0-7, 7-15, and >15 cm from the cut end) and completely pulverized and homogenized for analysis. The pulverized hair samples were extracted with methanol followed by further purification and the extracts were a...
Dumasia MC, Houghton E, Bradley CV, Williams DH.The metabolism and urinary excretion of 1,2(n)-3H-1-dehydrotestosterone were studied in cross-bred gelded horses. Approximately 40% of the dose was excreted in 24 h. The steroid metabolites were extracted by Amberlite XAD-2 resin and fractionated into glucuronides and sulphoconjugates. Unchanged 1-dehydrotestosterone was the only component identified by gas chromatography mass spectrometry after solvolysis of the sulphoconjugates. Positive and negative ion fast atom bombardment mass spectra were obtained on the purified 1-dehydrotestosterone sulphoconjugate isolated from horse urine and on the...
Edlund O, Bowers L, Henion J, Covey TR.Urine samples were spiked with [17-methyl-2H3]methandrostenolone as internal standard and extracted with a mixture of dichloromethane and cyclohexane. The organic phase was concentrated and injected onto a short octyl-silica column (30 mm x 4.6 mm I.D.) for separation of methandrostenolone and 17-epimethandrostenolone. The effluent from the column was connected to a Sciex TAGA 6000E triple quadrupole mass spectrometer equipped with an atmospheric pressure ion source for sampling of ions generated by a heated pneumatic nebulizer with corona discharge ionization. This ion source produced abundan...
Ishii H, Shibuya M, So YM, Wong JKY, Ho ENM, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Yamada M, Leung GN.IOX4 is a hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) inhibitor, which was developed for the treatment of anemia by exerting hematopoietic effects. The administration of HIF-PHD inhibitors such as IOX4 to horses is strictly prohibited by the International Federation of Horseracing Authorities and the Fédération Équestre Internationale. To the best of our knowledge, this is the first comprehensive metabolic study of IOX4 in horse plasma and urine after a nasoesophageal administration of IOX4 (500 mg/day, 3 days). A total of four metabolites (three mono-hydroxylated IOX4 and one ...
Ropp JK, Raub RH, Minton JE.Feeding diets high in soluble carbohydrates to growing horses has been implicated in the development of orthopedic diseases; as a result, substitution of dietary fat for soluble carbohydrates has received attention. Because IGF-I is integral to growth and cartilage development and because it is influenced by nutrition, we evaluated the effect of dietary fat substitution on metabolic endpoints and circulating GH and IGF-I in growing horses. Twelve Quarter Horse weanlings, four female and eight male, 151 to 226 d old, were blocked by sex and age and assigned to two treatment groups. Group one (C...
