Topic:High-performance Liquid Chromatography (HPLC)
Comparison of the broncoalveolar lavage fluid proteomics between foals and adult horses. Neonates have different cellular composition in their bronchoalveolar lavage fluid (BALF) when compared to foals and adult horses; however, little is known about the non-cellular components of BALF. The objective of this study was to determine the proteomic composition of BALF in neonatal horses and to compare it to that of foals and adult horses. Bronchoalveolar lavage fluid samples of seven neonates (< 1 week age), four 5 to 7-week-old foals, and six adult horses were collected. Quantitative proteomics of the fluid was performed using tandem mass tag labeling followed by high resolution l...
Segmental analysis and long-term monitoring of vadadustat in equine hair for the purpose of doping control. Vadadustat is a newly launched hypoxia-inducible factor stabilizer with anti-anemia and erythropoietic effects; however, its use in horses is expressly forbidden in both racing and equestrian competitions. Following our previous report on the pharmacokinetic study of vadadustat in horse plasma and urine, a long-term longitudinal analysis of vadadustat in horse hair after nasoesophageal administration (3 g/day for 3 days) to three thoroughbred mares is described in this study. Our main objective is to further extend the detection period of vadadustat for the purpose of doping control. Three...
An extensive screening method for the identification and quantitation of ecdysteroids in equine urine and plasma using liquid chromatography coupled with mass spectrometry. Recently, there has been a report suggesting that ecdysteroids can enhance sports performance, making them relevant substances in doping control. Hence, it is imperative to examine the analytical characteristics of ecdysteroids in biological samples to identify their misuse in competitive sports. Methods: To assess the doping of ecdysteroids such as ecdysone, ecdysterone, ponasterone A, turkesterone, and ajugasterone C, a fast and sensitive extraction and detection method was developed, optimized, and validated using equine urine and plasma. Different extraction techniques, namely, solid-phase...
The effects of orally administered trazodone on ambulation and recumbency in healthy horses. Trazodone, a serotonin receptor antagonist and reuptake inhibitor, might be a useful adjunctive treatment in the initial management of horses with acute laminitis if it minimizes ambulation or encourages recumbency. Objective: (1) Evaluate the effects of PO trazodone on ambulatory activity and recumbency in healthy horses; and (2) assess the pharmacokinetics of multiple PO doses of trazodone. Methods: In a randomized cross-over design, 8 healthy horses received placebo or trazodone at 2 doses (2.5 and 7.5 mg/kg) PO q12h for 48 hours with a 14-day washout period between treatments. Forelimb...
Pharmacokinetics of multiple oral doses of acetaminophen in equine neonates. To determine the pharmacokinetics and clinical safety of acetaminophen after oral administration of 40 mg/kg q 12 hours or 60 mg/kg q 24 hours for 14 days. Methods: 12 healthy light-breed neonatal foals. Methods: 6 foals received acetaminophen at 40 mg/kg q 12 hours and 6 foals received 60 mg/kg q 24 hours for 14 days. The study dates were January 31 to April 15, 2023. Physical examinations were performed daily. Plasma disposition of acetaminophen was determined after the first, mid-point drug administration. Hematology and biochemistry analysis was performed before the study, day 7, and the l...
Pharmacokinetics and plasma protein binding of a single dose of clodronate disodium are similar for juvenile sheep and horses. To determine the single-dose pharmacokinetics of clodronate disodium (CLO) in juvenile sheep and the plasma protein binding (PPB) of CLO in juvenile sheep and horses. Methods: 11 juvenile crossbred sheep (252 ± 6 days) for the pharmacokinetic study. Three juvenile crossbred sheep (281 ± 4 days) and 3 juvenile Quarter Horses (599 ± 25 days) for PPB analysis. Methods: CLO concentrations were determined using liquid chromatography-mass spectrometry. Pharmacokinetic parameters were calculated by noncompartmental analysis from plasma samples obtained at 0, 0.5, 1, 3, 6, 12, 24, 48, and 72 hours ...
A hydrophobic deep eutectic solvent-based vortex-assisted liquid-liquid microextraction applied for doping control of aromatase inhibitors from equine urine. Aromatase inhibitors (AIs) can indirectly cause increased testosterone in animals, which leads to the improvement of the athletic ability of horses. For the protection of horses and the consideration of fair competition, AIs were listed as prohibited drugs by the Federation Equestre Internationale (FEI). There were several disadvantages using traditional pretreatment methods before analyzing these drugs from biological samples. A rapid and green pretreatment method has been developed by utilizing the hydrophobic deep eutectic solvent (DES)-based vortex-assisted liquid-liquid microextraction (D...
Ketoprofen in horses: Metabolism, pharmacokinetics, and effects on inflammatory biomarkers. Ketoprofen is an anti-inflammatory drug that is commonly administered to racehorses for the alleviation of musculoskeletal pain and inflammation. This study represents a comprehensive examination of the metabolism (in vivo and in vitro), pharmacokinetics and ex vivo pharmacodynamics, of ketoprofen in horses. The in vitro metabolism as well as specific enzymes responsible for metabolism was determined by incubating liver microsomes and recombinant CYP450 and UGT enzymes with ketoprofen. For the in vivo portion, 15 horses were administered a single intravenous dose of 2.2-mg/kg ketoprofen. Blood...
High-throughput untargeted screening of biotherapeutic macromolecules in equine plasma by UHPLC-HRMS/MS: Application to monoclonal antibodies and Fc-fusion proteins for doping control. Many innovative biotherapeutics have been marketed in the last decade. Monoclonal antibodies (mAbs) and Fc-fusion proteins (Fc-proteins) have been developed for the treatment of diverse diseases (cancer, autoimmune diseases, and inflammatory disorders) and now represent an important part of targeted therapies. However, the ready availability of such biomolecules, sometimes characterized by their anabolic, anti-inflammatory, or erythropoiesis-stimulating properties, raises concerns about their potential misuse as performance enhancers for human and animal athletes. In equine doping control labo...
Simultaneous Determination of Pyrethrins, Pyrethroids, and Piperonyl Butoxide in Animal Feeds by Liquid Chromatography-Tandem Mass Spectrometry. The presence of insecticides like pyrethrins and synthetic pyrethroids, combined with the synergist piperonyl butoxide, in animal feeds can pose a risk to both animal and human health by contaminating the food chain. In this study, a simple and fast method was developed for the simultaneous determination of these compounds in contaminated animal feeds using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample preparation was carried out using a QuEChERS-based approach, and the method was validated with acceptable accuracy ranging from 84 to 115% and precision below 10%. The limit ...
Characterization of the Glycans of Equine κ-Casein. To study the protein-bound glycans of equine κ-casein, equine sodium caseinate was first obtained from raw mare's milk by acid precipitation and then fractionated by cation-exchange chromatography. The oligosaccharides of the obtained equine κ-casein were analyzed by RP-HPLC-UV-HRMS after β-elimination with simultaneous derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP). In addition to the acidic tetrasaccharide derivative Neu5Ac-Gal-[Neu5Ac]-GalNAc-2PMP known from bovine κ-casein, the acidic pentasaccharide derivative Neu5Ac-Gal-[Gal-GlcNAc]-GalNAc-2PMP was identified as the most ab...
Identification and kinetics of microsomal and recombinant equine liver cytochrome P450 enzymes responsible for in vitro metabolism of omeprazole. In humans, omeprazole is metabolised by cytochrome P450 (CYP450) CYP2C19 and CYP3A4 with differences in CYP2C19 genotypes leading to variable response to therapy. Despite a wide use of omeprazole in horses with evidence of variable therapeutic efficiency, information regarding enzymatic metabolism is not currently available. This study aims to describe the in vitro kinetics of omeprazole metabolism and determine which enzyme(s) are responsible for omeprazole metabolism in horses. Omeprazole (0-800 uM) was incubated with liver microsomes and a panel of equine recombinant CYP450s (eq-rCYP). Meta...
Identification of erythropoietin mimetic peptide 1 linear form in a sealed vial and its administration study in horses for doping control purpose. The erythropoietin mimetic peptide 1 linear form (EMP1-linear), GGTYSCHFGPLTWVCKPQGG-NH , was identified in an unknown preparation consisting of white crystalline powder contained in sealed glass vials using ultrahigh performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS). The white crystalline powder, allegedly used for doping racehorses, was found to contain around 2% (w/w) of EMP1-linear. EMP1-linear can be cyclised in equine plasma at physiological temperature of 37°C by forming an intramolecular disulfide bond to give EMP1, which is a well-known erythropoiesis st...
Evaluation of the effect of glucocorticoid treatment on adrenocortical functions by monitoring endogenous hydrocortisone in horses. Glucocorticoid preparations have anti-inflammatory effects, and are commonly used in the equine clinical setting; however, such treatments can cause a number of side effects. Adrenal insufficiency is an adverse effect induced by the suppression of adrenal function following drug administration. This study aimed to investigate the influence of two glucocorticoid preparations, dexamethasone and hydrocortisone, on adrenocortical function in horses. The usual doses of dexamethasone and hydrocortisone preparations in equine practice were administered intramuscularly to six horses, and peripheral bl...
Detection of gonadotropin-releasing hormone and its analogues in equine and canine urine by high-resolution data-independent acquisition. Gonadotropin-releasing hormone (GnRH) and its synthetic analogues are considered banned substances by the racing industry. GnRH is used as a pharmaceutical to regulate the female oestrous cycle, but the hormone is also thought to increase the production of testosterone in male animals. Using liquid chromatography in conjunction with high-resolution mass spectrometry (LC-HRMS) and data-independent acquisition (DIA), a method is presented for the detection of intact and truncated peptides of GnRH and its analogues down to the low picogram level in equine urine. The study of the catabolism of GnR...
Electrospray ionization mass spectrometry adduct formation by mobile phase additives: A case study using nitrile functional groups containing selective androgen receptor modulators. The formation of mass adducts is common during electrospray ionization mass spectrometry (ESI-MS). However, the mechanism that leads to adduct formation is poorly understood and difficult to control. Multiplication of mass adducts at once will adversely impact the sensitivity of mass analysis and cause misinterpretation of the level of detection. Prior studies on selective androgen receptor modulators (SARMs) revealed an immense mass adduct formation in both positive and negative ESI modes. Methods: In this study, additives in the mobile phases are investigated as a potential means of controll...
Performance assessment of an equine metabolomics model for screening a range of anabolic agents. Despite their ban, Anabolic Androgenic Steroids (AAS) are considered as the most important threat for equine doping purposes. In the context of controlling such practices in horse racing, metabolomics has emerged as a promising alternative strategy to study the effect of a substance on metabolism and to discover new relevant biomarkers of effect. Based on the monitoring of 4 metabolomics derived candidate biomarkers in urine, a prediction model to screen for testosterone esters abuse was previously developed. The present work focuses on assessing the robustness of the associated method and def...
Pharmacokinetics of aminocaproic acid in thoroughbred horses. The antifibrinolytic agent aminocaproic acid (ACA) is occasionally used prior to episodes of intense training in racehorses suffering from exercise-induced pulmonary hemorrhage. Although a previous study indicated that the drug is cleared rapidly in horses, some racetrack practitioners claim that recent adverse analytical findings for ACA in postrace samples were from ACA administrations 5-7 days before the race. The purpose of this study was to re-examine the pharmacokinetics of ACA in horses to address this apparent conundrum. Eight exercise-conditioned thoroughbred horses were administere...
In-depth metabolic study of nonsteroidal selective androgen receptor modulator GSK2881078 in thoroughbred horses and horse liver microsomes for doping control. Nonsteroidal selective androgen receptor modulators (SARMs) are a novel class of compounds that have not yet been clinically approved; however, they appear to have a better anabolic/androgenic ratio than steroids and cause slighter side effects. Sports drug testing laboratories are required to maintain continuously updated doping control analytical methods in light of the widespread misuse of SARMs in elite and amateur sports. This paper describes the metabolic conversion of SARM GSK2881078 in thoroughbred horses following oral administration and in vitro with equine liver microsomes. A liquid...
Selection and Validation of Reference Genes for Gene Expression Studies in an Equine Adipose-Derived Mesenchymal Stem Cell Differentiation Model by Proteome Analysis and Reverse-Transcriptase Quantitative Real-Time PCR. Adipose-derived stem cells (ADSCs) are used in tissue regeneration therapies. The objective of this study is to identify stable reference genes (RGs) for use in gene expression studies in a characterized equine adipose-derived mesenchymal stem cell (EADMSC) differentiation model. ADSCs were differentiated into adipocytes (ADs) or osteoblasts (OBs), and the proteomes from these cells were analyzed by liquid chromatography tandem mass spectrometry. Proteins that were stably expressed in all three cells types were identified, and the mRNA expression stabilities for their corresponding genes were ...
3-Methoxytyrosine as an indicator of dopaminergic manipulation in equine plasma. The use of catechol-O-methyltransferase inhibitors may mask doping agents, primarily levodopa, administered to racehorses and prolong the stimulating effects of dopaminergic compounds such as dopamine. It is known that 3-methoxytyramine is a metabolite of dopamine and 3-methoxytyrosine is a metabolite of levodopa thus these compounds are proposed to be potential biomarkers of interest. Previous research established a urinary threshold of 4,000 ng/mL for 3-methoxytyramine to monitor misuse of dopaminergic agents. However, there is no equivalent biomarker in plasma. To address this deficiency a...
Use of Liquid Chromatography–Tandem Mass Spectrometry to Quantify and Confirm the Fentanyl Metabolite N-[1-(2-Phenethy-4-Piperidinyl)] Maloanilinic Acid in Equine Urine for Doping Control. Fentanyl, a powerful synthetic mu opioid receptor agonist, is banned in equine sports by the Association of Racing Commissioners International and the Fédération Équestre Internationale. The presence of fentanyl in equine blood has been confirmed during routine post-race screening for doping substances in the authors' laboratory. While fentanyl can be detected and confirmed in blood, it is rapidly metabolized, and screening for the metabolite N-[1-(2-phenethy-4-piperidinyl)] maloanilinic acid (PMA) in equine urine is expected to allow for a longer detection time. In this study, a quantitati...
Metabolic study of selective androgen receptor modulator LY2452473 in thoroughbred horses for doping control. Since 2010, there has been an increasing number of adverse analytical findings related to selective androgen receptor modulators (SARMs) in competitive sports. It emphasizes the importance of comprehensive doping control analytical procedures that are capable of detecting SARM misuse. Methods: In this study, it is described how LY2452473, a SARM, was metabolized in thoroughbred horses after a single-dose oral administration and in vitro with equine liver microsome preparations. An investigation of the metabolism of LY2452473 in horses' urine, plasma, and hair matrices was carried out during th...
Physicochemical Characterization of a Recombinant eCG and Comparative Studies with PMSG Commercial Preparations. Equine chorionic gonadotropin (eCG) is a glycoprotein hormone widely used in timed artificial ovulation (TAI) and superovulation protocols to improve the reproductive performance in livestock. Until recently, the only eCG products available in the market for veterinary use consisted in partially purified preparations of pregnant mare serum gonadotropin (PMSG). Here, a bioactive recombinant eCG (reCG) produced in suspension CHO-K1 cells was purified employing different chromatographic methods (hydrophobic interaction chromatography and reverse-phase (RP)-HPLC) and compared with a RP-HPLC-purifi...
The Influence of Exercise Intensity on Tryptophan Metabolites in Thoroughbred Horses. Catabolism of tryptophan (Trp) is modulated by physical activity and provides a pool of active compounds: Trp is considered a calmative agent, kynurenine (Kyn) and 3-hydroxykynurenine (3-HKyn) show neurotoxic effects, kynurenic acid (Kyna) and xanthurenic acid (XA) have neuroprotective properties like nicotinamide (NAm), while serotonin is the neurotransmitter. The study was conducted to investigate the dependence of exercise intensity, measured by plasma lactic acid (LA) concentration, on the level of Trp, its catabolites (serotonin, Kyn, 3-HKyn, Kyna and XA), and NAm in Thoroughbred horses. ...
Synopsis of the pharmacokinetics, pharmacodynamics, applications, and safety of firocoxib in horses. According to and investigations, firocoxib (FX), a second-generation coxib, is a highly selective COX-2 inhibitor in horses. With a COX-1/COX-2 IC ratio of 643 in horses, FX spares the COX-1 inhibitory effects. It is approved for the treatment of musculoskeletal problems and lameness in horses and dogs with osteoarthritis (OA). For the treatment of OA in horses, both an injectable formulation for IV administration at a dose of 0.09 mg/kg for five days and an oral paste formulation at a dose of 0.1 mg/kg for 14 days are licensed. Numerous analytical methods were reported in the literature t...
Immunoprofiling of Equine Plasma against Deinagkistrodon acutus in Taiwan: Key to Understanding Differential Neutralization Potency in Immunized Horses. Snakebite envenoming is a public health issue linked to high mortality and morbidity rates worldwide. Although antivenom has been the mainstay treatment for envenomed victims receiving medical care, the diverse therapeutic efficacy of the produced antivenom is a major limitation. is a venomous snake that poses significant concern of risks to human life in Taiwan, and successful production of antivenom against envenoming remains a considerable challenge. Among groups of horses subjected to immunization schedules, few or none subsequently meet the quality required for further scale-up harvesti...
Pharmacodynamics and pharmacokinetics of nalbuphine in xylazine‑sedated horses. This study describes the selected pharmacodynamics and pharmacokinetics of nalbuphine (NAL) in xylazine (XYL)‑sedated horses. Five adult healthy horses were randomly received 2 treatments at a 1‑week interval; XYL treatment (0.55 mg/kg IV) and XYL/NAL treatment (XYL, 0.55 mg/kg IV; NAL, 0.3 mg/kg IV). The measured pharmacodynamic variables were sedative and analgesic effects and the effect on ataxia and some physiological parameters. for the pharmacokinetics of NAL, its plasma concentrations were measured using HPLC and a 2‑compartment analysis was performed. Greater and prolonged sedati...
Pharmacokinetic properties of pergolide mesylate following single and multiple-dose administration in donkeys (Equus asinus). Donkeys with clinical signs of pituitary pars intermedia dysfunction are treated with oral pergolide mesylate despite the lack of species-specific pharmacokinetic data. Objective: To evaluate the pharmacokinetics of intragastric and oral pergolide mesylate in healthy donkeys (Equus asinus). Methods: Pharmacokinetic study. Methods: Six healthy donkeys were administered pergolide mesylate (Prascend®) at 2 μg/kg bodyweight (bwt) intragastrically once, then once daily per os (PO) for 5 days. Blood samples were collected at 0, 10, 20, 30 and 45 min and 1, 1.5, 2, 3, 4, 6, 8, 12, 24, 36 and ...
Pharmacokinetics of single dose administration of three increasing doses of acetaminophen per os in 1-3-month-old foals. Acetaminophen is a common analgesic and antipyretic drug used in human medicine and might be an alternative to nonsteroidal anti-inflammatory drugs for treating pain and pyrexia in foals. The pharmacokinetics and safety of differing doses of acetaminophen have not been investigated in foals. Objective: To determine the plasma pharmacokinetics and any changes in haematology and biochemistry profiles following oral administration of single doses of acetaminophen at 10, 20, and 40 mg/kg to foals. Methods: Randomised cross-over pharmacokinetic study. Methods: Six Quarter Horse (two colts and fou...