High-performance Liquid Chromatography (HPLC) is an analytical technique used to separate, identify, and quantify components in a mixture. In equine research, HPLC is employed to analyze various biological samples from horses, such as blood, urine, and tissue, to detect and measure compounds like drugs, metabolites, and nutritional components. This technique is valued for its precision, sensitivity, and ability to handle complex matrices, making it suitable for pharmacokinetic studies, monitoring therapeutic drug levels, and assessing metabolic profiles in horses. The application of HPLC in equine studies provides insights into drug metabolism, nutritional status, and the biochemical effects of different treatments. This page compiles peer-reviewed research studies and scholarly articles that explore the applications, methodologies, and findings of HPLC in the context of equine science.
Rivolta AA, Bujold AR, Wilmarth PA, Phinney BS, Navelski JP, Horohov DW, Sanz MG.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...
Ishii H, Shibuya M, Kusano K, Sone Y, Kamiya T, Wakuno A, Ito H, Miyata K, Yamada M, Leung GN.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...
Karatt TK, Sathiq MA, Laya S, Ajeebsanu MPM, Karakka Kal AK, Subhahar MB, Perwad Z.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...
Hobbs K, Luethy D, Davis J, Mallicote M, Torcivia C, Kulp J, Stefanovski D, Futterman C, Cooper F, van Eps A.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...
Faivre C, Wong DM, Villarino NF, Court M, Gold JR.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...
Vergara-Hernandez FB, Nielsen BD, Kottwitz JJ, Panek CL, Robison CI, Paris BL, Welsh TH, Bradbery AN, Leatherwood JL, Colbath AC.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 ...
Chen Q, Wang Z, Chen H.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...
Knych HK, McKemie DS, Kass PH, Stanley SD, Blea J.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...
Pinetre J, Delcourt V, Becher F, Garcia P, Barnabé A, Loup B, Popot MA, Fenaille F, Bailly-Chouriberry L.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...
Xu X, Murphy LA.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 ...
Jaeser M, Wunderlich C, Henle T.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...
Ferlini Agne G, Somogyi AA, Sykes B, Knych H, Franklin S.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...
So YM, Wong JKY, Wong ASY, Tse ATL, Wan TSM, Ho ENM.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...
Kikuchi M, Nagata SI, Ishige T, Minamijima Y, Hirota KI, Tozaki T, Kakoi H, Kizaki K.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...
Timms M, Botteon A, Manos C, Griffin J, Levina V, Steel R.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...
Karatt TK, Muhammed Ajeebsanu M, Karakka Kal AK, Subhahar MB, Sathiq MA, Laya S.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...
Cloteau C, Dervilly G, Loup B, Delcourt V, Kaabia Z, Bagilet F, Groseille G, Dauriac K, Fisher S, Popot MA, Garcia P, Le Bizec B, Bailly-Chouriberry L.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...
Maxwell L, McCarrel TM, Hay S, Cole C.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...
Karatt TK, Sathiq MA, Laya S, Kal AKK, Subhahar MB, Muhammed Ajeebsanu MP, Philip M, Caveney MR, Graiban FM.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...
Riveroll AL, Skyba-Lewin S, Lynn KD, Mubyeyi G, Abd-El-Aziz A, Kibenge FST, Kibenge MJT, Cohen AM, Esparza-Gonsalez B, McD￮ L, Montelpare WJ.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 ...
Keen B, Cawley A, Reedy B, Noble G, Loy J, Fu S.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...
You Y, Proctor RM, Haughan J, Missanelli JR, Robinson MA.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...
Karatt TK, Sathiq MA, Laya S, Karakka Kal AK, Subhahar MB, M P MA, Philip M, Graiban FM, Caveney MR.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...
The protein journalJanuary 18, 2023
Volume 42, Issue 1 24-36 doi: 10.1007/s10930-023-10092-x
Rodríguez MC, Mussio PE, Villarraza J, Tardivo MB, Antuña S, Fontana D, Ceaglio N, Prieto C.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...
Staniszewska M, Kowalik S, Sadok I, Kędzierski W.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. ...
Fadel C, Giorgi M.According to in vitro and in vivo investigations, firocoxib (FX), a second-generation coxib, is a highly selective COX-2 inhibitor in horses. With a COX-1/COX-2 IC50 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...
Wu CJ, Liaw GW, Chen CK, Ouyang CH, Yang YX, Chu LC, Hsiao YC, Liu CH, Hsieh WC, Wang CY, Liou YS, Liu CC, Hsieh CH.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...
Hammad A, Gadallah S, Misk T, Sharshar A, Thabet N, Mourad A.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...
Xue C, Davis J, Berghaus LJ, Hanafi A, Vaughn SA, Hart KA.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 ...
Gold JR, Grubb T, Court M, Villarino NF.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...
Ito S, Wakamatsu K.The color of hair, skin, and eyes in animals mainly depends on the quantity, quality, and distribution of the pigment melanin, which occurs in two types: black to brown eumelanin and yellow to reddish pheomelanin. Microanalytical methods to quantify the amounts of eumelanin and pheomelanin in biological materials were developed in 1985. The methods are based on the chemical degradation of eumelanin to pyrrole-2,3,5-tricarboxylic acid and of pheomelanin to aminohydroxyphenylalanine isomers, which can be analyzed and quantitated by high performance liquid chromatography. This review summarizes a...
Heizmann CW, Berchtold MW, Rowlerson AM.The physiological role of the Ca2+-binding protein parvalbumin in skeletal muscle has been investigated by measuring the parvalbumin content by HPLC in a variety of mammalian muscles, including man, and comparing the results with the respective muscle relaxation properties and fiber type compositions. The parvalbumin concentrations were highest in the skeletal muscles of the smallest animal investigated (mouse, gastrocnemius: 4.9 g/kg), which has the highest relaxation speed, and lowest in the larger animals (horse, deep gluteal muscle: less than or equal to 0.001 g/kg) and man (vastus, tricep...
Albrecht S, Lane JA, Mariño K, Al Busadah KA, Carrington SD, Hickey RM, Rudd PM.The present study was conducted to obtain a comprehensive overview of oligosaccharides present in the milk of a variety of important domestic animals including cows, goats, sheep, pigs, horses and dromedary camels. Using an analytical workflow that included ultra-performance liquid chromatography-hydrophilic interaction liquid chromatography with fluorescence detection coupled to quadrupole time-of-flight MS, detailed oligosaccharide libraries were established. The partial or full characterisation of the neutral/fucosylated, phosphorylated and sialylated structures was facilitated by sequencin...
Wu DD, Yang CP, Wang MS, Dong KZ, Yan DW, Hao ZQ, Fan SQ, Chu SZ, Shen QS, Jiang LP, Li Y, Zeng L, Liu HQ, Xie HB, Ma YF, Kong XY, Yang SL, Dong XX....Abundant and diverse domestic mammals living on the Tibetan Plateau provide useful materials for investigating adaptive evolution and genetic convergence. Here, we used 327 genomes from horses, sheep, goats, cattle, pigs and dogs living at both high and low altitudes, including 73 genomes generated for this study, to disentangle the genetic mechanisms underlying local adaptation of domestic mammals. Although molecular convergence is comparatively rare at the DNA sequence level, we found convergent signature of positive selection at the gene level, particularly the gene in these Tibetan domest...
Liu X, Zhang Y, Li Y, Pan J, Wang D, Chen W, Zheng Z, He X, Zhao Q, Pu Y, Guan W, Han J, Orlando L, Ma Y, Jiang L.High altitude represents some of the most extreme environments worldwide. The genetic changes underlying adaptation to such environments have been recently identified in multiple animals but remain unknown in horses. Here, we sequence the complete genome of 138 domestic horses encompassing a whole altitudinal range across China to uncover the genetic basis for adaptation to high-altitude hypoxia. Our genome data set includes 65 lowland animals across ten Chinese native breeds, 61 horses living at least 3,300 m above sea level across seven locations along Qinghai-Tibetan Plateau, as well as 7...
Ross PF, Nelson PE, Richard JL, Osweiler GD, Rice LG, Plattner RD, Wilson TM.Fumonisin B1 (FB1) and FB2 were isolated from corn cultures of both Fusarium moniliforme and Fusarium proliferatum. Respective concentrations in culture materials of FB1 and FB2 ranged from 960 to 2,350 and 120 to 320 micrograms/g for F. moniliforme and from 1,670 to 2,790 and 150 to 320 micrograms/g for F. proliferatum. Thin-layer chromatography, gas chromatography-mass spectroscopy, high-performance liquid chromatography, and liquid secondary ion mass spectroscopy were used for detection. Fumonisins from F. proliferatum have not previously been reported.
Möstl E, Messmann S, Bagu E, Robia C, Palme R.After 14C-labelled cortisol infusion in ponies and pigs, faecal samples were collected. Extraction of 0.5 g faeces with 5 ml 80-90% methanol yielded the highest radioactivity in the supernatant. Most of the metabolites were ether soluble. After high performance liquid chromatography (HPLC), the presence of immunoreactive metabolites was demonstrated by measuring each HPLC fraction using enzyme immunoassays for cortisol, corticosterone and 11-oxoaetiocholanolone. Only the assay for 11-oxoaetiocholanolone revealed peaks with co-eluting radioactivity. For biological validation of the test system,...
Xu S, Luosang J, Hua S, He J, Ciren A, Wang W, Tong X, Liang Y, Wang J, Zheng X.To investigate genetic mechanisms of high altitude adaptations of animals living in the Tibetan Plateau, three mitochondrial genomes (mt-genome) of Tibetan horses living in Naqu (4,500 m) of Tibetan, Zhongdian (3,300 m) and Deqin (3,100 m) of Yunnan province were sequenced. The structures and lengths of these three mt-genomes are similar to the Cheju horse, which is related to Tibetan horses, but little shorter than the Swedish horse. The pair-wise identity of these three horses on nucleotide level is more than 99.3%. When the gene encoding the mitochondrial protein of Tibetan horses was analy...
Ross PF, Rice LG, Plattner RD, Osweiler GD, Wilson TM, Owens DL, Nelson HA, Richard JL.Ninety-eight samples of feeds associated with 44 cases of equine leukoencephalomalacia (ELEM) and 83 samples of feed associated with 42 cases of a porcine pulmonary edema syndrome (PPE) were analyzed for fumonisin B1 (FB1). For comparison purposes, 51 feed samples not associated with PPE or ELEM were also analyzed. Feed associated with ELEM contained FB1 ranging from less than 1 microgram/g to 126 micrograms/g with 75% of the cases having at least 1 sample above 10 micrograms/g. Feeds associated with PPE ranged from less than 1 microgram/g to 330 micrograms/g with 71% of the cases having at le...
Bulmer LS, Murray JA, Burns NM, Garber A, Wemelsfelder F, McEwan NR, Hastie PM.Gut microbiota have been associated with health, disease and behaviour in several species and are an important link in gut-brain axis communication. Diet plays a key role in affecting the composition of gut microbiota. In horses, high-starch diets alter the hindgut microbiota. High-starch diets are also associated with increased behavioural reactivity in horses. These changes in microbiota and behaviour may be associated. This study compares the faecal microbiota and behaviour of 10 naïve ponies. A cross-over design was used with experimental groups fed high-starch (HS) or high-fibre (HF) die...
Fornstedt B, Rosengren E, Carlsson A.The 5-S-cysteinyl derivatives of dopamine, dopa (3,4-dihydroxyphenylalanine) and dopac (3,4-dihydroxyphenylacetic acid) were synthesized and used as reference compounds in high performance liquid chromatography analyses of extracts from various brain regions of eight mammalian species. All three metabolites were detected in the brains of all the species studied. The regional distribution of the metabolites was similar to that of dopamine; the metabolite concentrations ranged from less than 0.1 percent to more than 1 percent of the dopamine level, the highest ratios generally being found in sub...
Gibson SJ, Polak JM, Allen JM, Adrian TE, Kelly JS, Bloom SR.The distribution of neuropeptide Y [NPY]-immunoreactive material was examined in the spinal cord and dorsal root ganglia of rat, guinea-pig, cat, marmoset, and horse. Considerable concentrations of NPY and similar distribution patterns of immunoreactive nerve fibres were found in the spinal cord of all species investigated. The dorsal root ganglia of the cat and the horse contained numerous immunoreactive nerve fibres, but in these species, as in the other three studied [rat, guinea-pig, marmoset], no positively stained cell bodies were found. Neuropeptide Y-immunoreactive nerves were observed...
Jörg A, Henderson WR, Murphy RC, Klebanoff SJ.Horse eosinophils purified to greater than 98% generated slow reacting substance (SRS) when incubated with the calcium ionophore A23187. On a per cell basis, eosinophils generated four to five times the SRS produced by similarly treated horse neutrophils. Eosinophil SRS production was inhibited by 5,8,11,14-eicosatetraynoic acid and augmented by indomethacin and arachidonic acid, suggesting that it was a product(s) of the lipoxygenase pathway of arachidonic acid metabolism. Compounds with SRS activity were purified by high-pressure liquid chromatography (HPLC) and identified by ultraviolet spe...
Byrd SK, McCutcheon LJ, Hodgson DR, Gollnick PD.This study examined the effects of acute high-intensity exercise on the rate and capacity of Ca2+ uptake and Ca2+-stimulated adenosinetriphosphatase (ATPase) activity of the sarcoplasmic reticulum and the reversibility of these effects. Thoroughbred horses were run at maximal O2 uptake on a high-speed treadmill until fatigued. Muscle temperatures and biopsy samples were collected at rest, immediately after exercise, and 30 and 60 min after exercise. Blood samples were collected at rest and 5 min after exercise. Muscle and blood (lactate concentration) were three- and fivefold greater than pre-...
Wilson TM, Ross PF, Rice LG, Osweiler GD, Nelson HA, Owens DL, Plattner RD, Reggiardo C, Noon TH, Pickrell JW.During the fall of 1989, an episode of equine leukoencephalomalacia involved 18 of 66 purebred Arabian horses at a breeding/training stable in Arizona. Of the 18 horses affected, the condition was fatal in 14. These horses, as well as 48 unaffected horses, had been fed a diet containing a substantial amount of white corn screenings. Gross pathologic findings included liquefactive necrosis in parts of the cerebral white matter and hemorrhagic foci of various sizes in the brain stem. Histopathologic findings included rarefied white matter with pyknotic nuclei and eosinophilic cytoplasm. Thin-lay...
Iwatani S, Zendo T, Yoneyama F, Nakayama J, Sonomoto K.A novel bacteriocin, lacticin Z, produced by Lactococcus lactis QU 14 isolated from a horse's intestinal tract was identified. Lacticin Z was purified through a three step procedure comprised of hydrophobic-interaction, cation-exchange chromatography, and reverse-phase HPLC. ESI-TOF MS determined the molecular mass of lacticin Z to be 5,968.9 Da. The primary structure of lacticin Z was found to consist of 53 amino acid residues without any leader sequence or signal peptide. Lacticin Z showed homology to lacticin Q from L. lactis QU 5, aureocin A53 from Staphylococcus aureus A53, and mutacin BH...
Conley AJ.Analytical advancements, especially methods using gas or liquid chromatography tandem mass spectrometry, have allowed more specific and reliable measurement of multiple steroid hormones in the plasma of mares throughout gestation and the periparturient period. Data such as these will form the central focus of this review. The comprehensive analyses possible with liquid chromatography tandem mass spectrometry illuminate the key physiological and developmental transitions that make equine gestation unique. Weeks 6 to 20 encompass endometrial cup formation and equine chorionic gonadotropic secret...
Pfau T, Witte TH, Wilson AM.During locomotion cyclical interchange between different forms of mechanical energy enhances economy; however, 100% efficiency cannot be achieved and ultimately some mechanical work must be performed de novo. There is a metabolic cost associated with fluctuations in mechanical energy, even in the most efficient animals. In this study we investigate the exchanges between different forms of mechanical energy involved in high-speed gallop locomotion in Thoroughbred race horses during over-ground locomotion using innovative, mobile data collection techniques. We use hoof-mounted accelerometers to ...
Dunnett M, Harris RC.The combined solid-phase extraction (Isolute PRS columns) and reversed-phase gradient HPLC method presented provides a sensitive, reproducible and selective quantification of carnosine, balenine, homocarnosine, histidine, 1-methylhistidine and 3-methylhistidine in equine and camel muscle and individual muscle fibres. Recoveries were 91-115%. Lower limits of detection were 0.005-0.010 mmol kg-1 dry muscle. The compounds were isolated from other physiological amino acids and small peptides and resolved within a single chromatographic run of 55 min. Concentrations of these compounds in equine myo...
Nelson GJ.The neutral lipids of the erythrocytes were investigated in several common mammals: cow, dog, goat, horse, pig, rabbit, rat, and sheep. Cholesterol content was determined by gas-liquid, thin-layer, and column chromatography, the last in conjunction with the IR spectrophotometry. The three methods yielded similar results. In every species investigated, cholesterol was the major neutral lipid; cholesteryl esters, triglycerides, and free fatty acids were detected only in trace amounts. It is concluded that these substances may have been contaminants from plasma lipoproteins or leukocytes rather t...
Zhang X, Li C, Nan Z.An evaluation was performed on the influence of mowing height (2.5, 5.0 or 7.5 cm) and mowing frequency (weekly or fortnightly) on levels of ergot alkaloids (ergine and ergonovine) formed in drunken horse grass, Achnatherum inebrians, grown under greenhouse conditions. Samples were taken monthly and alkaloids were extracted and analyzed by reverse-phase HPLC. Alkaloid levels increased more or less linearly with plant age over the first four months following establishment. Levels were higher in samples cut fortnightly compared to those cut weekly, and were higher when plants were cut at a mowin...
Mills PC, Smith NC, Casas I, Harris P, Harris RC, Marlin DJ.The effects of prolonged variable-intensity and short-term high-intensity exercise on indices of oxidative stress and iron homeostasis were compared in six fit horses under cool [20 degrees C, 40% relative humidity (RH)] or hot/humid (30 degrees C, 80% RH) environmental conditions. The exercise protocols were designed to simulate equine competition, including racing (intense exercise) or the speed and endurance phase of a 3-day event (prolonged exercise). Increased plasma concentrations of lipid hydroperoxides and haemolysate concentrations of oxidised glutathione (GSSG) were measured within 3...
Court MH, Von Moltke LL, Shader RI, Greenblatt DJ.The 6-hydroxylation of chlorzoxazone (CLZ) is currently being used in both in vivo and in vitro studies to quantify cytochrome P450 2E1 (CYP2E1) activity in humans. Comparatively little is known with regard to the biotransformation of this drug in other species. The NADPH-dependent biotransformation of CLZ was therefore studied using hepatic microsomes derived from humans and ten other mammalian species. In all species, 6-hydroxychlorzoxazone (6OH-CLZ) was the only metabolic product that could be identified by HPLC with ultraviolet detection. Enzyme kinetic analysis was used to characterize th...
Garcia-Villar R, Toutain PL, Alvinerie M, Ruckebusch Y.The pharmacokinetic disposition of xylazine hydrochloride is described after both intravenous and intramuscular injection of a single dose, in four domestic species: horse, cattle, sheep and dog, by an original high performance liquid chromatographic technique. Remarkably small interspecific differences are reported. After intravenous administration, systemic half-life (t1/2 beta) ranged between 22 min (sheep) and 50 min (horse) while the distribution phase is transient with half-life (t1/2 alpha) ranging from 1.2 min (cattle) to 5.9 min (horse). The peak level of drug concentration in the pla...
Weber JA, Freeman DA, Vanderwall DK, Woods GL.This study was conducted to identify embryonic products whose secretion was temporally associated with the oviductal transport period of the mare. Chemicals secreted by oviductal-transport-stage equine embryos were identified by incubating Day 6 or Day 7 early uterine embryos with 35S-methionine/cysteine, 3H-progesterone, or 3H-arachidonic acid for 24 h, and subsequently identifying radioactively labeled proteins (SDS-PAGE; n = 3 embryos), steroids (HPLC; n = 3 embryos), or prostaglandins (HPLC; n = 3 embryos) in the culture medium. Early uterine embryos secreted 116.1 +/- 45.5 pg of prostagla...
de Grauw JC, van de Lest CH, van Weeren PR.Articular tissues are capable of producing a range of eicosanoid mediators, each of which has individual biological effects and may be affected by anti-inflammatory treatment. We set out to develop and evaluate a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) approach for the simultaneous analysis of multiple eicosanoid lipid mediators in equine synovial fluid (SF), and to illustrate its use for investigation of the in vivo effects of non-steroidal anti-inflammatory drug (NSAID) treatment. Methods: Synovial fluid samples were obtained from normal joints of 6 adult...
Hustace JL, Firshman AM, Mata JE.To determine pharmacokinetics and oral bioavailability of metformin in healthy horses. Methods: 4 adult horses. Methods: 6 g of metformin was administered 3 times IV and PO (fed and unfed) to each horse, by use of a crossover design, with a 1-week washout period between treatments. Plasma metformin concentration was determined via high-pressure liquid chromatography. Results: Mean +/- SD distribution half-life of metformin following IV administration was 24.9 +/- 0.4 minutes with a volume of distribution of 0.3 +/- 0.1 L/kg. Mean area under the curve was 20.9 +/- 2.0 h.microg/mL for IV adminis...
Murray RC, Vedi S, Birch HL, Lakhani KH, Goodship AE.It was hypothesised that subchondral bone thickness, hardness and remodelling are influenced by exercise intensity, and by location within a joint. Dorsal carpal osteochondral injury is a major cause of lameness in horses undergoing high intensity training. This project aimed to determine the subchondral bone thickness, formation, resorption and hardness at sites with high and low incidence of pathology in 2 year-old horses undergoing 19 weeks high intensity treadmill training or low intensity exercise, and to compare these factors between exercise groups. Dorsal and palmar test sites were ide...
Tinworth KD, Wynn PC, Boston RC, Harris PA, Sillence MN, Thevis M, Thomas A, Noble GK.Determining circulating equine insulin concentrations is becoming increasingly important in equine clinical practice and research. Most available assays are optimized for human medicine, but there is strong equine cross-reactivity because of the highly conserved nature of insulin. To identify an accurate and reliable assay for equine insulin, 6 commercial immunoassays were evaluated for precision, accuracy, and specificity. Only 1 assay initially reached the requisite standard: Mercodia Equine Insulin Enzyme-linked Immunosorbent assay (ELISA). Plasma matrix interferences were identified when t...
Couto MA, Harwig SS, Cullor JS, Hughes JP, Lehrer RI.Endogenous, cysteine-rich antimicrobial peptides known as defensins are prominent components of human, rabbit, and rat neutrophils, yet little is known about their occurrence in other mammalian species. Although we did not detect mature (i.e., processed) defensins in equine neutrophil granules, we found that these granules contained small amounts of other cysteine-rich peptides with antimicrobial activity. One of these, eNAP-1, was purified by a combination of gel permeation and reversed-phase high-performance liquid chromatography from acid extracts prepared from the cytoplasmic granules of e...
