Analyze Diet

Topic:Biochemistry

The study of biochemistry in horses encompasses the chemical processes and substances that occur within equine organisms. This field investigates the molecular interactions and pathways that are fundamental to horse physiology, including metabolism, enzyme activity, and genetic expression. Key areas of interest include the examination of metabolic disorders, nutrient absorption, and the biochemical basis of muscle function and energy production. Researchers utilize biochemical analysis to understand health and disease mechanisms in horses, contributing to the development of diagnostic tools and therapeutic strategies. This page gathers peer-reviewed studies and scholarly articles that explore various biochemical processes and their implications for equine health and performance.
Modulating the oxidative environment during mesenchymal stem cells chondrogenesis with serum increases collagen accumulation in agarose culture.
Journal of orthopaedic research : official publication of the Orthopaedic Research Society    June 26, 2017   Volume 36, Issue 1 506-514 doi: 10.1002/jor.23618
Tangtrongsup S, Kisiday JD.Chondrogenesis of mesenchymal stem cells (MSCs) is induced in culture conditions that have been associated with oxidative stress, although the extent to which the oxidative environment affects differentiation and extracellular matrix (ECM) accumulation is not known. The objectives of this study were to evaluate the oxidative environment during MSCs chondrogenesis in conventional serum-free medium, and the effect of serum-supplementation on intracellular reactive oxygen species (ROS) and chondrogenesis. Young adult equine MSCs were seeded into agarose and cultured in chondrogenic medium, with o...
Comparison between chaotropic and detergent-based sample preparation workflow in tendon for mass spectrometry analysis.
Proteomics    June 22, 2017   Volume 17, Issue 13-14 1700018 doi: 10.1002/pmic.201700018
Ashraf Kharaz Y, Zamboulis D, Sanders K, Comerford E, Clegg P, Peffers M.Exploring the tendon proteome is a challenging but important task for understanding the mechanisms of physiological/pathological processes during ageing and disease and for the development of new treatments. Several extraction methods have been utilised for tendon mass spectrometry, however different extraction methods have not been simultaneously compared. In the present study we compared protein extraction in tendon with two chaotropic agents, guanidine hydrochloride (GnHCl) and urea, a detergent, RapiGest™, and their combinations for shotgun mass spectrometry. An initial proteomic analysi...
Evaluation of an in vitro system to simulate equine foregut digestion and the influence of acidity on protein and fructan degradation in the horse’s stomach.
Journal of animal physiology and animal nutrition    June 20, 2017   Volume 101 Suppl 1 51-58 doi: 10.1111/jpn.12635
Strauch S, Wichert B, Greef JM, Hillegeist D, Zeyner A, Liesegang A.The aim of this study was to improve an in vitro system in order to gather optimized information on the digestion of different forages in the horse's upper gastrointestinal tract. Therefore, foregut digestion of several forages was simulated in vitro (Part 1). The effect of different pH values on in vitro fructan degradation of two selected grasses (Part 2) was tested subsequently. Part 1: We hypothesized that our system produces representative results simulating digestive processes in the upper alimentary tract, but neglects microbial fermentation. In vitro digestion of six forages (grass ...
Online turbulent flow extraction coupled with liquid chromatography-tandem mass spectrometry for high throughput screening of anabolic steroids in horse urine.
Journal of pharmaceutical and biomedical analysis    June 19, 2017   Volume 145 46-51 doi: 10.1016/j.jpba.2017.06.036
Shin HD, Suh JH, Kim J, Cho HD, Lee SD, Han KS, Wang Y, Han SB.A high throughput method for simultaneous screening of anabolic steroids and their metabolites (4-esterendione, trenbolone, boldenone, oxandrolone, nandrolone, methandrostenolone, testosterone, 1-androstendione, ethisterone, normethandrolone, methyltestosterone, 16β-Hydroxystanozolol, epitestosterone, bolasterone, norethandrolone, danazol, stanozolol and androstadienone) in equine urine by online turbulent flow extraction coupled with liquid chromatography-tandem mass spectrometry was developed. The use of turbulent flow chromatography could simplify pretreatment of horse urine, which has com...
Function of bacteriophage G7C esterase tailspike in host cell adsorption.
Molecular microbiology    June 19, 2017   Volume 105, Issue 3 385-398 doi: 10.1111/mmi.13710
Prokhorov NS, Riccio C, Zdorovenko EL, Shneider MM, Browning C, Knirel YA, Leiman PG, Letarov AV.Bacteriophages recognize and bind to their hosts with the help of receptor-binding proteins (RBPs) that emanate from the phage particle in the form of fibers or tailspikes. RBPs show a great variability in their shapes, sizes, and location on the particle. Some RBPs are known to depolymerize surface polysaccharides of the host while others show no enzymatic activity. Here we report that both RBPs of podovirus G7C - tailspikes gp63.1 and gp66 - are essential for infection of its natural host bacterium E. coli 4s that populates the equine intestinal tract. We characterize the structure and funct...
Efficacy of inactivation of viral contaminants in hyperimmune horse plasma against botulinum toxin by low pH alone and combined with pepsin digestion.
Biologicals : journal of the International Association of Biological Standardization    June 17, 2017   Volume 48 24-27 doi: 10.1016/j.biologicals.2017.06.003
Torgeman A, Mador N, Dorozko M, Lifshitz A, Eschar N, White MD, Wolf DG, Epstein E.Assuring viral safety of horse plasma-derived products is fundamental for ethical and regulatory reasons. We previously demonstrated the ability of pepsin digestion at low pH to inactivate West Nile and Sindbis viruses in horse plasma. The present study further examined the efficiency of pepsin digestion to inactivate four additional viruses: HSV-1 and BVDV (lipid-enveloped), BPV and Reo-3 (nonenveloped). These viruses were spiked into hyperimmunized horse plasma against botulinum toxin and subjected to low pH (3.2) alone or combined with pepsin digestion (1200 units/ml). Peptic digestion inac...
Genotyping horse epithelial cells from fecal matter by isolation of polymerase chain reaction products.
Croatian medical journal    June 15, 2017   Volume 58, Issue 3 239-249 doi: 10.3325/cmj.2017.58.239
Dimsoski P.To show that application of the polymerase chain reaction (PCR) method modified for amplification of a low-copy number DNA samples, ie, the isolation of PCR products (IPCRp), would represent improvement in obtaining genotypes from a fecal DNA compared with previously used genotyping methods. Methods: The DNA from the horse fecal matter was extracted by modified Qiagen DNA Stool Mini Kit protocol. Following the extraction, the DNA genotypes from fecal samples were obtained by the most powerful PCR amplification method, the IPCRp. The IPCRp-based multiplex kit amplified biotin-labeled strands we...
The presence of minocycline in the tear film of normal horses following oral administration and its anticollagenase activity.
Veterinary ophthalmology    June 9, 2017   Volume 21, Issue 1 58-65 doi: 10.1111/vop.12479
Monk CS, Jeong SY, Gibson DJ, Plummer CE.Tetracyclines have activity against matrix metalloproteinases (MMP). Oral medications with effects on the ocular surface are of interest in patients where repeated topical dosing is limited. The aim of this study was to characterize the concentration of minocycline in the tears of normal horses after oral administration and to determine if this level directly inhibits MMP activity. Methods: Five healthy adult ponies were administered oral minocycline (Wedgewood Pharmacy; Swedesboro, NJ) at 4 mg/kg every 12 h for 5 days. Tears were collected at T = 2, 26, 50, 56, 74, 80, and 98 h. Tear minocycl...
Evidence of boldenone, nandrolone, 5(10)-estrene-3β-17α-diol and 4-estrene-3,17-dione as minor metabolites of testosterone in equine.
Drug testing and analysis    June 1, 2017   Volume 9, Issue 9 1337-1348 doi: 10.1002/dta.2192
Wong JKY, Leung DKK, Curl P, Schiff PJ, Lam KKH, Wan TSM.The detection of boldenone, nandrolone, 5(10)-estrene-3β,17α-diol, and 4-estrene-3,17-dione in a urine sample collected from a gelding having been treated with testosterone (500 mg 'Testosterone Suspension 100', single dose, injected intramuscularly) in 2009 led the authors' laboratory to suspect that these 'testicular' steroids could be minor metabolites of testosterone in geldings. Administration trials on six castrated horses with Testosterone Suspension 100 confirmed that low levels of boldenone, nandrolone, 5(10)-estrene-3β,17α-diol, and 4-estrene-3,17-dione could indeed be detected ...
Doping control study of AICAR in post-race urine and plasma samples from horses.
Drug testing and analysis    May 31, 2017   Volume 9, Issue 9 1363-1371 doi: 10.1002/dta.2205
Wong JKY, Kwok WH, Chan GHM, Choi TLS, Ho ENM, Jaubert M, Bailly-Chouriberry L, Bonnaire Y, Cawley A, Ming Williams H, Keledjian J, Brooks L....Acadesine, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, commonly known as AICAR, is a naturally occurring adenosine monophosphate-activated protein kinase (AMPK) activator in many mammals, including humans and horses. AICAR has attracted considerable attention recently in the field of doping control because of a study showing the enhancement of endurance performance in unexercised or untrained mice, resulting in the term 'exercise pill'. Its use has been classified as gene doping by the World Anti-Doping Agency (WADA), and since it is endogenous, it may only be possible to control del...
Effects of feeding two RRR-α-tocopherol formulations on serum, cerebrospinal fluid and muscle α-tocopherol concentrations in horses with subclinical vitamin E deficiency.
Equine veterinary journal    May 25, 2017   Volume 49, Issue 6 753-758 doi: 10.1111/evj.12692
Brown JC, Valberg SJ, Hogg M, Finno CJ.Alpha-tocopherol (α-TP) supplementation is recommended for the prevention of various equine neuromuscular disorders. Formulations available include RRR-α-TP acetate powder and a more expensive but rapidly water-dispersible liquid RRR-α-TP (WD RRR-α-TP). No cost-effective means of rapidly increasing serum and cerebrospinal fluid (CSF) α-TP with WD RRR-α-TP and then sustaining concentrations with RRR-α-TP acetate has yet been reported. Objective: To evaluate serum, CSF and muscle α-TP concentrations in an 8-week dosing regimen in which horses were transitioned from WD RRR-α-TP to RRR-α...
Repeatability of Oral Sugar Test Results, Glucagon-Like Peptide-1 Measurements, and Serum High-Molecular-Weight Adiponectin Concentrations in Horses.
Journal of veterinary internal medicine    May 24, 2017   Volume 31, Issue 4 1178-1187 doi: 10.1111/jvim.14725
Frank N, Walsh DM.Repeatability of the oral sugar test (OST) has not been evaluated. Objective: We hypothesized that OST glucose, insulin, active (aGLP-1) and total (tGLP-1) glucagon-like peptide 1, and high-molecular-weight (HMW) adiponectin results would be repeatable. Methods: Fifty-three horses from a Tennessee research facility (n = 23) and private practice in Missouri (n = 30), including animals with medical histories of equine metabolic syndrome. Methods: Two OSTs were performed 7-14 days apart and plasma glucose and insulin concentrations were measured at 0, 60, and 75 minutes; a positive result w...
From chromatogram to analyte to metabolite. How to pick horses for courses from the massive web resources for mass spectral plant metabolomics.
GigaScience    May 19, 2017   Volume 6, Issue 7 1-20 doi: 10.1093/gigascience/gix037
Perez de Souza L, Naake T, Tohge T, Fernie AR.The grand challenge currently facing metabolomics is the expansion of the coverage of the metabolome from a minor percentage of the metabolic complement of the cell toward the level of coverage afforded by other post-genomic technologies such as transcriptomics and proteomics. In plants, this problem is exacerbated by the sheer diversity of chemicals that constitute the metabolome, with the number of metabolites in the plant kingdom generally considered to be in excess of 200 000. In this review, we focus on web resources that can be exploited in order to improve analyte and ultimately metabol...
Comprehensive qualification and quantification of triacylglycerols with specific fatty acid chain composition in horse adipose tissue, human plasma and liver tissue.
Talanta    May 19, 2017   Volume 172 206-214 doi: 10.1016/j.talanta.2017.05.042
Guan M, Dai D, Li L, Wei J, Yang H, Li S, Zhang Y, Lin Y, Xiong S, Zhao Z.High levels of triacylglycerols (TGs) have been linked to cardiovascular disease and liver diseases. Comprehensively analyzing TGs is helpful to understand the TGs functions in these diseases. However, due to the existence of a large number of isomers TGs and the lack of commercial standards, precise analysis of individual triacylglycerol (TG) with specific fatty acid chain composition is full of challenge. In this work, ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization (ESI) mass spectrometry (MS) were employed for comprehensive qualification and quantificati...
Insulin signaling in various equine tissues under basal conditions and acute stimulation by intravenously injected insulin.
Domestic animal endocrinology    May 12, 2017   Volume 61 17-26 doi: 10.1016/j.domaniend.2017.04.003
Warnken T, Brehm R, Feige K, Huber K.The aim of the study was to analyze key proteins of the equine insulin signaling cascade and their extent of phosphorylation in biopsies from muscle tissue (MT), liver tissue (LT), and nuchal AT, subcutaneous AT, and retroperitoneal adipose tissues. This was investigated under unstimulated (B1) and intravenously insulin stimulated (B2) conditions, which were achieved by injection of insulin (0.1 IU/kg bodyweight) and glucose (150 mg/kg bodyweight). Twelve warmblood horses aged 15 ± 6.8 yr (yr), weighing 559 ± 79 kg, and with a mean body condition score of 4.7 ± 1.5 were included in the s...
Analysis of Chromosome Segregation, Histone Acetylation, and Spindle Morphology in Horse Oocytes.
Journal of visualized experiments : JoVE    May 11, 2017   Issue 123 55242 doi: 10.3791/55242
Franciosi F, Tessaro I, Dalbies-Tran R, Douet C, Reigner F, Deleuze S, Papillier P, Miclea I, Lodde V, Luciano AM, Goudet G.The field of assisted reproduction has been developed to treat infertility in women, companion animals, and endangered species. In the horse, assisted reproduction also allows for the production of embryos from high performers without interrupting their sports career and contributes to an increase in the number of foals from mares of high genetic value. The present manuscript describes the procedures used for collecting immature and mature oocytes from horse ovaries using ovum pick-up (OPU). These oocytes were then used to investigate the incidence of aneuploidy by adapting a protocol previous...
High metabolic activity of tissue-nonspecific alkaline phosphatase not only in young but also in adult bone as demonstrated using a new histochemical detection protocol.
General and comparative endocrinology    May 11, 2017   Volume 258 109-118 doi: 10.1016/j.ygcen.2017.05.008
Maly IP, Eppler E, Müller-Gerbl M.Tissue-nonspecific alkaline phosphatase (TNAP) is playing a key role in bone calcification, as has been demonstrated in different mammalian species including human and rodents. However, to investigate age-related changes during life history, histochemical demonstration of TNAP is severely hampered, particularly in the elderly, by technical difficulties associated with sectioning calcified tissue. Sufficient fixation must precede decalcification since poorly fixed bone tissue is exposed to the deleterious effects of decalcification reagents. In order to find a method that would allow cryosectio...
Effects of FSH addition to an enriched medium containing insulin and EGF after long-term culture on functionality of equine ovarian biopsy tissue.
Theriogenology    April 28, 2017   Volume 99 124-133 doi: 10.1016/j.theriogenology.2017.04.045
Aguiar FLN, Gastal GDA, Ishak GM, Gastal MO, Teixeira DIA, Feugang JM, Figueiredo JR, Gastal EL.The effect of FSH supplementation on an enriched cultured medium containing insulin (10 ng/mL) and EGF (50 ng/mL) was investigated on in vitro culture of equine ovarian biopsy tissue. Ovarian tissue fragments were collected from mares (n = 10) and distributed in the following treatments: noncultured control, cultured control, and cultured + FSH. Both treated groups were cultured for 7 or 15 days. The end points evaluated were: follicular morphology, estradiol levels in the culture medium, fluorescence intensity for TUNEL, EGFR and Ki-67 detection, and gene expression of GDF-9, BMP-15, a...
Evaluation of methodological aspects of digestibility measurements in ponies fed different haylage to concentrate ratios.
Animal : an international journal of animal bioscience    April 17, 2017   Volume 11, Issue 11 1922-1929 doi: 10.1017/S1751731117000751
Schaafstra FJWC, van Doorn DA, Schonewille JT, van Riet MMJ, Visser P, Blok MC, Hendriks WH.Methodological aspects of digestibility measurements were studied in four Welsh pony geldings consuming haylage-based diets with increasing proportions of a pelleted concentrate according to a 4×4 Latin square design experiment. Ponies were fed four experimental, iso-energetic (net energy (NE) basis) diets (i.e. 22 MJ NE/day) with increasing proportions of a pelleted concentrate (C) in relation to haylage (H). The absolute amounts of diet dry matter fed per day were 4.48 kg of H (100H), 3.36 and 0.73 kg of H and C (75H25C), 2.24 and 1.45 kg of H and C (50H50C) and 1.12 and 2.17 kg of H and C ...
The establishment of in vitro culture and drug screening systems for a newly isolated strain of Trypanosoma equiperdum.
International journal for parasitology. Drugs and drug resistance    April 13, 2017   Volume 7, Issue 2 200-205 doi: 10.1016/j.ijpddr.2017.04.002
Suganuma K, Yamasaki S, Molefe NI, Musinguzi PS, Davaasuren B, Mossaad E, Narantsatsral S, Battur B, Battsetseg B, Inoue N.Dourine is caused by Trypanosoma equiperdum via coitus with an infected horse. Although dourine is distributed in Equidae worldwide and is listed as an internationally important animal disease by the World Organization for Animal Health (OIE), no effective treatment strategies have been established. In addition, there are no reports on drug discovery, because no drug screening system exists for this parasite. A new T. equiperdum strain was recently isolated from the genital organ of a stallion that showed typical symptoms of dourine. In the present study, we adapted T. equiperdum IVM-t1 from...
Electrophilic aldehyde products of lipid peroxidation selectively adduct to heat shock protein 90 and arylsulfatase A in stallion spermatozoa.
Biology of reproduction    April 11, 2017   Volume 96, Issue 1 107-121 doi: 10.1095/biolreprod.116.145292
Hall SE, Aitken RJ, Nixon B, Smith ND, Gibb Z.Oxidative stress is a major determinant of mammalian sperm function stimulating lipid peroxidation cascades that culminate in the generation of potentially cytotoxic aldehydes. The aim of this study was to assess the impact of such aldehydes on the functionality of stallion spermatozoa. The impact of exposure to exogenous acrolein (ACR) and 4-hydroxynonenal (4HNE) was manifested in a highly significant dose- and time-dependent increase in mitochondrial reactive oxygen species (ROS), total cellular ROS, a decrease in sperm motility, and a time-dependent increase in lipid peroxidation. Notably, ...
Validated LC-MS-MS Method for Simultaneous Analysis of 17 Barbiturates in Horse Plasma for Doping Control.
Journal of analytical toxicology    April 8, 2017   Volume 41, Issue 5 431-440 doi: 10.1093/jat/bkx025
Liu Y, Uboh CE, Li X, Guan F, You Y, Maylin GA, Zhu F, Soma LR.A rapid and sensitive method for simultaneous screening, quantification and confirmation of 17 barbiturates in horse plasma using liquid chromatography-tandem mass spectrometry is described. Analytes were recovered from plasma by liquid-liquid extraction using methyl tert-butyl ether, separated on a C18 column, and analyzed in negative electrospray ionization mode. Multiple-reaction monitoring was employed for screening and quantification. Confirmation for the presence of the analytes was achieved by comparing ion intensity ratio. The ranges for limits of detection, quantification and confirma...
Comparison and validation of ELISA assays for plasma insulin-like growth factor-1 in the horse.
Open veterinary journal    March 31, 2017   Volume 7, Issue 1 75-80 doi: 10.4314/ovj.v7i1.12
Baskerville CL, Bamford NJ, Harris PA, Bailey SR.Insulin-like growth factor-1 (IGF-1) plays several important physiological roles, and IGF-related pathways have been implicated in developmental osteochondral disease and endocrinopathic laminitis. This factor is also a downstream marker of growth hormone activity and its peptide mimetics. Unfortunately, previously used assays for measuring equine IGF-1 (radioimmunoassays and ELISAs) are no longer commercially available, and many of the kits on the market give poor results when used on horse samples. The aim of the present study was to compare three different ELISA assays (two human and one ho...
Effect of the α2 -receptor agonists medetomidine, detomidine, xylazine, and romifidine on the ketamine metabolism in equines assessed with enantioselective capillary electrophoresis.
Electrophoresis    March 20, 2017   Volume 38, Issue 15 1895-1904 doi: 10.1002/elps.201700017
Sandbaumhüter FA, Theurillat R, Bettschart-Wolfensberger R, Thormann W.The combination of ketamine and an α -receptor agonist is often used in veterinary medicine. Four different α -receptor agonists, medetomidine, detomidine, xylazine, and romifidine, which differ in their chemical structure and thus in selectivity for the α -receptor and in the sedative and analgesic potency, are typically employed during surgery of equines. Recovery following anesthesia with ketamine and an α -receptor agonist is dependent on the α -receptor agonist. This prompted us to investigate (i) the inhibition characteristics for the N-demethylation of ketamine to norketamine and (...
The effect of flash-freezing temperature on stallion sperm DNA structure.
Theriogenology    March 16, 2017   Volume 95 113-117 doi: 10.1016/j.theriogenology.2017.03.005
Serafini R, Varner DD, Bissett W, Blanchard TL, Teague SR, Love CC.The effect of flash-freezing storage temperature on stallion sperm DNA has not been evaluated. Commonly, sperm are flash-frozen at various temperatures to preserve sperm DNA prior to analysis. It is unclear whether the temperature at which sperm are frozen and stored may affect the results of DNA assays. In this study, the neutral comet assay was used to evaluate the effect of flash-freezing storage temperature (freezer [-60 °C], dry ice [-78.5 °C], liquid nitrogen [-196 °C]) compared to fresh sperm DNA structure. In addition, intra- and inter-assay and intra- and inter-stallion variabil...
A foam model highlights the differences of the macro- and microrheology of respiratory horse mucus.
Journal of the mechanical behavior of biomedical materials    March 16, 2017   Volume 71 216-222 doi: 10.1016/j.jmbbm.2017.03.009
Gross A, Torge A, Schaefer UF, Schneider M, Lehr CM, Wagner C.Native horse mucus is characterized with micro- and macrorheology and compared to hydroxyethylcellulose (HEC) gel as a model. Both systems show comparable viscoelastic properties on the microscale and for the HEC the macrorheology is in good agreement with the microrheology. For the mucus, the viscoelastic moduli on the macroscale are several orders of magnitude larger than on the microscale. Large amplitude oscillatory shear experiments show that the mucus responds nonlinearly at much smaller deformations than HEC. This behavior fosters the assumption that the mucus has a foam like structure ...
Dynamics of 5-methylcytosine and 5-hydroxymethylcytosine during pronuclear development in equine zygotes produced by ICSI.
Epigenetics & chromatin    March 15, 2017   Volume 10 13 doi: 10.1186/s13072-017-0120-x
Heras S, Smits K, De Schauwer C, Van Soom A.Global epigenetic reprogramming is considered to be essential during embryo development to establish totipotency. In the classic model first described in the mouse, the genome-wide DNA demethylation is asymmetric between the paternal and the maternal genome. The paternal genome undergoes ten-eleven translocation (TET)-mediated active DNA demethylation, which is completed before the end of the first cell cycle. Since TET enzymes oxidize 5-methylcytosine to 5-hydroxymethylcytosine, the latter is postulated to be an intermediate stage toward DNA demethylation. The maternal genome, on the other ha...
Purified horse milk exosomes contain an unpredictable small number of major proteins.
Biochimie open    March 1, 2017   Volume 4 61-72 doi: 10.1016/j.biopen.2017.02.004
Sedykh SE, Purvinish LV, Monogarov AS, Burkova EE, Grigor'eva AE, Bulgakov DV, Dmitrenok PS, Vlassov VV, Ryabchikova EI, Nevinsky GA.Exosomes are 40-100 nm nanovesicles containing RNA and different proteins. Exosomes containing proteins, lipids, mRNAs, and microRNAs are important in intracellular communication and immune function. Exosomes from different sources are usually obtained by combination of centrifugation and ultracentrifugation and according to published data can contain from a few dozens to thousands of different proteins. Crude exosome preparations from milk of eighteen horses were obtained for the first time using several standard centrifugations. Exosome preparations were additionally purified by FPLC gel fi...
Testosterone metabolism of equine single CYPs of the 3A subfamily compared to the human CYP3A4.
Toxicology in vitro : an international journal published in association with BIBRA    February 24, 2017   Volume 41 83-91 doi: 10.1016/j.tiv.2017.02.017
Vimercati S, Büchi M, Zielinski J, Peduto N, Mevissen M.Cytochrome P450 enzymes (CYPs) are responsible for the phase I metabolism of drugs, xenobiotics and endogenous substances. Knowledge of single CYPs and their substrates is important for drug metabolism, helps to predict adverse effects and may prevent reduced drug efficacy in polypharmacy. In this study, three equine isoenzymes of the 3A subfamily, the equine flavoprotein NADPH-P450 oxidoreductase (POR), and the cytochrome b5 (CYB5) were cloned, sequenced and heterologously expressed in a baculovirus expression system. Testosterone, the standard compound for characterization of the human CYP3A...
Revealing the influence of glucocorticoid treatment on the excretion of anabolic-androgenic steroids in horses through in vitro digestive simulations and an in vivo case study.
Research in veterinary science    February 24, 2017   Volume 115 132-137 doi: 10.1016/j.rvsc.2017.02.024
Decloedt A, Damen S, Vanhaecke L.Anabolic-androgenic steroids (AAS) are strictly forbidden in equine sports because of their stimulating effect on muscle growth and performance. Nevertheless, low levels of AAS have been found in some horses, untreated with AAS. Glucocorticoids (GC), used as an anti-inflammatory therapy and structurally related to AAS, might play a role in this phenomenon. In order to unravel this possible correlation the influence of glucocorticoid treatment on the excretion of AAS was studied both in vivo and in vitro. In vivo effects were investigated by analysing urine samples collected from a gelding trea...
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