Oxidative stress in horses refers to an imbalance between the production of reactive oxygen species (ROS) and the ability of the horse's body to detoxify these reactive intermediates or repair the resulting damage. It can occur as a result of various physiological and environmental factors, such as exercise, illness, or exposure to toxins. Oxidative stress can lead to cellular damage, affecting lipids, proteins, and DNA. In horses, it is studied in the context of its potential impact on performance, health, and disease progression. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, effects, and management of oxidative stress in equine health.
Pagl R, Aurich C, Kankofer M.Activity of the anti-oxidative enzymes glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT), content of thiobarbituric acid reactive substances (TBARS) and SH-groups were determined in native stallion semen (n = 8 stallions). Semen was then diluted in Kenney extender, EquiPro((R)) extender either with or without addition of N-acetyl cysteine or phosphate-buffered saline (PBS) and stored for 72 h at 5 degrees C. Correlations between initial activity of enzymes and development of semen motility and membrane integrity were calculated. Activities of GSH-Px, SOD and CAT im...
Burnaugh L, Sabeur K, Ball BA.Low-level production of the superoxide anion (O2*-) is an important signal transduction event in sperm function including capacitation; however, excessive production of O2*- can be detrimental to sperm function. The objective of this study was to assess dihydroethidium (DHE) as a probe for O2*- in equine spermatozoa. Ejaculated spermatozoa were separated by centrifugation over a Percoll gradient (40:80), and loaded with DHE (2.0 microM) as well as with calcein-acetoxymethylester (CAM, 7.8 nM) to determine cell viability. In Experiment 1, cells were incubated with the xanthine-xanthine oxidase ...
Deaton CM, Marlin DJ, Deaton L, Smith NC, Harris PA, Schroter RC, Kelly FJ.Following a period of airway inflammation the clearance of inflammatory cells along the mucociliary escalator may impose a considerable oxidant load on the trachea. Objective: To determine the degree of oxidative stress in tracheal epithelial lining fluid (ELF) in comparison to that present in peripheral airways after an acute exposure to organic dust. Methods: Tracheal wash fluid and bronchoalveolar lavage fluid (BALF) were collected for cytology and antioxidant analyses from 6 recurrent airway obstruction (RAO)-affected horses and 6 healthy control horses before and after stabling on straw b...
Lykkesfeldt J, Svendsen O.Important infectious diseases in farm animals, such as pneumonia and enteritis, are thought to be associated with the so-called oxidative stress, i.e. a chemical phenomenon involving an imbalance in the redox status of the individual animal. The specifics of oxidative stress and how it may result in disease or be prevented are complex questions with no simple answers. However, the considerable literature on the subject suggests that many researchers consider oxidative stress-related mechanisms to be important early events in disease development. A particularly intriguing aspect is that, at lea...
van der Harst M, Bull S, Brama PA, Barneveld AB, van Weeren PR, van de Lest C.Osteoarthritis (OA) is a chronic debilitating joint disorder in which the importance of inflammation is increasingly recognized. In advanced cases, both the articular cartilage and the underlying bony layers are affected, but the exact sequence of events and their localization in the initial phase of pathogenesis remain uncertain. We measured nitric oxide (NO) end products in tissue layers that constitute the bearing surface of the joint, as possible indicators of physiological and pathological processes. Methods: Nitrite as a measure for NO and nitrotyrosine was measured in articular cartilag...
Rodríguez-Roldán V, García-Heredia JM, Navarro JA, Hervás M, De la Cerda B, Molina-Heredia FP, De la Rosa MA.Two synthetic genes coding for human and Arabidopsis cytochrome c, respectively, have been designed and constructed, and the recombinant proteins have been over-expressed in Escherichia coli cells. Thus a comparative analysis of the two heme proteins, including horse cytochrome c as a reference, has been performed. In addition to their physico-chemical properties, the redox behavior of the three proteins has been analyzed by following the kinetics of both their reduction by flavin semiquinones (lumiflavin, riboflavin, and FMN) and oxidation by cytochrome c oxidase. The resulting data indicate ...
Deaton CM.Equine recurrent airway obstruction (RAO) is a naturally occurring respiratory disease in horses with many similarities to human asthma and, as a result, has been used as an animal model of this disease. Oxidative stress has been demonstrated to occur in a range of respiratory diseases in human beings including asthma. Quantitatively, horses have a greater non-enzymatic antioxidant capacity in the pulmonary epithelial lining fluid compared to human beings due to high ascorbic acid concentrations, which reflects their ability to synthesise ascorbic acid. Consequently, a greater oxidative load i...
Becker F, Kurth J, Schneider F, Nürnberg G, Heinrich H, Kanitz W.The aim of this study was to prove if oxidation-reduction levels in the follicular fluid were new functional indices of follicular health and whether there was a high level of accordance with endocrinological parameters and with the growth stage as detected by ultrasound monitoring of individual follicles during the oestrous cycle in mares. Follicles were classified as growing and regressing follicles using ultrasonography. Altogether 48 follicles with a diameter from 20 to 56 mm were aspirated by transvaginal ultrasound guided follicular aspiration. Follicular concentration of oestradiol and ...
Sabeur K, Ball BA.To identify the generation of the superoxide anion by equine spermatozoa. Methods: Multiple ejaculates collected from 3 Thoroughbred stallions. Methods: Induced superoxide production by reduced nicotinamide adenine dinucleotides (NAD[P]H; ie, reduced nicotinamide adenine dinucleotide [NADH] and reduced nicotinamide adenine dinucleotide phosphate [NADPH]) was measured by use of a nitroblue tetrazolium (NBT) reduction assay on whole spermatozoa and a cytochrome c reduction assay on isolated membrane fractions of spermatozoa. Localization of superoxide generation was determined by use of NBT cyto...
Luciano AM, Goudet G, Perazzoli F, Lahuec C, Gérard N.The in vitro developmental competence of equine oocytes is still low in comparison with other domestic mammals. A major factor affecting the viability of cells during in vitro culture is the increased oxidative stress. Oxidative modifications could be responsible for oocyte incompetence for in vitro maturation (IVM). Cysteamine, a glutathione (GSH) synthesis enhancer, has been shown to increase intracellular GSH content and to improve embryo development when added during IVM of bovine, porcine, and ovine oocytes. The aim of the present study was (1) to determine whether equine cumulus-oocyte c...
McFarlane D, Cribb AE.To determine whether a deficiency in systemic or local (pars intermedia) antioxidant capacity is associated with pituitary pars intermedia oxidative stress and pituitary pars intermedia dysfunction (PPID) in horses. Methods: Blood samples from 20 horses with PPID and 20 healthy client-owned horses, archived paraffin-embedded adrenal gland and substantia nigra tissues from 20 horses, and pituitary gland tissue from 16 horses. Methods: Total glutathione, superoxide dismutase, and glutathione peroxidase activities were determined in RBCs. Accumulation of a systemic marker of oxidative stress (3-n...
Kinnunen S, Atalay M, Hyyppä S, Lehmuskero A, Hänninen O, Oksala N.Increased oxidative stress during prolonged endurance exercise may end up with muscle damage, fatigue and decreased physical performance. We have recently shown that acute exercise at moderate intensity induced lipid peroxidation, protein oxidation and oxygen radical absorbance capacity (ORAC) in trained trotters. The aim of this study was to measure the changes in oxidative stress and antioxidant defense following an 80-km ride in the blood of endurance horses. Blood samples were collected before and immediately after the ride. Unlike to our previous studies performed on trotters, in enduranc...
Kramaric P, Pavlica Z, Koklic T, Nemec A, Erzen NK, Sentjurc M.The mechanism of recurrent airway obstruction (RAO) in horses was investigated by measuring the membrane domain structure and oxy-redoxy activity in phagocytes isolated from bronchoalveolar lavage fluid (BAL) and from the blood of healthy and RAO horses by electron paramagnetic resonance (EPR). Differences in the activity of intracellular antioxidant enzymes CAT, GPx, and SOD measured in phagocytes of RAO horses in comparison to healthy horses showed that the phagocytes were affected by oxidative stress. In comparison with polymorphonuclear leukocytes (phagocytes) from the blood of healthy hor...
Deaton CM, Marlin DJ, Smith NC, Harris PA, Dagleish MP, Schroter RC, Kelly FJ.Effects of acute airway inflammation induced by organic dust inhalation on pulmonary antioxidant status were investigated in healthy horses and horses affected by recurrent airway obstruction. Exposure to organic dust induced acute airway neutrophilia, which was associated with increases in elastase and decreases in ascorbic acid concentrations in bronchoalveolar lavage fluid. However, markers of oxidative stress were unaffected, as was hydrogen peroxide in breath condensate. Decreases in ascorbic acid correlated with increased respiratory resistance (P = .001) when both groups were combined. ...
Baumber J, Ball BA.To determine glutathione peroxidase (GPX) and superoxide dismutase (SOD)-like activities in spermatozoa, seminal plasma, and reproductive tissues (ie, testis, epididymis, bulbourethral gland, prostate, vesicular gland, and ampulla) in horses. Methods: Seminal plasma from 17 stallions, spermatozoa from 5 stallions, and reproductive tissues from 3 stallions. Methods: Activity of GPX was determined by use of assays measuring oxidation of NADPH in the presence of exogenous glutathione, cumene hydroperoxide, and glutathione reductase. Activity of SOD-like enzymes was determined by use of the nitrob...
Matera MG, Calzetta L, Peli A, Scagliarini A, Matera C, Cazzola M.Increasing clinical epidemiological and experimental evidence indicates that excess of production of reactive oxygen free radicals (ROS) induced by an oxidative stress is involved in the pathogenesis of a number of human airway disorders, as well as equine recurrent airway obstruction. Free-radicals modulate the activation of transcription factors, such as nuclear factor-(NF)-kappaB and activator protein (AP)-1, in several different cells. This activation leads to expression of many pro-inflammatory cytokines, including interleukin (IL)-1beta. We have hypothesized that equine airway sensitizat...
Kinnunen S, Hyyppä S, Lehmuskero A, Oksala N, Mäenpää P, Hänninen O, Atalay M.Strenuous exercise is a potent inducer of oxidative stress, which has been suggested to be associated with disturbances in muscle homeostasis, fatigue and injury. There is no comprehensive or uniform view of the antioxidant status in horses. We have previously shown that moderate exercise induces protein oxidation in trotters. The aim of this study was to measure the antioxidative capacity of the horse in relation to different antioxidant components and oxidative stress markers after a single bout of moderate exercise to elucidate the mechanisms of antioxidant protection in horses. Eight clini...
Aurich C.The spermatozoon is a highly specified cell that has the abilities of active motility and fertilization of the ovum. Damage to the sperm plasma membrane results in the irreversible loss of its functions. Because of the high content of unsaturated fatty acids in the plasma membrane, mammalian sperm are sensitive to oxidative stress. While mild peroxidation appears to promote capacitation of the sperm cell, excessive peroxidation will damage the plasma membrane and results in loss of motility and fertility. The functional integrity of the sperm plasma membrane can be determined by functional tes...
Wyse C, Cathcart A, Sutherland R, Ward S, McMillan L, Gibson G, Padgett M, Skeldon K.Exercise-induced oxidative stress (EIOS) refers to a condition where the balance of free radical production and antioxidant systems is disturbed during exercise in favour of pro-oxidant free radicals. Breath ethane is a product of free radical-mediated oxidation of cell membrane lipids and is considered to be a reliable marker of oxidative stress. The heatshock protein, haem oxygenase, is induced by oxidative stress and degrades haemoglobin to bilirubin, with concurrent production of carbon monoxide (CO). The aim of this study was to investigate the effect of maximal exercise on exhaled ethane...
Neild DM, Brouwers JF, Colenbrander B, Agüero A, Gadella BM.In this study we used a new method to detect reactive oxygen species (ROS) induced damage at the level of the sperm plasma membrane in fresh and frozen-thawed stallion sperm. Lipid peroxidation (LPO) in sperm cells was assessed by a fluorescent assay involving the labeling of stallion sperm with the LPO reporter probe C11-BODIPY(581/591). The peroxidation dependent spectral emission shift of this membrane probe could be localized using inverted spectral confocal microscopy and quantified on living and deteriorated sperm cells using flow cytometry. Mass spectrometric analysis of the main endoge...
Shaw FL, Handy RD, Bryson P, Sneyd JR, Moody AJ.The aim of the study was to investigate whether a single hyperbaric oxygen exposure causes oxidative stress in isolated platelets. Methods: Isolated horse platelets were exposed to 100% oxygen at 2.2 atmospheres, or 100% oxygen under normobaric conditions, or air under normobaric conditions for 90 min. Results: There were no differences in platelet SOD activity between conditions, but there was a rise in SOD in all cases after 24 h (in control platelets at 24 h, SOD was 11.9 +/- 1.9 nmol/min/mg protein compared to initial background levels of 8.2 +/- 1.9 nmol/min/mg protein) (P < 0.05). Nei...
Baumber J, Ball BA, Linfor JJ.To evaluate the effect of the addition of enzyme scavengers and antioxidants to the cryopreservation extender on characteristics of equine spermatozoa after freezing and thawing. Methods: 2 ejaculates collected from each of 5 stallions. Methods: Equine spermatozoa were cryopreserved in freezing extender alone (control samples) or with the addition of catalase (200 U/mL), superoxide dismutase (200 U/mL), reduced glutathione (10 mM), ascorbic acid (10 mM), alpha-tocopherol (25, 50, 100, or 500 microM or 1 mM), or the vehicle for alpha-tocopherol (0.5% ethanol). After thawing, spermatozoal motili...
Almeida J, Ball BA.The objective of this study was to compare the effect of alpha-tocopherol and its ester, alpha tocopherol succinate, on lipid peroxidation and motility of equine spermatozoa. In experiment one, spermatozoa were incubated with dl-alpha-tocopherol (5, 25, 100 or 500 microM), DL-alpha tocopherol succinate (5, 25, 100 or 500 microM) or vehicle (0.5% ethanol) at 38 degrees C, and sperm motility was determined at 30, 60 and 120 min. In experiment two, spermatozoa loaded with the lipophilic probe, C11BODIPY(581/591), were incubated with dl-alpha-tocopherol (50 and 100 microM), DL-alpha-tocopherol suc...
Deaton CM, Marlin DJ, Smith NC, Roberts CA, Harris PA, Schroter RC, Kelly FJ.Inhaled ozone can induce oxidative injury and airway inflammation. Horses affected by recurrent airway obstruction (RAO) have a decreased pulmonary antioxidant capacity, which may render them more susceptible to oxidative challenge. It is currently unknown whether RAO-affected horses are more susceptible to oxidative stress than those unaffected by RAO. Objective: To determine whether ozone exposure induces greater oxidative stress and airway inflammation in RAO-affected horses in remission than in healthy horses. Methods: Seven healthy control horses and 7 RAO-affected horses were exposed to ...
Kim JS, Hinchcliff KW, Yamaguchi M, Beard LA, Markert CD, Devor ST.The purpose of the present study was to determine the age-related changes in myosin heavy chain (MHC) composition and muscle oxidative and glycolytic capacity in 18 horses ranging in age from two to 30 years. Muscle samples were collected by excisional biopsy of the semimebranosus muscle. MHC expression and the key enzymatic activities were measured. There was no significant correlation between horse age and the proportions of type-IIA and type-IIX MHC isoforms. The percentage of type-I MHC isoforms decreased with advancing age. Muscle citrate synthase activity decreased, whereas lactate dehyd...
McFarlane D, Dybdal N, Donaldson MT, Miller L, Cribb AE.Equine pituitary pars intermedia dysfunction (PPID) is a spontaneously occurring progressive disease affecting aged horses and ponies. The pathogenesis of PPID is poorly understood, but the available evidence supports a loss of dopaminergic inhibition of the melanotropes of the pars intermedia. Horses with PPID have increased plasma concentrations of pars intermedia pro-opiomelanocortin-derived peptides that decrease in response to dopamine or dopamine agonist administration. Dopamine and dopamine metabolite concentrations are decreased in the pars intermedia of affected horses compared to age...
Escribano BM, Castejón FM, Vivo R, Santisteban R, Agüera EI, Rubio MD.Using simple techniques, the neutrophil function, in its phagocytosis and oxidative metabolism stages, was evaluated in horses. This was done before and after moderate exercise at the aerobic-anaerobic threshold (standardized heart rate 150 beats/min and lactate level of 3.07 +/- 0.21 mmol/L). The objective was to determine whether regular training and moderate exercise improved the neutrophil function. A group of 19 horses was used; 11 of these were untrained and the remainder trained for national jumping events. The exercise test consisted of a 5 min trot followed by a 3 min gallop on a long...
Ferreira-Dias G, Claudino F, Carvalho H, Agrícola R, Alpoim-Moreira J, Robalo Silva J.The primary objective of this study was to evaluate the possible role of leptin, body weight and immune status on reproductive activity throughout the transition period from cyclicity to seasonal anestrus, during anestrus and resumption of ovarian activity in Lusitano mares. Mares in good body condition were monthly monitored throughout 2 years (10 mares in each year) for evaluation of their reproductive status by sequential ultrasonography and plasma progesterone determinations. On the second year, all mares were weighed. Progesterone and leptin were assayed by radioimmunoassay (RIA). Paramet...
Kankofer M, Kolm G, Aurich J, Aurich C.Sperm cell membranes are susceptible to peroxidative damage by an excess of reactive oxygen species (ROS). Antioxidative defence systems consisting of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) physiologically control the balance between ROS production and neutralization. In the present study the hypothesis was tested that lipid peroxidation occurs during storage of semen at 5 degrees C and that semen extender has positive effects on the antioxidative potential of equine semen. The aim of the study was to determine the activity of GSH-Px, SOD and CAT and the...
Poole DC, Petrisko RN, Anderson L, Fedde MR, Erickson HH.During exercise, the horse can achieve oxygen uptakes and ventilations in excess of 200 ml/kg/min and 1800 l/min, respectively. Whether the diaphragm has the capacity to contribute substantially to inspiratory effort in the exercising horse is not known. To investigate the potential for the horse diaphragm to generate tension, lung displacement and sustain ventilatory function, we measured diaphragm thickness, muscle length and oxidative enzyme activity (citrate synthase) within the ventral, medial and dorsal costal and crural diaphragm. In the diaphragms of 6 mature horses (5 Thoroughbreds, o...
Treulen F, Aguila L, Arias ME, Jofré I, Felmer R.In vitro manipulation of spermatozoa leads to deleterious changes of structure and function that occur mainly due to oxidative stress, therefore, prevention or treatment is a strategy to improve the functions of processed sperm. In the present study, the aim was to evaluate the effects of MnTBAP supplementation, a compound with antioxidant activity, on in vitro capacitation conditions of thawed equine sperm. For this purpose, stallion spermatozoa (2 × 10 cells/mL) were incubated in the sperm-TLP base medium for 4 h in which there were three different conditions: non-capacitating, capacitating...
Almeida BFM, Amatti LZ, de Souza GG, Garcia LV, Montechiesi DF, Ignácio FS, de Oliveira PL, Costa LR, Floriano BP, Bosculo MRM, Joaquim JGF, Rubio CP.With the purpose of assessing the effects of uterine ozone therapy and anticoagulant sampling on oxidative stress (OS) parameters in mares, ten mares underwent three consecutive days of uterine ozone therapy by flushing the uterus with ozonated lactated Ringer's solution followed by insufflation with ozone‑oxygen gas. Serum samples were obtained at baseline and days 3, 6, 10 and 17 to determine the effect of ozone therapy on OS markers. Plasma obtained with anticoagulants citrate, ethylenediaminetetraacetic acid (EDTA) and heparin were at baseline and 6 days following therapy to determine t...
Kirschvink N, Bureau F, Art T, Lekeux P.The 8-epi-PGF2alpha is a marker of oxidative stress which is increased in lungs of asthmatic humans and heaves-susceptible horses. 8-Epi-PGF2alpha has also been demonstrated to be an in vitro and in vivo bronchoconstrictor in humans and rodents. We hypothesised that inhaled 8-epi-PGF2alpha was a bronchoconstrictor in healthy and heaves-susceptible horses in clinical remission. The effect on ventilatory mechanics of nebulised 8-epi-PGF2alpha was compared to that of PGF2alpha and U46619, a thromboxane A2 agonist. Pulmonary resistance (R(L)) and dynamic compliance (Cdyn) were assessed in six heal...
Tkachenko AG, Winston GW.Preincubation of horse liver alcohol dehydrogenase (HLADH) with the oxidative agent, tert-butyl hydroperoxide (tBOOH) results in a twofold stimulation of the ethanol dehydrogenase activity of this enzyme. This stimulation was dependent on tBOOH concentration up to 100 mM; above this concentration tBOOH did not further stimulate ethanol oxidation by HLADH. Active-site-directed reagents and classical ADH binary complexes were used to probe the possible mechanism of this activating effect. The rate and extent of stimulation by tBOOH is strongly reduced by binary complexes with NAD(+) or NADH, who...
Hodgson DR, Rose RJ.Muscle biopsy samples were collected from the middle gluteal muscle of seven horses undergoing a nine-month endurance training programme. Samples were collected before the programme began and again after three, six and nine months of training. A fifth sample was collected three months after training ceased. Serial muscle sections were reacted histochemically for myosin adenosine triphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) pre-incubation, and muscle fibres identified as type I, IIA, IIB or IIC. The oxidative capacity of individual fibres was assessed, using the reduc...
Pourali Dogaheh S, Boivin R, Lavoie JP.Severe equine asthma is characterized by airway hyperresponsiveness, neutrophilic inflammation and structural alterations of the lower airways. In asthmatic horses with neutrophilic inflammation, there is insensitivity to corticosteroids characterized by the persistence of neutrophils within the airways with therapy. We hypothesized that hypoxia or oxidative stress in the microenvironment of the lung contributes to this insensitivity of neutrophils to corticosteroids in asthmatic horses. Blood neutrophils isolated from horses with severe asthma (N = 8) and from healthy controls (N = 8)...
Ponthier J, Franck T, Detilleux J, Mottart E, Serteyn D, Deleuze S.Despite improvement of techniques, semen of 20% of stallions remains unfreezable. Recent studies focused on the impact of reactive oxygen species and oxidant enzymes on semen characteristics. Myeloperoxidase (MPO) is a pro-oxidant enzyme contained in and released by neutrophils during degranulation or after cell lysis. It is responsible for the formation of hypochlorous acid, a strong oxidant agent, which could damage spermatozoa. The aim of this study was to determine the relation between MPO concentration and characteristics of frozen semen from stallions. Thirty-five straws from different s...
Flaminio MJ, Rush BR, Davis EG, Hennessy K, Shuman W, Wilkerson MJ.This paper describes a method for simultaneously measuring phagocytosis and oxidative burst activity in equine peripheral blood leukocytes by flow cytometry. Opsonized propidium iodide-labelled Staphylococcus aureus (PI-Sa) was used to measure the uptake of bacteria by equine phacocytes and the oxidative burst activity by oxidation of dihydrorhodamine 123. The requirements to achieve optimal activity of phagocytosis and oxidative burst are described. The advantage of the simultaneous technique is that it provides both independent and comparative values for phagocytosis and the oxidative burst,...
Gharehaghajlou Y, Raidal SL, Freccero F, Padalino B.Transportation may lead to oxidative stress (OS) and gastric ulceration in horses, and optimal feed management before, or during, transportation is unclear. This study aimed to evaluate the effects of transportation after three different feeding strategies on OS and to explore possible associations between OS and equine gastric ulcer syndrome (EGUS). Twenty-six mares were transported by truck for 12 hours without food or water. Horses were randomly divided into 3 groups; (1) fed 1 hour before departure (BD), (2) fed 6 hours BD, (3) fed 12 hours BD. Clinical examinations and blood collections w...
Geelen SN, Jansen WL, Sloet van Oldruitenborgh-Oosterbaan MM, Breukink HJ, Beynen AC.The aim of this study was to establish the dose-response relationship between fat intake and heparin-released plasma lipoprotein lipase (LPL) activity in horses. Eight mature trotters were fed 4 rations with different fat levels (3.0, 5.0, 7.7, or 10.8% fat in the dry matter) according to a 4 X 4 Latin square design. The experimental rations consisted of hay and different concentrates; the concentrates and hay were given in a 3:1 ratio on an energy basis. Soybean oil was added to the concentrates at the expense of isoenergetic amounts of glucose. Blood samples were taken at the end of each die...
McGorum BC, Wilson R, Pirie RS, Mayhew IG, Kaur H, Aruoma OI.The aetiopathogenesis of equine grass sickness (EGS) is unknown. The role of free radical-mediated neuronal damage has not previously been investigated in this condition. Objective: To investigate the potential contribution of oxidative damage and antioxidant status to neurodegeneration in EGS. Methods: Systemic levels of surrogate biomarkers were determined in 10 horses with acute EGS and in 2 control populations; 10 healthy horses co-grazing with the 10 EGS horses at the onset of clinical disease, and 10 healthy mares grazing where EGS has not been reported. Results: EGS horses had alteratio...
Spinaci M, Nerozzi C, Mislei B, Blanco-Prieto O, Mari G, Galeati G, Bucci D.The growing and widespread use of glyphosate-based herbicides (GBHs) has raised an intense public debate about the impact of environmental contamination on animal and human health, including male fertility. The aim of this study was to deepen the impact of glyphosate (Gly) and GBHs on mammalian sperm investigating the effect of in vitro exposure of stallion spermatozoa to Gly and to its commercial formulation Roundup® (R). Spermatozoa were incubated at 37 °C with different Gly or R concentrations (from 0.5 to 720 μg/mL Gly or R at the same Gly-equivalent concentrations). After 1 h of in...
Nogueira BCF, Orozco AMO, Argumedo AK, de Oliveira Faustino A, de Oliveira LL, da Fonseca LA, Campos AK.Ticks have saliva rich in immunoregulatory molecules that interfere with the host's physiology in order to feed. This study aimed to evaluate the concentration of acute phase proteins and circulating oxidative stress in response to infestation by Amblyomma sculptum and Dermacentor nitens in two breed horses, Mangalarga Marchador and Breton Postier, to define resistance or susceptibility to ticks. Among the oxidative stress markers, we observed lower malondialdehyde and nitric oxide in horses with tick infestation, consequently not altering the antioxidant enzymes. Breton Postier with tick infe...
Beghelli D, Zallocco L, Angeloni C, Bistoni O, Ronci M, Cavallucci C, Mazzoni MR, Nuccitelli A, Catalano C, Hrelia S, L쫌hini A, Giusti L.Intense exercise can cause inflammation and oxidative stress due to the production of reactive oxygen species. These pathophysiological processes are interdependent, and each one can induce the other, creating a vicious circle. A placebo-controlled blind study was carried out in show jumping horses (n. 16) to evaluate the effects of a commercial dietary supplement (Dolhorse® N.B.F. Lanes srl, Milan, Italy) containing Verbascum thapsus leaf powder (1.42%), Curcuma longa (14.280 mg/kg), and Boswellia serrata (Roxb ex Colebr) (14.280 mg/kg) extracts. Before and after 10 days of dietary supplemen...
Kitaoka Y, Hoshino D, Mukai K, Hiraga A, Takemasa T, Hatta H.To examine the changes in monocarboxylate transporter (MCT) 1 and MCT4 content and in indicators of energy metabolism in the gluteus medius muscle (GMM) of Thoroughbreds during growth. Methods: 6 Thoroughbreds (3 males and 3 females). Methods: Samples of GMM were obtained when horses were 2, 6, 12, and 24 months old. Muscle proteins were separated via SDS-PAGE; amounts of MCT1 and MCT4 and peroxisome proliferator-activated receptor-γ coactivator-1α content were determined by use of western blotting. Muscle activities of phosphofructokinase and citrate synthase were measured biochemically; la...
Moiseeva SA, Postnikova GB.The influence of Cu2+ concentration, pH, and ionic strength of the solution as well as redox-inactive zinc ions on the rate of oxidation of sperm whale, horse, and pig oxymyoglobins (oxy-Mb) by copper ions has been studied. These myoglobins have homologous spatial structures and equal redox potentials but differ in the number of histidines located on the surface of the proteins. It was shown that oxy-Mb can be oxidized in the presence of Cu2+ through two distinct pathways depending on which histidine binds the reagent and how stable the complex is. A slow pH-dependent catalytic process is obse...
Bolann BJ, Ulvik RJ.The redox interaction between O2.- and ferritin cannot solely be regarded as as a Fe(II) release reaction. We demonstrate that native copper bound to horse spleen ferritin and apoferritin, stimulated the decay of O2.- in a catalytic reaction. Copper was determined by atomic absorption spectrophotometry. Decay of O2.- was monitored spectrophotometrically as the decrease in (A250-A360) at pH 9.5. The catalytic effect was linearly related to the copper content of the protein. Ferritin copper was less efficient than equimolar CuCl2, and iron-poor ferritin was more efficient than iron-rich ferritin...
Mills PC, Ng JC, Thornton J, Seawright AA, Auer DE.Four unfit thoroughbred horses were exercised on a treadmill twice, 5 weeks apart. Exercise consisted of stepwise increments in treadmill speed up to a maximum of 12 m s-1 and then maintained at this speed until the horses were fatigued. Two of the horses were administered phenylbutazone (4.4 mg kg-1) intravenously immediately before the first exercise period and the other two horses immediately before the second exercise period. Clinical observation revealed stiffness of gait and palpable soreness over the lumbar-sacral region in the horses 24 h after the exercise concluded. Mean plasma aspar...
Merlo B, Iacono E, Bucci D, Spinaci M, Galeati G, Mari G.In vitro embryo production in the horse is still not as efficient as in other species. Oxidative stress negatively affects oocyte and embryo culture. To attenuate/minimize the oxidative stress, antioxidants such as low-molecular thiol compounds can be added to culture media. Beta-mercaptoethanol (BME) has been shown to improve maturation and embryo development in different species. The aim of this study was to investigate whether the addition to maturation medium of BME at common (0.1 mM) and high (0.7 mM) concentration could improve oocyte maturation also in the horse. Equine oocytes recove...
Martins HS, Souza MR, Penna CF, da Silva GC, Côrtes SF, Stahlberg R, Lagares MA.Cooled semen has been used routinely to prolong sperm viability until artificial insemination time. However, spermatozoa are subjected to oxidative stress. The aim of the present work was to investigate the protective and antioxidant effect of the milk proteins lactoferrin (Lf) and caseinate added to equine semen cooling extenders. Semen from six stallions was cooled at 5 °C after resuspension with C1) milk- and glucose-based, C2) 0.6% caseinate, C3) C2 + Lf 200 μg ml-1 , C4) C2 + Lf 500 μg ml-1 and C5) C2 + Lf 1000 μg ml-1 extenders, and kept at 5 °C for 24 h. Sperm motili...
Benbarek H, Ayad A, Deby-Dupont G, Boukraa L, Serteyn D.The purpose of this study was to explore the potential modulation of equine neutrophil oxidative burst by a series of classical NSAIDs which was subsequently monitored by the luminol or lucigenin-enhanced chemiluminescence (CL) technique. A significant dose-dependent inhibition of the luminol CL was observed with the majority of investigated drugs. This inhibition was very significant for phenylbutazone and Indomethacin; while for aspirin, a higher concentration is required. The action of Ketoprofen was significant during the first 5 min and only when the concentration was above 1 mM. Indometh...
Harvey JW, Kaneko JJ.Partially purified haemoglobin solutions of man, horse, car and dog were oxidized with ascorbate, acetylphenylhydrazine, nitrite, and H2O2 at 25 degrees C and with ascorbate and acetylphenylhydrazine at 37 degrees C. Haemoglobins of the carnivores were more easily oxidized with ascorbate, nitrite, and H2O2 than equine and human haemoglobins. Feline haemoglobin, in general, appeared more susceptible to oxidation, particularly oxidative denaturation, than those of the other species. In addition, results of the incubations at 37 degrees C suggest that feline haemoglobin B might be more susceptibl...
Rifkind JM.The reduced glutathione in the erythrocyte was found to inhibit the autoxidation of purified horse hemoglobin. It was observed that much higher concentrations of oxidized glutathione also stabilize hemoglobin. The stabilization by oxidized glutathione most likely involves the formation of a mixed disulfide with the reactive β-93 sulfhydryl groups on the hemoglobin. A similar effect is also observed with N-ethyl- maleimide and HgCl2 which also react with the sulfhydryl groups. The apparent stabilization by reduced glutathione is partially due to the reduction of ferrihemoglobin formed by autox...
Davis MS, Bayly WM, Hansen CM, Barrett MR, Blake CA.Exercise is associated with the development of oxidative stress, but the specific source and mechanism of production of pro-oxidant chemicals during exercise has not been confirmed. We used equine skeletal muscle mitochondria to test the hypothesis that hyperthermia and acidosis affect mitochondrial oxygen consumption and production of reactive oxygen species (ROS). Skeletal muscle biopsies were obtained at rest, after an acute episode of fatiguing exercise, and after a 9-wk conditioning program to increase aerobic fitness. Mitochondrial oxygen consumption and ROS production were measured simu...
Muñoz-Prieto A, Llamas-Amor E, Contreras-Aguilar MD, Ayala I, Martín Cuervo M, Cerón JJ, Hansen S.Ammonia (NH3) and bicarbonate (HCO3) have been related to gastric ulcers in humans. Ammonia is considered a possible cause of gastric ulcers, whereas bicarbonate has a protective function. The presence of ulcers in the stomach of horses is defined as Equine Gastric Ulcer Syndrome (EGUS), which is a frequent disease in this species, and it has been associated with changes in saliva composition, such as in analytes related to inflammation, immune system and oxidative stress. The objectives of this study were (1) to perform an analytical validation of two automated spectrophotometric assays, one ...
Whitfield-Cargile CM, Chung HC, Coleman MC, Cohen ND, Chamoun-Emanuelli AM, Ivanov I, Goldsby JS, Davidson LA, Gaynanova I, Ni Y, Chapkin RS.The equine gastrointestinal (GI) microbiome has been described in the context of various diseases. The observed changes, however, have not been linked to host function and therefore it remains unclear how specific changes in the microbiome alter cellular and molecular pathways within the GI tract. Further, non-invasive techniques to examine the host gene expression profile of the GI mucosa have been described in horses but not evaluated in response to interventions. Therefore, the objectives of our study were to (1) profile gene expression and metabolomic changes in an equine model of non-ster...
Meissner JM, Chmielińska A, Ofri R, Cisło-Sankowska A, Marycz K.Corneal ulcers, characterized by severe inflammation of the cornea, can lead to serious, debilitating complications and may be vision-threatening for horses. In this study, we aimed to investigate the role of endoplasmic reticulum (ER) stress in corneal stem progenitor cell (CSSC) dysfunction and explore the potential of equine adipose-derived stromal stem cell (ASC)-derived extracellular vesicles (EVs) to improve corneal wound healing. We showed that CSSCs expressed high levels of CD44, CD45, and CD90 surface markers, indicating their stemness. Supplementation of the ER-stress-inducer tunicam...
Asahi Y, Arai T, Tanaka Y.In older horses, basal metabolic rate decreases, and plasma metabolite and hormone concentrations related to energy metabolism change. The occurrence of age-related diseases, which increases in old animals, may enhance inflammatory reactivity (inflammaging). Finding the appropriate treatment for inflammaging at an early stage may prevent various age-related diseases. Changes in metabolite and hormone concentrations and enzyme activities involved in energy metabolism in the plasma of clinically healthy riding horses of various ages were measured to identify biomarkers of inflammaging (persisten...
Muñoz-Prieto A, Llamas-Amor E, Cerón JJ, Hansen S.Equine gastric ulcer syndrome (EGUS) is a prevalent condition in horses, affecting up to 93% of racehorses. Comprising the equine squamous gastric disease (ESGD) and the equine glandular gastric disease (EGGD), EGUS poses significant health challenges. Saliva, a non-invasive and easily obtainable sample, is increasingly recognized for its potential as a source of biomarkers in horses. This study investigates changes in saliva analytes using automated assays before and after EGUS treatment, aiming to identify biomarkers indicative of treatment success or failure. A total of 28 horses diagnosed ...
