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.
Raidal SL, Bailey GD, Love DN.Flow cytometric techniques were developed for the evaluation of oxidative burst activity in equine peripheral blood neutrophils and lymphocytes, as well as bronchoalveolar lavage derived pulmonary alveolar macrophages and lymphocytes. The oxidation of dichlorofluorescin was measured by the increased fluorescence of cells stimulated with phorbol myristate acetate or a variety of other stimulants. Flow cytometry was a suitable method for the evaluation of the intracellular oxidation in all cell populations evaluated. Analysis was rapid and cell separation before analysis was not required. Hetero...
Chiaradia E, Avellini L, Rueca F, Spaterna A, Porciello F, Antonioni MT, Gaiti A.Since it has been suggested that lipid peroxidation following free radical overproduction may be one of the causes of physical exercise-induced myopathies and hemolysis in horses, we looked for the possible relationships between these phenomena and muscle fiber damage. We use a homogeneous group of Maremmana stallions which, after a 3-month training period, underwent a series of physical exercises of increasing intensity. We determined the contents of malondialdehyde (MDA), one of the main lipid peroxidation end-products, and glutathione the substrate of one of the most important free radical ...
Pamplona R, Requena JR, Portero-Otín M, Prat J, Thorpe SR, Bellmunt MJ.The non-enzymatic modification of aminophospholipids with lipoperoxidation-derived aldehydes and glycoxidation-derived products have been reported previously. However, it remains unknown whether intracellular membranes are damaged by these glycoxidation-derived products. To investigate this issue, we tested whether aminophospholipids from mitochondrial membranes are damaged by glycoxidative stress the mitochondrion being identified as the major site of reactive-species production in the cell. We have used a selected-ion-monitoring/gas-chromatography/mass-spectrometry assay for carboxymethyleth...
Davidson MG, Geoly FJ, Gilger BC, McLellan GJ, Whitley W.A group of Walker Hounds and Beagles that were fed a diet of table scraps were examined because of slow, progressive loss of vision. Clinical and microscopic features of the disease were correlated to the dogs' micronutrient status. Sensory retinal degeneration, predominantly in the central tapetal fundus, was found in all dogs, and severity of changes varied with age of the dog. Plasma, serum, and tissue concentrations of vitamin E were low in affected dogs (10 to 40% of control values). Lipofuscin accumulation was found on microscopic examination in retinal pigment epithelium, smooth muscle ...
Chang M, Zhang F, Shen L, Pauss N, Alam I, van Breemen RB, Blond SY, Bolton JL.The risk factors for women developing breast and endometrium cancers are all associated with a lifetime of estrogen exposure. Estrogen replacement therapy (ERT) in particular has been correlated with a slight increased cancer risk, although the numerous benefits of ERT may negate this harmful side effect. Equilenin and equilin are equine estrogens which make up between 30% and 45% of the most widely prescribed estrogen replacement formulation, Premarin (Wyeth-Ayerst). In this study we have synthesized the catechol metabolites of equilenin [4-hydroxyequilenin (4-OHEN)] and equilin [4-hydroxyequ...
Perkins G, Valberg SJ, Madigan JM, Carlson GP, Jones SL.Marked electrolyte abnormalities characterized by profound hyperkalemia, hyponatremia, hypocalcemia, and hyperphosphatemia were noted in 4 neonatal foals with acute rhabdomyolysis and pigmenturia. In 2 foals, rhabdomyolysis developed 4-6 days after admission for dysmaturity, and in 2 foals, rhabdomyolysis was evident on presentation. Rhabdomyolysis was a consequence of selenium deficiency with or without vitamin E deficiency, possibly combined with increased oxidant stress due to sepsis or hypoxia and reperfusion injury after parturition. Foals gained from 7 to 15% of their initial body weight...
Kooreman K, Babbs C, Fessler J.To evaluate and compare oxidative processes during ischemia and reperfusion of the equine large colon and jejunum. Methods: 2 groups of 6 anesthetized horses undergoing a terminal procedure. Methods: Isolated loops of large colon and jejunum were subjected to 2 hours of ischemia, followed by 2 hours of reperfusion. Tissue specimens were taken after 105 minutes of ischemia and 10, 30, 60, and 120 minutes of reperfusion. Mesenteric arterial and venous blood samples were collected for blood gas analysis at the same times to evaluate ischemia and reoxygenation. Oxidative processes in tissues were ...
Wang ZW, Nara M, Wang YX, Kotlikoff MI.The effects of sulfhydryl reduction/oxidation on the gating of large-conductance, Ca(2+)-activated K+ (maxi-K) channels were examined in excised patches from tracheal myocytes. Channel activity was modified by sulfhydryl redox agents applied to the cytosolic surface, but not the extracellular surface, of membrane patches. Sulfhydryl reducing agents dithiothreitol, beta-mercaptoethanol, and GSH augmented, whereas sulfhydryl oxidizing agents diamide, thimerosal, and 2,2'-dithiodipyridine inhibited, channel activity in a concentration-dependent manner. Channel stimulation by reduction and inhibit...
Siciliano PD, Parker AL, Lawrence LM.The effect of vitamin E intake on indicators of muscle integrity was studied in exercised horses. Nineteen horses were blocked by sex and then assigned to one of three diets: no supplemental vitamin E (BASAL), BASAL plus 80 IU of supplemental vitamin E/kg DM (80), or BASAL plus 300 IU of supplemental vitamin E/kg DM (300). The BASAL diet contained less than 44 IU of vitamin E/kg DM, but it was adequate in all other nutrients. During the 90-d treatment period, horses were exercised 5 d/wk; in addition, serum and middle gluteal muscle alpha-tocopherol concentrations were measured at 0, 30, and 9...
Birch HL, Rutter GA, Goodship AE.Hypoxia has been suggested as a possible cause of tissue degeneration and subsequent rupture in equine tendons. To determine whether low oxygen tension is likely to be detrimental to tendon cell function, experiments were designed to investigate oxidative energy metabolism in freshly isolated and cultured equine tendon cells. Freshly isolated tenocytes and cultured fibroblasts possessed activities of the mitochondrial enzyme citrate synthase similar to those of other mammalian cells, with well defined oxidative metabolism. D-[6(-14)C]-glucose oxidation was measurable in both freshly isolated a...
Mills PC, Higgins AJ.The athletic ability of the horse is facilitated by vital physiological adaptations to high-intensity exercise, including a thin (but strong) pulmonary blood-gas barrier, a large pulmonary functional reserve capacity and a consequent maximum oxygen uptake (VO2max) far higher than in other species. A high pulmonary artery pressure also serves to enhance pulmonary function, although stress failure of lung capillaries at high pulmonary transmural pressures, and the contribution of other factors which act in the exercising horse to increase pulmonary vascular tone, may lead to pathological or path...
Vodela JK, Dalvi RR.This study was conducted to determine and compare the activities of glutathione-S-transferase (GST) in red blood cells of cattle, horses, pigs, goats, dogs, rabbits, rats and mice. The highest GST activity was found in mouse red blood cells followed by that of rats, dogs, cattle, pigs, goats and horses with the lowest activity in rabbits. There were significant differences between the GST activities from these various species. The species differences in GST activities correlate with the reported variable responses of the different species to different toxicants since erythrocyte GST plays a si...
Mills PC, Smith NC, Harris RC, Harris P.Allopurinol was administered to six horses in a cross-over study to determine the relative contribution of xanthine oxidase (XO) activity to the formation of reactive oxygen species (ROS) in the horse during intense exercise. Exercise increased the mean (SEM) plasma lipid hydroperioxide concentration to a maximum of 492.7 (33.4) microM within one minute of exercise completion and maximum levels of both oxidised glutathione (GSSG) in haemolysates of red blood cells and the glutathione redox ratio (GRR) occurred 20 minutes after exercise (87.2 [12.2] microM and 8.9 [0.9] per cent, respectively)....
Conley KE, Jones C.We test the hypothesis that myoglobin is important for O2 supply near the oxidative capacity of muscle. This hypothesis is evaluated with a simple model that incorporates the properties of heart and skeletal muscle tissue taken from steers and horses exercising at their maximum O2 consumption rate. These tissue samples allowed us to set the bounds on oxidative demand and O2 flux from red blood cells to the core of the muscle fiber, to estimate the blood and tissue capacities for O2 diffusion, and to define the capillary blood PO2 driving this O2 flux. A model combining blood convection with ti...
Rivero JL, Talmadge RJ, Edgerton VR.The histochemical myofibrillar ATPase (mATPase) method is used routinely for identification of equine skeletal muscle fiber types, but important problems have been observed with the subdivision of fast fiber population when using this method. To verify the use of this qualitative method, a number of equine muscle biopsies were analyzed with a combination of histochemical, immunohistochemical, electrophoretic, and morphometric techniques. The influence of training on these interrelations was also evaluated. Methods: Five young (2-3 years old) thoroughbred horses were intensively trained for 8 m...
Mills PC, Roberts CA, Smith NC.To investigate the effects of ozone and airway inflammation on indices of oxidant injury in horses. Methods: 5 clinically normal horses and 25 horses referred for poor performance. Methods: Blood, tracheal wash, and bronchoalveolar lavage fluid samples were collected before and after ozone exposure (n = 5) or from clinical cases (n = 25), and were analyzed for reduced glutathione (GSH), glutathione disulfide (GSSG), and free and total iron (Fe) values. A scoring system (0 to 5) was used to assess airway inflammation on the basis of clinical signs and cytologic analysis of the tracheal wash and...
Räsänen LA, Wiitanen PA, Lilius EM, Hyyppä S, Pösö AR.Plasma concentration of uric acid, total peroxyl radical-trapping antioxidative parameter (TRAP), blood lactate concentration and plasma activity of xanthine oxidase (XO) were measured in six Standardbreed trotters after six bouts of exercise with increasing intensity on two separate days three days apart. Blood samples were taken immediately, 5, 10, 15, 30 and 60 min after each heat and 2, 4, and 6 hr after the last heat. Exercise caused an increase in TRAP and in the concentrations of lactate and uric acid. Plasma uric acid concentration increased exponentially with respect to time after the...
Kuwabara M, Inukai N, Inanami O, Miyake YI, Tsunoda N, Maki Y, Sato F.Hotbred (Thoroughbred) horses were grouped into three classes according to the levels of constant physical exercise (foals, 6 months old; racing horses, 5 years old; horses for breeding, 6-10 years old), and lipid peroxide levels in their sera were measured as thiobarbituric acid-reactive substances. No significant differences were observed among them. The superoxide-scavenging abilities of sera were measured next; to examine the antioxidative properties of hotbreds, and were found to be highest in the racing horses. The higher scavenging ability of the racing horses might contribute to keep t...
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...
Olszewski MA, Robinson NE, Yu MF, Derksen FJ.During acute bouts of recurrent airway obstruction (heaves) in horses, neutrophils that are capable of increased production of reactive oxygen species accumulate in the airways. In the study reported here, the effect of hydrogen peroxide (H2O2; 1 microM to 0.1M), one of these reactive oxygen species products, on the responses of isolated trachealis muscle of horses was determined. Before and after incubation with H2O2, contractile responses to acetylcholine, electrical field stimulation (EFS), 127 mM KCl, and relaxation responses to isoproterenol and activation of the nonadrenergic noncholiner...
Moore RM, Muir WW, Granger DN.Restoration of blood flow after a period of intestinal ischemia is necessary to maintain cell function and viability; however, the reintroduction of oxygen can initiate a cascade of events that exacerbates tissue injury. Intestinal I-R injury is manifested as increased microvascular and mucosal permeability, and mucosal necrosis. Reperfusion injury begins with the accumulation of hypoxanthine from ATP metabolism and the conversion of XDH to XO during ischemia. Upon reperfusion, the XO catalyzes the conversion of hypoxanthine to superoxide radicals in the presence of oxygen. Superoxide radicals...
Avellini L, Silvestrelli M, Gaiti A.Oxidative stress develops when the generation of free radicals exceeds the antioxidant capacity of cells or extracellular fluids. It can also occur as a result of physical exercise, and the pathogenesis of exercise-induced myopathies and haemolysis in horses may be related to changes in lipid peroxidation caused by free radicals. Cells have developed biochemical protection against oxidative stress and, as tissues seem to increase their antioxidant defences under chronic activation, training may be one of the ways of increasing antioxidant defences. Accordingly, we tested some enzymatic antioxi...
Ichinose T, Miller MG, Shibamoto T.Free malonaldehyde formed in the microsomes prepared from livers of monkey, rat, rabbit, mouse, cow, pig, dog, sheep and horse upon CCl4 oxidation was derivatized by reaction with N-methylhydrazine to form 1-methylpyrazole which was subsequently analyzed by capillary gas chromatography. Among the livers from animals tested, the monkey and rat livers produced the most malonaldehyde upon CCl4 treatment. Horse liver showed the greatest resistance to CCl4 oxidation. The gas chromatography method used in the present study exhibited an accurate and specific measurement of free malonaldehyde that mig...
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...
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...
Mihajlovic V, Cascone O, Biscoglio de Jiménez Bonino MJ.1. Reactivity of methionine residues towards Chloramine-T was studied in the equine growth hormone. 2. With a 20.0-fold molar excess of reagent over methionine, full oxidation of the four residues of the protein is achieved. 3. Methionine 4 is the most reactive group, followed by methionines 72 and 178--methionine 123 being the less reactive residue. 4. As judged by circular dichroism spectra and binding assays, protein conformation and binding capacity to specific receptors remains unchanged even after full oxidation of all four methionine residues. 5. Results agree with data previously obtai...
Auer DE, Ng JC, Seawright AA.Free radical oxidation products, namely conjugated dienes, ultraviolet fluorescence (excitation 325 nm, emission 395 nm) and visible fluorescence (excitation 360 nm, emission 460 nm) were measured in equine synovial fluid exposed to free radicals in vitro and in the plasma and synovial fluids of horses with synovial effusions. The synovial effusions were induced by intra-articularly administered carrageenin (0.3 ml, 1%), which rarely resulted in clinical lameness. The free radicals were generated in vitro by mixtures of iron and ethylene diamine tetra acetate (Fe/EDTA) or mixtures of hypoxanth...
Armstrong RB, Essén-Gustavsson B, Hoppeler H, Jones JH, Kayar SR, Laughlin MH, Lindholm A, Longworth KE, Taylor CR, Weibel ER.The purpose of this study was to describe the relationships between 16 physiological, biochemical, and morphological variables presumed to relate to the oxidative capacity in quadriceps muscles or muscle parts in Standardbred horses. The variables included O2 delivery (blood flow) and mean capillary transit time (MTT) during treadmill locomotion at whole animal maximal O2 consumption (VO2max, 134 +/- 2 ml.min-1 x kg-1), capillary density and capillary-to-fiber ratio, myoglobin concentration, oxidative enzyme activities, glycolytic enzyme activities, fiber type populations, and fiber size. Thes...
Żak A, Siwińska N, Chełmecka E, Bażanów B, Romuk E, Adams A, Niedźwiedź A, Stygar D.The study aims to assess the impact of age, pituitary pars intermedia dysfunction (PPID) and insulin dysregulation (ID) in horses on selected oxidative stress markers. The study includes 32 horses, divided into three groups: "young" adult group (aged 8-16 years old) "geriatric" group (aged 18-24 years old) and the "PPID" group (aged 15-31 years old). The PPID group was further divided into two subgroups: PPID ID+ and PPID ID- based on presence or absence of ID. We measured serum antioxidant stress markers in all horses: total oxidant status (TOS), total antioxidant capacity (TAC), ceruloplasmi...
Ducharme NG, Fortier LA, Kraus MS, Hobo S, Mohammed HO, McHugh MP, Hackett RP, Soderholm LV, Mitchell LM.To evaluate whether administering a tart cherry juice blend (TCJB) prior to exercise would reduce skeletal and cardiac muscle damage by decreasing the inflammatory and oxidative stress response to exercise in horses. Methods: 6 horses. Methods: Horses were randomly allocated into 2 groups in a crossover study with a 2-week washout period and orally administered either TCJB or a placebo solution (1.42 L, twice daily) in a double-masked protocol for 2 weeks prior to a stepwise incremental exercise protocol. Horses were tested for serum activities of creatine kinase and aspartate aminotransferase...
Salinas C, Espinosa G, Morales N, Henríquez C, Morán G, Gajardo G, Burgos RA, Uberti B.Obesity and insulin dysregulation (ID) are increasingly prevalent conditions in equid populations worldwide. Immune impairment is well described in humans with metabolic dysfunction and is reported but still incompletely understood in horses. This study evaluated the effect of acute induced transient hyperglycemia on apoptosis, phagocytosis and oxidative burst activity of peripheral blood polymorphonuclear cells (PMN) of lean and obese adult horses with or without insulin dysregulation. Seventeen adult horses were allocated into three groups based on their body condition score (BCS) and metabo...
Marzano G, Moscatelli N, Di Giacomo M, Martino NA, Lacalandra GM, Dell'Aquila ME, Maruccio G, Primiceri E, Chiriacò MS, Zara V, Ferramosca A.Conventional sperm selection techniques used in ARTs rely on centrifugation steps. To date, the different studies reported on the effects of centrifugation on stallion sperm motility provided contrasting results and do not include effects on mitochondrial functionality and different oxidative parameters. The effects of different centrifugation protocols (300 ×g for 5', 300 ×g for 10', 1500 ×g for 5' and 1500 ×g for 10' vs no centrifugation) on motility and oxidative status in cryopreserved stallion sperm, were analyzed. After centrifugation, almost all motility parameters were significantl...
Benbarek H, Deby-Dupont G, Deby C, Serteyn D.The capacity of the two cytokines TNF-alpha and IL-1beta to directly stimulate the oxidative activity of polymorphonuclear neutrophils remains debated. The purpose of this study was to verify if a direct stimulation of equine neutrophils by TNF-alpha and IL-1beta was possible. Equine neutrophils were isolated from blood by discontinuous density gradient centrifugation. The cell viability after isolation was >98%. The neutrophils were used at 1.25 x 10(6) cells by assay, immediately after isolation. The oxidative activity of neutrophils was measured by luminol- or lucigenin-enhanced chemilumine...
de Vasconcelos Franco JS, Faheem M, Chaveiro A, Moreira da Silva F.The effects of supplementation of α-tocopherol and different freezing rates (FRs) on the ability of stallion sperm to fertilize bovine oocytes with intact zona pellucida were investigated, in an attempt to develop a model to assess cryopreserved sperm function. Semen was obtained from four purebred Lusitano stallions (n = 4). Each ejaculate was subjected to cryopreservation with a commercial extender (Ghent, Minitub Iberia, Spain), without any supplementation (control) or supplemented with 2-mM α-tocopherol. The semen was exposed to two different FRs between 5 °C and -15 °C: slow (5 °C...
Wong DM, Ghosh A, Fales-Williams AJ, Haynes JS, Kanthasamy AG.The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also ...
Contreras-Aguilar MD, Rubio CP, González-Arostegui LG, Martín-Cuervo M, Cerón JJ, Ayala I, Henriksen IH, Jacobsen S, Hansen S.Changes in the oxidative status of the blood of horses suffering from gastric ulcers and colic of intestinal aetiology (CIE) have been reported. However, saliva can also be a source of biomarkers of oxidative status. Therefore, this study aims to validate automated assays for the measurement of oxidative status biomarkers (ferric reducing ability of saliva/serum-FRAS/FRAP, cupric reducing antioxidant capacity-CUPRAC, the Trolox equivalent antioxidant capacity-TEAC, uric acid, and advanced oxidation protein products-AOPP) in the saliva and serum of horses, to assess their changes in the differe...
Auer DE.The role of oxygen-derived free radicals is considered critical to the etio-pathogenesis of equine inflammatory joint disease. In vivo, the superoxide radical in the joint may be derived either from activated polymorphonuclear leukocytes or from an ischemia/reperfusion cycle. In the presence of ferrous iron, it may generate the highly reactive hydroxyl radical (OH *). Predisposing factors may include synovitis, exercise-induced ischemia and minor traumatic injury to the joints. Unlike other inflammatory mediators, oxygen-derived free radicals may damage tissue directly and these reactive speci...
Dunnett CE, Marlin DJ, Harris RC.The aim of the present study was to relate changes in muscle oxidative capacity and free fatty acid flux in response to oil supplementation to fuel utilisation during subsequent exercise of varying intensities. Following 10 weeks of oil supplementation there was an increased capacity for fat utilisation during low and moderate intensity exercise as indicated by a lower respiratory exchange ratio (RER) (P<0.05). We suggest that this was contributed to by a parallel increase in the oxidative capacity of muscle as indicated by a significant increase in the activity of muscle citrate synthase (...
Rietbroek NJ, Dingboom EG, Schuurman SO, Hengeveld-van der Wiel E, Eizema K, Everts ME.To determine whether postnatal development of oxidative capacity and capillary supply of skeletal muscle is affected by various movement regimens in horses. Methods: 35 foals. Methods: Dutch Warmblood foals were allocated into 3 groups (box stall rest, box stall rest with training, and free pasture exercise). Training comprised an increasing number of gallop sprints from 1 week after birth to 22 weeks of age. From 22 to 48 weeks, the 3 groups were combined and allowed to exercise freely. Capillary supply (diffusion index [ie, area supplied by 1 capillary]), citrate synthase (CS) activity, and ...
Polack EW, King JM, Cummings JF, Mohammed HO, Birch M, Cronin T.To compare concentrations of trace minerals in the spinal cord of horses with equine motor neuron disease (EMND) with those of horses without neurologic disease (control horses). Methods: 24 horses with EMND and 22 control horses. Methods: Spinal cord trace mineral concentrations in horses with EMND and control horses were analyzed by use of inductively coupled plasma atomic emission spectroscopy (calcium, phosphorus, sodium, potassium, magnesium, copper, iron, manganese, nickel, zinc, aluminum, cobalt, and chromium), atomic absorption spectrophotometry (lead and cadmium), flameless atomic abs...
Corradini I, Georges K, Jose-Cunilleras E.To determine the effects of time after sampling on CO-oximetry measurements of equine blood samples and the effects of adding ascorbic acid (AscAc) and methylene blue (MetBlue) to samples with methemoglobinemia. Methods: Experimental study. Methods: University teaching hospital. Methods: Thirty healthy adult horses assigned to 5 groups. Methods: Repeated CO-oximetry determinations were performed on venous (n = 6) and arterial blood samples (n = 7) stored at 0°C for 48 hours. Methemoglobinemia was induced in vitro in 17 additional blood samples. Six were used as untreated controls, 6 had ...
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...
Crowley J, Po E, Celi P, Muscatello G.Oxidative stress (OS) is most simply defined as an imbalance between oxidants and antioxidants. Oxidative stress has been suggested to play roles in various equine respiratory diseases and the significance of OS in the pathogenesis of Rhodococcus equi pneumonia is unknown. Objective: To measure and relate biomarkers of OS to lesions consistent with R. equi pneumonia. Methods: Case-control study. Methods: Various OS biomarkers were measured from blood and exhaled breath condensate (EBC) samples collected from 26 foals between 1 and 2 months of age (n = 12 cases and n = 14 controls) on 2 Thoro...
Williams CA, Kronfeldt DS, Hess TM, Saker KE, Waldron JN, Crandell KM, Hoffman RM, Harris PA.This study tested the development of oxidative stress and the effects of antioxidant supplementation in an 80-km ride. A precompetition survey revealed that no competitor would participate without vitamin E supplementation; therefore, 46 horses were paired for past performances and randomly assigned to two groups of 23 each for 3 wk of supplementation before the ride. One group (E) was orally supplemented with 5,000 IU of vitamin E per day; the other group (E+C) received that dose of vitamin E plus 7 g/d of vitamin C. Blood samples, temperature, and heart rate were taken the day before the rac...
Tsubone H, Hanafusa M, Endo M, Manabe N, Hiraga A, Ohmura H, Aida H.The present study aimed to clarify changes of oxidative stress and antioxidative functions in treadmill-exercised Thoroughbred horses (n=5, 3 to 7 years old), using recently developed techniques for measurement of serum d-ROMs for oxidative stress, and BAP for antioxidative markers. Also, the effect of nasogastric administration of hydrogen-rich water (HW) or placebo water preceding the treadmill exercise on these parameters was examined. Each horse was subjected to a maximum level of treadmill exercise in which the horses were exhausted at an average speed of 13.2 ± 0.84 m/sec. Blood samples...
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...
Bartak M, Chodkowski M, Słońska A, Bańbura MW, Cymerys J.In the present study, the influence of the infection with equine herpesvirus type 1 (non-neuro-pathogenic and neuropathogenic strains of EHV-1) on the morphology and distribution of mitochondrial network in equine dermal cell line was investigated. Our results indicate that EHV-1-infection caused changes in the mitochondrial morphology manifested mostly by fission and reactive oxygen species generation.
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...
Nogueira BCF, Campos AK, Alves RS, de Cássia Vieira Faria R, Sarandy MM, Fonseca E Silva F, Gonçalves RV.Amblyomma sculptum is frequently observed parasitizing horses, responsible for economic losses, damage to the host''s skin and transmission of pathogens. The oxidative stress profile and inflammatory mechanisms involved in this parasitism remain poorly studied. Thus, this study aimed to assess the histopathological changes and oxidative profile responses of horses in the attachment site of A. sculptum to find variations that indicate resistance and susceptibility between the breeds to this tick, based on the hypothesis that resistant animals have a greater inflammatory response and lesser numb...
Al-Khaldi K, Yimer N, Sadiq MB, Firdaus Jesse Bin Abdullah F, Salam Babji A, Al-Bulushi S.Diluents and various biological products have been used in different animal species, with promising outcomes in post-thaw sperm quality. Nevertheless, only a few reports are available for the semen of Arabian horses. Edible bird's nest (EBN) - a product of the salivary secretions of swiftlet species is widely known to have both antioxidant and anti-inflammatory properties. Presently, there is no data available on the role of EBN supplemented in different extenders and its effect on semen quality in stallion semen. Two in vitro experiments were conducted to examine the effects of edible bird's ...
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...
Bahrami A, Divar MR, Azari M, Kafi M.In the present study, we aimed to evaluate the possible protective effects of the nicotinic acid (NA) at three concentrations (10, 20, and 40 mM) on the equine cooled and frozen-thawed spermatozoa quality markers including viability, plasma membrane or acrosome integrity, DNA fragmentation, lipid peroxidation, and total oxidant levels. We also evaluated the effects of NA on preservation of the post-thaw sperm quality after 6 hours of cold storage before freezing. Five stallions were used for semen collections. The current experiment was repeated six times using pooled semen samples from two ...
Meijer AE, van den Hoven R.In this communication, the results of a histochemical and biochemical enzyme study on gluteus medius muscle of horses, sensitive to exertional myopathy, during attacks of rhabdomyolysis are presented. For the biochemical study the biopsy specimens investigated were selected by means of histological and enzyme histochemical staining methods. Dissected specimens were used which contained groups of muscle fibres with a high or low activity of glucose-6-phosphate dehydrogenase. The activity of glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, glutathione reductase, glutathione per...
Mills PC, Higgins AJ.The athletic ability of the horse is facilitated by vital physiological adaptations to high-intensity exercise, including a thin (but strong) pulmonary blood-gas barrier, a large pulmonary functional reserve capacity and a consequent maximum oxygen uptake (VO2max) far higher than in other species. A high pulmonary artery pressure also serves to enhance pulmonary function, although stress failure of lung capillaries at high pulmonary transmural pressures, and the contribution of other factors which act in the exercising horse to increase pulmonary vascular tone, may lead to pathological or path...
Mouithys-Mickalad A, Storms N, Franck T, Ceusters J, de la Rebière de Pouyade G, Deby-Dupont G, Serteyn D.Experimental laminitis, characterized by a failure of the dermal-epidermal interface of the foot, can be induced in horses by the oral administration of a black walnut extract (BWE). In the early phase of this severe and painful disease, an activation of neutrophil occurs, with the release of myeloperoxidase (MPO), a pro-oxidant enzyme of neutrophils, in plasma, skin, and laminar tissue. Juglone, a naphthoquinone derivative endowed with redox properties, is found in walnuts and has been incriminated in this neutrophil activation. We report for the first time the inhibitory activity of juglone ...
Deaton CM, Marlin DJ, Smith NC, Roberts CA, Harris PA, Kelly FJ, Schroter RC.Vitamin C (ascorbic acid) is a non-enzymatic antioxidant important in protecting the lung against oxidative damage and is decreased in lung lining fluid of horses with airway inflammation. To examine possible therapeutic regimens in a species with ascorbate-synthesising capacity, we studied the effects of oral supplementation of two forms of ascorbic acid, (each equivalent to 20 mg ascorbic acid per kg body weight) on the pulmonary and systemic antioxidant status of six healthy ponies in a 3 x 3 Latin square design. Two weeks supplementation with ascorbyl palmitate significantly increased mean...
