The physiology of horses encompasses the study of the biological functions and processes that occur within the equine body. This includes the examination of various systems such as the cardiovascular, respiratory, musculoskeletal, digestive, and nervous systems. Understanding equine physiology is essential for comprehending how horses adapt to different environmental conditions, perform physical activities, and respond to health challenges. Research in this field often focuses on the mechanisms of energy metabolism, thermoregulation, and muscle function during exercise, as well as the physiological responses to stress and disease. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine physiology, providing insights into the biological processes that support the health and performance of horses.
Rigoleto Júnior WL, Dias de Camargo Neto W, de Paula Nogueira G, Ferrari TA, Bertan Membrive CM, Giometti IC, Castilho C.The objective of this study was to quantify serum progesterone levels, uterine features, and pregnancy rates in acyclic, embryo recipient mares using a bovine progesterone-releasing intravaginal device in a commercial embryo transfer (ET) program. The study included 73 recipient mares of unknown breed, aged 3-10 years, weighing 350-500 kg, and kept under an intensive management system on Tifton 85 (Cynodon spp.) pastures with water and mineral salt ad libitum. The horses were divided into two groups: a group with a progesterone-releasing intravaginal device (1 g progesterone, G-IVP4, n = 24...
Ask K, Rhodin M, Tamminen LM, Hernlund E, Haubro Andersen P.Equine orthopedic pain scales are targeted towards horses with moderate to severe orthopedic pain. Improved assessment of pain behavior and pain-related facial expressions at rest may refine orthopedic pain detection for mild lameness grades. Therefore, this study explored pain-related behaviors and facial expressions and sought to identify frequently occurring combinations. Orthopedic pain was induced by intra-articular LPS in eight horses, and objective movement asymmetry analyses were performed before and after induction together with pain assessments at rest. Three observers independently ...
Egenvall A, Engström H, Byström A.Biomechanical studies of walk, especially walk on the circle, are scarce, while circles or curved tracks are frequently used during equestrian activities. To study horse-rider-circle interactions on the circle, the first steps would be to investigate how the unridden, freely walking horse is influenced by circular movement, and then add a rider. The aim was to study horse vertical trunk movements, and sagittal cannon angles (protraction-retraction) during walk in straight-line and on the circle without rider, and on the circle with a rider using minimal influence. Methods: Ten horses were ridd...
Lotz J, Içli S, Liu D, Caliskan S, Sieme H, Wolkers WF, Oldenhof H.Rational design of cryopreservation strategies for oocytes and ovarian cortex tissue requires insights in the rate at which cryoprotective agents (CPA) permeate and concomitant water transport takes place. The aim of the current study was to investigate possible differences in permeation kinetics of different CPAs (i.e., glycerol/GLY, ethylene glycol/EG, dimethyl sulfoxide/DMSO, and propylene glycol/PG), in equine oocytes as well as ovarian tissue. Membrane permeability of oocytes to water (Lp) and to CPAs (Ps) was inferred from video microscopic imaging of oocyte volume responses during perfu...
Jaramillo C, Arias MP, Mosqueda D, Darby S, Renaud D, Gómez DE.This study aimed at describing selected hematological, biochemical, and acid-base variables of adult horses living at sea level and comparing them to those living at 5 different altitudes. One hundred and thirty-eight healthy Paso Fino horses > 2 years old were enrolled. Altitudes included the following: altitude A (0 to 50 m above sea level, masl; n = 23), B (1000 to 1050 masl; n = 25), C (1450 masl; n = 30), D (1950 to 2050 masl; n = 30), and E (2950 to 3100 masl; n = 30). A portable blood gas analyzer was used to determine selected biochemical and acid-base variab...
Lee HY, Kim JY, Kim KH, Jeong S, Cho Y, Kim N.Horses have been studied for exercise function rather than food production, unlike most livestock. Therefore, the role and characteristics of tissue landscapes are critically understudied, except for certain muscles used in exercise-related studies. In the present study, we compared RNA-Seq data from 18 Jeju horse skeletal muscles to identify differentially expressed genes (DEGs) between tissues that have similar functions and to characterize these differences. We identified DEGs between different muscles using pairwise differential expression (DE) analyses of tissue transcriptome expression d...
Papas M, Catalán J, Recuero S, Morrell JM, Yeste M, Miró J.This study sought to determine whether single layer centrifugation (SLC) of fresh donkey semen with Equicoll has any impact on sperm quality parameters and on the modulation of endometrial reaction following semen deposition using an in vitro model. Seventeen ejaculates from five jackasses were obtained using an artificial vagina and diluted in a skim-milk extender. Samples were either selected through SLC (Equicoll) or non-treated (control). Two experiments were performed. The first one consisted of incubating selected or non-selected spermatozoa at 38 °C for 180 min. Integrity and lipid dis...
Autry JM, Karim CB, Perumbakkam S, Finno CJ, McKenzie EC, Thomas DD, Valberg SJ.Ca regulation in equine muscle is important for horse performance, yet little is known about this species-specific regulation. We reported recently that horse encode unique gene and protein sequences for the sarcoplasmic reticulum (SR) Ca-transporting ATPase (SERCA) and the regulatory subunit sarcolipin (SLN). Here we quantified gene transcription and protein expression of SERCA and its inhibitory peptides in horse gluteus, as compared to commonly-studied rabbit skeletal muscle. RNA sequencing and protein immunoblotting determined that horse gluteus expresses the gene (SERCA1) as the predomin...
Pourmohammad R, Mohri M, Seifi HA, Sardari K.Limited information existed on performance tests in Iranian Arab horses. Objective: The objective of this study is to investigate time related changes of cardiac troponin I (cTnI), atrial natriuretic peptide (ANP) and oxidative/antioxidant biomarkers in the serum of Arabian horses before and after regular training. Methods: Blood samples were collected from jugular vein of 25 Arabian horses before exercise; 5 h and 18 h after exercise and used to measure the cTnI, ANP, malondialdehyde (MDA), ferric reducing antioxidant power (FRAP), glutathione peroxidase (GPX), and superoxide dismutase (SOD) ...
DNA repairNovember 12, 2020
Volume 97 103022 doi: 10.1016/j.dnarep.2020.103022
Chen L, Bellone RR, Wang Y, Singer-Berk M, Sugasawa K, Ford JM, Artandi SE.Squamous cell carcinoma (SCC) occurs frequently in the human Xeroderma Pigmentosum (XP) syndrome and is characterized by deficient UV-damage repair. SCC is the most common equine ocular cancer and the only associated genetic risk factor is a UV-damage repair protein. Specifically, a missense mutation in horse DDB2 (T338M) was strongly associated with both limbal SCC and third eyelid SCC in three breeds of horses (Halflinger, Belgian, and Rocky Mountain Horses) and was hypothesized to impair binding to UV-damaged DNA. Here, we investigate DDB2-T338M mutant's capacity to recognize UV lesions in ...
Boakari YL, El-Sheikh Ali H, Schnobrich M, Lofrumento K, Scoggin C, Bradecamp E, Scoggin K, Esteller-Vico A, Claes A, Lawrence L, Ball B.High blood urea nitrogen (BUN) concentration is linked to low fertility in cows and ewes; however, this relationship has not been reported in mares. The study characterized the relationship between BUN and follicular fluid urea nitrogen (FUN) during follicle growth (Experiment 1) and the impact of BUN from embryo donors on the pregnancy outcome of recipient mares (Experiment 2). In experiment one, follicular fluid and blood samples were collected from mares during diestrus with growing follicles and during estrus with pre-ovulatory follicles (n = 16 and 10 mares, respectively). In experiment...
Acri G, Testagrossa B, Giudice E, Arfuso F, Piccione G, Giannetto C.Raman spectroscopy is a rapid qualitative and quantitative technique that allows the simultaneous determination of several components, both biomolecules both chemical compounds, in the biological fluids to assess the metabolic status. In this study, the serum composition was evaluated in regularly trained athletic horses using Raman spectroscopy to identify biomarkers of sports performance. Five clinically healthy and regularly trained Italian Saddle horses were subjected to a standardized obstacle course (350 m/minute; eleven 1.25 high jumps) preceded by a warm-up. On the collected sera, at ...
Tong L, Stewart M, Johnson I, Appleyard R, Wilson B, James O, Johnson C, McGreevy P.The current project aims to build on knowledge of the nociceptive capability of equine skin to detect superficial acute pain, particularly in comparison to human skin. Post-mortem samples of gluteal skin were taken from men ( = 5) and women ( = 5), thoroughbreds and thoroughbred types (mares, = 11; geldings, = 9). Only sections that contained epidermis and dermis through to the hypodermis were analysed. Epidermal depth, dermal depth and epidermal nerve counts were conducted by a veterinary pathologist. The results revealed no significant difference between the epidermal nerve counts of human...
Ignácio FS, Montechiesi DF, Bergfelt DR, Orlandi CMB, Carvalho LR, Puoli Filho NJ, Meira C.The present study was designed to evaluate luteinization rates subsequent to aspiration of dominant follicles (≥25 mm) in the absence of a functional CL (progesterone <1 ng/mL) and characterize the temporal changes in plasma concentrations of progesterone following aspiration-induced luteinization during the estrous cycle in mares. A total of 29 estrous cycles involving 15 mares in a cross-over design were randomly assigned to five groups: 1) ASP-F≥25 mm (n = 6; follicle aspiration 25-29 mm), 2) ASP-F≥30 mm (n = 6; follicle aspiration 30-34 mm), 3) ASP-F≥35 mm (n = 6; foll...
Janczarek I, Stachurska A, Kędzierski W, Wiśniewska A, Ryżak M, Kozioł A.Predatory attacks on horses can become a problem in some parts of the world, particularly when considering the recovering gray wolf populations. The issue studied was whether horses transformed by humans and placed in stable-pasture environments had retained their natural abilities to respond to predation risk. The objective of the study was to determine the changes in cardiac activity, cortisol concentrations, and behavior of horses in response to the vocalizations of two predators: the gray wolf (Canis lupus), which the horses of the breed studied had coevolved with but not been exposed to r...
Reef VB, Davidson EJ, Slack J, Stefanovski D.Cardiac arrhythmias are common in horses during exercise, especially immediately post-exercise. The objectives of this study were to: (1) describe the frequency and type of cardiac arrhythmias detected in horses during incremental high-speed treadmill exercise testing (ITET); (2) determine if arterial blood gas (ABG) changes at peak and immediately post-exercise were associated with arrhythmias; and (3) determine whether upper or lower airway disease was associated with exercising cardiac arrhythmias. Horses (n = 368) presenting for an ITET underwent resting and exercising upper airway endosco...
Witkowska-Piłaszewicz O, Maśko M, Domino M, Winnicka A.In horse racing the most acceptable way to objectively evaluate adaptation to increased exertion is to measure lactate blood concentration. However, this may be stressful for the horse, therefore, a simple, noninvasive procedure to monitor race progress is desirable. Forty Thoroughbreds attended race training, with blood samples collected at rest, immediately after, and 30 min after exercise. The lactate concentration was determined 60 s after blood collection using an Accusport. Thermal imaging of the neck and trunk areas was performed following international veterinary standards from a dista...
Rosa B.Xenobiotic transport proteins play an important role in determining drug disposition and pharmacokinetics. Our understanding of the role of these important proteins in humans and pre-clinical animal species has increased substantially over the past few decades, and has had an important impact on human medicine; however, veterinary medicine has not benefitted from the same quantity of research into drug transporters in species of veterinary interest. Differences in transporter expression cause difficulties in extrapolation of drug pharmacokinetic parameters between species, and lack of knowledg...
Bailey SR, Forbes G, Selvadurai N, McLarney K, Jones S, Steel CM.The administration of alkalinising agents including bicarbonate is of concern to racing authorities because resultant alkalosis may enhance performance and interfere with the detection of drugs in post-race urine. A threshold for total carbon dioxide (TCO ) of 36.0 mmol/L in plasma (with action limit of 37.0 mmol/L) has been set. Serial dosing of sodium bicarbonate has gained popularity in human athletes but has not been studied in horses previously. Sodium bicarbonate (200 g per horse) and 60 g of an electrolyte-vitamin complex was administered in 2-L water via nasogastric intubation to five ...
Genton M, Robert C, Jerbi H, Huet H, Cordonnier N, Vitte-Rossignol A, Perkins JD, Rossignol F.To describe the innervation of the thyrohyoideus (TH) muscle and to confirm our findings with stimulation of first cervical (C1) nerve branches. Methods: Ex vivo phase 1 and clinical phase 2. Methods: Fourteen head and neck specimens and 17 client-owned horses. Methods: In phase 1, the cranial nerve (CN) XII and the C1 nerve were dissected with their branches in 20 dissections were performed on 14 specimens (6 left and right side and 8 only left or right) Anatomy was noted. Samples of nerve bifurcations were collected for histological confirmation of anatomical findings. First cervical nerve b...
McCrae P, Guigand C, Jones KB, Thueson ES, Troudt TA, Warlick LM, Sides RH, Jones JH, Bayly WM, Léguillette R.High pulmonary blood pressure contributes to exercise-induced pulmonary hemorrhage. The objective of this study was to use bioimpedance spectroscopy to assess body fluid compartment volumes under 3 conditions in 6 racehorses: i) Pre- and post-supramaximal treadmill exercise (control); ii) Exercise 4 hours after furosemide (0.5 mg/kg body weight, IV); iii) Exercise, removal of ~14 L of blood and subsequent reinfusion of the blood. Statistical analysis used linear mixed effects models. Body compartment volumes did not change during the control runs. Total body water (TBW) ( = 0.007, = 0.007), e...
Thorringer NW, Weisberg MR, Jensen RB.The competition for customers increases the search for new grain processing methods for equine feed, but the effect on starch digestibility and metabolic responses varies. Therefore, to evaluate the effect of the processing methods, toasting and micronizing, on starch digestion and the effect on metabolic responses, the mobile bag technique (MBT) and plasma glucose and insulin concentrations in the blood were used to estimate nutrient disappearance and metabolic responses pre-cecally. Further, cecal pH, ammonium nitrogen (N), and short-chain fatty acid (SCFA) concentrations were used to estima...
Packard GC.I re-examined published data for ontogenetic change in relative mass of the brain in six species of mammal (i.e., sheep, pig, cow, horse, rat, cat) to illustrate an insidious problem with conventional analyses of brain-body allometry. Graphical displays of logarithmic transformations of the original data for each species give the appearance of two discrete mathematical distributions, but untransformed observations nonetheless conform to a single distribution that is well described by a single, nonlinear equation. The concept of biphasic, allometric growth by the brain consequently is an artifa...
Anderson SL, Duke-Novakovski T, Robinson AR, Townsend HGG, Singh B.The objective of this study was to determine the effect of pulmonary intravascular macrophage depletion on systemic inflammation and ex vivo neutrophil apoptosis using an experimental model of intestinal ischemia and reperfusion injury in horses. Neutrophils were isolated before and after surgery from horses that were randomized to three treatment groups, namely, sham celiotomy (CEL, = 4), intestinal ischemia and reperfusion (IR, = 6), and intestinal ischemia and reperfusion with gadolinium chloride treatment to deplete pulmonary intravascular macrophages (PIMs, IRGC, = 6). Neutrophil apopt...
Scavone D, Sgorbini M, Borges AS, Oliveira-Filho JP, Vitale V, Paltrinieri S.Paraoxonase-1 (PON-1) is an antioxidant enzyme, whose activity decreases during the acute phase response in many species. Little is known about PON-1 and its role as a negative acute phase protein during septic inflammation in horses, but promising findings about its utility in diagnosing SIRS and predicting the outcome in diseased horses, were recently highlighted. The objective of the study was to investigate the behaviour of PON-1 in horses after experimentally induced endotoxemia. To this aim, PON-1 activity was measured on 66 plasma samples collected from six clinically healthy mares, pre...
Gugliandolo E, Crupi R, Biondi V, Licata P, Cuzzocrea S, Passantino A.Although inflammation is an important physiological response, it plays a prominent role in several diseases across the mammalian species. In horses, in particular, inflammation secondary to bacterial infection or translocation is one of the most frequent causes of morbidity and mortality. Research in new molecules with anti-inflammatory and immunomodulatory proprieties and safe use profile is constantly an active field; natural compounds are an important source of molecules with peculiar properties such as antioxidants, anti-inflammatory and immune modulating. Silibinin, a natural polyphenolic...
Ebert M, Moore-Colyer MJS.The aim of this study was to estimate the energy requirements of Thoroughbred racehorses in active training for flat racing. Twenty-two Thoroughbred racehorses in England were measured over periods from 6 to 15 wk, which included periods of active race training and temporarily reduced training. Energy intake was determined by measuring daily feed consumption. Energy output was measured using heart rate monitors during 730 training sessions, relating heart rate (HR) to oxygen consumption (VO2) and converting VO2 to energy. Field maintenance requirements were calculated by deducting the marginal...
Gacem S, Bompart D, Valverde A, Catalán J, Miró J, Soler C.This study was conducted to determine optimum image capture frame rates (FRO) when there was evaluation of different types of counting chambers used for CASA-Mot determinations of stallion sperm motility. Sperm VCL was determined at frame rates of 25-250 f/s in: 1) Spermtrack® (Spk) 10 and 20 chambers (drop displacement-type chambers 10 and 20 μm-deep respectively; and 2) ISAS®D4C10, ISAS®D4C20 (10 and 20 μm-deep respectively) and ISAS®D4C20 L (20 μm-deep) capillary loaded chambers. Values for different sperm kinematic variables were determined using each chamber at 250 f/s, whi...
Williams SH, Vinyard CJ, Wall CE, Hylander WL.We investigated patterns of jaw-muscle coordination during rhythmic mastication in three species of ungulates displaying the marked transverse jaw movements typical of many large mammalian herbivores. In order to quantify consistent motor patterns during chewing, electromyograms were recorded from the superficial masseter, deep masseter, posterior temporalis and medial pterygoid muscles of goats, alpacas and horses. Timing differences between muscle pairs were evaluated in the context of an evolutionary model of jaw-muscle function. In this model, the closing and food reduction phases of masti...
Oinas J, Ronkainen AP, Rieppo L, Finnilä MAJ, Iivarinen JT, van Weeren PR, Helminen HJ, Brama PAJ, Korhonen RK, Saarakkala S.Articular cartilage undergoes structural and biochemical changes during maturation, but the knowledge on how these changes relate to articular cartilage function at different stages of maturation is lacking. Equine articular cartilage samples of four different maturation levels (newborn, 5-month-old, 11-month-old and adult) were collected (N = 25). Biomechanical tensile testing, Fourier transform infrared microspectroscopy (FTIR-MS) and polarized light microscopy were used to study the tensile, biochemical and structural properties of articular cartilage, respectively. The tensile modulus ...
Antczak DF, de Mestre AM, Wilsher S, Allen WR.A remarkable feature of equine pregnancy is the development of the invasive trophoblast of the chorionic girdle and its formation of the gonadotrophin-secreting endometrial cup cells in early gestation. The details of this process have been revealed only slowly over the past century, since the first description of the endometrial cups in 1912. This centennial presents an opportunity to review the characteristics of the cells and molecules involved in this early, critical phase of placentation in the mare. The invasiveness of the chorionic girdle trophoblast appears to represent an atavistic at...
Bucci D, Isani G, Spinaci M, Tamanini C, Mari G, Zambelli D, Galeati G.Spermatozoa, as other eukaryotic cells, need hexoses to produce energy to maintain membrane homeostasis, to move along the female genital tract and to carry the male genome to the female gamete. GLUTs are a family of proteins that permit and improve the passive transport of hexoses inside cells. This study was aimed at investigating the presence and localization of GLUTs 1, 2, 3 and 5 in boar, stallion and dog spermatozoa by both immunofluorescence and western blotting. GLUTs exhibited a peculiar distribution along the sperm cell depending on the isoforms considered, the hexose they transport ...
Christensen JW, Zharkikh TL, Antoine A, Malmkvist J.During riding, horses are frequently exposed to pressure from the rider, e.g. through the bit and reins, but few studies have investigated at which point rein tension becomes uncomfortable for the horse. Objective: To investigate how much rein tension young inexperienced horses are willing to accept in order to obtain a food reward; whether the tension acceptance changes during 3 consecutive test days; and whether rein tension correlates with the expression of conflict behaviour and heart rate. Objective: Pressure-naïve horses will apply only little rein tension in the first voluntary trial, ...
Evans JH, Barbenel JC.Tendon normally fulfills its primary role as a flexible force transmitting element very effectively and yet failure of this passive tissue leads to great disability. As a connective tissue its structure is relatively simple and the peculiar helical arrangement of collagen fibres confers highly non-linear as well as time-dependent mechanical properties. Functional significance cannot be attributed to any facet of mechanical response until the physiological pattern of loading is established. In particular the rate of deformation and the minimum force experienced by tendon in normal locomotion ha...
Hodson E, Clayton HM, Lanovaz JL.Video (60 Hz) and force (2000 Hz) data were collected from 5 sound horses during walking. Forelimb data were analysed for 8 strides (4 left, 4 right) per horse to determine sagittal plane kinematics and ground reaction forces (GRFs). The results suggested that brachial rotation was responsible for protraction and retraction of the limb as a whole, while rotations of the scapula and antebrachium elevated the distal limb during breakover and early swing then lowered it in preparation for ground contact. The coffin joint was flexed maximally at the time of peak longitudinal braking force, which o...
Waller AP, Geor RJ, Spriet LL, Heigenhauser GJ, Lindinger MI.Oral acetate supplementation enhances glycogen synthesis in some mammals. However, while acetate is a significant energy source for skeletal muscle at rest in horses, its effects on glycogen resynthesis are unknown. We hypothesized that administration of an oral sodium acetate-acetic acid solution with a typical grain and hay meal after glycogen-depleting exercise would result in a rapid appearance of acetate in blood with rapid uptake by skeletal muscle. It was further hypothesized that acetate taken up by muscle would be converted to acetyl CoA (and acetylcarnitine), which would be metaboliz...
Stull CL.Nine trailer loads of horses (n = 306) transported to slaughter facilities with distances ranging 596 to 2,496 km were studied to characterize the type of horses used in commercial markets and the physiological responses and number of injuries due to transportation under summer environmental conditions. Slaughter horse candidates were middle-aged (11.4+/-.4 yr), possessed moderately fleshy body condition, weighed 432+/-3.3 kg, and were of Quarter Horse or Thoroughbred breeding. The mean weight loss during commercial transport was 4%. The percentage of injured horses was greater (P < .05) fo...
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...
Billinghurst RC, Brama PA, van Weeren PR, Knowlton MS, McIlwraith CW.To identify metabolic biomarkers that can be evaluated in serum for monitoring the effects of exercise on skeletal development in mammals. Methods: Sera of foals from three groups (box-stall rest, pasture and training) were serially collected over the first 5 months of life and assayed for eight biomarkers of cartilage and bone metabolism. Sub-populations from each group were sampled for an additional 6 months of identical exercise. Results: When expressed as a percentage of baseline values, lower serum levels of the carboxy-terminal propeptides of type II collagen (CPII), and higher serum lev...
Bailey SR, Menzies-Gow NJ, Harris PA, Habershon-Butcher JL, Crawford C, Berhane Y, Boston RC, Elliott J.To determine whether pasture, and specifically the addition of fructan carbohydrate to the diet, induces exaggerated changes in serum insulin concentration in laminitispredisposed (LP) ponies, compared with ponies with no history of the condition, and also to determine insulin responses to the dexamethasone suppression test. Methods: Prospective study. Methods: 10 LP and 11 control adult nonobese mixed-breed ponies. Methods: Insulin-modified IV glucose tolerance tests were performed (5 ponies/group). In diet studies, ponies were kept on pasture and then changed to a hay diet (10 ponies/group)....
Jung H, Roser JF, Yoon M.Spermatogonial stem cells (SSCs) continuously undergo self-renewal and differentiation to sustain spermatogenesis throughout adulthood in males. In stallions, SSCs may be used for the production of progeny from geldings after cryopreservation and therapy for infertile and subfertile stallions. Undifferentiated cell transcription factor 1 (UTF1) is a putative marker for undifferentiated spermatogonia in humans and rats. The main purposes of this study are to determine the following: 1) changes in the expression pattern of UTF1 at various reproductive stages of stallions, 2) subpopulations of sp...
Ollivier FJ, Brooks DE, Kallberg ME, Komaromy AM, Lassaline ME, Andrew SE, Gelatt KN, Stevens GR, Blalock TD, van Setten GB, Schultz GS.To examine in vitro effects of various antiproteolytic compounds on activity of matrix metalloproteinase (MMP)-2 and -9 in the tear film of horses with active corneal ulcers. Methods: Samples of tear film obtained from the eyes of 34 horses with active ulcerative keratitis. Methods: Horses were sedated, and tear samples were collected from the lower fornix of 34 ulcerated eyes by use of capillary tubes. The protease inhibitors 0.2% EDTA, 0.1% doxycycline, 10% N-acetylcysteine (NAC), 0.1% solution of a modified dipeptide that contains hydroxamic acid (ie, ilomostat), 0.1% alpha1-proteinase inhi...
Regis WC, Fattori J, Santoro MM, Jamin M, Ramos CH.The work in the literature on apomyoglobin is almost equally divided between horse and sperm whale myoglobins. The two proteins share high homology, show similar folding behavior, and it is often assumed that all folding phenomena found with one protein will also be found with the other. We report data at equilibrium showing that horse myoglobin was 2.1 kcal/mol less stable than sperm whale myoglobin at pH 5.0, and aggregated at high concentrations as measured by gel filtration and analytical ultracentrifugation experiments. The higher stability of sperm whale myoglobin was identified for both...
St George L, Hobbs SJ, Richards J, Sinclair J, Holt D, Roy SH.High-pass filtering (HPF) is a fundamental signal processing method for the attenuation of low-frequency noise contamination, namely baseline noise and movement artefact noise, in human surface electromyography (sEMG) research. Despite this, HPF is largely overlooked in equine sEMG research, with many studies not applying, or failing to describe, the application of HPF. An optimal HPF cut-off frequency maximally attenuates noise while minimally affecting sEMG signal power, but this has not been investigated for equine sEMG signals. The aim of this study was to determine the optimal cut-off fre...
Brama PA, van den Boom R, DeGroott J, Kiers GH, van Weeren PR.Matrix metalloproteinases (MMPs) are considered candidate biomarkers for both physiological and pathological tissue remodelling because of their key role in articular cartilage homeostasis. As disruption of the collagenous architecture is thought to be pivotal in chronic degenerative diseases such as osteoarthritis (OA), the collagenases form an interesting subset of the MMPs. The significance of any biomarker in synovial fluid (SF) can be assessed properly only when fluctuations in patterns induced by physiological processes such as development and growth, and by external influences and inter...
McDowell KJ, Sharp DC, Grubaugh W, Thatcher WW, Wilcox CJ.Cycling pony mares were bred and used to test the effect of restricted conceptus mobility on luteal maintenance (i.e. maternal recognition of pregnancy). In Experiment 1, uterine horns were ligated to restrict conceptus mobility to one uterine horn, Group 1; one horn plus the uterine body, Group 2; or one horn, the body and approximately 80% of the second horn, Group 3. Pregnancies were monitored with real-time ultrasonography. Four of five mares in Group 1 and two of four mares in Group 2 returned to estrus (Day 16.0 +/- 1.9 and 14.5 +/- 0.7, respectively) and subsequently lost the embryonic ...
Crook TC, Wilson A, Hodson-Tole E.Locomotion requires successful negotiation of different terrains, but we currently know little of how the musculoskeletal system adapts to cope with positive and negative slopes. Objective: To compare the effects of treadmill speed and gradient on equine hindlimb muscle mean electromyographic (EMG) intensity. Methods: Surface EMG recorded the activity of gluteus medius (GM), biceps femoris (BF), vastus lateralis (VL), gastrocnemius lateralis (GL) and extensor digitorum longus (EDL) in 6 horses at walk (1.4-1.6 m/s) and trot (2.6-3 m/s) on 3 different treadmill gradients (0, 10% and -10%). Sign...
Walther S, Rusitzka TV, Diesterbeck US, Czerny CP.Our understanding of how equine immunoglobulin genes are organized has increased significantly in recent years. For equine heavy chains, 52 IGHV, 40 IGHD, 8 IGHJ and 11 IGHC are present. Seven of these IGHCs are gamma chain genes. Sequence diversity is increasing between fetal, neonatal, foal and adult age. The kappa light chain contains 60 IGKV, 5 IGKJ and 1 IGKC, whereas there are 144 IGLV, 7 IGLJ, and 7 IGLC for the lambda light chain, which is expressed predominantly in horses. Significant transcriptional differences for IGLV and IGLC are identified in different breeds. Allotypic and allel...
Bonelli F, Meucci V, Divers TJ, Jose-Cunilleras E, Corazza M, Tognetti R, Guidi G, Intorre L, Sgorbini M.The diseases most frequent associated with SIRS in adult horses are those involving the gastrointestinal tract. An early diagnosis should be the goal in the management of horses with SIRS. Objective: The objective of this study was to evaluate the plasma procalcitonin (PCT) concentration in healthy and SIRS horses to assess differences between the two groups. Methods: Seventy-eight horses (30 healthy and 48 SIRS). Methods: Prospective in vivo multicentric study. Horses were classified as SIRS if at least 2 of the following criteria were met: abnormal leukocyte count or distribution, hypertherm...
Scaravaggi I, Borel N, Romer R, Imboden I, Ulbrich SE, Zeng S, Bollwein H, Bauersachs S.Previous endometrial gene expression studies during the time of conceptus migration did not provide final conclusions on the mechanisms of maternal recognition of pregnancy (MRP) in the mare. This called for a cell type-specific endometrial gene expression analysis in response to embryo signals to improve the understanding of gene expression regulation in the context of MRP. Laser capture microdissection was used to collect luminal epithelium (LE), glandular epithelium and stroma from endometrial biopsies from Day 12 of pregnancy and Day 12 of the oestrous cycle. RNA sequencing (RNA-Seq) showe...
Park SB, Seo MS, Kang JG, Chae JS, Kang KS.Amniotic fluid (AF) is a well-known source of stem cells. However, there have been no reports regarding equine AF stem cells. We have isolated equine AF-derived multipotent stem cells (MSC) (eAF-MSC) and show that these cells exhibit self-renewal ability and multilineage differentiation. Methods: AF was obtained from thoroughbred mares and mononuclear cells (MNC) were isolated by Ficoll-Paque density gradient. We measured the cumulative population doubling level (CPDL) and characterized the immunophenotype by flow cytometry. To investigate differentiation ability, a trilineage differentiation ...
Schwartz D, Pusterla N, Jacobsen S, Christopher MM.Serum amyloid A (SAA) is a major acute phase protein in horses. A new point-of-care (POC) test for SAA (Stablelab) is available, but studies evaluating its analytical accuracy are lacking. Objective: To evaluate the analytical performance of the SAA POC test by 1) determining linearity and precision, 2) comparing results in whole blood with those in serum or plasma, and 3) comparing POC results with those obtained using a previously validated turbidimetric immunoassay (TIA). Methods: Assay validation. Methods: Analytical validation of the POC test was done in accordance with American Society o...
Ortega Ferrusola C, González Fernández L, Macías García B, Salazar-Sandoval C, Morillo Rodríguez A, Rodríguez Martinez H, Tapia JA, Peña FJ.The ability of stallion spermatozoa to produce nitric oxide (NO) before (fresh) and after freezing and thawing (FT) was evaluated by means of flow cytometry after loading the sperm suspension with the probe, 4,5-diaminofluorescenin diacetate. The presence of NO synthase (NOS) was investigated by Western blotting using anti-NOS1, anti-NOS3, or anti-universal NOS antibodies (Abs). While NO was detected both in fresh and FT sperm suspensions, its production increased after cryopreservation only when egg yolk was removed from the extender. Anti-NOS1 Ab intensively labeled a single band with an app...
Allen WR, Skidmore JA, Stewart F, Antczak DF.Measurement of the concentrations of equine chorionic gonadotrophin (eCG) in the serum of pregnant mares and Jenny donkeys carrying normal intraspecies and hybrid interspecies pregnancies suggested that the production of this hormone may be influenced by parental gene imprinting. Specifically, a differential expression of maternal and paternal genes may control the size and secretory activity of the structures that secrete eCG, the fetal endometrial cups. However, bisection of an interspecies mule embryo followed by transfer of the resulting demi-embryos and other intact mule embryos to horse ...
Chiocchetti R, Rinnovati R, Tagliavia C, Stanzani A, Galiazzo G, Giancola F, Silva M, Capodanno Y, Spadari A.Growing evidence recognises cannabinoid receptors as potential therapeutic targets for pain. Consequently, there is increasing interest in developing cannabinoid receptor agonists for treating pain. As a general rule, to better understand the actions of a drug, it would be of extreme importance to know the cellular distribution of its specific receptors. The localisation of cannabinoid receptors in the dorsal root ganglia of the horse has not yet been investigated. Objective: To localise the cellular distribution of canonical and putative cannabinoid receptors in the equine cervical dorsal roo...
Cappelli K, Capomaccio S, Viglino A, Silvestrelli M, Beccati F, Moscati L, Chiaradia E.Endurance exercise induces metabolic adaptations and has recently been reported associated with the modulation of a particular class of small noncoding RNAs, microRNAs, that act as post-transcriptional regulators of gene expression. Released into body fluids, they termed circulating miRNAs, and they have been recognized as more effective and accurate biomarkers than classical serum markers. This study examined serum profile of miRNAs through massive parallel sequencing in response to prolonged endurance exercise in samples obtained from four competitive Arabian horses before and 2 h after the ...
Pead S, Durrant E, Webb B, Larsen C, Heaton D, Johnson J, Watt GD.The binding of Cd2+, Zn2+, Cu2+, Ni2+, Co2+, Mn2+, and Mg2+ to apo, holo, reconstituted horse spleen ferritin (HoSF), and native holo HoSF with phosphate removed was measured by gel-exclusion chromatography. Three classes of strong binding interactions (Kd < 10(-7) M) with apo HoSF at pH 7.5 were found for the various M2+ studied: high stoichiometric binding (30-54 M2+/HoSF) for Cd2+, Zn2+, Cu2+, with two protons released per metal bound; intermediate binding (16 M2+/HoSF) for Ni2+ and Co2+, with one proton released per metal bound; and low levels of binding (2-12 M2+/HoSF) for Mn2+, Mg2+, and...
Horn R, Stewart AJ, Jackson KV, Dryburgh EL, Medina-Torres CE, Bertin FR.Diagnosis of pituitary pars intermedia dysfunction (PPID) is problematic because of large variations in ACTH concentrations. Objective: Compare the test characteristics of baseline and post-thyrotropin-releasing hormone (TRH) stimulation plasma ACTH concentrations in horses using diagnostic cutoff values (DCOVs) and reference intervals (RIs) and determine the clinical consequences of using each method. Methods: One hundred six mature horses: 72 control cases and 34 PPID cases. Methods: Prospective case-controlled study. Horses underwent monthly TRH stimulation tests. Diagnostic cutoff values w...
