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.
Tydén E, Tjälve H, Larsson P.Among the cytochrome P450 enzymes (CYP), families 1-3 constitute almost half of total CYPs in mammals and play a central role in metabolism of a wide range of pharmaceuticals. This study investigated gene and protein expression and cellular localisation of CYP1A, CYP2A, CYP2C, CYP2D and CYP2E in equine intestine and liver. Real-time polymerase chain reaction (RT-PCR) was used to analyse gene expression, western blot to examine protein expression and immunohistochemical analyses to investigate cellular localisation. Results: CYP1A and CYP2C were the CYPs with the highest gene expression in the ...
Valentini S, Castagnetti C, Musella V, Spinella G.Objective of this study was to describe intraocular measurements in newly born foals (1-7 days of age) and assess the association between globe measurements and gender, laterality, and body weight. B-scan ultrasonographic biometry was performed on both eyes of 22 healthy foals (44 eyes) ages 1-7 days using a 10-MHz transducer. Intraocular measurements (anterior chamber depth, central lens thickness, vitreous chamber depth, axial globe length, longitudinal globe length, lens poles distance) were carried out using the ultrasound internal calipers. The influence of gender (male or female), latera...
Yeste M, Estrada E, Rocha LG, Marín H, Rodríguez-Gil JE, Miró J.Although cryopreservation of stallion spermatozoa allows long-term preservation of spermatozoa from particular stallions and facilitates international trade, it is understood to inflict damages on sperm cells that may finally reduce their fertilizing ability. In addition, individual differences are known to exist in the sperm ability to withstand freeze-thawing protocols. To date, these differences have mainly been reported on the basis of sperm motility and membrane integrity. For this reason, the present work sought to determine differences between good (good freezability ejaculates: GFE) an...
Luna SP, Lopes C, Rosa AC, Oliveira FA, Crosignani N, Taylor PM, Pantoja JC.To validate a model for investigating the effects of analgesic drugs on mechanical, thermal and electrical stimulation testing. Objective: To investigate repeatability, sensitivity and specificity of nociceptive tests. Methods: Randomised experiment with 2 observers in 2 phases. Methods: Mechanical (M), thermal (TL) and electrical (E) stimuli were applied to the dorsal metacarpus (M-left and TL-right) and coronary band of the left thoracic limb (E) and a thoracic thermal stimulus (TT) was applied caudal to the withers in 8 horses (405 ± 43 kg). Stimuli intensities were increased until a clear...
Butcher MT, Bertram JE, Syme DA, Hermanson JW, Chase PB.The digital flexors of horses must produce high force to support the body weight during running, and a need for these muscles to generate power is likely limited during locomotion over level ground. Measurements of power output from horse muscle fibers close to physiological temperatures, and when cyclic strain is imposed, will help to better understand the in vivo performance of the muscles as power absorbers and generators. Skinned fibers from the deep (DDF) and superficial (SDF) digital flexors, and the soleus (SOL) underwent sinusoidal oscillations in length over a range of frequencies (0....
Rendle DI, Litchfield E, Gough S, Cowling A, Hughes KJ.Previous reports suggest that adrenocorticotrophic hormone (ACTH) degrades rapidly, limiting its use as a diagnostic test. Objective: This study quantified effects of processing delays on ACTH concentrations and investigated the addition of N-phenylmaleimide (maleimide), a protease inhibitor, as a means of reducing ACTH degradation. Methods: Experimental study. Methods: Venous blood was collected from 8 healthy horses and 8 horses with pituitary pars intermedia dysfunction (PPID) with a range of ACTH concentrations. Baseline ACTH concentrations were established immediately using a chemilumines...
Blanke A, Aupperle H, Seeger J, Kubick C, Schusser GF.Clinical, anatomical and histological aspects of the equine acoustic organ have been poorly investigated and illustrated in literature so far. It is understood that an intact acoustic organ and hearing function are of vital importance for the well-being of flight animals like horses. The knowledge of the acoustic organ is usually transferred analogously from other mammals to horses. The purpose of this study was to provide a detailed and complete histological description of the healthy equine auditory organ, and to determine its congruity to other mammalians. Anatomical dissections and histolo...
Reisinger N, Schaumberger S, Nagl V, Hessenberger S, Schatzmayr G.The pathogenesis of laminitis is not completely identified and the role of endotoxins (lipopolysaccharides, LPS) in this process remains unclear. Phytogenic substances, like milk thistle (MT) and silymarin, are known for their anti-inflammatory and antioxidant properties and might therefore have the potential to counteract endotoxin induced effects on the hoof lamellar tissue. The aim of our study was to investigate the influence of endotoxins on lamellar tissue integrity and to test if MT and silymarin are capable of inhibiting LPS-induced effects in an in vitro/ex vivo model. In preliminary ...
Summerfield A, Auray G, Ricklin M.Dendritic cells (DC) have a main function in innate immunity in that they sense infections and environmental antigens at the skin and mucosal surfaces and thereby critically influence decisions about immune activation or tolerance. As professional antigen-presenting cells, they are essential for induction of adaptive immune responses. Consequently, knowledge on this cell type is required to understand the immune systems of veterinary mammals, including cattle, sheep, pigs, dogs, cats, and horses. Recent ontogenic studies define bona fide DC as an independent lineage of hematopoietic cells orig...
Ortega-Ferrusola C, Gracia-Calvo LA, Ezquerra J, Pena FJ.Doppler ultrasonography is an important tool in the andrological evaluation in humans; however, this method is not so extensively used by equine andrologists. Spectral or pulse Doppler is a useful non-invasive method for the early diagnosis of subfertility problems in the male, especially those triggered by vascular disturbance. The identification of any disturbance in the blood flow of the testis is crucial for a correct diagnosis of various testicular and scrotal disorders but also to monitor the therapeutic outcome following treatment. The aim of this review is to provide an update on the c...
Dall'Olio S, Scotti E, Fontanesi L, Tassinari M.The myostatin (MSTN) gene encodes a protein known to be a negative regulator of muscle mass in mammalian species. Different polymorphisms of the horse (Equus caballus) MSTN gene have been identified, including single nucleotide polymorphisms and a short interspersed nuclear element (SINE) insertion of 227 bp within the promoter of the gene. The SINE insertion has been associated with performance traits in Thoroughbred racehorses and it was proposed as a predictor of optimum racing distance. The aims of this study were to perform in silico analysis to identify putative gains or abrogation of tr...
Butler CL, Houpt KA.The objectives of this study were to determine the prevalence of pawing behavior in a population of Standardbred racehorses and the relationship of pawing frequency to time of day. Standardbreds (n=41) were observed using instantaneous scan sampling twice daily, in the morning before training and in the afternoon after training. A majority of the horses, twenty-four (58.5%) of the 41 horses showed pawing behavior at least once (median=7, interquartile range=2-15). After training, there were a median of 4 (interquartile range 1-11) observations of pawing or 11.2% of total observations. In the m...
Hesselkilde EZ, Almind ME, Petersen J, Flethøj M, Præstegaard KF, Buhl R.Despite increased focus on cardiac arrhythmias in horses, the nature and prevalence is still poorly described. Case reports suggest that arrhythmias occurring secondary to systemic disease are seen more commonly in the clinic than arrhythmias caused by cardiac disease. The aim of this study was to investigate the prevalence of arrhythmias in colic horses referred for hospital treatment. Associations between electrolyte disturbances and arrhythmias were also investigated. Results: Heart rate was 37.4 ± 3.7 bpm in the control group, and 51.6 ± 11.8 bpm, in the colic group, which was ...
Sykes BW, Underwood C, McGowan CM, Mills PC.The objectives were to document the pharmacokinetics of intravenous, enteric-coated oral and plain oral omeprazole in fasted horses and to investigate the impact of feeding on the bioavailability of an enteric-coated omeprazole. Twelve horses received four treatments: intravenous omeprazole (0.5 mg/kg) in the fasted state (IV-Fasted), enteric-coated omeprazole (4 mg/kg) orally in the fasted state (ECO-Fasted), enteric-coated omeprazole (4 mg/kg) orally in the fed state (ECO-Fed) and plain omeprazole (4 mg/kg) orally in the fasted state (PL-Fasted). Plasma omeprazole concentrations were det...
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...
Moreira JJ, Moraes AP, Brossi PM, Machado TS, Michelacci YM, Massoco CO, Baccarin RY.This experimental controlled study was performed to evaluate the composition of autologous processed plasma (APP), and the effects of APP intra-articular injection into healthy equine metacarpophalangeal joints. The effects on joints were analysed with a short-phase protocol and a prolonged-phase protocol using saline-injected joints as controls. For the short protocol, horses received one intra-articular APP injection. Synovial fluid samples were collected prior to the injection and 3, 6, 24, 48, and 16 h after treatment. For the prolonged protocol, the joints received three weekly injections...
Whitworth DJ, Banks TA.There has been unprecedented interest in recent years in the use of stem cells as therapy for an array of diseases in companion animals. Stem cells have already been deployed therapeutically in a number of clinical settings, in particular the use of mesenchymal stem cells to treat osteoarthritis in horses and dogs. However, an assessment of the scientific literature highlights a marked disparity between the purported benefits of stem cell therapies and their proven abilities as defined by rigorously controlled scientific studies. Although preliminary data generated from clinical trials in huma...
Proudman CJ, Hunter JO, Darby AC, Escalona EE, Batty C, Turner C.The intestinal bacterial community of the horse is a key determinant of intestinal and whole body health. Understanding the bacterial community structure and function is an important foundation for studies of intestinal health and disease. Objective: To describe the faecal bacterial community and volatile organic compounds (VOCs) of the faecal metabolome of healthy Thoroughbred racehorses and to characterise responses to dietary supplementation with amylase-rich malt extract. Methods: Intervention study. Methods: Faecal samples were collected noninvasively before and 6 weeks after supplementat...
Claes A, Ball BA, Scoggin KE, Esteller-Vico A, Kalmar JJ, Conley AJ, Squires EL, Troedsson MH.Anti-Müllerian hormone (AMH) is a granulosa-cell-derived glycoprotein, which plays an important inhibitory role during folliculogenesis. Concentrations of AMH are highly correlated with antral follicle counts (AFCs) in other species, which in turn are related to follicular reserve. Relatively little is known about AMH and AFC in the mare. Objective: To determine plasma AMH concentrations and AFCs in mares of different ages, to measure the repeatability of AMH concentrations and AFCs within and across oestrous cycles and to assess the relationship between plasma AMH concentrations and AFCs wit...
Borena BM, Meyer E, Chiers K, Martens A, Demeyere K, Broeckx SY, Duchateau L, Spaas JH.Mammal skin plays a pivotal role in several life preserving processes and extensive damage may therefore be life threatening. Physiological skin regeneration is achieved through ongoing somatic stem cell differentiation within the epidermis and the hair follicle. However, in severe pathological cases, such as burn wounds, chronic wounds, and ulcers, the endogenous repair mechanisms might be insufficient. For this reason, exogenous purification and multiplication of epithelial-like stem/progenitor cells (EpSCs) might be useful in the treatment of these skin diseases. However, only few reports a...
Sleeper MM, Durando MM, Holbrook TC, Payton ME, Birks EK.To determine whether echocardiographic variables differed between successful (elite) and less successful (nonelite) Arabian endurance horses. Methods: 34 Arabian horses that competed in endurance racing. Methods: Horses were assigned to either an elite or nonelite group on the basis of results of a previous competition, and a standardized echocardiographic examination was performed on each horse within 1 to 4 weeks after that competition. Multivariable logistic regression with backward stepwise elimination was used to create a prediction model for the determination of horse status (elite or no...
Pereira GR, Lorenzo PL, Carneiro GF, Bilodeau-Goeseels S, Kastelic J, Liu IK.The objectives of this study were firstly to determine whether the stimulatory function of equine growth hormone (eGH) on equine oocyte maturation in vitro is mediated via cyclic adenosine monophosphate (cAMP); and secondly if the addition of eGH in vitro influences oocyte nuclear maturation and if this effect is removed when GH inhibitors are added to the culture. Cumulus-oocyte complexes (COCs) were recovered from follicles <25 mm in diameter and randomly allocated as follows: (i) control (no additives); and (ii) 400 ng/ml of eGH. A specific inhibitor against cyclic AMP-dependent protein ...
Springer NL, Smith E, Brooks MB, Stokol T.To develop a flow cytometric assay to quantify platelet-derived microparticles (PMPs) in equine whole blood and plasma. Methods: Citrate-anticoagulated whole blood from 30 healthy adult horses. Methods: Platelet-poor plasma (PPP) was prepared from fresh whole blood by sequential low-speed centrifugation (twice at 2,500 × g). Samples of fresh whole blood and PPP were removed and stored at 4° and 24°C for 24 hours. Platelet-derived microparticles were characterized in fresh and stored samples on the basis of the forward scatter threshold (log forward scatter < 10(1)) and labeling with anne...
Donadeu FX, Fahiminiya S, Esteves CL, Nadaf J, Miedzinska K, McNeilly AS, Waddington D, Gérard N.Several aspects of equine ovarian physiology are unique among domestic species. Moreover, follicular growth patterns are very similar between horses and humans. This study aimed to characterize, for the first time, global gene expression profiles associated with growth and preovulatory (PO) maturation of equine dominant follicles. Granulosa cells (GCs) and theca interna cells (TCs) were harvested from follicles (n = 5) at different stages of an ovulatory wave in mares corresponding to early dominance (ED; diameter ≥22 mm), late dominance (LD; ≥33 mm) and PO stage (34 h after administration...
Lygren T, Hansen S, Langberg H, Fjeldborg J, Jacobsen S, Nielsen MO, Schjerling P, Markussen B, Thomsen PD, Berg LC.Insulin-like growth factor 1 (IGF-1) has important roles in anabolic processes in the musculoskeletal system and has been reported to decrease with age in both people and horses. Objective: The objective of this study was to determine serum IGF-1 levels in the aging horse from early to late adulthood (age range 5-27 years). Methods: Healthy horses (n = 72) were used in a cross-sectional study, while 37 paired serum samples were available for a longitudinal study. Serum IGF-1 protein was determined using an ELISA kit validated for use in equine samples. Results: No association was found betw...
Knych HK, Steffey EP, Casbeer HC, Mitchell MM.Foal responses to a broader range of plasma fentanyl concentrations than currently reported are desirable to support (or not) clinical use. Objective: To describe fentanyl plasma concentrations following an escalating i.v. fentanyl dosing schedule in foals aged 5-13 days and describe selected, associated dose- and time-related behavioural and physiological responses to plasma fentanyl concentration. Methods: Experimental. Methods: Fentanyl was administered i.v. in an escalating fashion (2, 4, 8, 16 and 32 μg/kg bwt) at 10-min intervals. Blood samples were collected before and at selected time...
Braune S, Walter M, Schulze F, Lendlein A, Jung F.For in vitro studies assessing the interaction of platelets with implant materials, common and standardized protocols for the preparation of platelet rich plasma (PRP) are lacking, which may lead to non-matching results due to the diversity of applied protocols. Particularly, the aging of platelets during prolonged preparation and storage times is discussed to lead to an underestimation of the material thrombogenicity. Here, we study the influence of whole blood- and PRP-storage times on changes in platelet morphology and function. Blood from apparently healthy subjects was collected according...
Desjardin C, Vaiman A, Mata X, Legendre R, Laubier J, Kennedy SP, Laloe D, Barrey E, Jacques C, Cribiu EP, Schibler L.MicroRNAs (miRNAs) are an abundant class of small single-stranded non-coding RNA molecules ranging from 18 to 24 nucleotides. They negatively regulate gene expression at the post-transcriptional level and play key roles in many biological processes, including skeletal development and cartilage maturation. In addition, miRNAs involvement in osteoarticular diseases has been proved and some of them were identified as suitable biomarkers for pathological conditions. Equine osteochondrosis (OC) is one of the most prevalent juvenile osteoarticular disorders in horses and represents a major concern f...
Niedzwiedz A, Jaworski Z.Systemic oxidative stress in horses with recurrent airway obstruction (RAO) is poorly characterized. Objective: The goal of this study was to investigate whether equine RAO is associated with systemic disturbances in the oxidant-antioxidant equilibrium. Methods: Seven healthy horses and 7 horses with symptomatic RAO. Methods: A prospective study. Healthy and RAO-affected horses were exposed to a 48-hour challenge with moldy hay and straw to induce clinical exacerbation of RAO. Venous blood was collected and the activities of the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidas...
Nevins M, Heinemann F, Janke UW, Lombardi T, Nisand D, Rocchietta I, Santoro G, Schupbach P, Kim DM.The objective of this proof-of-principle multicenter case series was to examine the bone regenerative potential of a newly introduced equine-derived bone mineral matrix (Equimatrix) to provide human sinus augmentation for the purpose of implant placement in the posterior maxilla. There were 10 patients requiring 12 maxillary sinus augmentations enrolled in this study. Histologic results at 6 months demonstrated abundant amounts of vital new bone in intimate contact with residual graft particles. Active bridging between residual graft particles with newly regenerated bone was routinely observed...
Busse NI, Gonzalez ML, Krason ML, Johnson SE.Consumption of β-hydroxy β-methylbutyrate (HMB) alters muscle composition and metabolism leading to strength and agility improvements in human athletes. To determine if HMB affects athletic performance and muscle function in horses, Thoroughbred geldings were fed a control (CON; n = 5) or HMB (n = 6) supplement for 6 wk prior to completing a standardized exercise test (SET). Gluteus medius (GM) muscle biopsies were obtained before the SET for fiber typing. Heart rate, biceps femoris (BF) and semitendinosus (ST) surface electromyograms (EMG), and fore and hind limbs metacarpophalangeal joint ...
Battut I, Colchen S, Fieni F, Tainturier D, Bruyas JF.The purpose of this study was to evaluate the exact age when the equine embryo reaches the uterus. The time of ovulation was determined by hourly ultrasound examinations starting 32 h after an injection of crude equine pituitary gonadotrophin or human chorionic gonadotrophin, or after the first of 4 injections of buserelin. Nonsurgical uterine flushings were carried out 144 h (Day 6), 156 h (Day 6.5) or 168 h (Day 7) after ovulation. Induction of ovulation was attempted in 101 oestrous cycles and 61 of 101 mares (60.4%) ovulated 32-44 h post injection. Sixty embryo collections were performed w...
Szóstek-Mioduchowska AZ, Shiotani H, Yamamoto Y, Sadowska A, Wójtowicz A, Kozai K, Hojo T, Kimura K, Skarzynski DJ, Okuda K.Glucocorticoids (GCs) are known to play an important role in maintaining basal and stress-related homeostasis by interacting with endocrine mediators and prostaglandins (PGs). Although a growing body of evidence shows that GCs exert their regulatory action at a multitude of sites in the reproductive axis through corticosteroid receptors, little is known about the direct role of cortisol, an active form of GCs, in the equine endometrium. Thus, the study aimed to determine the effect of cortisol on PGF synthesis in the endometrial tissue and cells in vitro. In Exp.1, the immunolocalization and ...
Pashen RL, Allen WR.The effects of fetal gonadectomy on steroid production and the maintenance of pregnancy in the mare were studied. Removal of the fetal gonads resulted in an immediate fall in maternal plasma concentrations of conjugated and unconjugated oestrogens whereas progestagen levels remained unchanged. Hormone profiles in mares carrying sham-operated fetuses remained similar to those in unoperated control mares. Plasma levels of 13,14-dihydro-15-oxo-PGF-2 alpha (PGFM) were much lower, and uterine contractions weaker, during labour in mares carrying gonadectomized foals than in control mares. Pregnancy ...
Prieto D, Hernández M, Rivera L, García-Sacristán A, Simonsen U.The distribution of neuropeptide Y (NPY)-immunoreactive (IR) nerves, as well as the functional effects of NPY and the Y1- and Y2-receptor agonists, [Leu31,Pro34]NPY and NPY(13-36), respectively, have been investigated in vitro in both visceral and arterial smooth muscle of the horse intravesical ureter. NPY-IR nerve fibres were widely distributed along the entire length of the ureter, although the intravesical part was the most richly innervated region, and the only one where NPY-IR ganglion cells were found. NPY (10(-7) M) did not affect either basal tone or spontaneous rhythmic contractions ...
Hansen S, Sun L, Baptiste KE, Fjeldborg J, Horohov DW.Diseases of the lower airways represent some of the most common conditions affecting horses of all ages, but the type and severity tends to follow the horses' age. The age-related dysregulation of pro-inflammatory cytokines may, in part contribute to the development of the diseases. Therefore, we hypothesize that the expression of pro-inflammatory cytokines increases with age. Peripheral blood mononuclear cells (PBMC) and bronchoalveolar lavage (BAL) cells from clinically healthy horses of different ages were used for the investigation. The cells were stimulated and the production of IFN-γ an...
Pine L, Reeves MW.Various sugars were tested for their effect on the differential rate of synthesis of M protein during the growth of Streptococcus pyogenes strain 0055 M12T12. In a semisynthetic medium alone, a high rate of M protein synthesis occurred with glucose as a substrate; decreasing rates of synthesis occurred with sucrose and trehalose, in that order, although the rates of growth were approximately equal with all sugars. A period of derepressed synthesis of M protein occurred in the lag phase of growth and in the stationary period as the substrates were being depleted. Although glucose inhibited the ...
Rivero JL, Galisteo AM, Agüera E, Miró F.Muscle biopsies were taken from the middle gluteal muscle of 143 untrained horses (83 Andalusians [AN] and 60 Arabians [AR]) ranging from 10 days to 24 years old. The horses were separated according to breed and sex and allotted to five age groups: A, 0 to three months; B, yearlings; C, two to three years; D, five to 10 years; and E, 11 to 24 years. There was an increase in the percentage of type I fibres (about 100 per cent) as well as a decrease in the percentage of type IIB fibres (AN, 50 per cent; AR, 40 per cent) over the five age groups. The percentage of type IIA fibres rose significant...
Desideri A, Stefanini S, Polizio F, Petruzzelli R, Chiancone E.Apoferritin has been selectively labeled with a maleimide nitroxide derivative at Cys-126, located in the hydrophilic 3-fold channels. Titration of this derivative with Fe(II), which gives rise to the initial Fe(III)-apoferritin complex, produces, at low metal-to-protein ratios, a decrease of the intensity of the label EPR signal due to the occurrence of a magnetic dipolar interaction. A label-metal distance ranging between 8-12 A can be estimated from titrations performed with VO(IV), which is known to bind in the 3-fold channels, and likewise produces a decrease in the label EPR signal. The ...
Akens MK, Hurtig MB.Bovine articular cartilage is often used to study chondrocytes in vitro. It is difficult to correlate in vitro studies using bovine chondrocytes with in vivo studies using other species such as rabbits and sheep. The aim of this investigation was to study the effect of species, anatomical location and exogenous growth factors on chondrocyte proliferation in vitro. Methods: Equine (EQ), bovine (BO) and ovine (OV) articular chondrocytes from metacarpophalangeal (fetlock (F)), shoulder (S) and knee (K) joints were cultured in tissue culture flasks. Growth factors (rh-FGFb: 10 ng/ml; rh-TGFbeta: 5...
Antosiewicz J, Porschke D.Hemoglobins from normal human cells, from sickle cells, and from horse were investigated by electrooptical methods in their oxy and deoxy forms. The reduced linear dichroism measured as a function of the electric field strength demonstrates the existence of permanent dipole moments in the range of 250-400 Debye units. The reduced limiting dichroism is relatively small (< or = 0.1); it is negative for hemoglobin from sickle cells and positive for the hemoglobins from normal human cells and from horse. The dichroism decay time constants are in the range from about 55 to 90 ns. Calculations of th...
Yamaguchi T, Hirakawa R, Ochiai H.Lipid compositions of mammalian erythrocyte membranes are different among species. Therefore, the information on hemolysis from mammalian erythrocytes is useful to understand membrane properties of human erythrocytes. In this work, pressure-induced hemolysis and hypotonic one were examined using erythrocytes of human, sheep, cow, cat, dog, pig, horse, rat, and mouse. Pressure-induced hemolysis was suppressed by membrane sphingomyelin, whereas hypotonic hemolysis decreased upon increment of cell diameter. Mass spectra of erythrocyte membrane lipids demonstrated that sphingomyelin with an acyl c...
Suske A, Pöschke A, Schrock P, Kirschner S, Brockmann M, Staszyk C.There is increasing interest in diseases of infundibula of equine maxillary cheek teeth. Imperfect infundibular cementogenesis has been recognized as an aetiopathological factor for the onset of infundibular necrosis. In this article, infundibular development was examined with particular attention to infundibular blood vessels and cementogenesis. Forty-one deciduous maxillary premolars prior to eruption were investigated using routine histological and immunohistological methods to visualize blood vessels and the enamel organ. Selected specimens were scanned by micro-computed tomography to anal...
Vandeplassche GM, Wesson JA, Ginther OJ.Sexual behavior, follicular development and ovulation, and concentrations of circulating gonadotropins during the estrous cycle were studied during the summer in 7 jennies. Mean behavioral estrous length was 6.4 +/- 0.6 days (mean +/- SEM, n=19; 5.6 +/- 0.5 days preovulatory and 0.8 +/- 0.2 days post-ovulatory). Mean diestrous length was 19.3 +/- 0.6 days (n=14). Females in estrus typically showed posturing, mouth clapping, clitoral winking, urinating and tail raising. Mouth clapping began approximately one day sooner and lasted approximately one day longer than winking and tail raising, so th...
Yachida Y, Tsuchihashi K, Gasa S.A novel GM3 O-acetylated at C-4 and at C-9 of N-glycolylneuraminic acid (4,9-di-O-Ac GM3), together with a second GM3 O-acetylated at O-4 of the neuraminic acid and O-6 of D-galactose (4,6'-di-O-Ac GM3) were isolated from equine erythrocytes as a mixture in approximate 1:1 ratio. These two major species were chromatographically inseparable. Their structures, especially the positions of the acetoxy group(s), were determined by means of 1D- and 2D-1H NMR and fast atom bombardment-MS as well as by gas chromatography-MS of partially O-methylated O-trimethylsilylated monosaccharides derived from th...
Shojaee A, Parham A, Ejeian F, Nasr Esfahani MH.Equine adipose-derived mesenchymal stem cells (eq-ASCs) possess excellent regeneration potential especially for treatment of musculoskeletal disorders. Besides their common characteristics, MSCs harvested from different species reveal some species-specific and donor-dependent behaviors. Hence, the molecular analysis of MSCs may shed more light on their future clinical application of these cells. This study aimed to investigate some behavioral aspects of eq-ASCs in vitro which may influence the efficacy of stem cell therapy. For this purpose, MSCs of a donor horse were isolated, characterized a...
Sims D, Horne MM, Creighan M, Donald A.The objective of this ultrastructural investigation was to determine if populations of pericytes in equine dermal and skeletal muscle capillaries increase in a head-to-foot direction, as has been reported in human skeletal muscles. Samples of equine microvessels were obtained from the longissimus dorsi skeletal muscle 150 cm. from the ground, from the dermis above this muscle, from the extensor carpi radiali muscle at 55 cm. from the ground, from the dermis adjacent to that muscle, and from dermis 15 cm. from the ground, just above the hoof wall. Tissues were processed for transmission electro...
Baldwin AL, Chea I.This study explored whether aromatherapy increases the parasympathetic component (root mean square of successive differences [RMSSD]) of heart rate variability (HRV) in horses. Horses are highly sensitive, easily stressed, have an acute sense of smell, and have been shown to benefit from aromatherapy. The protocol, performed on eight dressage horses, followed a crossover design with an experimental treatment of humidified essential oil (lavender, Lavandula angustifolia) and a control treatment of humidified air. Heart rate variability was recorded for 7 minutes before, during, and immediately...
Mizuguchi M, Nara M, Ke Y, Kawano K, Hiraoki T, Nitta K.Interactions between Ca2+ and the Asp side chains in the Ca2+-binding site of equine lysozyme were investigated by Fourier-transform infrared (FT-IR) spectroscopy. In the spectrum of equine lysozyme, the intensities of the bands at about 1595 cm-1 and 1578 cm-1 in the region of the COO antisymmetric stretches increased upon Ca2+ binding. In the region of the COO- symmetric stretches, the loss of intensity at about 1388 cm-1 and gains of intensities at about 1423 cm-1 and 1403 cm-1 were observed due to Ca2+ binding to equine lysozyme. The spectral changes for equine lysozyme indicate that the C...
Hudson N, Mayhew I, Pearson G.Equine dysautonomia (grass sickness) is a common, frequently fatal disease of horses characterised by dysfunction of the gastrointestinal tract. Interstitial cells of Cajal are the c-Kit-immunoreactive cells responsible for the generation of pacemaker activity in gastrointestinal smooth muscle. Impairment of this pacemaker action has been implicated in several motility disorders in humans and laboratory mammals. The aim of this study was to test the hypothesis that changes in interstitial cells of Cajal may be involved in the pathophysiology of the intestinal dysfunction observed in equine gra...
Petrucci L, Maranesi M, Verini Supplizi A, Dall'Aglio C, Mandara MT, Quassinti L, Bramucci M, Miano A, Gobbetti A, Catone G, Boiti C, Zerani M.The objectives of this study were to evaluate in horse testes the expression of kisspeptin (KiSS) and GnRH1 neuropeptides and their cognate receptors, KiSS1R and GnRH1R, as well as their action on testosterone, GnRH1, prostaglandin F2α (PGF2α), and PGE2 synthesis and cyclooxygenase 1 (COX1) and COX2 activity by Leydig cells in vitro. Testes were obtained from 9 sexually mature horses by surgical castration. Immunohistochemistry, evidenced the presence of KiSS, KiSS1R, GnRH, and GnRH1R in Leydig cells, whereas germinal and Sertoli cells were positive only for GnRH1. Transcripts for both neur...
Satterlee JD, Moench SJ, Erman JE.Cytochrome-c peroxidase (ferrocytochrome-c:hydrogen-peroxide oxidoreductase, EC 1.11.1.5) forms a noncovalent 1:1 complex with horse cytochrome c in low ionic strength solution that is detectable by proton NMR spectroscopy. When the entire proton hyperfine-shifted spectrum is considered only five hyperfine resonances exhibit unambiguously detectable shifts: the heme 8-CH3 and 3-CH3 resonances, single proton resonances near 19 ppm and -4 ppm and the methionine-80 methyl group. These shifts are very similar to those observed for the covalently crosslinked complex of cytochrome-c peroxidase and h...
Terpstra AH, Sanchez-Muniz FJ, West CE, Woodward CJ.1. By means of density gradient ultracentrifugation, the density profile of the serum lipoproteins was studied in 14 species of domestic and laboratory animals: the pig, chicken, rhesus monkey, rabbit, dog, horse, sheep, cat, mouse, goat, cow, guinea-pig, trout and rat. 2. The concentration of cholesterol in whole serum and the lipoprotein fractions of these animal species was also determined. 3. There were large differences in the density profile of the serum lipoproteins among the various animals studied and the results indicate that the density limits employed for human serum lipoproteins a...
Murphy BA, Vick MM, Sessions DR, Cook RF, Fitzgerald BP.Peripheral clocks receive timing signals from the master mammalian pacemaker in the suprachiasmatic nucleus (SCN) and function to adaptively anticipate daily changes that influence local physiology. Evidence suggests that peripheral immune activation may act as a resetting signal for circadian clocks in peripheral tissues. We wished to investigate whether acute systemic inflammation could synchronize clock gene expression in equine peripheral blood, a tissue that does not normally oscillate in this species. We report that in vivo administration of lipopolysaccharide (LPS) results in significan...
Ginther OJ, Gastal EL, Gastal MO, Beg MA.The functional and temporal relationships between circulating gonadotropins and ovarian hormones in mares during Days 7-27 (ovulation = Day 0) was studied using control, follicle ablation, and ovariectomy groups (n = 6 mares/group). In the follicle-ablation group, all follicles > or = 6 mm were ablated on Day 7, and every 2 days thereafter, newly emerging follicles were also ablated. Estradiol concentrations decreased (P < 0.01) similarly in the controls and the follicle-ablation group between Days 7 and 11 and by Day 15 began to increase in the controls and continued to decrease in the ...
Catania KC.In March 1800, Alexander von Humboldt observed the extraordinary spectacle of native fisherman collecting electric eels (Electrophorus electricus) by "fishing with horses" [von Humboldt A (1807) Ann Phys 25:34-43]. The strategy was to herd horses into a pool containing electric eels, provoking the eels to attack by pressing themselves against the horses while discharging. Once the eels were exhausted, they could be safely collected. This legendary tale of South American adventures helped propel Humboldt to fame and has been recounted and illustrated in many publications, but subsequent investi...
Esteves CL, Sharma R, Dawson L, Taylor SE, Pearson G, Keen JA, McDonald K, Aurich C, Donadeu FX.Expression of several putative markers of pluripotency (OCT4, SOX2, NANOG, LIN28A, REX1, DNMT3B and TERT) was examined in a range of equine tissues, including early embryos, induced pluripotent stem cells (iPSCs), testis, adipose- and bone marrow-derived mesenchymal stromal cells (MSCs), and keratinocytes. Transcript levels of all markers were highest in embryos and iPSCs and, except for SOX2, were very low or undetectable in keratinocytes. Mean expression levels of all markers were lower in testis than in embryos or iPSCs and, except for DNMT3B, were higher in testis than in MSCs. Expression ...
Wu Y, Stoddart MJ, Wuertz-Kozak K, Grad S, Alini M, Ferguson SJ.Articular cartilage plays an essential role in joint lubrication and impact absorption. Through this, the mechanical signals are coupled to the tissue's physiological response. Healthy synovial fluid has been shown to reduce and homogenize the shear stress acting on the cartilage surfaces due to its unique shear-thinning viscosity. As cartilage tissues are sensitive to mechanical changes in articulation, it was hypothesized that replacing the traditional culture medium with a healthy non-Newtonian lubricant could enhance tissue development in a cartilage engineering model, where joint-kinemati...
Caraty A, Decourt C, Briant C, Beltramo M.Kisspeptins (Kp) are a family of neuropeptides produced mainly by two hypothalamic neuronal cell populations. They have recently emerged as a major regulator of the gonadotropin axis and their action is located upstream of the gonadotropin-releasing hormone (GnRH) cell population. In less than 10 yr a growing body of literature has demonstrated the involvement of these peptides in most, if not all, aspects of reproductive axis maturation and function. In contrast to these abundant basic research studies, few experiments have evaluated the potential application of Kp as tools to manipulate repr...
