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.
Szóstek AZ, Siemieniuch MJ, Galvão AM, Lukasik K, Zieba D, Ferreira-Dias GM, Skarzynski DJ.Cell cultures are useful for determining the responses of specific cell types to various factors under controlled conditions and for obtaining a better understanding of in vivo physiologic processes. The aims of the present study were (i) to establish methodologies for isolation, culture and cryopreservation of equine endometrial epithelial and stromal cells; and (ii) to determine the effect of passage and cryopreservation on endometrial cell physiology, based on their basal and oxytocin (OT)-stimulated prostaglandin (PG) release. Epithelial and stromal cells were obtained by enzymatic digesti...
Wattrang E, Palm AK, Wagner B.Synthetic oligodeoxyribonucleotides (ODN) may prove useful immune modulators in equine medicine. It is however important to assess the effects of each specific ODN in the species it is intended to be used in. The present study therefore aimed to evaluate some ODN for induction of cytokine production; i.e. type I interferons (IFN), IFN-γ, tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β), and proliferation of equine peripheral blood mononuclear cells (PBMC). A panel of four ODN containing unmethylated cytosine-guanosine sequences (CpG) was used: ODN 1 and ODN 8 repre...
Kulikov E, Kropinski AM, Golomidova A, Lingohr E, Govorun V, Serebryakova M, Prokhorov N, Letarova M, Manykin A, Strotskaya A, Letarov A.Lytic coliphage vB_EcoP_G7C and several other highly related isolates were obtained repeatedly from the samples of horse feces held in the same stable thus representing a component of the normal indigenous intestinal communities in this population of animals. The genome of G7C consists of 71,759 bp with terminal repeats of about 1160 bp, yielding approximately 73 kbp packed DNA size. Seventy-eight potential open reading frames, most of them unique to N4-like viruses, were identified and annotated. The overall layout of functional gene groups was close to that of the original N4 phage, with som...
Herrera-Luna CV, Budik S, Aurich C.Glucocorticoids (GCs) are important mediators of the stress response and have been implicated in the function and regulation of testicular functions in different species. In many tissues, intracellular glucocorticoid activity is controlled by either or both of the two known isoforms of 11β-hydroxysteroid dehydrogenase (11βHSD) type 1 and 2, which interconvert active and inactive GCs. Little is known about the effects of stress on fertility in the equine species. The main objective of the present study was to investigate the expression of receptors for GCs and adrenocorticotropic hormone [ACT...
Schramme M, Josson A, Linder K.The suspensory ligament is difficult to image accurately, partly because it contains ligamentous fibers, as well as noncollagenous adipose and muscle tissue in the normal horse. Our hypothesis was that magnetic resonance (MR) imaging would be more accurate than ultrasonography in identifying the size of the suspensory ligament and the presence and size of noncollagenous tissues within the ligament. Eleven horses were used for ultrasonographic and MR imaging and histologic evaluation of the rear suspensory ligament. The origin and body of the normal suspensory ligament had a heterogenous appear...
Puppione DL, Della Donna L, Bassilian S, Souda P, MacDonald MH, Whitelegge JP.As a continuation of our proteogenomic studies of equine apolipoproteins, we have obtained molecular masses for several of the apolipoproteins associated with the HDL in horse cerebrospinal fluid (CSF). Using electrospray-ionization mass spectrometry (ESI-MS), we report on values for apolipoproteins, A-I and A-II, as well as acylated apoA-I. In comparison with our previously published data on equine plasma apolipoproteins, there appears to be a higher percentage of acylated apoA-I in the CSF than in plasma. As was the case in plasma, apoA-II circulates as a homodimer. These studies also reveal...
Caston SS.Care of equine wounds in the field can be a challenging endeavor. Many times, wound care is complicated by chronicity or by prior inappropriate care in addition to the great degree of tissue trauma that occurred when the horse was wounded. Recognizing involvement of synovial structures, loss of skin, and damage to bone are critical in the initial examination of wounds and will guide future care. Education of clients is also important in that preparing them for possible outcomes during healing may help improve compliance and proper treatment of wound. Owners and trainers often perform much of t...
Macías García B, Ortega Ferrusola C, Aparicio IM, Miró-Morán A, Morillo Rodriguez A, Gallardo Bolaños JM, González Fernández L....Glycerol is, to date, the most widely used cryoprotectant to freeze stallion spermatozoa at concentrations between 2% and 5%. Cryoprotectant toxicity has been claimed to be the single most limiting factor for the success of cryopreservation. In order to evaluate the toxic effects of the concentrations of glycerol used in practice, stallion spermatozoa were incubated in Biggers Whitten and Whittingham (BWW) media supplemented with 0%, 0.5%, 1.5%, 2.5%, 3.5%, and 5% glycerol. In two additional experiments, a hyposmotic (75 mOsm/kg) and a hyperosmotic (900 mOsm/kg) control media were included. Sp...
Rose MT.The objective of this study was to determine the effect of platelet derived growth factor BB (PDGF), epidermal growth factor (EGF), transforming growth factor β1 (TGFβ1), insulin like growth factor-1 (IGF-1) and fibroblast growth factor-2 (FGF-2) on the proliferation and migration of equine oral mucosa and leg skin fibroblast cell lines, using an in vitro scratch assay. Fibroblasts from the two sites were firstly grown to confluence and then an area of cells removed (cell void area). Cell migration alone (with the addition of the mitosis inhibitor mitomycin-C to the culture media) and prolif...
Becker-Birck M, Schmidt A, Wulf M, Aurich J, von der Wense A, Möstl E, Berz R, Aurich C.Bringing the head and neck of ridden horses into a position of hyperflexion is widely used in equestrian sports. In our study, the hypothesis was tested that hyperflexion is an acute stressor for horses. Salivary cortisol concentrations, heart rate, heart rate variability (HRV) and superficial body temperature were determined in horses (n = 16) lunged on two subsequent days. The head and neck of the horse was fixed with side reins in a position allowing forward extension on day A and fixed in hyperflexion on day B. The order of treatments alternated between horses. In response to lunging, ...
Korosue K, Murase H, Sato F, Ishimaru M, Endo Y, Nambo Y.The purpose of this study was to observe the changes in body temperature before parturition using a wireless temperature monitoring device (WTMD) and to evaluate the usefulness of body temperature measurements using a digital rectal thermometer (DRT) and a microchip transponder thermometry device (MTTD) for predicting parturition in mares. The body temperatures using a WTMD at 0 hr and -1 hr were significantly different from those at the same time on Days 1-5 (P<0.01). The temperature differences between the morning of Day 0 and at -3 hr, -2 hr, -1 hr and 0 hr using the DRT and MTTD showed ...
Perkins GA, den Bakker HC, Burton AJ, Erb HN, McDonough SP, McDonough PL, Parker J, Rosenthal RL, Wiedmann M, Dowd SE, Simpson KW.Little is known about the gastric mucosal microbiota in healthy horses, and its role in gastric disease has not been critically examined. The present study used a combination of 16S rRNA bacterial tag-encoded pyrosequencing (bTEFAP) and fluorescence in situ hybridization (FISH) to characterize the composition and spatial distribution of selected gastric mucosal microbiota of healthy horses. Biopsy specimens of the squamous, glandular, antral, and any ulcerated mucosa were obtained from 6 healthy horses by gastroscopy and from 3 horses immediately postmortem. Pyrosequencing was performed on bio...
Li G, Lee P, Mori N, Yamamoto I, Arai T.Continuous high intensity training may induce alterations to enzyme activities related to glucose and lipid metabolism in horses. In our study, five Thoroughbred race horses (3 male and 2 female, avg age=5 yrs old) were compared against five riding horses (1 male, 1 female, 3 gelding, avg age=13 yrs old) in terms of energy metabolism, by examining plasma malate (MDH) and lactate (LDH) dehydrogenase activities and M/L ratio. MDH is involved in NADH and ATP generation, whereas LDH can convert NADH back into NAD(+) for ATP generation. An increase in plasma M/L ratio can reflect heightened energy ...
Stokes AM, Lavie NL, Keowen ML, Gaschen L, Gaschen FP, Barthel D, Andrews FM.This study investigated the use of a wireless ambulatory capsule (WAC; SmartPill(®) pH.p GI Monitoring System) to determine WAC-gastric emptying time (GET) in ponies. Objective: To measure WAC-GET and compare it to those findings with GET assessed by nuclear scintigraphy (S-GET). Objective: WAC-GET will be slower than S-GET, but will be significantly correlated. Methods: Seven healthy adult mixed-breed pony mares were used in this study. Feed was withheld for 12 h prior to the WAC administration. After administration, a complete-feed diet was fed to allow the WAC to pass into the stomach. Lum...
Nostell KE, Essén-Gustavsson B, Bröjer JT.The branched chain amino acid leucine is a potent stimulator of insulin secretion. Used in combination with glucose it can increase the insulin response and the post exercise re-synthesis of glycogen in man. Decreased plasma amino acid concentrations have been reported after intravenous or per oral administration of leucine in man as well as after a single per oral dose in horses. In man, a negative correlation between the insulin response and the concentrations of isoleucine, valine and methionine have been shown but results from horses are lacking. This study aims to determine the effect of ...
Kang OD, Ryu YC, Yun YM, Kang MS.The changes in physiologic parameters by swim exercise duration were examined in five female well-trained Jeju crossbred riding horses that had riding experience of more than three years without swim training experience. The horses were performed with swim exercise for 10 min (60.0 m/min) once a day for 14 days. Physiologic characteristics and haematic parameters were measured before swimming, immediately after swimming, and after a 10 min rest at first day (D0), 7 days (D7), and 14 days (D14) of training. After 14 days of swim training, heart rate (p<0.05), blood glucose (p<0.05), lacta...
Cavens VJ, Gemensky-Metzler AJ, Wilkie DA, Weisbrode SE, Lehman AM.To describe the long-term histologic and intraocular pressure (IOP) lowering effects of diode laser transscleral cyclophotocoagulation (TSCP) on the normal equine eye. Methods: Eight normal adult horses. Methods: TSCP was performed in one randomly assigned eye. Sixty spots were treated at settings of 1500 ms and 1500 mW. Two horses were randomly selected for euthanasia at 2, 4, 12, or 24 weeks post-TSCP. Both eyes were enucleated and histologically evaluated. Intraocular pressure was measured by applanation tonometry prior to TSCP, immediately post-TSCP, twice daily for 7 days post-TSCP and th...
Tydén E, Löfgren M, Pegolo S, Capolongo F, Tjälve H, Larsson P.Recently, seven CYP3A isoforms - CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, CYP3A97 and CYP129 - have been isolated from the horse genome. In this study, we have examined the hepatic and intestinal gene expression of these CYP3A isoforms using TaqMan probes. We have also studied the enzyme activity using luciferin-isopropyl acetal (LIPA) as a substrate. The results show a differential gene expression of the CYP3A isoforms in the liver and intestines in horses. In the liver, CYP3A89, CYP3A94, CYP3A96 and CYP3A97 were highly expressed, while in the intestine there were only two dominating isof...
Phillips JC, Lembcke LM, Noltenius CE, Newman SJ, Blackford JT, Grosenbaugh DA, Leard AT.To determine the tissue-restricted expression pattern of tyrosinase mRNA in canine and equine melanocytic tumors and relative tyrosinase and major histocompatibility complex (MHC) I mRNA expression in variants of melanocytic tumors. Methods: 39 canine and 8 equine tumor samples and 10 canine and 6 equine normal tissue samples. Methods: RNA was isolated from formalin-fixed, paraffin-embedded tissues. Real-time PCR assays were designed to amplify canine and equine tyrosinase, S18 ribosomal RNA, and major histocompatibility complex I transcripts. Relative expression was determined by use of S18 a...
Gallardo Bolaños JM, Miró Morán Á, Balao da Silva CM, Morillo Rodríguez A, Plaza Dávila M, Aparicio IM, Tapia JA, Ortega Ferrusola C, Peña FJ.Apoptosis has been recognized as a cause of sperm death during cryopreservation and a cause of infertility in humans, however there is no data on its role in sperm death during conservation in refrigeration; autophagy has not been described to date in mature sperm. We investigated the role of apoptosis and autophagy during cooled storage of stallion spermatozoa. Samples from seven stallions were split; half of the ejaculate was processed by single layer centrifugation, while the other half was extended unprocessed, and stored at 5°C for five days. During the time of storage, sperm motility (C...
Vigani A, Shih A, Queiroz P, Pariaut R, Gabrielli A, Thuramalla N, Bandt C.New volumetric variables of preload, such as total end-diastolic volume index (TEDVI) and active circulation volume index (ACVI) and central blood volume index (CBVI), may represent good indicators of preload and predictors of fluid responsiveness. During acute changes of intravascular volume these variables would allow a more accurate intervention. Objective: The aim of the present study was to investigate the changes in TEDVI, ACVI, CBVI in a juvenile model of hemorrhagic shock and resuscitation. Methods: Twelve anaesthetized ponies (3-8 months of age) were studied at normovolaemia (BASE), a...
Tennent-Brown BS.In hospitalized horses, hypovolemia and the resulting decrease in tissue perfusion is the most common cause of hyperlactatemia. Therefore, measurement of blood lactate concentration can be a useful tool for guiding fluid therapy. Similarly, measuring blood lactate concentration can be used to assess the need for and adequacy of transfusions in horses receiving whole blood. Inflammatory leukocytes within closed body cavities consume glucose and produce lactate. Simultaneous measurement of blood lactate concentration and lactate concentration of peritoneal, pleural, or synovial fluid has been us...
Ma G, Feineis S, Osterrieder N, Van de Walle GR.Major histocompatibility complex class I (MHC-I) molecules play an important role in host immunity to infection by presenting antigenic peptides to cytotoxic T lymphocytes (CTLs), which recognize and destroy virus-infected cells. Members of the Herpesviridae have developed multiple mechanisms to avoid CTL recognition by virtue of downregulation of MHC-I on the cell surface. We report here on an immunomodulatory protein involved in this process, pUL56, which is encoded by ORF1 of equine herpesvirus type 1 (EHV-1), an alphaherpesvirus. We show that EHV-1 pUL56 is a phosphorylated early protein w...
Iacono E, Brunori L, Pirrone A, Pagliaro PP, Ricci F, Tazzari PL, Merlo B.Mesenchymal stem cells (MSCs) have been derived from multiple sources of the horse including umbilical cord blood (UCB) and amnion. This work aimed to identify and characterize stem cells from equine amniotic fluid (AF), CB and Wharton's Jelly (WJ). Samples were obtained from 13 mares at labour. AF and CB cells were isolated by centrifugation, while WJ was prepared by incubating with an enzymatic solution for 2 h. All cell lines were cultured in DMEM/TCM199 plus fetal bovine serum. Fibroblast-like cells were observed in 7/10 (70%) AF, 6/8 (75%) CB and 8/12 (66.7%) WJ samples. Statistically ...
Tsuzuki N, Otsuka K, Seo J, Yamada K, Haneda S, Furuoka H, Tabata Y, Sasaki N.This study evaluated the therapeutic effects of a gelatin-β-TCP sponge (sponge) incorporating BMP-2 (BMP-2/sponge) on bone regeneration in equines. Six bone defects were created in third metacarpals of five thoroughbred horses, and a total of six treatments were applied in a randomized manner. The treatments were BMP-2/sponge, BMP-2/gelatin hydrogel sheet (sheet), free BMP-2, bFGF/sheet, plain sponge, and plain sheet. The defects were monitored for 16 weeks by radiography and then examined by histological analysis. Radiographic evaluation scores of bone regeneration revealed significantly gre...
Balao da Silva C, Macías-García B, Morillo Rodriguez A, Gallardo Bolaños JM, Tapia JA, Aparicio IM, Morrell JM, Rodriguez-Martínez H....The only known means of effectively separating populations of X and Y bearing sperms is the Beltsville sexing technology. The technology implies that each individual sperm is interrogated for DNA content, measuring the intensity of the fluorescence after staining the spermatozoa with Hoechst 33342. Because there are no data regarding the effect of the staining on stallion sperm, ejaculates were incubated up to 90 min in presence of 0, 4.5, 9, 22.5, 31.5, 45, 54, 67.5, 76.5 and 90 μM of Hoechst 33342, in two media, KMT or INRA-Tyrodes. After 40 and 90 min of incubation, motility (CASA) and mem...
Nam GH, Ahn K, Bae JH, Cho BW, Park KD, Lee HK, Yang YM, Kim TH, Seong HH, Han K, Kim HS.In the mitochondrial matrix, the OXCT1 gene catalyzes the reversible transfer of coenzyme A from succinyl-CoA to acetoacetate in a reaction related to energy production from ketone bodies. Here, horse OXCT1 gene containing coenzyme A transferase domain was identified in the transcriptome analysis of cDNAs derived from skeletal muscles. Horse OXCT1 gene consisted of 1761 [corrected] nucleotide sequences with an open reading frame of 1560 nucleotides encoding a protein of 520 putative amino acid residues.The number of non-synonymous substitutions was lower than the number of synonymous substitut...
Holve DL.To determine the effect of sedation with detomidine on intraocular pressure (IOP) in standing horses and whether topical ocular application of anesthetic alters this effect. Methods: Clinical trial. Methods: 15 clinically normal horses. Methods: Horses were assigned to group 1 (n = 7) or 2 (8). Intraocular pressure measurements were obtained at baseline (before sedation) and 10 minutes after IV administration of detomidine (0.02 mg/kg [0.009 mg/lb]). Group 1 horses had an additional IOP measurement at 20 minutes after sedation. For group 2 horses, topical ocular anesthetic was administered 10 ...
Vosmer J, Liesegang A, Wanner M, Zeyner A, Suter D, Hoelzle L, Wichert B.The aim of the present study was to compare carbohydrate degradation of forages which store carbohydrates either predominantly as fructan or starch, in horses' hindgut. The effects of an abrupt change from hay-based feeding to green fodder-based feeding on the caecal flora were tested with the in vitro hindgut simulation technique 'Caesitec'. Six trials with different forages (English ryegrass, tall fescue, grass mixture-horses, grass mixture-cows, lucerne, white clover) were conducted. During a 4-day stabilisation period, samples were taken once a day before loading the fermenters with hay. A...
Simones P, De Geest JP, Lauwers H.The pectinate ligaments of ten horses, two donkeys, five oxen, five sheep, ten goats, five dogs, five cats, thirty pigs and two rabbits were studied under the stereomicroscope and the scanning electron microscope. In the horse and the donkey, the pectinate ligament was very prominent and was characterized by sturdy interconnected strands and relatively small intertrabecular spaces. The pectinate ligaments of ruminants were composed of shorter strands, separated by relatively larger spaces. Fusion between adjacent strands, resulting in the formation of fenestrated sheets, was regularly observed...
Martoriati A, Lalmanach AC, Goudet G, Gérard N.A growing body of evidence suggests that the ovary is a site of inflammatory reactions, and thus, ovarian cells could represent sources and targets of the interleukin-1 (IL-1) system. The aim of the present work was to investigate the expression of IL-1alpha, IL-1beta, IL-1ra, IL-1R1, and IL-1R2 genes in equine cumulus cells and oocytes. Moreover, the influence of IL-1beta on in vitro maturation of cumulus-oocytes complexes (COCs) was examined. COCs were collected using ultrasound-guided follicular puncture in vivo. Oocytes and cumulus cells were isolated from preovulatory and subordinate foll...
Liu N, Yu W, Guo X, Chen J, Xia D, Yu J, Li D.Lytic polysaccharide monooxygenases (LPMOs) belonging to the auxiliary activity 9 family (AA9) are widely found in aerobic fungi. These enzymes are O-dependent copper oxidoreductases that catalyze the oxidative cleavage of cellulose. However, studies that have investigated AA9 LPMOs of aerobic fungi in the herbivore gut are scare. To date, whether oxidative cleavage of cellulose occurs in the herbivore gut is unknown. Results: We report for the first time experimental evidence that AA9 LPMOs from aerobic thermophilic fungi catalyze the oxidative cleavage of cellulose present in the horse gut t...
Coelho CS, Silva ASBA, Santos CMR, Santos AMR, Vintem CMBL, Leite AG, Fonseca JMC, Prazeres JMCS, Souza VRC, Siqueira RF, Manso Filho HC, Simões JSA.The purpose of this study was to investigate stressful responses during a 6-week training protocol in young Lusitano horses used for dressage. The hypothesis was that the proposed training protocol would improve fitness and ensure the welfare of the animals by reducing stress predictors. Nine 4-year-old horses were evaluated before (M1) and six weeks after (M2) beginning a training protocol. The training program was performed six times per week and included 40−80 min of individually intensity-adjusted preparatory exercises for dressage. For both moments, the horses were examined before (T0) ...
Tranquilli WJ, Thurmon JC, Neff-Davis CA, Davis LE, Benson GJ, Hoffman W, Lock TF.Plasma glucose and serum insulin concentrations in Thoroughbreds administered xylazine hydrochloride (1.1 mg/kg; IV) and ketamine hydrochloride (2.2 mg/kg; IV) at dosages sufficient to induce short periods of recumbency and anesthesia were measured. Samples of blood were collected from 6 adult horses before, during, and after the anesthetic period. Plasma glucose (mg/dl) was significantly increased above control (-30 minute concentration) from 15 to 150 minutes after xylazine administration with the peak value occurring at 30 minutes. Serum insulin (microU/ml) was significantly decreased from ...
Coli A, Nocchi F, Lamanna R, Iorio M, Lapi S, Urciuoli P, Scatena F, Giannessi E, Stornelli MR, Passeri S.The amnion is a particular tissue whose cells show features of multipotent stem cells proposed for use in cellular therapy and regenerative medicine. From equine amnion collected after the foal birth we have isolated MSCs (mesenchymal stem cells), namely EAMSCs (equine amnion mesenchymal stem cells), from the mesoblastic layer. The cells were grown in α-MEM (α-modified minimum essential medium) and the effect of EGF (epidermal growth factor) supplementation was evaluated. To assess the growth kinetic of EAMSCs we have taken into account some parameters [PD (population doubling), fold increas...
Nizolek DJ, White KK.Degenerative arthrosis is perhaps the most common debilitating disease of performance horses. Treatment should be based upon a knowledge of the anatomy and physiology of normal joints and upon an understanding of the processes of degeneration and repair. These topics are briefly reviewed. Although rest is probably, the most beneficial therapy, physical and pharmaceutical treatments are often employed in an effort to speed recovery. The effects and relative benefits of intrasynovial injections of corticosteroids, hyaluronica cid, and Arteparon are considered in detail. Although local corticoste...
Valk N, Doherty TJ, Blackford JT, Abraha TW, Frazier DL.The effect of phenylbutazone on gastric emptying in horses was determined by measuring serum concentrations of acetaminophen. Gastric emptying was determined in normal fasted horses (n = 6), horses given endotoxin intravenously (n = 6), horses given intravenous phenylbutazone (n = 6), and horses given intravenous phenylbutazone plus endotoxin (n = 6). The mean time to reach maximum serum acetaminophen concentration (Tmax), the maximum serum concentration (Cmax), and the area under the serum acetaminophen concentration versus time curve (AUC) were compared among treatment groups. Phenylbutazone...
Nollet H, Van Ham L, Verschooten F, Vanderstraeten G, Deprez P.To determine the usefulness of magnetic motor-evoked potentials (MMEPs) for assessing the integrity of the cervical, thoracic, and thoracolumbar spinal cord in horses with bilateral hind limb ataxia. Methods: 9 horses and 1 donkey with bilateral hind limb ataxia of various degrees. Methods: The motor cortex was stimulated magnetically, and MMEPs were recorded bilaterally from the extensor carpi radialis and cranial tibial muscles. Results: In 5 horses and 1 donkey, MMEPs with normal onset latencies and peak-to-peak amplitude were recorded from the extensor carpi radialis muscles, whereas abnor...
Bousquet-Mélou A, Formentini E, Picard-Hagen N, Delage L, Laroute V, Toutain PL.The present study aimed to characterize the adrenal response to ACTH. A model was developed that coupled the nonlinear disposition of cortisol with a physiologically based model for cortisol secretion by the adrenals. It was assumed that the response to ACTH resulted from two mechanisms: a stimulation of the cortisol secretion rate and control of the duration of the secretion. Seven dose levels of ACTH were tested in horses, a species similar to man as regards adrenal function. The main result was that the secretion rate of the adrenal gland can be modelized by a zero order process that is max...
Kristensen F, Firth EC.Using agarose as a supporting matrix, electrophoresis was conducted on 50 serum samples and 20 cerebrospinal fluid samples from clinically normal horses (n = 50) of various ages and breeds. The technique was shown to be reliable. A positive correlation between age and gamma-globulin concentration was found in young horses. Features of the electrophoretograms of serum and cerebrospinal fluid samples are discussed, and a nomenclature based on Rf values is proposed.
Gallivan GJ, McDonell WN, Forrest JB.Ventilation and gas exchange were studied in healthy, adult horses and cows, two large species with different lung structures and different breathing patterns. The oxygen uptake (VO2), carbon dioxide output (VCO2), respiratory rate (fR), minute ventilation (VE), alveolar ventilation (VA), alveolar oxygen pressure (PAO2), and VE/VO2 ratio were higher in the cows, while the tidal volume (VT) and physiological dead space (VD) were larger in the horses. The arterial blood gases, alveolar-arterial oxygen pressure difference (PAO2-PaO2) and VD/VT ratio did not differ between the two species. The hig...
Mills PC, Hills Y, Hills BA.To investigate the presence of surface-active phospholipid (SAPL, or surfactant) in equine tendon and tendon sheath fluid. Methods: The left front flexor tendon and sheath were removed from five Thoroughbred horses. Phospholipid was extracted from tendon sheath fluid using Folch reagent and quantified using spectroscopy. Transmission electron microscopy (TEM) was used to observe the tendon surfaces. Results: The presence of phospholipid (90.6 (SD 4.3) microg/ml) in tendon sheath fluid, plus the appearance of oligolamellar layers and lamellar bodies on the tendon surface were indicative of SAPL...
Vafaei F, Kohram H, Zareh-Shahne A, Ahmad E, Seifi-Jamadi A.This study was aimed to evaluate the effect of permeable cryoprotectants in combination with trehalose or sucrose on the freezing capacity of stallion sperm. For this purpose, the ejaculates (n = 24) were collected from four healthy mature Turkmen stallions. The ejaculates were pooled and diluted with one of the extenders containing a combination of 5% of permeating (dimethylacetamide [DMA]; dimethylformamide [DMF] or glycerol) and 50 mM of nonpermeating cryoprotectant agents (CPAs) (sucrose or trehalose) to a final concentration of 200 × 10 spermatozoa/mL. The extended samples were cryopr...
MacEachern KE, Smith GL, Nolan AM.Equine endothelial cells were isolated from the pulmonary artery by enzymatic digestion and grown to confluency. The cells were characterised by positive immunofluorescent staining for von Willebrand factor and NADPH-diaphorase staining for nitric oxide synthase. Measurements of endothelins indicated that there were significant release rates from the cells for up to six hours. Measurements of intracellular calcium concentration showed that the application of bradykinin caused a transient increase in calcium concentration with similar characteristics to those observed in other endothelial cell ...
Sasaki N, Okamura K, Yamada H.To examine the effects of various doses of mosapride, a 5-hydroxytryptamine 4 receptor agonist, on motility of the small intestine and cecum in horses by use of electrical activity and to determine the dose that provides the optimal response. Methods: 6 healthy adult Thoroughbreds. Methods: Electrical activity of the small intestine and cecum was recorded before and after mosapride administration by use of an electrogastrograph. Mosapride (0.5, 1, 1.5, and 2 mg/kg) was dissolved in 200 mL of water and administered orally to horses through a nasogastric tube. Three hours after drug administrati...
Toutain PL, Lassourd V, Costes G, Alvinerie M, Bret L, Lefebvre HP, Braun JP.The present study was undertaken to measure the weight of muscle destroyed by an intramuscular injection of phenylbutazone (PBZ) in horses. In six horses, CK disposition parameters were evaluated after intravenous (i.v.) and intramuscular (i.m.) administration of a CK horse preparation. The same horses received PBZ, a potentially irritating agent, by i.v. and i.m. (neck and hindquarter) routes. Data were analysed using compartmental approaches and instantaneous CK flux was calculated using a discrete deconvolution method. For a 150 U/kg CK dose, the steady-state volume of distribution was 0.05...
Risberg ÅI, Spadavecchia C, Ranheim B, Hendrickson EH, Lervik A, Haga HA.To elicit and evaluate the NWR (nociceptive withdrawal reflex) in 2 and 11 day old foals, to investigate if buprenorphine causes antinociception and determine if the NWR response changes with increasing age. The effect of buprenorphine on behaviour was also evaluated. Methods: Prospective, experimental cross-over trial. Methods: Nine Norwegian Fjord research foals. Methods: Buprenorphine, 10 μg kg(-1) was administered intramuscularly (IM) to the same foal at 2 days and at 11 days of age. The NWR and the effect of buprenorphine were evaluated by electromyograms recorded from the left deltoid m...
The measure of hair cortisol concentration (HCC) is becoming an emerging approach to monitor mid-/long-term stress in animals, so it is more and more important to develop accurate and reliable methods. In the light of this, the aim of the present study was to compare mane HCCs of 47 horses with different managements, by means of an immunoassay (ELISA) and liquid chromatography coupled to hybrid high-resolution mass spectrometry (LC-HRMS/MS). After the washing step, the ground hair was extracted with methanol. The extract was evaporated and redissolved in two different aqueous solutions, depend...
Morrice-West AV, Hitchens PL, Walmsley EA, Wong ASM, Whitton RC.Understanding the relationship between the training practices of Thoroughbred racehorses and race performance is important to ensure advice given to trainers for injury prevention or management is practical and consistent. We assessed associations between intended volume and speed of gallop training (i.e., typical workloads for horses free of injury or other performance limiting conditions) and rest practices on official trainer career and previous season success rates (rate of wins and places, prizemoney per start). Sixty-six Australian Thoroughbred trainers were surveyed. Multivariable negat...
Cecchini S, Paciolla M, Caputo AR, Bavoso A.In order to counteract harmful effects of oxidative stress due to pathological conditions or physical exercise, horses are often administered dietary supplements having supposed high antioxidant activities. The aim of the present study was to identify the in vitro antioxidant potential of "ImmuPlus", a polyherbal formulation (Global Herbs LTD, Chichester, West Sussex, Great Britain), containing three medicinal plants (Withania somnifera, Tinospora cordifolia, and Emblica officinalis), known in Ayurveda for their use in human disease treatment. Extracts obtained by different solvents (water, me...
Duehlmeier R, Hacker A, Widdel-Bigdely A, von Engelhardt W, Sallmann HP.Glucose homeostasis depends on insulin-regulated glucose uptake in the skeletal muscles and fat tissues via glucose transporter (GLUT) 4 translocation into cellular plasma membranes. The present study sought to elucidate GLUT4 expression, GLUT1 and GLUT4 translocation and glucose uptake in the skeletal muscles of Shetland ponies. Semitendinosus muscle explants were removed by open muscle biopsy from six Shetland pony geldings under general anaesthesia. The expression of GLUT4 was analysed by measuring muscle crude membrane (CM) GLUT4 protein contents. To determine the insulin-stimulated GLUT t...
Forro M, Cieslar S, Ecker GL, Walzak A, Hahn J, Lindinger MI.The purposes of this study were 1) to determine the compartmentation of body water in horses by using indicator dilution techniques and 2) to simultaneously measure bioelectrical impedance to current flow at impulse current frequencies of 5 and 200 kHz to formulate predictive equations that could be used to estimate total body water (TBW), extracellular fluid volume (ECFV), and intracellular fluid volume (ICFV). Eight horses and ponies weighing from 214 to 636 kg had catheters placed into the left and right jugular veins. Deuterium oxide, sodium thiocyanate, and Evans blue were infused for the...
Ghaoui Rel-H, Thomson PC, Evans G, Maxwell WM.Membrane vesicles, separated by differential centrifugation from the seminal plasma, were detected in the sperm-rich ejaculate fractions of four boars and three stallions, and in the whole ejaculates of seven rams. The volume and percentage of vesicles, determined by a stereological technique, were higher in the sperm-rich than in the post-sperm-rich fractions of the boar and stallion ejaculates, and no vesicles were detected in the pre sperm-rich fractions. Vesicles were examined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). For boar, stallion and ram semen...
Merkl M, Ertl R, Handschuh S, Aurich C, Schäfer-Somi S.In the present study, we assessed the presence of the ATP-binding-cassette (ABC) transporter molecules ABCA1 in spermatozoa of adult stallions and in testicular and epididymal tissue of prepubertal and adult stallions. For this purpose, semen samples from six fertile Shetland pony stallions aged 4 to 19 years were collected. Semen was collected from each stallion on three consecutive days. Ejaculates were analyzed immediately after collection, and only ejaculates meeting minimal requirements for fertile stallions were further evaluated. ABCA1 immunosignal was localized after staining of semen ...
Morrell JM, Rocha A.One of the most commonly encountered challenges in equine breeding is endometritis, which can be difficult to resolve and causes considerable economic losses to the industry. It is a multifactorial condition, developing as an exaggerated form of the normal physiological response to breeding. Seminal plasma proteins, spermatozoa, bacteria and debris initiate an inflammatory response; the resulting fluid and neutrophils are then cleared from the uterus along with the debris. However, in some mares, the response is prolonged or exaggerated, with much fluid formation and neutrophil infiltration le...
Serpa PBS, Woolcock A, Taylor SD, Pires Dos Santos A.Oxidative stress refers to the accumulation of reactive oxygen species (ROS). Most assays for ROS detection are costly, laborious, and usually use indirect markers. The use of 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) is a possible alternative. This substance becomes a fluorochrome when oxidized by ROS, with the resultant fluorescence proportional to ROS concentration. Erythrocytes are highly exposed to ROS, resulting in cell damage and consequently impaired oxygen delivery. The effects of this exposure in physiologic and pathologic conditions necessitate an improvement in ROS detec...
Khanna AK, McDonell WN, Dyson DH, Taylor PM.The cardiopulmonary effects of eucapnia (arterial CO2 tension [PaCO2] 40.4 +/- 2.9 mm Hg, mean +/- SD), mild hypercapnia (PaCO2, 59.1 +/- 3.5 mm Hg), moderate hypercapnia (PaCO2, 82.6 +/- 4.9 mm Hg), and severe hypercapnia (PaCO2, 110.3 +/- 12.2 mm Hg) were studied in 8 horses during isoflurane anesthesia with volume controlled intermittent positive pressure ventilation (IPPV) and neuromuscular blockade. The sequence of changes in PaCO2 was randomized. Mild hypercapnia produced bradycardia resulting in a significant (P < 0.05) decrease in cardiac index (CI) and oxygen delivery (DO2), while ...
Stephano MA, Guidolin R, Higashi HG, Tambourgi DV, Sant'Anna OA.The main features associated with pit viper envenomations include the intense local lesions such as oedema, necrosis, acute renal failure and other effects. The severity of these reactions to snakebite depends on the degree of envenomation. Lachesis muta venom (LMV) has weak lethal activity, but due to the large amount often inoculated, the effects are extremely severe and demand anti-venom with a high neutralizing capacity. LMV had the lowest neutralizing antibody induction capacity in horses when compared with that of other venoms. For example, Bothrops anti-venom serum neutralizes 180 times...
Kirsch K, Fercher C, Horstmann S, von Reitzenstein C, Augustin J, Lagershausen H.Show jumping is a highly specialized equestrian discipline that requires technical skill but also power and fitness. Monitoring the horses' aerobic performance is therefore essential in order to verify whether the training has induced the desired cardiovascular and muscular adaptations. This study therefore aimed at evaluating the validity of non-specific and discipline-specific field exercise tests for objective evaluation of aerobic performance in show jumpers. For this purpose, data obtained from horses competing at Junior and Young Rider level during show jumping competitions as well as fi...
