The topic of muscle in horses encompasses the study of equine muscle structure, function, and physiology. Muscles in horses are responsible for movement, posture, and various metabolic processes. They are composed of muscle fibers that contract and relax to produce motion and generate force. Research in this area often focuses on muscle development, adaptation to exercise, and the impact of nutrition and training on muscle performance. Conditions such as muscle fatigue, injury, and disorders like equine exertional rhabdomyolysis are also explored. This page compiles peer-reviewed research studies and scholarly articles that investigate the anatomy, physiology, and clinical aspects of muscle in equine species.
De Ceulaer K, Delesalle C, Van Elzen R, Van Brantegem L, Weyns A, Van Ginneken C.Intestinal strangulation often leads to enterectomy after which ileus can develop. This has prompted research to look into possible pathophysiological processes triggering equine ileus. However, morphological changes of the small intestinal smooth muscle in relation to equine colic have not yet been studied. Objective: The presence of some smooth muscle proteins was morphologically assessed and quantified in control and colic horses. In addition, the up- or down-regulation of heat shock proteins (HSP20 and HSP27) influencing the contractility of smooth muscles was studied. Methods: Cranial res...
Kander A, Warde P.This article explores the proposition that a reason for high agricultural productivity in the early nineteenth century was relatively high energy availability from draught animals. The article is based on the collection of extensive new data indicating different trends in draught power availability and the efficiency of its use in different countries of Europe. This article shows that the proposition does not hold, and demonstrates that, although towards the end of the nineteenth century England had relatively high numbers of draught animals per agricultural worker, it also had low number of w...
Kitaoka Y, Masuda H, Mukai K, Hiraga A, Takemasa T, Hatta H.The aim of this study was to investigate the effects of training and detraining on the monocarboxylate transporter (MCT) 1 and MCT4 levels in the gluteus medius muscle of Thoroughbred horses. Twelve Thoroughbred horses were used for the analysis. For 18 weeks, all the horses underwent high-intensity training (HIT), with running at 90-110% maximal oxygen consumption (VO2 max ) for 3 min, 5 days week(-1). Thereafter, the horses either underwent detraining for 6 weeks by either 3 min of moderate-intensity training (MIT) at 70% VO2 max, 5 days week(-1) (HIT-MIT group) or stall rest (HIT-SR group)....
Prause AS, Guionaud CT, Stoffel MH, Portier CJ, Mevissen M.To evaluate the expression of the 5-hydroxytryptamine 4 (5-HT4) receptor subtype and investigate the modulating function of those receptors on contractility in intestinal tissues obtained from horses without gastrointestinal tract disease. Methods: Smooth muscle preparations from the duodenum, ileum, and pelvic flexure collected immediately after slaughter of 24 horses with no history or signs of gastrointestinal tract disease. Methods: In isometric organ baths, the contractile activities of smooth muscle preparations in response to 5-hydroxytryptamine and electric field stimulation were asses...
van den Hoven R, Bauer A, Hackl S, Zickl M, Spona J, Zentek J.In this preliminary study, time-dependent changes in plasma CK and AST activity, tyrosine (Tyr), 3-methyl-histidine (3mHis), glucose and lactate concentrations were analysed in nine horses under two different conditions. Furthermore, intramuscular concentrations of Tyr, 3mHis and activities of cathepsin B, acid phosphatase (ACP), glucose-6-phosphate dehydrogenase (G6PDH) and mRNA expression of ubiquitin were determined at the same time. After studying the effects of exercise alone, the effects of exercise and feeding of an experimental protein/amino acid (AA) supplement were analysed. Horses w...
McCue ME, Anderson SM, Valberg SJ, Piercy RJ, Barakzai SZ, Binns MM, Distl O, Penedo MC, Wagner ML, Mickelson JR.The GYS1 gene mutation that is causative of Type 1 Polysaccharide Storage Myopathy (PSSM) has been identified in more than 20 breeds of horses. However, the GYS1 mutation frequency or Type 1 PSSM prevalence within any given breed is unknown. The purpose of this study was to determine the frequency of the GYS1 mutation and prevalence of genetic susceptibility to Type 1 PSSM in selected breeds from Europe and North America. The GYS1 mutation was detected in 11 breeds, including, in order of increasing allele frequency, Shires, Morgans, Appaloosas, Quarter Horses, Paints, Exmoor Ponies, Saxon-Thu...
Chen H, Wang L, Zeller M, Hornshaw M, Wu Y, Zhou M, Li J, Hang X, Cai J, Chen T, Shaw C.From defensive skin secretions acquired from two species of African hyperoliid frogs, Kassina maculata and Kassina senegalensis, we have isolated two structurally related, C-terminally amidated tridecapeptides of novel primary structure that exhibit a broad spectrum of biological activity. In reflection of their structural novelty and species of origin, we named the peptides kassorin M (FLEGLLNTVTGLLamide; 1387.8 Da) and kassorin S (FLGGILNTITGLLamide; 1329.8 Da), respectively. The primary structure and organisation of the biosynthetic precursors of kassorins M and S were deduced from cloned s...
Mykkänen AK, Koho NM, Reeben M, McGowan CM, Pösö AR.Polymorphisms in human lactate transporter proteins (monocarboxylate transporters; MCTs), especially the MCT1 isoform, can affect lactate transport activity and cause signs of exercise-induced myopathy. Muscles express MCT1, MCT4 and CD147, an ancillary protein, indispensable for the activity of MCT1 and MCT4. We sequenced the coding sequence (cDNA) of horse MCT4 for the first time and examined polymorphisms in the cDNA of MCT1, MCT4 and CD147 of 16 healthy horses. To study whether signs of myopathy are linked to the polymorphisms, biopsy samples were taken from 26 horses with exercise-induced...
Hill EW, McGivney BA, Gu J, Whiston R, Machugh DE.Thoroughbred horses have been selected for traits contributing to speed and stamina for centuries. It is widely recognized that inherited variation in physical and physiological characteristics is responsible for variation in individual aptitude for race distance, and that muscle phenotypes in particular are important. Results: A genome-wide SNP-association study for optimum racing distance was performed using the EquineSNP50 Bead Chip genotyping array in a cohort of n = 118 elite Thoroughbred racehorses divergent for race distance aptitude. In a cohort-based association test we evaluated geno...
Martin AM, Elliott JA, Duffy P, Blake CM, Ben Attia S, Katz LM, Browne JA, Gath V, McGivney BA, Hill EW, Murphy BA.Circadian rhythms are innate 24-h cycles in behavioral and biochemical processes that permit physiological anticipation of daily environmental changes. Elucidating the relationship between activity rhythms and circadian patterns of gene expression may contribute to improved human and equine athletic performance. Six healthy, untrained mares were studied to determine whether locomotor activity behavior and skeletal muscle gene expression reflect endogenous circadian regulation. Activity was recorded for three consecutive 48-h periods: as a group at pasture (P), and individually stabled under a ...
Russo D, Bombardi C, Grandis A, Furness JB, Spadari A, Bernardini C, Chiocchetti R.The distribution and chemical phenotypes of sympathetic and dorsal root ganglion (DRG) neurons innervating the equine ileocecal junction (ICJ) were studied by combining retrograde tracing and immunohistochemistry. Immunoreactivity (IR) for tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DBH), neuronal nitric oxide synthase (nNOS), calcitonin gene-related peptide (CGRP), substance P (SP), and neuropeptide Y (NPY) was investigated. Sympathetic neurons projecting to the ICJ were distributed within the celiac (CG), cranial mesenteric (CranMG), and caudal mesenteric (CaudMG) ganglia, as well ...
Ducharme NG, Cheetham J, Sanders I, Hermanson JW, Hackett RP, Soderholm LV, Mitchell LM.The success rate of prosthetic laryngoplasty is limited and may be associated with significant sequelae. Nerve muscle pedicle transplantation has been attempted but requires a year before function is restored. Objective: To determine the optimal parameters for functional electrical stimulation of the recurrent laryngeal nerve in horses. Methods: An experimental in vivo study was performed on 7 mature horses (2-21 years). A nerve cuff was placed on the distal end of the common trunk of the recurrent laryngeal nerve (RLN). In 6 horses the ipsilateral adductor branch of RLN was also transected. T...
Butcher MT, Chase PB, Hermanson JW, Clark AN, Brunet NM, Bertram JE.Equine digital flexor muscles have independent tendons but a nearly identical mechanical relationship to the main joint they act upon. Yet these muscles have remarkable diversity in architecture, ranging from long, unipennate fibers ("short" compartment of DDF) to very short, multipennate fibers (SDF). To investigate the functional relevance of the form of the digital flexor muscles, fiber contractile properties were analyzed in the context of architecture differences and in vivo function during locomotion. Myosin heavy chain (MHC) isoform fiber type was studied, and in vitro motility assays w...
Mosing M, Auer U, Bardell D, Jones RS, Hunter JM.This clinical study evaluated the speed of reversal of profound rocuronium block in ponies using sugammadex and investigated the differences in onset and recovery from block in three different muscle groups. Methods: Anaesthesia was induced and maintained with isoflurane in oxygen 100% in eight ponies. Neuromuscular monitoring was performed at each site using acceleromyography: in the extensor muscles of the pelvic limb (peroneal nerve) and thoracic limb (radial nerve), and in the orbicularis oris muscle (OOM; facial nerve). Rocuronium 0.6 mg kg(-1) i.v. was administered, followed 5 min later ...
Walmsley EA, Steel CM, Richardson JL, Hesse KL, Whitton RC.To describe the clinical presentation, ultrasound findings, management and outcome in horses with muscle tear injuries of the hindlimbs. Methods: Retrospective case series Procedure Medical records of eight horses were reviewed and information on signalment, history, presenting complaint, physical examination findings and further diagnostic tests were recorded. Diagnosis of muscle injury was determined by the presence of abnormal ultrasound findings, compared with the contralateral limb, and, when required, nuclear scintigraphy. Follow-up information was obtained via telephone interviews with ...
Lorenzo JM, Fuciños C, Purriños L, Franco D.The effects of sex, slaughtered age (9 vs. 12 months) and livestock production system (freedom extensive system vs. semi extensive system) of "Galician Mountain" foals breed on the fatty acid composition were studied. The sex and slaughtered age of the animals had no statistical significance in the intramuscular fatty acids. Furthermore, the livestock production system showed differences in the fatty acid profiles from the Longissimus dorsi. The feeding system showed significant differences in PUFA content (P<0.001) higher in freedom extensive production system that semi extensive system, wher...
Finno CJ, Eaton JS, Aleman M, Hollingsworth SR.A 23-year-old female mule was presented for bilateral ocular abnormalities and an abnormal pelvic limb gait. Results: Anisocoria, unilateral enophthalmos, medial strabismus, ptosis, pupillary light reflex deficits, and bilateral reticulated pigmentary retinopathy were observed on ophthalmic examination. Neurologic abnormalities included right-sided facial nerve paralysis, extensive symmetric muscle atrophy, and asymmetric pelvic limb ataxia with an abnormal pelvic limb gait. A positive titer (1:40) for equine protozoal myeloencephalitis (EPM) associated with Neospora hughesi was obtained from ...
McGivney BA, McGettigan PA, Browne JA, Evans AC, Fonseca RG, Loftus BJ, Lohan A, MacHugh DE, Murphy BA, Katz LM, Hill EW.Digital gene expression profiling was used to characterize the assembly of genes expressed in equine skeletal muscle and to identify the subset of genes that were differentially expressed following a ten-month period of exercise training. The study cohort comprised seven Thoroughbred racehorses from a single training yard. Skeletal muscle biopsies were collected at rest from the gluteus medius at two time points: T(1) - untrained, (9 +/- 0.5 months old) and T(2) - trained (20 +/- 0.7 months old). Results: The most abundant mRNA transcripts in the muscle transcriptome were those involved in mus...
Aleman M, Nieto JE.To investigate gene expression of the major proteolytic systems and growth regulators in skeletal muscle of horses with myopathy associated with pituitary pars intermedia dysfunction (PPID). Methods: 14 horses with PPID-associated myopathy and 7 healthy control horses. Methods: Horses with PPID and controls were age matched (15 to 28 years old). Muscle biopsy specimens were collected from both groups and processed for RNA and cDNA extraction. Validation of the most stable housekeeping genes for skeletal muscle was performed and used to compare gene expression of the following proteolytic syste...
Crook TC, Cruickshank SE, McGowan CM, Stubbs N, Wilson AM, Hodson-Tole E, Payne RC.Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the...
Jedziniak P, Szprengier-Juszkiewicz T, Olejnik M, Zmudzki J.A confirmatory method for the determination of residues of nine non-steroidal anti-inflammatory drugs and one metabolite in animal muscles has been developed. After enzymatic hydrolysis samples were extracted with acetonitrile and cleaned up using alumina and C(18) SPE cartridges. Liquid chromatography-tandem mass spectrometry was used for the separation and determination of analytes. The method was validated in bovine muscles, according to the Commission Decision 2002/657/EC criteria. Applicability of the method in the analysis of swine, horse and chicken muscles was checked by precision and ...
Echigoya Y, Okabe H, Itou T, Endo H, Sakai T.Muscle glycogen synthase (GYS1) is the rate-limiting enzyme in glycogen synthesis, and its activity is regulated by the phosphorylation states of certain amino acid residues encoded by the GYS1 gene. In the present study, the authors molecularly characterized the full-length equine GYS1 (eGYS1) cDNA and found that it contains a less common polyadenylation signal (AATACA). An amino acid alignment with other mammalian GYS1 showed that the phosphorylation sites in eGYS1 are completely conserved. Genomic DNA analysis revealed that the equine-specific substitutions (Glu 16 Asp and Ala 252 Thr) were...
Bouwman FG, van Ginneken MM, van der Kolk JH, van Breda E, Mariman EC.The aim of the study was to identify new biomarkers for acute tying-up in horses. Skeletal muscle biopsies were taken from 3 horses suffering from acute tying-up and 3 healthy horses. We performed 2D gel electrophoresis and mass spectrometry for identification of proteins that are differentially expressed in tying-up. 2D gel electrophoresis of skeletal muscle sequential extracts yielded more than 350 protein spots on each gel, of which 14 were differentially expressed more than two-fold (p<0.05). In-gel digestion followed by peptide mass fingerprinting enabled identification of three significa...
Borgia LA, Valberg SJ, McCue ME, Pagan JD, Roe CR.To evaluate effects of fats with odd and even numbers of carbon atoms on muscle metabolism in exercising horses with polysaccharide storage myopathy (PSSM). Methods: 8 horses with PSSM (6 females and 2 males; mean +/- SD age, 6.3 +/- 3.9 years). Methods: Isocaloric diets (grain, triheptanoin, corn oil, and high-fat, low-starch [HFLS] feed) were fed for 3 weeks each; horses performed daily treadmill exercise. Grain was fed to establish an exercise target, and HFLS feed was fed as a negative control diet. Daily plasma samples were obtained. For each diet, a 15-minute exercise test was performed,...
Guschlbauer M, Hoppe S, Geburek F, Feige K, Huber K.Post operative ileus (POI) in horses is a severe complication after colic surgery. A commonly used prokinetic drug is lidocaine, which has been shown to have stimulatory effects on intestinal motility. The cellular mechanisms through which lidocaine affects smooth muscle activity are not yet known. Objective: To examine the effects of lidocaine on smooth muscle in vitro and identify mechanisms by which it may affect the contractility of intestinal smooth muscle. Objective: Ischaemia and reperfusion associated with intestinal strangulation can cause smooth muscle injury. Consequently, muscle ce...
Unger-Torroledo L, Straub R, Lehmann AD, Graber F, Stahl C, Frey J, Gerber V, Hoppeler H, Baum O.The lethal toxin of Clostridium sordellii (TcsL) evokes severe, mostly fatal disease patterns like toxic shock syndrome in humans and animals. Since this large clostridial toxin-induced severe muscle damaging when injected intramuscularly into mice, we hypothesized that TcsL is also associated with equine atypical myopathy (EAM), a fatal myodystrophy of hitherto unknown etiology. Transmission electron microscopy revealed skeletal and heart muscles of EAM-affected horses to undergo degeneration ultrastructurally similar to the damage found in TcsL-treated mice. Performing immunohistochemistry, ...
Mama KR, Grimsrud K, Snell T, Stanley S.Detomidine hydrochloride is used to provide sedation, muscle relaxation and analgesia in horses, but a lack of information pertaining to plasma concentration has limited the ability to correlate drug concentration with effect. Objective: To build on previous information and assess detomidine for i.v. and i.m. use in horses by simultaneously assessing plasma drug concentrations, physiological parameters and behavioural characteristics. Objective: Systemic effects would be seen following i.m. and i.v. detomidine administration and these effects would be positively correlated with plasma drug con...
McGivney BA, Eivers SS, MacHugh DE, MacLeod JN, O'Gorman GM, Park SD, Katz LM, Hill EW.Selection for exercise-adapted phenotypes in the Thoroughbred racehorse has provided a valuable model system to understand molecular responses to exercise in skeletal muscle. Exercise stimulates immediate early molecular responses as well as delayed responses during recovery, resulting in a return to homeostasis and enabling long term adaptation. Global mRNA expression during the immediate-response period has not previously been reported in skeletal muscle following exercise in any species. Also, global gene expression changes in equine skeletal muscle following exercise have not been reported...
Bouwman FG, van Ginneken MM, Noben JP, Royackers E, de Graaf-Roelfsema E, Wijnberg ID, van der Kolk JH, Mariman EC, van Breda E.The major aim of the present study was to investigate the proteome of standardbred horses at different stages of training and intensified training. We searched for biomarkers using small skeletal muscle biopsies of live animals. 2D gel electrophoresis and mass spectrometry were successfully applied to investigate training-induced differential expression of equine muscle biopsy proteins. Despite the poor resolution of the equine genome and proteome, we were able to identify the proteins of 20 differential spots representing 16 different proteins. Evaluation of those proteins complies with adapt...
Karren BJ, Thorson JF, Cavinder CA, Hammer CJ, Coverdale JA.To investigate the maternal plane of nutrition and role of Se yeast on muscle Se concentration, plasma glutathione peroxidase (Gsh-Px) activity, and colostrum Se concentration in mares and their foals, 28 Quarter Horse mares (465 to 612 kg of BW, and 6 to 19 yr of age) were used in a study with a randomized complete block design. Mares were blocked by expected foaling date and randomly assigned to dietary treatments within blocks. Dietary treatments were arranged as a 2 x 2 factorial with 2 planes of nutrition, pasture or pasture + grain mix (fed at 0.75% of BW on an as-fed basis) and 2 concen...
Yu M, Wang Z, Robinson NE.To determine the presence and function of alpha 2-adrenoceptors on cholinergic nerves innervating horse airway smooth muscle, the effects of some alpha 2-adrenoceptor agents on contractions of and acetylcholine (ACh) release from equine airway smooth muscle preparations were studied. Muscle contractions were elicited by either electrical field stimulation (EFS) or exogenous ACh. ACh release was induced by EFS and measured by high-pressure liquid chromatography and electrochemical detection. The alpha 2-adrenoceptor agonists clonidine (10(-7) to 10(-5) M) and UK-14,304 (10(-8) to 10(-6) M) conc...
Madigan JE, Valberg SJ, Ragle C, Moody JL.Severe muscle cramping not associated with exercise was observed in 5 horses. Focal muscle groups in various regions underwent intermittent visible contraction. Intermittent prolapse of the third eyelid, sweating, pawing, muscle tremors, and muscle fasciculations also were observed. Clinical signs often were misconstrued as signs of colic. Percussion of muscle induced contraction of muscle groups. Concentrations of serum electrolytes and the acid-base balance were within reference limits, but activities of creatine kinase and aspartate transaminase were moderately high. Muscle biopsy revealed ...
van den Burg MM, Eizema K, de Graaf-Roelfsema E, van Breda E, Wijnberg ID, van der Kolk JH, Everts ME.To investigate the effects of acute exercise and long-term training on Na(+),K(+)-ATPase content, mRNA isoforms, and protein concentration in equine muscle. Methods: 6 Standardbreds. Methods: Horses performed a bout of exercise on a treadmill before and after 18 weeks of combined interval and endurance training. Muscle biopsy specimens were obtained from vastus lateralis muscle (VLM) and pectoralis descendens muscle (PDM) before and after exercise. The Na(+),K(+)-ATPase content, mRNA isoforms, and protein concentrations were determined by use of [(3)H]ouabain binding, real-time PCR assay, and ...
LaVigne EK, Jones AK, Londoño AS, Schauer AS, Patterson DF, Nadeau JA, Reed SA.Success as equine athletes requires proper muscle growth in young horses. Muscle hypertrophy occurs through protein synthesis and the contribution of muscle satellite cells, which can be stimulated or inhibited by cytokines and growth factors present during exercise and growth. The hypotheses of this study were that 1) the LM area in young horses would increase over 1 yr, and 2) specific cytokines and growth factors (IL-1β, IL-6, tumor necrosis factor [TNF]-α, IGF-I, and fibroblast growth factor [FGF]-2) would alter proliferation and differentiation of satellite cells isolated from young hor...
Gottlieb-Vedi M, Dahlborn K, Jansson A, Wroblewski R.In this study, 4 Standardbred geldings were exercised at 20 and 35 degrees C. The exercise test (ET) consisted of 2 exercise bouts separated by 2 h of rest in their boxes. Blood samples were taken before, during and after the second exercise bout and muscle (m. gluteus medius) biopsies were taken before the first exercise bout and after an intensive trot over 2600 m in the second exercise bout. The blood samples were analysed for plasma potassium and total plasma protein concentration (TPP) and the muscle fibres were analysed for elemental composition by x-ray microanalysis. The intracellular ...
Dunnett M, Harris RC, Sewell DA.Taurine (TAU) is found in large but variable amounts in the skeletal muscles of many species. It has been reported that slow twitch muscles in the rat exhibit higher TAU levels than fast twitch muscles. Variation in muscle taurine content may be attributable to differences in the fibre type composition of different muscles. TAU content (mmol kg-1 dry muscle) and percentage type-1, type-2A, and type-2B fibre section area (f.s.a.) were measured in muscle samples taken from up to six sites in the middle gluteal muscle of four horses and one pony at post mortem and in biopsy samples taken from twe...
Goetz TE, Manohar M, Nganwa D, Gustafson R.The effects of 1.1, 1.5 and 1.8 MAC (minimum alveolar concentration) isoflurane-02 anaesthesia on skeletal muscle blood flow, 02 delivery and vascular resistance were studied in the non-dependent region of seven healthy normothermic, isocapnoeic ponies. Muscle blood flow was determined with 15 microns diameter radionuclide labelled microspheres that were injected into the left ventricle. Muscle blood flow during anaesthesia was compared to unanaesthetised (control) measurements. Isoflurane administration caused a dose dependent decrease in mean aortic pressure, and skeletal muscle (temporalis,...
Gim JA, Lee S, Kim DS, Jeong KS, Hong CP, Bae JH, Moon JW, Choi YS, Cho BW, Cho HG, Bhak J, Kim HS.With the advent of next-generation sequencing technology, genome-wide maps of DNA methylation are now available. The Thoroughbred horse is bred for racing, while the Jeju horse is a traditional Korean horse bred for racing or food. The methylation profiles of equine organs may provide genomic clues underlying their athletic traits. We have developed a database to elucidate genome-wide DNA methylation patterns of the cerebrum, lung, heart, and skeletal muscle from Thoroughbred and Jeju horses. Using MeDIP-Seq, our database provides information regarding significantly enriched methylated regions...
Beekley MD, Ideus JM, Brechue WF, Kearns CF, McKeever KH.The purpose of this study was to examine changes in myosin heavy chain (MHC) composition due to chronic clenbuterol administration with or without exercise in mares. Unfit Standardbred mares (aged 10+/-3 years) were divided into four groups: clenbuterol (2.4 micro/kg BW twice daily) plus exercise (3 days/week for 20 min at 50% VO(2max); CLENEX; n=6), clenbuterol only (CLEN; n=6), exercise only (EX; n=5), and control (CON; n=6). Muscle biopsies were obtained from gluteus medius muscle before and after the eight-week training/administration period. MHC composition was determined via SDS gel elec...
Mesoangioblasts (MABs) are vessel-associated stem cells that express pericyte markers and are originally isolated from the embryonic dorsal aorta. From postnatal small vessels of skeletal muscle and heart, it is possible to isolate cells with similar characteristics to embryonic MABs. Adult MABs have the capacity to self-renew and to differentiate into cell types of mesodermal lineages upon proper culture conditions. To date, the origin of MABs and the relationship with other muscle stem cells are still debated. Recently, in a phase I-II clinical trial, intra-arterial HLA-matched MABs were pro...
Gleadhill A, Marlin D, Harris PA, Michell AR.Measurement of renal function in horses poses a particular challenge because plasma creatinine is influenced by muscle mass which is highly developed and variable between individuals, while conventional clearance methods involve potentially daunting problems, particularly urine collection and bladder washout. This paper provides data which enable technetium-diethyleneaminopentacetic acid (Tc-DTPA) clearance to be used to calculate glomerular filtration rate (GFR)/extracellular fluid volume (ECFV) as an expression of GFR in horses, as previously validated in humans, dogs and calves. Apart from ...
Physick-Sheard PW.The quality of the overall response to exercise in the horse is very similar to that seen in man and laboratory animals; differences are mainly quantitative and persist when relative body weight is taken into account. The apparently greater flow capacity of the equine muscle bed during maximal whole-body exercise implicates the extent of central circulatory adaptations as the limiting factor in performance but implies a role for increase in arteriolar capacitance/muscle capillarity as an appropriate response to intense endurance training. The blood oxygen-carrying capacity of the horse is ofte...
Benamou AE, Marlin DJ, Callingham BC, Hiley RC, Lekeux R.There is currently little published information about the effects of endothelin-1 (ET-1), a potent endogenous spasmogen of vascular and airway smooth muscle, on pulmonary vasculature and airways or which ET receptor subtypes mediate ET-1-induced vasoconstrictive and bronchoconstrictive action in the horse. Objective: To investigate the effect of endothelin-1 (ET-1) on smooth muscle from isolated equine pulmonary artery and bronchus. In addition, the roles of ETA and ETB receptors in ET-1 mediated contraction in these tissues were assessed. Methods: The force generation of ring segments from pu...
Herszberg B, McCue ME, Larcher T, Mata X, Vaiman A, Chaffaux S, Chérel Y, Valberg SJ, Mickelson JR, Guérin G.Glycogen storage diseases or glycogenoses are inherited diseases caused by abnormalities of enzymes that regulate the synthesis or degradation of glycogen. Deleterious mutations in many genes of the glyco(geno)lytic or the glycogenesis pathways can potentially cause a glycogenosis, and currently mutations in fourteen different genes are known to cause animal or human glycogenoses, resulting in myopathies and/or hepatic disorders. The genetic bases of two forms of glycogenosis are currently known in horses. A fatal neonatal polysystemic type IV glycogenosis, inherited recessively in affected Qu...
Olszewski MA, Robinson NE, Yu MF, Derksen FJ.During acute bouts of recurrent airway obstruction (heaves) in horses, neutrophils that are capable of increased production of reactive oxygen species accumulate in the airways. In the study reported here, the effect of hydrogen peroxide (H2O2; 1 microM to 0.1M), one of these reactive oxygen species products, on the responses of isolated trachealis muscle of horses was determined. Before and after incubation with H2O2, contractile responses to acetylcholine, electrical field stimulation (EFS), 127 mM KCl, and relaxation responses to isoproterenol and activation of the nonadrenergic noncholiner...
Polikepahad S, Paulsen DB, Moore RM, Costa LR, Venugopal CS.To immunohistochemically determine the expression of endothelin (ET) receptors in bronchial smooth muscle and epithelium of healthy horses and horses affected by summer pasture-associated obstructive pulmonary disease (SPAOPD). Methods: Tissue specimens obtained from 8 healthy and 8 SPAOPD-affected horses. Methods: Horses were examined and assigned to healthy and SPAOPD groups. Horses were then euthanatized, and tissue specimens containing bronchi of approximately 4 to 8 mm in diameter were immediately collected from all lung lobes, fixed in zinc-formalin solution for 12 hours, and embedded in...
Edner A, Essén-Gustavsson B, Nyman G.During anaesthesia in the horse, muscle blood flow has been found to be reduced, possibly leading to hypoxia or ischaemia in the muscle. The aim of this study was to use the muscle biopsy and microdialysis techniques to determine whether long-term inhalation anaesthesia in laterally recumbent horses induces metabolic changes in gluteal muscle indicative of anaerobic metabolism. Muscle biopsies and plasma samples were taken from seven horses at the start and end of halothane anaesthesia. In six isoflurane-anaesthetised horses, given three pharmacological provocations (dobutamine, detomidine, ac...
Matsui A, Ohmura H, Asai Y, Takahashi T, Hiraga A, Okamura K, Tokimura H, Sugino T, Obitsu T, Taniguchi K.In man, muscle protein synthesis is accelerated by administering amino acids (AA) and glucose (Glu), because increased availability of amino acids and increased insulin secretion, is known to have a protein anabolic effect. However, in the horse, the effect on muscle hypertrophy of such nutrition management following exercise is unknown. Objective: To determine the effect of AA and Glu administration following exercise on muscle protein turnover in horses. We hypothesise that administration of AA and Glu after exercise effects muscle hypertrophy in horses, as already shown in man and other ani...
Beech J, Fletcher JE, Lizzo F, Johnston J.In vitro twitch characteristics of the semimembranosus muscle were evaluated in 9 clinically normal horses, in 15 horses with chronic intermittent rhabdomyolysis (CIR) and in 2 horses with myotonia. Effects of phenytoin on in vitro muscle twitch and clinical signs of CIR and myotonia were evaluated in these same horses. Times to 90% relaxation were prolonged in the horses with CIR (mean +/- SEM, 186 +/- 5.9 ms) and in 2 horses with myotonia (197 and 177 ms) compared with those in clinically normal horses (mean +/- SEM, 146 +/- 2.1 ms). Horses with CIR also had significantly (P less than 0.05) ...
Adair HS, Levine D. The purpose of this study was to examine the tissue temperature changes that occur at various depths during 1.0-MHz ultrasound (US) treatments of the epaxial muscles in horses. Ten healthy adult mares with no lameness or orthopedic disease weighing between 465 and 576 kg were studied. Two 1.0 MHz US treatments, one at an intensity of 1.0 W/cm and one at 2.0 W/cm, were administered to the epaxial region. Needle thermistors were inserted in the epaxial muscles below the skin surface at depths of 1.0, 3.0, and 5.0 cm, directly under the US treatment area. Depths were verified with diagnostic u...
Ruckebusch Y, Roger T.The electromyogram of the terminal ileum, the caecum and the proximal right ventral colon was recorded in fasted conscious ponies receiving intravenously equiactive doses of pilocarpine (0.05 mg/kg) and carbachol (0.01 mg/kg) as acetylcholine analogues; cisapride (0.1 mg/kg) and metoclopramide (2 mg/kg) facilitating acetylcholine release from myenteric neurones and naloxone (0.05 mg/kg) as an antagonist of the endogenous inhibitory opioid system. Both cisapride and naloxone induced typical migrating spike bursts in the colon associated with contractions of caecal body and caecal base. Both pil...
Marti M, Mevissen M, Althaus H, Steiner A.The goal of this study was to investigate the effect of bethanechol (BeCh) on contractility patterns of smooth muscle preparations of equine duodenum descendens, jejunum, caecum and pelvic flexure in vitro. Concentration-response relationships were developed for BeCh using in vitro assays with and without preincubation of muscarinic (M) receptor antagonists for M2 and M3 receptors. BeCh induced a significant, concentration-dependent increase in contractile response in equine intestine in specimens with circular orientation. The maximal effect was largest for jejunal specimens with no differenc...
Jedziniak P, Szprengier-Juszkiewicz T, Olejnik M, Zmudzki J.A confirmatory method for the determination of residues of nine non-steroidal anti-inflammatory drugs and one metabolite in animal muscles has been developed. After enzymatic hydrolysis samples were extracted with acetonitrile and cleaned up using alumina and C(18) SPE cartridges. Liquid chromatography-tandem mass spectrometry was used for the separation and determination of analytes. The method was validated in bovine muscles, according to the Commission Decision 2002/657/EC criteria. Applicability of the method in the analysis of swine, horse and chicken muscles was checked by precision and ...
Fernandez-Fuente M, Martin-Duque P, Vassaux G, Brown SC, Muntoni F, Terracciano CM, Piercy RJ.Several human and animal myopathies, such as malignant hyperthermia (MH), central core disease and equine recurrent exertional rhabdomyolysis (RER) are confirmed or thought to be associated with dysfunction of skeletal muscle calcium regulation. For some patients in whom the genetic cause is unknown, or when mutational analysis reveals genetic variants with unclear pathogenicity, defects are further studied through use of muscle histopathology and in vitro contraction tests, the latter in particular, when assessing responses to ryanodine receptor agonists, such as caffeine. However, since musc...
Mosing M, Auer U, Bardell D, Jones RS, Hunter JM.This clinical study evaluated the speed of reversal of profound rocuronium block in ponies using sugammadex and investigated the differences in onset and recovery from block in three different muscle groups. Methods: Anaesthesia was induced and maintained with isoflurane in oxygen 100% in eight ponies. Neuromuscular monitoring was performed at each site using acceleromyography: in the extensor muscles of the pelvic limb (peroneal nerve) and thoracic limb (radial nerve), and in the orbicularis oris muscle (OOM; facial nerve). Rocuronium 0.6 mg kg(-1) i.v. was administered, followed 5 min later ...
Fortier Guillaume J, Laroche D, Babault N.The objective of this study was to identify the key biomechanical patterns (functional muscles and kinematics) of amateur horse riders during various cross-country jumps in equestrian. Eleven riders first performed a control condition that corresponded to jumps over three different obstacles (log wall, brush and tree trunk) before jumping over the same three obstacles in a cross-country course. 3D Kinematics and electromyographic (EMG) activity was synchronously collected which included seven muscles of the riders back, lower and upper limbs. Maximum voluntary isometric strength of knee extens...
Roger T, Ruckebusch Y.The contractile activity of the equine large intestine exhibited a biphasic response to feeding: enhancement of migrating complexes passing along the colon and an increase of 50% in cyclic variations in smooth muscle at intervals of 20 min on the left ventral colon for a period of 5 to 7 h postfeeding. The cholinergic agonist, bethanechol (50 micrograms/kg subcutaneously), induced both the migrating complexes and the cyclic variations at intervals of 10-15 min. In contrast, the intra-arterial infusion of PGF2 alpha (3 micrograms/kg/min) increased the contractile activity during infusion, but w...
Higuchi T, Ichijo S, Osame S, Ohishi H.In order to clarify the cause of white muscle disease (W.M.D.) in foals, tocopherol and selenium concentrations in serum and glutathione peroxidase activities in blood were measured. Examination was made on the samples from horses affected with W.M.D., the foal kept with them in the same stable, the foals kept in the stables without affected foals, and respective mares. The heavy-breed horses in Fukuoka prefecture and Tokachi district were also examined for comparison. Serum tocopherol levels of these foals were normal because after intake of colostrum. Mares of affected foals showed lower toc...
Belloli C, Carcano R, Arioli F, Beretta C.We used isolated equine digital arteries to study the vasodilatory mechanism of isoxsuprine, and fowl caecum preparations to investigate the affinity of the drug for beta-adrenoceptors. Isoxsuprine is a potent vasodilator of arterial smooth muscle that has been precontracted by an alpha-adrenoceptor agonist such as noradrenaline (log EC50 = -6.33 [-5.98; -6.68]). The present study indicates that its effect is due to alpha-adrenoceptor blockade since: (1) after a long lasting exposure to cumulative doses of isoxsuprine the vasoconstricting action of noradrenaline cannot be restored; (2) isoxsup...
Prause AS, Guionaud CT, Stoffel MH, Portier CJ, Mevissen M.To evaluate the expression of the 5-hydroxytryptamine 4 (5-HT4) receptor subtype and investigate the modulating function of those receptors on contractility in intestinal tissues obtained from horses without gastrointestinal tract disease. Methods: Smooth muscle preparations from the duodenum, ileum, and pelvic flexure collected immediately after slaughter of 24 horses with no history or signs of gastrointestinal tract disease. Methods: In isometric organ baths, the contractile activities of smooth muscle preparations in response to 5-hydroxytryptamine and electric field stimulation were asses...
