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.
Beldarrain LR, Morán L, Sentandreu MÁ, Insausti K, R Barron LJ, Aldai N.A full-randomized block design was used for the study of the FA composition and meat quality parameters, considering ageing time as a split-plot factor. Chemical and fatty acid composition of steaks (longissimus thoracis and lumborum muscle) from 15 month old semiextensively reared Hispano-Bretón horses were characterized (day 0), and the effect of vacuum ageing (0, 7, 14 and 21 days) on several meat quality parameters (pH, instrumental color and texture and cook loss) was determined. The average fat content of horse loin was 3.31%, and the n-3 polyunsaturated fatty acid content, although hig...
de Meeûs d'Argenteuil C, Boshuizen B, Oosterlinck M, van de Winkel D, De Spiegelaere W, de Bruijn CM, Goethals K, Vanderperren K, Delesalle CJG.Equine bioenergetics have predominantly been studied focusing on glycogen and fatty acids. Combining omics with conventional techniques allows for an integrative approach to broadly explore and identify important biomolecules. Friesian horses were aquatrained (n = 5) or dry treadmill trained (n = 7) (8 weeks) and monitored for: evolution of muscle diameter in response to aquatraining and dry treadmill training, fiber type composition and fiber cross-sectional area of the M. pectoralis, M. vastus lateralis and M. semitendinosus and untargeted metabolomics of the M. pectoralis and M. vastus late...
O'Hara V, Cowan A, Riddell D, Massey C, Martin J, Piercy RJ.Horse racing is a popular and financially important industry worldwide and researchers and horse owners are interested in genetic and training influences that maximise athletic performance. An association has been found between the presence of a short interspersed nuclear element (SINE) mutation in the myostatin (MSTN) gene promoter and optimal race distance in Thoroughbred horses. There is previous laboratory evidence that this mutation reduces MSTN expression in a cell culture model and influences skeletal muscle fibre type proportions in horses. Manipulating MSTN expression has been propose...
Urschel KL, McKenzie EC.Skeletal muscle comprises 40% to 55% of mature body weight in horses, and its mass is determined largely by rates of muscle protein synthesis. In order to support exercise, appropriate energy sources are essential: glucose can support both anaerobic and aerobic exercise, whereas fat can only be metabolized aerobically. Following exercise, ingestion of nonfiber carbohydrates and protein can aid muscle growth and recovery. Muscle glycogen replenishment is slow in horses, regardless of dietary interventions. Several heritable muscle disorders, including type 1 and 2 polysaccharide storage myopath...
Latham CM, Dickson EC, Owen RN, Larson CK, White-Springer SH.To test the hypothesis that complexed trace mineral supplementation would increase antioxidant capacity and decrease muscle oxidative stress and damage in young horses entering an exercise training program, Quarter Horses (mean [Formula: see text] SD; 9.7 ± 0.7 mo) balanced by age, sex, and BW were assigned to receive complexed (CTM; n = 8) or inorganic (INORG; n = 8) trace minerals at -12 week relative to this study. Blood and muscle samples were collected before (week 0) and after 12 week of light exercise training surrounding a 1.5-h trailer stressor. Muscle glutathione peroxid...
Suagee-Bedore JK, Shen Y, Porr S, Girard ID, Bennett-Wimbush K, Wagner AL.Exercising horses are commonly plagued by muscle fatigue and soreness, which can result in reduced performance ability. In the present study, ten unconditioned horses were fed 200g per day DigestaWell NRG, a commercial dietary supplement containing Yucca schidigera and Trigonella foenum-graecum, two herbs shown in other species to reduce post-exercise muscle pain and soreness. A control, unsupplemented group contained ten horses of similar age, breed, and gender. Horses completed a 50 minutes, ridden standardized exercise test of moderate intensity immediately prior to (Period1) and after 28 d...
Graham-Thiers PM, Bowen LK.Feeding management in horses suggests feeding horses in advance of exercise, particularly the grain portion of the diet. Plasma amino acids () peak at 3 to 6 h postfeeding depending on the AA. The timeframe between feeding and exercise may affect the availability of AA during and after exercise. The purpose of this study was to observe the differences in plasma AA in horses fed prior to exercise or after exercise. Eight light type horses were fed a diet with adequate protein and AA for horses in light to moderate exercise. After an adjustment period, horses completed a standardized exercise te...
Dietrich J, Handschuh S, Steidl R, Böhler A, Forstenpointner G, Egerbacher M, Peham C, Schöpper H.As the longissimus dorsi muscle is the largest muscle in the equine back, it has great influence on the stability of the spine and facilitates proper locomotion. The longissimus muscle provides support to the saddle and rider and thereby influences performance in the horse. Muscular dysfunction has been associated with back disorders and decline of performance. In general, muscle function is determined by its specific intramuscular architecture. However, only limited three-dimensional metrical data are available for the inner organisation of the equine longissimus dorsi muscle. Therefore, we a...
Silva MAB, Lupianhes AFG, Lage JB, Sande LAP, Rosa RC, Lombardi LA, Espindula AP.Activation of the trunk and lower limb muscles, namely the multifidus, rectus abdominis, rectus femoris, and tibialis anterior, was analyzed using surface electromyographyin 40 young, healthy, and sedentary individuals. Methods: Data were collected from sneaker-clad subjects with independent gait and during hippotherapy using saddles and blankets, with the feet in and out of the stirrups. Results: Surface electromyography results demonstrated a statistically significantly greater activation of the rectus femoris comparison to tibialis anterior muscle during hippotherapy. No statistically signi...
Ferrando Meseguer E, Roig Sánchez S, Pino Almero L, Romano Bataller A, Mínguez Rey MF.Talipes equinovarus or clubfoot is a congenital deformity of the foot with bone, muscle, and tendon involvement. It's one of the most frequent foot malformations in pediatric orthopedics. Although generally idiopathic, it may have a syndromic cause and be associated with musculoskeletal, neurological, or connective tissue conditions. The treatment of choice in idiopathic clubfoot is the Ponseti method based on manipulation and fixation with serial casts that seek progressive correction of the deformity. The Ponseti method effectiveness has been demonstrated in arthrogryposis and myelomeningoce...
Zsoldos RR, Khayatzadeh N, Soelkner J, Schroeder U, Hahn C, Licka TF.Type 1 polysaccharide storage myopathy caused by genetic mutation in the glycogen synthase 1 gene is present in many breeds including the Noriker and Haflinger horses. In humans, EMG has already been used to document changes in the muscle activity patterns of patients affected by human glycogen storage disorders. Therefore, the aim of the present study was to describe gluteus muscle activity with surface electromyography (sEMG) in Haflinger and Noriker horses with known GYS1 mutation status during walk and trot. Thirty-two horses (11 Haflinger and 21 Noriker horses) with homozygous non-affecte...
Banse HE, Whitehead AE, McFarlane D, Chelikani PK.Pituitary pars intermedia dysfunction (PPID) is a common endocrine disorder of aged horses, with muscle atrophy as one of the clinical signs. We sought to compare muscle mass and regulation of skeletal muscle proteolysis between horses with PPID and muscle atrophy to older horses without PPID, and to assess the impact of treatment with pergolide (dopaminergic agonist) on PPID horses. We hypothesized that PPID-associated muscle atrophy is a result of increased proteolysis, and that markers of muscle atrophy and proteolysis would improve over time with pergolide treatment. Markers of muscle atro...
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...
Aldrich K, Velez-Irizarry D, Fenger C, Schott M, Valberg SJ.Recurrent exertional rhabdomyolysis (RER) is a chronic muscle disorder of unknown etiology in racehorses. A potential role of intramuscular calcium (Ca2+) dysregulation in RER has led to the use of dantrolene to prevent episodes of rhabdomyolysis. We examined differentially expressed proteins (DEP) and gene transcripts (DEG) in gluteal muscle of Thoroughbred race-trained mares after exercise among three groups of 5 horses each; 1) horses susceptible to, but not currently experiencing rhabdomyolysis, 2) healthy horses with no history of RER (control), 3) RER-susceptible horses treated with dant...
Mrugala D, Leatherwood JL, Morris EF, Dickson EC, Latham CM, Owen RN, Beverly MM, Kelley SF, White-Springer SH.Conjugated linoleic acid (CLA) improves oxidative stress and mitochondrial biogenesis in various species but has not been thoroughly investigated in horses. We collected blood and muscle samples from lightly exercising horses before and 6 and 12 wk after receiving either soybean oil (CON; n = 5) or CLA (CLA; n = 5) supplementation. Samples were analyzed for markers of mitochondrial characteristics, antioxidant status, oxidative stress, and muscle damage. Data were analyzed using a linear model with repeated measures. In the triceps brachii (TB), citrate synthase (CS) activity was higher in CON...
St George L, Clayton HM, Sinclair J, Richards J, Roy SH, Hobbs SJ.Selection and training practices for jumping horses have not yet been validated using objective performance analyses. This study aimed to quantify the differences and relationships between movement and muscle activation strategies in horses with varying jump technique to identify objective jumping performance indicators. Surface electromyography (sEMG) and three-dimensional kinematic data were collected from horses executing a submaximal jump. Kinematic variables were calculated based on equestrian-derived performance indicators relating to impulsion, engagement and joint articulation. Horses ...
Park S, Park S, Yoo J, Jee YS.This study investigated whether equine riding affects static or dynamic mechanical contractions on the thighs and trunk muscles in inactive women. Methods: Participants consisted of 30 women with a mean (SD) age of 21.06 (0.44) years. They were randomly allotted as follows: equine group (EQG, n= 15) and control group (CON, n= 15). Two types of muscle contraction properties in their thighs and trunk were measured through a tensiomyography (static muscle tester) and an isokinetic device (dynamic muscle tester), respectively. Using the body weights of EQG and CON as covariates, a 2-way between-gr...
Dockalova H, Zeman L, Horky P.Veterinarians can recommend milk thistle for the treatment of equine liver disease and laminitis. Milk thistle seed cakes were fed in the range of normal feed doses in this study. The milk thistle seed cakes were fed (twice a day) to the experimental group of the horses ( = 5) and biochemical blood markers (TP, Albumin, ALT (alanine transaminase), AST (aspartate transaminase), ALP (alkaline phosphatase), GGT (gamma-glutamyltransferase), Bilirubin, Cholesterol, HDL (high-density lipoprotein), LDL (low-density lipoprotein), TAG (triacylglycerol), BHB (beta-hydroxybutyric acid), NEFA (non-esterif...
Ahmed W, Elbrønd VS, Harrison AP, Hart JO, Williams RE.Back pain is a common condition in horses, yet despite this, quantitative assessments of the efficacy of treatment are scarce. Mechanical nociceptive thresholds (MNTs) and acoustic myography (AMG) recordings were obtained, both preinterventionand postintervention, from the left and right epaxial muscles in eight healthy general riding horses (mean age 17 ± 6 yrs). Using an algometer, MNT readings were taken at each of the 6 preselected points along the thoracolumbar M. longissimus and M. gluteus medius region. AMG recordings of the M. longissimus and M. gluteus medius were taken while wal...
Autry JM, Karim CB, Perumbakkam S, Finno CJ, McKenzie EC, Thomas DD, Valberg SJ.Ca regulation in equine muscle is important for horse performance, yet little is known about this species-specific regulation. We reported recently that horse encode unique gene and protein sequences for the sarcoplasmic reticulum (SR) Ca-transporting ATPase (SERCA) and the regulatory subunit sarcolipin (SLN). Here we quantified gene transcription and protein expression of SERCA and its inhibitory peptides in horse gluteus, as compared to commonly-studied rabbit skeletal muscle. RNA sequencing and protein immunoblotting determined that horse gluteus expresses the gene (SERCA1) as the predomin...
Steel CM, Walmsley EA, Anderson GA, Coles CA, Ahern B, White JD.As myosin heavy chain (MyHC) profile of muscle fibres is heavily influenced by neural input, changes in MyHC expression are expected in horses clinically affected with recurrent laryngeal neuropathy (RLN) yet, this has not been thoroughly investigated. Objective: To describe the changes in MyHC and fibre diameter in left cricoarytenoideus dorsalis (L-CAD) muscle of horses with clinical signs of RLN. Methods: Observational cohort study. Methods: Immunohistochemistry was used to assess the MyHC-based fibre-type proportion, size and grouping in the L-CAD of 10 Thoroughbred horses, five clinically...
Journée SL, Journée HL, Berends HI, Reed SM, de Bruijn CM, Delesalle CJG.Transcranial electrical (TES) and magnetic stimulation (TMS) are both used for assessment of the motor function of the spinal cord in horses. Muscular motor evoked potentials (mMEP) were compared intra-individually for both techniques in five healthy horses. mMEPs were measured twice at increasing stimulation intensity steps over the extensor carpi radialis (ECR), tibialis cranialis (TC), and caninus muscles. Significance was set at < 0.05. To support the hypothesis that both techniques induce extracranially elicited mMEPs, literature was also reviewed. Results: Both techniques show the pr...
Schaefer RJ, Cullen J, Manfredi J, McCue M.A gene's response to an environment is tightly bound to the underlying genetic variation present in an individual's genome and varies greatly depending on the tissue it is being expressed in. Gene co-expression networks provide a mechanism to understand and interpret the collective transcriptional responses of genes. Here, we use the Camoco co-expression network framework to characterize the transcriptional landscape of adipose and gluteal muscle tissue in 83 domestic horses (Equus caballus) representing 5 different breeds. In each tissue, gene expression profiles, capturing transcriptional re...
Moro LN, Viale DL, Bastón JI, Arnold V, Suvá M, Wiedenmann E, Olguín M, Miriuka S, Vichera G.The application of new technologies for gene editing in horses may allow the generation of improved sportive individuals. Here, we aimed to knock out the myostatin gene (MSTN), a negative regulator of muscle mass development, using CRISPR/Cas9 and to generate edited embryos for the first time in horses. We nucleofected horse fetal fibroblasts with 1, 2 or 5 µg of 2 different gRNA/Cas9 plasmids targeting the first exon of MSTN. We observed that increasing plasmid concentrations improved mutation efficiency. The average efficiency was 63.6% for gRNA1 (14/22 edited clonal cell lines) and 96.2% ...
Loos CMM, McLeod KR, Stratton SC, van Doorn DA, Kalmar ID, Vanzant ES, Urschel KL.Activation of the mechanistic target of rapamycin (mTOR)-controlled anabolic signaling pathways in skeletal muscle of rodents and humans is responsive to the level of dietary protein supply, with maximal activation and rates of protein synthesis achieved with 0.2 to 0.4 g protein/kg body weight (BW). In horses, few data are available on the required level of dietary protein to maximize protein synthesis for maintenance and growth of skeletal muscle. To evaluate the effect of dietary protein level on muscle mTOR pathway activation, five mares received different amounts of a protein supplement t...
Peters S, Wilson J, Boyette J.The objective of this study was to determine the influence of age on expression of insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein (IGFBP5), myostatin (MSTN), and myosin (MYH1) genes which are related to growth and muscle development in the American Quarter Horse. Thus, horses (n = 10) from weanling, yearling, 2-, 3-, and 10-year-old age classes were sampled and gene expression was assessed by RT-qPCR. ΔC was calculated using the hypoxanthine-guanine phosphoribosyltransferase gene as an internal normalizer. The generalized linear model was used to determine di...
González-Medina S, Hyde C, Lovera I, Piercy RJ.Measurement of hypoglycin A (HGA) and its toxic metabolite, methylenecyclopropylacetic acid (MCPA), in equine serum confirms a diagnosis of atypical myopathy (AM), a pasture-associated toxic rhabdomyolysis with high mortality linked to the ingestion of Acer trees plant material. Supportive diagnostic tests include plasma acyl-carnitine profiling and urine organic acid testing, but these are not specific for AM. Previously reported HGA and MCPA analytical techniques used liquid chromatography-mass spectrometry (LC-MS) with a derivatising step, but the latter prolongs testing and increases costs...
Veronesi F, Di Palma S, Gabrielli S, Morganti G, Milardi GL, Middleton B, Lepri E.The only species currently known to inhabit the fibers of skeletal and cardiac muscles in horses are , and . We describe herein the invasion of myofibers in a horse by , a sheep-specific species with low virulence in the original host. A hunter gelding was referred to a veterinary surgeon in Newmarket (UK). The anamnestic data reported that the horse had an initial history of swelling of the right forelimb with fluid on the front of the carpus and edema spreading up the forearm. Subsequently, 2 firm lumps were found on the left pectoral muscle adjacent to the axilla of the left forelimb. Hist...
Valberg SJ.There are 5 single-gene mutations that are known to cause muscle disease in horses. These mutations alter the amino acid sequence of proteins involved in cell membrane electrical conduction, muscle energy metabolism, muscle contraction, and immunogenicity. The clinical signs depend on the pathway affected. The likelihood that an animal with a mutation will exhibit clinical signs depends on the mode of inheritance, environmental influences, and interactions with other genes. Selection of a genetic test for use in diagnostic or breeding decisions requires a knowledge of clinical signs, mode of i...
Brard S, Ricard A.A genome-wide association study was performed to identify single nucleotide polymorphisms (SNPs) associated with jumping performances of warmbloods in France. The 999 horses included in the study for jumping performances were sport horses [mostly Selle Français (68%), Anglo-Arabians (13%) and horses from the other European studbooks]. Horses were genotyped using the Illumina EquineSNP50 BeadChip. Of the 54,602 SNPs available on this chip, 44,424 were retained after quality testing. Phenotypes were obtained by deregressing official breeding values for jumping competitions to use all available ...
Schuback K, Essén-Gustavsson B, Persson SG.The aim of the present study was to investigate the effect of creatine (Cr) supplementation on muscle metabolic response in connection with a maximal treadmill exercise test, known to cause a marked anaerobic metabolic response and adenine nucleotide degradation. First, 6 Standardbred trotters performed a standardised maximal exercise test until fatigue (baseline test). The test used was an inclined incremental treadmill test in which the speed was increased by 1 m/s, starting at 7 m/s, every 60 s until the horse could no longer keep pace with the treadmill. After this baseline test, the horse...
Saitua A, Becero M, Argüelles D, Castejón-Riber C, Sánchez de Medina A, Satué K, Muñoz A.Horse trainers often claim that exercise on a water treadmill (WT) leads to a greater muscle power and development compared to terrestrial locomotion, because of the greater viscosity of water compared to air. This research assesses locomotor changes measured with accelerometers fixed in the pectoral region and in the sacrum midline in six horses subjected to exercise sessions of 40 min duration on a WT without water (DT), and with water at the depth of fetlock (FET) and carpus (CAR) with velocities of 6 km/h and at the depth of stifle (STF) at 5 km/h. Another five horses performed the same ex...
Gao S, Nanaei HA, Wei B, Wang Y, Wang X, Li Z, Dai X, Wang Z, Jiang Y, Shao J.Heterosis has been widely exploited in animal and plant breeding programs to enhance the productive traits of hybrid progeny from two breeds or species. However, its underlying genetic mechanisms remain enigmatic. Transcriptome profiling analysis can be used as a method for exploring the mechanism of heterosis. Here, we performed genome-wide gene expression and alternative splicing (AS) analyses in different tissues (muscle, brain, and skin) from crosses between donkeys and horses. Our results indicated that 86.1% of the differentially expressed genes (DEGs) and 87.2% of the differential alter...
Byström A, Hardeman AM, Serra Bragança FM, Roepstorff L, Swagemakers JH, van Weeren PR, Egenvall A.Work on curved tracks, e.g. on circles, is commonplace within all forms of horse training. Horse movements in circles are naturally asymmetric, including the load distribution between inner and outer limbs. Within equestrian dressage the horse is expected to bend the back laterally to follow the circle, but this has never been studied scientifically. In the current study 12 horses were measured (optical motion capture, 100 Hz) trotting on left and right circles and on the straight without rider (soft surface). Data from markers placed along the spine indicated increased lateral bending to the...
Kim JS, Hinchcliff KW, Yamaguchi M, Beard LA, Markert CD, Devor ST.Exercise training improves functional capacity in aged individuals. Whether such training reduces the severity of exercise-induced muscle damage is unknown. The purpose of the present study was to determine the effect of 10 wk of treadmill exercise training on skeletal muscle oxidative capacity and exercise-induced ultrastructural damage in six aged female Quarter horses (>23 yr of age). The magnitude of ultrastructural muscle damage induced by an incremental exercise test before and after training was determined by electron microscopic examination of samples of triceps, semimembranosus, an...
de Meeûs d'Argenteuil C, Boshuizen B, Vidal Moreno de Vega C, Leybaert L, de Maré L, Goethals K, De Spiegelaere W, Oosterlinck M, Delesalle C.Training-induced follow-up of multiple muscle plasticity parameters in postural stability vs. locomotion muscles provides an integrative physiological view on shifts in the muscular metabolic machinery. It can be expected that not all muscle plasticity parameters show the same expression time profile across muscles. This knowledge is important to underpin results of metabolomic studies. Twelve non-competing Standardbred mares were subjected to standardized harness training. Muscle biopsies were taken on a non-training day before and after 8 weeks. Shifts in muscle fiber type composition and mu...
Snow DH, Guy PS.The use of the technique of percutaneous needle biopsy in obtaining skeletal muscle samples in the horse is described. The biochemical, ultrastructural and histochemical investigations that can be carried out on this biopsy specimen are outlined. Analyses performed on the specimen may be used to obtain information on racing potential and state of fitness. These studies on normal horses will provide information for future investigations into the structural and biochemical alterations in muscle disorders in the equine.
Turlo AJ, Mueller-Breckenridge AJ, Zamboulis DE, Tew SR, Canty-Laird EG, Clegg PD.The main challenge in tendon injury management is suboptimal tissue healing that fails to re-establish original tendon function. Tissue bioengineering is a promising approach for tendon therapy, with potential to improve its functional outcomes. However, evaluation criteria for tissue-engineered tendon are unclear due to the lack of specific markers of differentiated tendon. The study aim was to identify a panel of genes that characterised tendons in comparison to cartilage or muscles and validate those genes, both in human and key species used as models for tendon diseases. Gene expression pr...
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...
Cheung TK, Warren LK, Lawrence LM, Thompson KN.Surface electrodes were used to record electromyographic (EMG) activity of the long digital extensor muscle on the right hindlimb of 8 Thoroughbred horses for 8 s at the walk and 8 s at the trot before (unfatigued) and after (fatigued) an exercise test. The exercise test was performed on a motorised treadmill set on a 10% grade. Each test started at a speed of 6 m/s which was increased by 1 m/s each minute until the horse fatigued as indicated by its inability to keep pace with the treadmill with minimal encouragement. Observations were made on the horses prior to conditioning (untrained state...
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...
Li C, White SH, Warren LK, Wohlgemuth SE.Aging is associated with decreased mitochondrial content and function in skeletal muscle, possibly due to compromised biogenesis and autophagic removal of dysfunctional mitochondria. The aim of this study was to compare markers of mitochondrial content and biogenesis and of autophagy between skeletal muscle from young and aged American Quarter Horses. Citrate synthase protein and mtDNA copy number were decreased in triceps brachii (TB) muscle (P<0.05) from aged horses, suggesting an age-related decline in mitochondrial content. Concomitantly, mRNA expression of PGC-1α and TFAM, regulators ...
Kline KH, Bechtel PJ.1. Cross sections from the middle of the gluteus medius were removed from 10 adult horses and used to evaluate changes in histochemically determined muscle fiber type and biochemically determined metabolic enzyme activities as a function of sample depth. 2. Muscle fiber types determined using histochemical methods for myosin ATPase (pH 9.4) and succinic dehydrogenase (SDH) activity indicated percent fast-twitch glycolytic (FG) muscle fibers decreased and slow-twitch oxidative (SO) fibers increased as a function of increasing sampling depth. 3. Percent histochemically determined fast-twitch oxi...
Rigby SL, Barhoumi R, Burghardt RC, Colleran P, Thompson JA, Varner DD, Blanchard TL, Brinsko SP, Taylor T, Wilkerson MK, Delp MD.Persistent, postmating endometritis affects approximately 15% of mares and results in reduced fertility and sizable economic losses to the horse-breeding industry. Mares that are susceptible to postmating endometritis have delayed uterine clearance associated with reduced uterine contractility. Unfortunately, the mechanism for reduced uterine contractility remains an enigma. The present study examined the hypothesis that mares with delayed uterine clearance have an intrinsic contractile defect of the myometrium. Myometrial contractility was evaluated in vitro by measuring isometric tension gen...
Erber M, Geisel O.The prevalence of Sarcocystis spp. in horses was investigated in a survey at the Munich abattoir during 1978/79. Muscle specimens (oesophagus, diaphragm, sublingual muscle, myocardium) were examined using tryptic digestion. Out of 200 horses 31 (15.5%) were found to be carriers of sarcocysts. No parasites were found in the myocardium. In three animals sarcocysts could be isolated and differentiated in fresh preparations. Cysts with 5 to 11 microns by less than 0.5 microns hairlike, unstable protrusions were classified as Sarcocystis equicanis, whereas those with 2.5 to 4.5 microns by 0.8 to 1....
Park JW, Choi JY, Hong SA, Kim NY, Do KT, Song KD, Cho BW.This study was performed to reveal the molecular structure and expression patterns of horse glutamate-cysteine ligase catalytic subunit () and glutamate-cysteine ligase modifier subunit () genes whose products form glutamate cysteine ligase, which were identified as differentially expressed genes in the previous study. Methods: We performed bioinformatics analyses, and gene expression assay with quantitative polymerase chain reaction (qPCR) for horse and genes in muscle and blood leukocytes of Thoroughbred horses. Results: Expression of showed the same pattern in both blood and muscle tissu...
Edner A, Nyman G, Essén-Gustavsson B.To study in horses (1) the relationship between cardiovascular variables and muscle perfusion during propofol-ketamine anaesthesia, (2) the physiological effects of a single intravenous (IV) detomidine injection, (3) the metabolic response of muscle to anaesthesia, and (4) the effects of propofol-ketamine infusion on respiratory function. Methods: Prospective experimental study. Methods: Seven standardbred trotters, 5-12 years old, 416-581 kg. Methods: Anaesthesia was induced with intravenous (IV) guaifenesin and propofol (2 mg kg) and maintained with a continuous IV infusion of propofol (0.15...
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...
Valberg SJ, Soave K, Williams ZJ, Perumbakkam S, Schott M, Finno CJ, Petersen JL, Fenger C, Autry JM, Thomas DD.Sarcolipin (SLN), myoregulin (MRLN), and dwarf open reading frame (DWORF) are transmembrane regulators of the sarcoplasmic reticulum calcium transporting ATPase (SERCA) that we hypothesized played a role in recurrent exertional rhabdomyolysis (RER). Objective: Compare coding sequences of SLN, MRLN, DWORF across species and between RER and control horses. Compare expression of muscle Ca2+ regulatory genes between RER and control horses. Methods: Twenty Thoroughbreds (TB), 5 Standardbreds (STD), 6 Quarter Horses (QH) with RER and 39 breed-matched controls. Methods: Sanger sequencing of SERCA reg...
Dockalova H, Zeman L, Horky P.Veterinarians can recommend milk thistle for the treatment of equine liver disease and laminitis. Milk thistle seed cakes were fed in the range of normal feed doses in this study. The milk thistle seed cakes were fed (twice a day) to the experimental group of the horses ( = 5) and biochemical blood markers (TP, Albumin, ALT (alanine transaminase), AST (aspartate transaminase), ALP (alkaline phosphatase), GGT (gamma-glutamyltransferase), Bilirubin, Cholesterol, HDL (high-density lipoprotein), LDL (low-density lipoprotein), TAG (triacylglycerol), BHB (beta-hydroxybutyric acid), NEFA (non-esterif...
Zsoldos RR, Voegele A, Krueger B, Schroeder U, Weber A, Licka TF.The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and med...
Issouf M, Vargas A, Boivin R, Lavoie JP.Smooth muscle has a central role in bronchospasm-induced airway obstruction in asthma. Alternative mRNA splicing of the smooth muscle myosin heavy chain (myh11) gene produces four different isoforms, one of which (SMB) is characterized by the inclusion of the exon5b, which doubles the smooth muscle cells contraction velocity. Deciphering the regulation of the expression levels of the SMB isoform would represent a major step for the understanding of the triggers and pathways leading to airway smooth muscle contraction in asthma. Our objective was therefore, to study the splicing regulation mech...
Kim MJ, Kim T, Oh S, Yoon B.Horseback riding is an effective exercise for improving postural control and balance. To reduce costs and improve accessibility, simulated horseback riding has been developed; but no differential effects of simulated and real horseback riding on muscle activation patterns in older adults have been studied. Thus, we compared muscle activation patterns for older and younger adults engaged in real and simulated horseback riding exercises, using surface electromyography recordings of the erector spinae, rectus abdominis, internal oblique abdominis, and rectus femoris muscles. We recorded muscle ac...
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...
Ball BA, Scoggin KE, Troedsson MH, Squires EL.Biological effects of prostaglandin E2 are mediated via one of four receptors designated EP1, EP2, EP3 and EP4 which are encoded by separate genes. In general, EP1 and EP3 induce smooth muscle contraction whereas EP2 and EP4 induce smooth muscle relaxation. The objective of the current study was to characterize the expression of the genes for PGE2 receptors (EP2 and EP4) in the horse oviduct based upon immunohistochemistry (IHC) and quantitative PCR (qPCR). Oviductal tissue was collected from mares at estrus (n=5), at 5 days post-ovulation (n=4), and from prepubertal mares (n=5). Isthmic and a...
Badin L, Alibran É, Pothier K, Bailly N.Equine-assisted interventions (EAI) can improve a variety of health problems in older adults and thus promote their well-being. This systematic review aimed to synthesize studies on EAI to understand better their effects on the health of older adults. Unassigned: A systematic search guided by the PRISMA 2020 approach was performed on specific databases: Medline (PubMed), EMBASE, PsycINFO, and Cochrane Library. Peer-reviewed articles published in the English language from inception to June 2022 were retrieved. Methodological quality was established using the modified version of the Downs and Bl...
Pösö AR, Eklund-Uusitalo S, Hyyppä S, Pirilä E.In response to stress, cells synthesise heat shock proteins (HSP) to maintain protein homeostasis. To study whether exercise and training induce expression of HSP72 in the middle gluteal muscle, 10 Finnhorses performed a submaximal 60 min exercise test on a treadmill. Test A was performed after 3 months of training, and the other two tests 2 (B) and 5 (C) weeks later. Blood samples were taken during and after the tests, and biopsy samples before, immediately after and 23 h after each test. HSP72 mRNA was analysed using a digoxigenin-labelled probe. Blood lactate concentration in the 3 tests va...
Ropka-Molik K, Stefaniuk-Szmukier M, Musiał AD, Piórkowska K, Szmatoła T.The ACTN3 gene codes for α-actinin-3, a protein localized in the Z-line in the skeletal muscle. Actinin-3 is critical in anchoring the myofibrillar actin filaments and plays a key role in muscle contraction. ACTN3 (α-actinin-3) cross-links glycogen phosphorylase (GP), which is the key enzyme catalysing glycogen metabolism. The aim of present study was to establish the expression level of the ACTN3 gene (for both isoforms separately and together in the gene expression analysis) in the gluteus medius muscle in order to verify if the α-actinin-3 gene can be related to training intensity in Ara...
