In vitro research involving horses refers to the study of equine cells, tissues, or biological molecules outside their normal biological context, typically in controlled laboratory environments. This research approach allows scientists to investigate cellular processes, molecular interactions, and the effects of various treatments without the ethical and logistical complexities of in vivo studies. In vitro studies contribute to understanding equine physiology, pathology, and pharmacology by providing insights into cellular responses to pathogens, drugs, and other stimuli. This page compiles peer-reviewed research studies and scholarly articles that explore various in vitro methodologies and their applications in equine science, including cell culture techniques, molecular assays, and drug efficacy testing.
Boone CW, Harell GS, Bond HE.Large-scale separation of mixtures of mammalian cells was obtained with the A-1X zonal centrifuge rotor and density gradients consisting of Ficoll dissolved in modified Eagle's MEM suspension-culture medium. The cells remained viable as tested by plating efficiency or by motility observed with time-lapse photography. Rabbit thymocyte and HeLa cell mixtures were separated with 99 and 89 per cent purity, respectively. Mixtures of thymocytes and suspension-cultured, human acute leukemia cells (Roswell Park strain LKID) were separated with 93 and 91% purity, respectively. HeLa cells were isolated ...
Abrahams M.The mechanical behaviour of horse and human tendon, as characterised by the stress-strain curve, has been examined with respect to load-strain cycling and strain rate. It was found that the tendon stress-strain curve for successive cycles was reporducible provided that strain on the specimen did not exceed 2·0–4·0%. If this strain level was exceeded, a permanent deformation occurred. This phenomenon was verified by histological studies on strained tendon which showed that some of the collagen fibres did not return to their original orientation. Variation in the rate of strain was found to ...
Rogers HJ.Under a variety of conditions of concentration, Eh, and pH, horse anti- serum and normal horse serum exerted similar bacteriostatic effects against Type A. Ferric iron abolished the bacteriostatic effect when added during the first 2 hours of incubation at Eh+60 mV. Ferrous iron abolished the bacteriostatic effect when added after 3 hours. Ferric iron abolished the bacteriostatic effect at—140 mV. A mixture consisting of horse β- and γ-globulins together with human transferrin exerted a bacteriostatic effect similar to that of whole serum. This system responded in the same way as whole se...
Rockey JH.Eight antigenically unique immunoglobulins have been identified in purified equine anti-p-azophenyl-beta-lactoside (Lac) antibody isolated from a single horse. The Fc fragments of the gammaGa-, gammaGb-, gammaGc-, and -gammaA-globulins have been shown to possess unique antigenic determinants. Common gammaG- and gammaA-Fc fragment antigenic determinants, which were absent from the 10Sgamma(1)- and gammaM-globulins, have also been observed. All antibody populations share two antigenically distinct light (B, L) chain variants. The association of anti-Lac antibody with the hapten p-(p-dimethylamin...
Haque RU.A technique for identifying and characterizing staphylococcal hemolysins by first separating them electrophoretically in barbital-buffered agar gel (pH 8.4) at 5 ma/cm for 2 hr and then determining their hemolytic activities by exposing them to human, horse, rabbit, and sheep erythrocytes is described. The alpha-hemolysin produced by a White variant of the Wood 46 strain of Staphylococcus aureus migrated 18 mm towards the cathode, and it lysed horse, rabbit, and sheep erythrocytes, whereas a Clear variant of the Wood 46 strain of S. aureus produced a lysin which migrated similarly to the alpha...
Friis NF, Bech J.Döhle bodies were observed in a horse suffering from a chronic pleurisy. The bodies were demonstrated in about 80 % of the neutro-phils in blood smears prepared during an acute flare-up of the disease. One to 4 bodies were found in each cell, situated in the periphery of the cytoplasm. The size of the bodies was 1–3 μ and the shape rodlike or oval. They stained blue with M-G-G. Blood smears were examined from 50 horses suffering from various diseases, but Döhle bodies could not be demonstrated in any of these cases. Döhle-Körperchen wurden bei einem Pferd mit chronischer Pleuritis beoba...
Darlington RW, James C.Darlington, R. W. (St. Jude Children's Research Hospital, Memphis, Tenn.), and C. James. Biological and morphological aspects of the growth of equine abortion virus. J. Bacteriol. 92:250-257. 1966.-The growth of equine abortion virus (EAV) was studied by bioassay and electron microscopy in L-cell monolayer and suspension cultures, and in HeLa and BHK 21/13 cell monolayers. Results of virus assay (plaque-forming units) indicated that production of cell-associated virus (CAV) began at 6 to 9 hr after infection in all of the cell strains used. Virus release occurred 1 to 2 hr later. By 15 to 20 h...
Channing CP.OUR knowledge of the pathways of steroid biosynthesis in the ovary has been gained mainly by incubations of ovaries in vitro1,2. The tissues incubated have contained numerous cell types: granulosa cells, theca interna cells, stromal cells, interstitial cells, and sometimes luteal cells. Possibly such mixtures of two or more different cell types are able to secrete hormones that one cell type cannot secrete by itself3–9. Furthermore, during such incubations in vitro an exchange of precursors and products between different cell types may be facilitated because of breakdown of naturally occurri...
Black JA, Leaf G.1. The effects of cyanogen bromide on horse-heart cytochrome c and horse-heart myoglobin have been investigated. Cytochrome c yielded four fragments, of which two were haemopeptides. The two colourless peptides had amino acid compositions corresponding to those that are expected, on the basis of the sequence proposed for horse-heart cytochrome c by Margoliash, Smith, Kreil & Tuppy (1961), from cleavage at both methionine residues. Of the two haemopeptides, one was isolated and shown to be that derived from cleavage at only one methionine residue, that nearer to the C-terminus of the peptid...
HARDY FM, ARBITER D.Hardy, Frank M. (Fort Detrick, Frederick, Md.), and David Arbiter. Lipid inclusions in L cells associated with Venezuelan equine encephalomyelitis virus infection. J. Bacteriol. 89:1101-1103. 1965.-Venezuelan equine encephalomyelitis (VEE) virus has been shown to induce changes of lipid components within the L cell. Lipid inclusions in the form of dark granular bodies were observed in the L cell after aqueous osmium tetroxide fixation and Sudan black staining. Microscopic examination of cells as early as 8 hr after infection with VEE virus showed an increase in the concentration of these inclu...
Grześkowiak Ł, Riedmüller J, Vahjen W, Zentek J.Storage procedures are known to affect the detectability of toxins in equine and human feces. We assessed the impact of different storage conditions on the detectability of toxins in swine feces. Specimens were inoculated with toxins, 112 ng/g of toxin A (TcdA) and 16 ng/g of toxin B (TcdB) and subjected to the following 3 storage treatments: 4°C, -30°C, repetitive freezing at -30°C and thawing. Toxin determination was assessed at 1, 2, 7, 14, and 21 d with ELISA. A decrease in concentrations of TcdA with time was observed for samples stored at 4°C and repetitive freezing-thawing ( ≤0....
Marquardt J, Heymer J, Heinz H, Adolf GR, Deegen E.Recombinant equine interferon-beta 1 (reqIFN-beta 1) induces an antiviral state in blood mononuclear cells (BMC) of horses. Maximal protection against replication of vesicular stomatitis virus is achieved 6 hours after treatment with IFN in vitro and in vivo. Duration of the protective effect depends on the dose of IFN in vitro and in vivo. Availability of reqIFN-beta 1 in cultures of BMC for up to 48 hours does not prolong the antiviral state. The protective effect on BMC after treatment with IFN has similar duration in vivo and in vitro. Monitoring of the effect of IFN in vivo is, thus, simp...
Madsen K, Martens A, Haspeslagh M, Meulyzer M, Gustafsson K.Medical grade honey (MGH) has been introduced as a protective measure against surgical site infections in equine surgery, but the effect on suture material has not been investigated. Objective: To evaluate the effect of MGH on the tensile properties of three synthetic absorbable suture materials. Methods: In vitro experiments. Methods: Ten strands of Polydioxanone USP 2 (PD2), Polyglactin 910 USP 2 (PG2) and Polyglecaprone USP 2-0 (PC2-0) were incubated 1, 7, 14, 21 and 28 days in MGH, phosphate-buffered saline (PBS), equine plasma (EP) and MGH mixed with equine plasma (HP). Mechanical testi...
Kwak YB, Yoon J, Yoo HH.SR9009, a peroxisome proliferator-activated receptor δ (PPARδ) agonist, is known for its potential benefits in energy homeostasis. It failed to receive the United States Food and Drug Administration (USFDA) approval and its illegal distribution has raised concerns. As a result, it has been classified as a prohibited substance by the World Anti-Doping Agency and the International Federation of Horseracing Authorities (IFHA). This study emphasizes the application of the in-silico molecular networking technology to analyze phase I drug metabolites in horses, distinguishing it from conventional ...
Mattei DN, Harman RM, Van de Walle GR, Smith R, Grivel JC, Abdelalim EM, Vinardell T.Mesenchymal stromal cells (MSCs) have regenerative and immunomodulatory potential and may be used to treat injured tissues. Pregnancy has been associated with increased MSCs in the peripheral circulation in multiple species, but to date, there are no reports on this matter in horses. This study aimed to evaluate the effect of pregnancy on isolation efficiency and proliferation capacity of equine MSCs derived from the peripheral blood (PB) of mares. Venous blood samples were collected at the 11th month of gestation and 1 month after delivery from clinically healthy Arabian mares that presented ...
Arroyo-Salvo C, Río S, Bogetti ME, Plaza J, Miragaya M, Yaneff A, Davio C, Fissore R, Gervasi MG, Gambini A, Perez-Martinez S.Factors contributing to the limited success of in vitro fertilization in horses remain to be studied. In this work, we elucidated the effect of different essential capacitation media components, bicarbonate, and bovine serum albumin or polyvinyl-alcohol, and the incubation microenvironment on sperm parameters associated with capacitation, acrosome reaction, and their ability to activate oocytes via heterologous intracytoplasmic spermatozoa injection in equine cryopreserved spermatozoa. Methods: Frozen-thawed spermatozoa underwent incubation at different time intervals in either Tyrode's albumi...
Aguila L, Cabrera P, Arias ME, Silva M, Felmer R.Intracytoplasmic sperm injection (ICSI) in horses is currently employed for clinical and commercial uses, but the protocol could be optimized to improve its efficiency. We have hypothesized that destabilization of plasma and acrosomal membranes prior to injection would positively impact the developmental potential of equine zygotes generated by ICSI. This study evaluated effects of the sperm treatment with lysolecithin on plasma and acrosomal membranes and on oocyte activation ability, initially following heterologous ICSI on bovine oocytes and subsequently employing equine oocytes. The effect...
Fuentes F, Contreras MJ, Arroyo-Salvo C, Cabrera P P, Silva M, Merino O, Arias ME, Felmer R.Although under appropriate laboratory conditions, sperm from different mammalian species can be capacitated in vitro, the optimal conditions for sperm capacitation in the stallion have been elusive. This study evaluated the effect of different capacitating inducers in Whitten and Tyrode media and assessed their impact on capacitation-related factors. Stallion sperm were incubated with different combinations of capacitating inducers at 38.5 °C in an air atmosphere. Sperm quality variables such as motility, mitochondrial membrane potential, and lipid peroxidation were assessed. Membrane fluidi...
Silva AH, Lucena JEC, Taran FMP, Cunha DS, Almeida JAT, Lima RS, Dias WS, Santiago JM.This study aimed to compare the digestibility of tropical grasses by horses by the in vivo method using mobile nylon bags with the in vitro digestibility method using horse feces as a source of inoculum. Five horses were used in a 2 × 5 factorial design with randomized blocks featuring two methods (in vivo and in vitro) and five grasses: Tifton 85 hay (Cynodon spp.), sixweeks threeawn grass (Aristida adsencionis, Linn), Alexandergrass (Brachiaria plantaginea (Link) Hitchc.), capim-de-raiz (Chloris orthonoton, Doell), and Sabi grass (Urochloa mosambicensis). No difference (P>0.05) was foun...
Luis-Calero M, Ortiz-Rodríguez JM, Fernández-Hernández P, Muñoz-García CC, Pericuesta E, Gutiérrez-Adán A, Marinaro F, Embade N, Conde R....In vitro embryo production is a highly demanded reproductive technology in horses, which requires the recovery (in vivo or post-mortem) and in vitro maturation (IVM) of oocytes. Oocytes subjected to IVM exhibit poor developmental competence compared to their in vivo counterparts, being this related to a suboptimal composition of commercial maturation media. The objective of this work was to study the effect of different concentrations of secretome obtained from equine preovulatory follicular fluid (FF) on cumulus-oocyte complexes (COCs) during IVM. COCs retrieved in vivo by ovum pick up (OPU) ...
Stedman JM, Lutter JD, Hallman C, Laverty S, Richard H, Santschi EM.High-field MRI of the equine stifle provides high-resolution information about soft tissues that is useful in the diagnosis of stifle lameness. The aim of this prospective anatomic study was to describe the appearance, position, size, and shape of the equine femorotibial ligaments, meniscal ligaments, and menisci using 3 Tesla MRI under extended, extended-loaded, and flexed conditions. Additionally, histologic examination of the collateral and cruciate ligaments (CLs) of a single stifle was performed to compare with MRI images. In extension, mild variations in MRI signal intensity were apparen...
Giraldo A, Koch TG, Madan P, Lepage S, Monteith G, Alizadeh AH, Tran A, Mortagy N, Koenig JB.There is a knowledge gap regarding the effect of extracorporeal shockwave treatment (ESWT) on the stress response and immunomodulatory and anti-inflammatory properties of equine umbilical cord blood mesenchymal stromal cells (CB-MSCs). The objective of this study was to investigate the presence of cellular oxidative stress, inflammatory response, and production of growth factors in CB-MSCs after treatment with ESWT. We hypothesized that CB-MSCs treated with ESWT will experience higher levels of cellular stress and increased production of anti-inflammatory cytokines and growth factors compared ...
Heidari N, Faragher RGA, Pattison G, Dudhia J, Smith RKW.Tendinopathy is a common age-related disease which causes significant morbidity for both human athletes and performance horses. In the latter, the superficial digital flexor tendon is an excellent model for human tendinopathies because it is a functional homologue of the human Achilles tendon and a primary site of injuries with strong similarities to the human disease. Corticosteroids have been previously used clinically to treat tendinopathic inflammation, but they upregulate the p53-p21 axis with concomitant reductions in cell proliferation and collagen synthesis in human tenocytes. This phe...
Sibthorpe PEM, Fitzgerald DM, Sillence MN, de Laat MA.Equine insulin dysregulation (ID) is a significant metabolic problem because the hyperinsulinaemia that develops increases the animal's risk of developing laminitis, a debilitating foot condition. The role of gastrointestinal factors, such as incretin hormones, in the pathogenesis of ID and hyperinsulinaemia in horses is poorly understood, particularly in comparison to other species. Glucagon-like peptide-2 (GLP-2) is an intestinotrophic peptide released from L cells in the gastrointestinal tract and is implicated in metabolic dysfunction in other species. The aim of this study in vitro was to...
Philip M, Kal AKK, Subhahar MB, Karatt TK, Graiban FM, Ajeebsanu MM, Joseph M, Jose SV.Phosphodiesterase 4 (PDE4) inhibitors are a newer class of drugs that induce bronchodilation and have anti-inflammatory effects, making them susceptible to misuse as performance enhancers in competitive sports. Methods: This study explores the metabolic conversion of PDE4 inhibitor ibudilast in thoroughbred horses after oral administration and in vitro using equine liver microsomes and Cunninghamella elegans. A liquid chromatography-high resolution mass spectrometry method was used to postulate the plausible structures of the detected metabolites. Results: A total of 20 in vivo metabolites wer...
Aguiar LH, Pinto CRF.Sperm capacitation is considered the main factor limiting conventional in vitro fertilization (IVF) in horses. A recent scientific breakthrough in sperm processing for IVF in horses has resulted in embryos and foals being produced; however, various aspects of the IVF process remain to be fully elucidated. Lysine acetylation has been shown to play a role in sperm capacitation in several species and the objective of this study was to detect and evaluate this process in the horse. Ejaculates of two stallions were collected and incubated in different conditions with deacetylase inhibitors to induc...
Vaughn SA, Berghaus LJ, Hart KA.Breed differences exist between horses and ponies in circulating concentrations of several hormones, notably ACTH and insulin. These hormones regulate stress and metabolic responses, but in other species, they also impact leukocyte oxidant responses. The effects of these hormones on equine leukocytes have not been evaluated to date. If equine leukocytes are similarly regulated, breed differences in increased plasma hormone concentrations or altered sensitivity to them at the leukocyte level could result in breed-related differences in oxidant responses or oxidative status. The objective of thi...
Lessiak U, Melchert M, Walter I, Kummer S, Nell B, Tschulenk W, Pratscher B.Angiogenesis plays a crucial role in various physiological and pathological conditions. However, research in equine angiogenesis is relative limited, necessitating the development of suitable models. To effectively analyze angiogenesis in-vitro, it is essential to target the specific cells responsible for this process, namely endothelial cells. Human umbilical vein endothelial cells (HUVECs) are one of the most used models for studying angiogenesis in humans. Serving as an equivalent to HUVECs, we present a comprehensive isolation protocol for equine umbilical vein endothelial cells (EqUVECs...
Muñoz-García CC, Luis-Calero M, Fernández-Hernández P, Pizarro-Hernández A, Fernández-González R, Gutiérrez-Adán A, Sánchez-Calabuig MJ....The present study aimed to evaluate whether primed anoestrus mares are suitable recipients for embryos produced by intracytoplasmic sperm injection (ICSI). Anoestrus was confirmed in four mares and daily doses of oestradiol benzoate (6 mg in total) over 5 days were administered; after 3 days of rest, oral altrenogest was administered at 0.088 mg/kg and embryos (1 to 5 embryos per mare; 15 in total) were transferred 3.5 days after progesterone onset. Uterine lavage was conducted 48 h after transfer. The results revealed an 80% embryo recovery rate, and among the retrieved embryos, 6...
Luis-Calero M, Muñoz-García CC, Fernández-Hernández P, Macías-García B, González-Fernández L.A protocol for conventional in vitro fertilization (IVF) in horses using fresh semen has been described, using a prolonged incubation in FERT-TALP medium (22 h) at 38.2°C in the presence of penicillamine, hypotaurine and epinephrine (PHE). Our work aimed to develop a protocol that maintains quality parameters in frozen-thawed equine spermatozoa incubated for 22 h in the presence of PHE using different media (FERT-TALP and INRA96) and incubation temperatures (30 and 38.2°C). Twelve frozen ejaculates from four stallions were thawed and then incubated in either FERT-TALP or INRA96 with PHE...
Philip M, Karakka Kal AK, Subhahar MB, Karatt TK, Graiban FM, Ajeebsanu MM, Joseph M, Jose SV.The phosphodiesterase 4 (PDE4) inhibitors constitute a relatively modern class of medications that are known for inducing bronchodilation and exhibiting anti-inflammatory properties within the body. Due to these properties, there is concern regarding their potential misuse as performance-enhancing substances in competitive sports. This study delves into the metabolic conversion of roflumilast in thoroughbred horses following oral administration and in vitro experimentation using equine liver microsomes and Cunninghamella elegans. High-performance liquid chromatography coupled with a Q Exactiv...
Springer RW, Cherry NM, Muir JP, Raub RH, Wellmann KB, Jones TN.Recent changes in legislation have put hempseed meal (Cannabis sativa L.; HSM) under consideration as a potential livestock feedstuff. Digestibility of HSM has been researched in other species, however, there are little data in horses. The study objective was to determine the in vitro true digestibility (IVTD) of HSM compared to common equine feedstuffs. An in vitro split-split plot design used four geldings (8.5 ± 3.9yr; 558.4 ± 31.0kg; 6.0 ± 0.4 BCS) to investigate the IVTD of HSM compared to alfalfa hay (ALF), Coastal Bermudagrass hay (CBH), soybean meal (SBM), rice bran pellets (RBP), a...
de Lima AE, Mendes RP, Piñeros DDV, Alibrando BB, de Zoppa ALV, da Silva LCLC, de Freitas SH, Corrêa RR.Sinusitis is common in horses. Sinoscopy is used for visualization of sinus cavities and can be used for diagnostic and therapeutic purposes. In this surgical procedure, a larger chamber is created and communication with other sinus compartments facilitated. To compare the applicability of different surgical approaches and rigid endoscopy systems for sinus inspection and fenestration of the maxillary septal bulla, and to examine the impact of different lens angles on the effectiveness of the procedure. Six chemically preserved cadaveric equine heads were used. Frontal and caudal maxillary port...
Gagliardi R, Koch DW, Loeser R, Schnabel LV.Osteoarthritis (OA) is a debilitating disease that impacts millions of individuals and has limited therapeutic options. A significant hindrance to therapeutic discovery is the lack of in vitro OA models that translate reliably to in vivo preclinical animal models. An alternative to traditional inflammatory cytokine models is the matrikine stimulation model, in which fragments of matrix proteins naturally found in OA tissues and synovial fluid, are used to stimulate cells of the joint. The objective of this study was to determine if matrikine stimulation of equine synovial fibroblasts and chond...
Khatibzadeh SM, Dahlgren LA, Caswell CC, Ducker WA, Werre SR, Bogers SH.Biofilms reduce antibiotic efficacy and lead to complications and mortality in human and equine patients with orthopedic infections. Equine bone marrow-derived mesenchymal stromal cells (MSC) kill planktonic bacteria and prevent biofilm formation, but their ability to disrupt established orthopedic biofilms is unknown. Our objective was to evaluate the ability of MSC to reduce established S. aureus or E. coli biofilms in vitro. We hypothesized that MSC would reduce biofilm matrix and colony-forming units (CFU) compared to no treatment and that MSC combined with the antibiotic, amikacin sulfate...
Bianchera A, Borghetti P, Ravanetti F, Bertocchi L, De Angelis E, Bettini R.Hyaluronic acid (HA) is a key component of synovial fluid as it plays a crucial role in joint physiology. Its biological activity is influenced by molecular weight, local concentration, and persistence in joints. High-molecular-weight HA has a consolidated history of clinical use, whereas little is known about the metabolic effect of low-molecular-weight hyaluronate on cartilage differentiation. This study explores the potential of HA-based nanoparticles (NPs) on chondrocytes differentiation in vitro. Starting from 25 kDa and 250 kDa sodium hyaluronate solutions, two types of NPs were prepared...
Egli P, Boone L, Huber L, Higgins C, Gaonkar PP, Arrington J, Naskou MC, Peroni J, Gordon J, Lascola KM.Platelet lysate (PL) demonstrates antimicrobial and anti-inflammatory properties offering potential for treatment of bacterial pneumonia in horses. It remains unknown whether nebulization is suitable for PL administration in horses. This pilot study characterized particle size and flow rate of pooled equine PL (single preparation) nebulized using an equine-specific nebulizer (Flexivent®). Unassigned: Protein composition and antimicrobial activity were compared before and after nebulization. Protein composition was evaluated according to growth factor, antimicrobial peptide and cytokine concen...
Nogacka AM, García A, de Los Reyes-Gavilán CG, Arboleya S, Gueimonde M.Horses are hindgut fermenters that harbor a complex intestinal microbiota (IM) which provides key enzymes aiding in the breakdown of complex carbohydrates present in their herbivorous diet. Therefore, these animals are deeply dependent on their IM for digestion and nutrition. Consequently, IM imbalances may result in alteration of fermentation patterns with impact on the animal health and the risk of disease. In this context, strategies for assisting the maintenance of a healthy IM in horses are of interest. However, there is limited research concerning the use of probiotics to improve hindgut...
Cardeti G, Manna G, Cersini A, Nardini R, Rosati S, Reina R, Cittadini M, Sittinieri S, Altigeri A, Marcario GA, Scicluna MT.The mechanisms of the innate immunity control of equine infectious anemia virus in horses are not yet widely described. Equine monocytes isolated from the peripheral blood of three Equine infectious anemia (EIA) seronegative horses were differentiated in vitro into macrophages that gave rise to mixed cell populations morphologically referable to M1 and M2 phenotypes. The addition of two equine recombinant cytokines and two EIA virus reference strains, Miami and Wyoming, induced a more specific cell differentiation, and as for other species, IFNγ and IL4 stimulation polarized horse macrophages...
