Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:In Vitro Research
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.
Effects of ischemia and the cyclooxygenase inhibitor flunixin on in vitro passage of lipopolysaccharide across equine jejunum. To determine whether ischemia and flunixin affect in vitro lipopolysaccharide (LPS) absorption in samples of the jejunum of horses. Methods: 12 horses. Methods: Horses were anesthetized, a midline celiotomy was performed, and the jejunum was located. Two 30-cm sections of jejunum (60 cm apart) were selected. One segment was designated as control tissue; ischemia was induced in the other segment for 120 minutes. Horses were then euthanatized. Mucosa from each jejunal segment was mounted on Ussing chambers and treated with or without flunixin. Tissues from 6 horses were used to assess permeabili...
Use of parentage testing to determine optimum insemination time and culture media for oocyte transfer in mares. Parentage identification was used to test the developmental competence of oocytes cultured under different conditions and fertilized in vivo after oocyte transfer. Oocytes were collected transvaginally from follicles of estrous mares approximately 22 h after administration of human chorionic gonadotropin. Oocytes were cultured for approximately 16 h in one of three media, with or without addition of hormones and growth factors. Groups of three or four oocytes, cultured in different media, were transferred into the oviduct contralateral to a recipient's own ovulation. Recipients were inseminate...
Characteristics of the in vitro hypoxic pulmonary vasoconstrictor response in isolated equine and bovine pulmonary arterial rings. Hypoxaemia accompanies dorsal recumbency in the horse and frequently complicates general anaesthesia. The physiology associated with this phenomenon is poorly understood. One possible cause of poor tolerance to dorsal recumbency is an absent or reduced response to hypoxic pulmonary vasoconstriction (HPV). This study compared the HPV response in isolated pulmonary artery vessels from equivalent regions of equine and bovine lung. Methods: Equine and bovine, in vitro study. Methods: Equine and bovine pulmonary arteries were removed from the lungs of euthanased horses and cattle. Measurements of i...
Influence of breathing pattern and lung inflation on impulse oscillometry measurements in horses. The objective of this paper was to determine if changes in ventilation patterns could influence the outcome of respiratory function measurements performed with our impulse oscillometry system (IOS) in horses. In a first study, IOS tests were performed in vitro on six isolated equine lungs. Lung inflation levels were controlled by modifying depressurisation inside an artificial thorax and different ventilation patterns were imposed. In a second in vivo study, transient variations in breathing pattern were evaluated both with the IOS and a current reference technique (CRT) in five healthy mature...
Crystallization of a proteolyzed form of the horse pancreatic lipase-related protein 2: structural basis for the specific detergent requirement. Horse pancreatic lipase-related proteins PLRP1 and PLRP2 are produced by the pancreas together with pancreatic lipase (PL). Sequence-comparison analyses reveal that the three proteins possess the same two-domain organization: an N-terminal catalytic domain and a C-terminal domain, which in PL is involved in colipase binding. Nevertheless, despite the high level of sequence identity found, they exhibit distinct enzymatic properties. The intrinsic sensitivity of the peptide bond between Ser245 and Thr246 within the flap region of PLRP2 to proteolytic cleavage probably complicates PLRP2 crystalli...
African horsesickness virus serotyping and identification of multiple co-infecting serotypes with a single genome segment 2 RT-PCR amplification and reverse line blot hybridization. Since protection against African horsesickness (AHS) is serotype-specific, rapid serotyping of AHSV is crucial to identify the correct vaccine serotype for efficient control of the spread of AHS outbreaks, especially when they occur in non-endemic regions. This paper describes the first one-day serotyping procedure that requires only a single RT-PCR and hybridization and which can identify multiple serotypes in mixed infections in one assay. The same region of genome segment 2 of all nine AHSV serotypes is amplified in a single RT-PCR. A universal primer set, designed to amplify the 5'-termina...
Equine papillomavirus type 1: complete nucleotide sequence and characterization of recombinant virus-like particles composed of the EcPV-1 L1 major capsid protein. Equus caballus papillomavirus type 1 (EcPV-1) was isolated from a cutaneous papilloma, the most common neoplasm in horses. The complete EcPV-1 nucleotide sequence and genomic organization were determined. Phylogenetic analysis showed that EcPV-1 is a close-to-root papillomavirus, with only distant relationships to the fibropapillomaviruses and the benign cutaneous papillomaviruses. To produce EcPV-1 virus-like particles (VLPs), the EcPV-1 L1 major capsid protein was expressed in insect cells using a recombinant baculovirus vector. The self-assembled EcPV-1 VLPs were morphologically indistingui...
Tenocyte response to cyclical strain and transforming growth factor beta is dependent upon age and site of origin. The effect of strain and transforming growth factor beta on equine tendon fibroblasts (tenocytes) was assessed in vitro. Tenocytes were isolated from flexor and extensor tendons of horses from foetal to 10 years of age. These cells were cultured until confluent on collagen-coated silicone dishes. Cyclic biaxial strain of 9+/-1% was applied at 0.5 Hz for 24 hours with or without added TGFbeta1 or 3 (10 ng/ml). Proliferation and synthetic responses were dependent on the tendon of origin. Neither strain nor TGFbeta caused flexor tenocytes to proliferate significantly, while strain alone did proli...
Characterization of the role of glutathione in repin-induced mitochondrial dysfunction, oxidative stress and dopaminergic neurotoxicity in rat pheochromocytoma (PC12) cells. Repin, a major constituent in extracts of the plant Centaurea repens is thought to be the active principal responsible for the development of equine nigropallidal encephalomalacia (ENE), a fatal Parkinson-like neurodegenerative disorder in horses. Although the exact mechanism by which ingestion of this weed causes ENE is uncertain, a limited body of experimental evidence suggests a critical role for the glutathione redox system. In the present study, the mechanism of repin neurotoxicity was examined in PC12 cells with a focus on determining the role of glutathione (GSH) in repin-induced mitoch...
Molecular characterisation of fructose transport in equine small intestine. Fructose can be a suitable carbohydrate supplement for horses before and/or during endurance exercise. In comparison to glucose, the ingestion of fructose results in a lower insulin peak and less marked fluctuations in blood glucose during exercise, potentially avoiding hypoglycaemia-induced exhaustion. Objective: To assess the capacity of the equine small intestine to absorb fructose and to determine the mechanism, molecular structure and properties of equine intestinal fructose transport. Methods: Using PCR-based strategies, RNA isolated from equine small intestine and primers designed to ho...
Development of a neutralizing monoclonal antibody-based blocking ELISA for detection of equine herpesvirus 1 antibodies. A single-dilution, sensitive and specific monoclonal antibody-based blocking enzyme-linked immunosorbent assay (B-ELISA) was developed as an alternative to the cumbersome virus neutralization test (VNT) for detection of equine herpesvirus-1 (EHV-1) antibodies. Neutralizing monoclonal antibodies (1H6 and 9C6) raised against EHV-1 (Hisar-90-7 strain) and sera from 70 horses (30 known negative and 40 known positive for EHV-1 antibodies by VNT) were used for standardization of the B-ELISA. Using a single serum dilution of 1:250 in B-ELISA, 100% specificity was obtained with both monoclonal antibod...
Topological assignment of the N-terminal extension of plasma gelsolin to the gelsolin surface. The actin-binding protein gelsolin is highly conserved in vertebrates and exists in two isoforms, a cytoplasmic and an extracellular variant, generated by alternative splicing. In mammals, these isoforms differ only by an N-terminal extension in plasma gelsolin, a short sequence of up to 25 amino acids. Cells and tissues may contain both variants, as plasma gelsolin is secreted by many cell types. The tertiary structure of equine plasma gelsolin has been elucidated, but without any information on the N-terminal extension. In this paper, we present topographical data on the N-terminal extension...
Ultrasound-guided atlanto-occipital puncture for myelography in the horse. Complications of cervical myelography arising from the puncture of the subarachnoid space to collect the cerebrospinal fluid and to inject the contrast medium have been described in humans and animals. In this study, 2 ultrasound-guided procedures were developed for puncture of the atlanto-occipital subarachnoid space, collection of cerebrospinal fluid, and injection of contrast medium. Myelography was performed on 6 ataxic horses using these procedures. The first attempt to puncture the subarachnoid space was successful in 5 horses and in one horse, a second attempt was necessary. Collection ...
Comparison of 4 blood storage methods in a protocol for equine pre-operative autologous donation. To compare viability of equine whole blood stored by 4 different methods, and to establish optimal storage protocols for an equine autologous blood donation program. Methods: In vitro study of stored equine whole blood. Animals- Six healthy adult horses. Methods: Blood from each horse was collected into 4 different containers: glass bottles containing acid-citrate-dextrose solution (ACD), plastic bags containing ACD, citrate-phosphate-dextrose (CPD), and CPD with supplemental adenine (CPDA-1). Blood was stored for 5 weeks and sampled at 2-day intervals. Standard hematologic and biochemical var...
Evidence that use of an inactivated equine herpesvirus vaccine induces serum cytotoxicity affecting the equine arteritis virus neutralisation test. Several laboratories worldwide have recently experienced problems related to serum cytotoxicity with the equine arteritis virus (EAV) neutralisation test (VN) when using Office International des Epizooties (OIE) reference laboratory prescribed rabbit kidney (RK-13) indicator cells. Cytotoxicity can be mistaken for viral cytopathic effect and has led to increasing difficulties in test interpretation, consequently causing disruption to both equine breeding and disease surveillance. Results from experimental and field-derived data suggest that this serum cytotoxicity is associated with use of a t...
Assessment of Sarcocystis neurona sporocyst viability and differentiation between viable and nonviable sporocysts using propidium iodide stain. Sarcocystis neurona has become recognized as the major causative agent of equine protozoal myeloencephalitis (EPM) in the Americas. At least 3 pathogenic species of Sarcocystis, including S. neurona, can be isolated from opossums. Methods are needed to ascertain whether these isolates are viable and capable of causing infections. In this study, the nuclear stain propidium iodide (PI) was used to differentiate between live (viable) and heat-killed (nonviable) S. neurona sporocysts. PI was excluded by live sporocysts but penetrated compromised sporocyst membrane and stained sporozoite nuclei of ...
IL-4 induced CD23 (FcepsilonRII) up-regulation in equine peripheral blood mononuclear cells and pulmonary alveolar macrophages. The objectives of this study were to quantify the induction of equine CD23 transcripts in equine peripheral blood mononuclear cells (PBMCs) and pulmonary alveolar macrophages cultured with recombinant equine IL-4 (rEq IL-4). PBMCs were isolated from blood drawn from four healthy horses. Bronchoalveolar lavage (BAL) fluid was collected from three healthy horses and alveolar macrophages were purified using adherence to plastic for 120 min. PBMCs and alveolar macrophages were cultured using four different conditions: rEq IL-4 and LPS, LPS alone, rEq IL-4 alone and a media control. Total RNA was i...
Engineered articular cartilage: influence of the scaffold on cell phenotype and proliferation. Articular cartilage defects do not heal. Biodegradable scaffolds have been studied for cartilage engineering in order to implant autologous chondrocytes and help cartilage repair. We tested some new collagen matrices differing in collagen type, origin, structure and methods of extraction and purification, and compared the behavior of human chondrocytes cultured on them. Human chondrocytes were grown for three weeks on four different equine type I collagen matrices, one type I, III porcine collagen matrix and one porcine type II collagen matrix. After 21 days, samples were subjected to histoche...
The complete map of the Ig heavy chain constant gene region reveals evidence for seven IgG isotypes and for IgD in the horse. This report contains the first map of the complete Ig H chain constant (IGHC) gene region of the horse (Equus caballus), represented by 34 overlapping clones from a new bacterial artificial chromosome library. The different bacterial artificial chromosome inserts containing IGHC genes were identified and arranged by hybridization using overgo probes specific for individual equine IGHC genes. The analysis of these IGHC clones identified two previously undetected IGHC genes of the horse. The newly found IGHG7 gene, which has a high homology to the equine IGHG4 gene, is located between the IGHG3 ...
Association of a mutation in the ryanodine receptor 1 gene with equine malignant hyperthermia. Equine malignant hyperthermia MH has been suspected but never genetically confirmed. In this study, we investigated whether mutations in a candidate gene, RyR1, were associated with MH in two clinically affected horses. RyR1 gene sequences revealed polymorphisms in exons 15, 17, and 46 in WTRyR1 and MHRyR1 horses with one derived amino acid change in MHRyR1 exon 46, R2454G. The MHRyR1 horses were genetically heterozygous for this mutation, but presented an MH phenotype with halothane challenge. Skeletal sarcoplasmic reticulum from a R2454G heterozygote collected during a fulminant MH episode s...
In-vitro contraction of the equine aortic valve. The equine aortic valve is subject to non-inflammatory degenerative changes, associated with aortic valvular regurgitation (AR). This disease shares pathological and epidemiological features with AR in humans, and may serve as a useful model to study in-vitro functional responses associated with aging and disease. The study aim was to determine the contractile properties of the normal equine aortic valve. Methods: The contractile responses of equine aortic valves to angiotensin II, the thromboxane-mimetic U44069, endothelin-1, 5-hydroxytryptamine and the alpha-adrenoceptor agonists medetomidin...
Adaptive immunity is the primary force driving selection of equine infectious anemia virus envelope SU variants during acute infection. Equine infectious anemia virus (EIAV) is a lentivirus that causes persistent infection in horses. The appearance of antigenically distinct viral variants during recurrent viremic episodes is thought to be due to adaptive immune selection pressure. To test this hypothesis, we evaluated envelope SU cloned sequences from five severe combined immunodeficient (SCID) foals infected with EIAV. Within the SU hypervariable V3 region, 8.5% of the clones had amino acid changes, and 6.4% had amino acid changes within the known cytotoxic T lymphocyte (CTL) epitope Env-RW12. Of all the SU clones, only 3.1% ...
Viability of equine articular chondrocytes in alginate beads exposed to different oxygen tensions. Ischaemia and reperfusion are suspected to alter chondrocyte metabolism. Here, we studied the effects of three oxygen (O2) tensions on the viability of equine articular chondrocytes isolated from the cartilage of the distal interphalangeal joint of horses. Chondrocytes were cultured in alginate beads under 1%, 5% or 21% gas phase O2 concentration for 14 days, cellular growth kinetics were measured (n=6), and the cells were observed by light microscopy after staining for necrotic and apoptotic cell detection. For information about the metabolic status, the intracellular adenosine triphosphate (...
Step-wise dilution for removal of glycerol from fresh and cryopreserved equine spermatozoa. Osmotic stress is an important component of the damage to spermatozoa during cryopreservation. Osmotic injury, due to hyperosmolar freezing extenders, changes in relative solute concentration in the extra cellular medium during freezing and differences in the relative permeabilities of penetrating cryoprotectants, such as glycerol, and water occur when cryopreserved spermatozoa are diluted into isosmotic media or when spermatozoa are placed in the female reproductive tract. The purpose of the study reported here was to evaluate the effect of step-wise dilution for the removal of the permeating...
Aquaporin water channels AQP1 and AQP3, are expressed in equine articular chondrocytes. Chondrocytes exist in an unusual and highly variable ionic and osmotic environment in the extracellular matrix of articular cartilage. Alterations to the ionic and osmotic environment of chondrocytes influence the volume and ionic content of the cells, which, in turn, modifies the rate at which extracellular matrix macromolecules are synthesized and degraded. Thus, regulation of the water and solute content of chondrocytes will profoundly affect their anabolic and catabolic functions. The water content of cells is effectively influenced by the abundance of aquaporin (AQP) water channels. Recen...
Evaluation of alternative cryoprotectants for preserving stallion spermatozoa. Although use of cryopreserved stallion spermatozoa is currently accepted by many breed registries, utilization of this technique remains limited due to poor fertility for some stallions. One reason for these results is osmotic stress that spermatozoa experiences when the cryoprotectant (glycerol) is added to the cells prior to freezing and removal from the cells after thawing. In an effort to minimize osmotic damage, alternative cryoprotectants, having lower molecular weights and greater membrane permeability than glycerol, were evaluated to determine their effectiveness for cryopreserving sta...
Methanol as a cryoprotectant for equine embryos. Equine embryos (n=43) were recovered nonsurgically 7-8 days after ovulation and randomly assigned to be cryopreserved in one of two cryoprotectants: 48% (15M) methanol (n=22) or 10% (136 M) glycerol (n=21). Embryos (300-1000 microm) were measured at five intervals after exposure to glycerol (0, 2, 5, 10 and 15 min) or methanol (0, 15, 35, 75 and 10 min) to determine changes (%) in diameter over time (+/-S.D.). Embryos were loaded into 0.25-ml plastic straws, sealed, placed in a programmable cell freezer and cooled from room temperature (22 degrees C) to -6 degrees C. Straws were then seeded, h...
Effect of matrix depleting agents on the expression of chondrocyte metabolism by equine chondrocytes. This study was carried out to investigate the effect of two enzymes (collagenase and chondroitinase) and two cytokines/metabolites (interleukin-1beta and retinoic acid) of known catabolic activity on the expression of cartilage metabolism/phenotype in equine articular cartilage. Articular cartilage explants from 11 horses (5-13 years old) were treated for 48 h and assayed for total sulphated glycosaminoglycan (GAG), the incorporation of 35S-sulphate, collagen degradation and mRNA expression of the proteoglycans collagen II, collagen IIA, collagen III, collagen IX, collagen X, collagen XI and g...
Integration of sperm sexing technology into the ART toolbox. Sex-sorting of mammalian spermatozoa has applications for genetic improvement of farm animals, in humans for the control of sex-linked disease, and in wildlife as a captive management strategy and for the re-population of endangered species. Considerable research has been undertaken worldwide on the Beltsville sperm sexing technology, the only effective method for pre-selection of sex of offspring. The combination of this method with assisted reproductive technologies has resulted in the birth of offspring in a wide range of animals, including cattle, the only livestock species in which sperm ...
