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.
Evans JW, Roser JF, Mikuckis GM.Human chorionic gonadotrophin (hCG) can be used to study horse luteinizing hormone (LH) receptors in stallion testicular tissue. hCG was more stable than horse LH during radioiodination when compared by their abilities to bind to testicular receptor sites. During incubation, neither hormone lost binding activity at 4 degrees C. Horse LH lost binding activity during incubation at 25 degrees C and both hormones lost binding activity at 37 degrees C. Both hormones bound to the same receptor sites which are specific for the hormones. The receptor sites were not degraded when incubated at 4 degrees...
Srivastava SK, Barnum DA.Lymphocyte stimulation was observed in whole equine blood in the presence of phytohaemagglutinin and M protein extracted from a typical strain of Streptococcus equi. Blood samples were collected from several healthy horses and horse and pony foals and cultured in vitro with varying concentrations of phytohaemagglutinin and M protein for several days. Phytohaemagglutinin was found to induce lymphocyte stimulation in these animals. Highest mean stimulation indices in horse foals (49.3 +/- 24.4) and pony foals (54.7 +/- 32.0) were observed with 0.625 and 1.25 micrograms/mL phytohaemagglutinin, re...
da Silva MH, Bier OG.Horse antiserum to the venom of Crotalus durissus terrificus, A South American rattlesnake, inhibits the phospholipase activity of the crude venom. There is a close relationship between this inhibitory property and the neutralizing potency of the antiserum in vivo. This may provide the basis for a rigorous standardization of anticrotalid venom in vitro.
Rideout MI, Burns SJ, Simpson RB.Sterile filtrates were prepared from equine isolates of Klebsiella pneumoniae (genitalium), Proteus mirabilis, Pseudomonas aeruginosa, Escherichia coli, Streptococcus zooepidemicus, Streptococcus equisimilis, Actinobacillus equuli, and Corynebacterium equi and mixed individually with extended stallion semen. When diluted in the extended semen the filtrates represented bacterial populations of 0.5 x 10(6), 1 x 10(6), 2 x 10(6) and 4 x 10(6) cells/ml. pH values were recorded for each filtrate. Specimens were monitored for percentage motile spermatozoa at 30-min intervals until they reached 10% o...
Zink MC, Johnson JA, Prescot JF, Pascoe PJ.The in-vitro interaction of Corynebacterium equi and foal alveolar macrophages was examined qualitatively and quantitatively using cells collected by sequential bronchoalveolar lavage at 2-week intervals from birth until 14 weeks of age. Total and differential counts were performed on the recovered cells. Macrophages were identified using the non-specific esterase strain. Cultures of the alveolar macrophages were challenged with C. equi suspensions and the process and extent of ingestion was examined by light and electron microscopy. Few macrophages were recovered from the lungs of foals less ...
Yilma T, McGuire TC, Perryman LE.Equine dermal cells induced with poly I:C + DEAE-dextran produced low levels of interferon tentatively classified as equine interferon beta (EqIFN-beta). In contrast, dermal cells initially primed with EqIFN-beta and then superinduced with poly I:C + DEAE-dextran in the presence of cycloheximide and actinomycin D produced greater than 100-fold EqIFN-beta. Equine blood mononuclear cells induced with Newcastle disease virus and phytohemagglutinin produced high levels of interferons tentatively classified as equine interferon alpha (EqIFN-alpha) and equine interferon gamma (EqIFN-gamma), respecti...
Dixon JB, Jenkins P, Allan D.Culture of murine lymph node cells together with living protoscolices of Echinococcus granulosus is described. The presence of the parasite induced potent blastic transformation in lymphocytes of unimmunized mice as indicated by tritiated thymidine incorporation. The response was markedly reduced by killing the parasite immediately prior to culture. No blastogenic activity was detectable in supernatants from living parasites cultured alone. Protoscolices from artificially infected syngeneic mice were effective stimuli, as were protoscolices from naturally infected horse and sheep. Stimulation ...
Potempa J.The proteolytic activity of the elastase-like proteinase from granules of horse blood leukocytes is retained on a column of Cibacron Blue-Sepharose and can be eluted with 0.5 M KSCN. During this procedure its mol. wt. is reduced from 49000 to 30000 and isoelectric point is shifted towards higher pH. The inactive protein not adsorbed on Cibacron Blue-Sepharose is strongly acidic and shows a mol. wt. of 20000. Upon mixing this protein with the modified enzyme the native proteinase is reconstituted as shown by polyacrylamide gel electrophoresis at pH 8.3 and isoelectric focusing in a sucrose grad...
Shivers CA, Liu IK.Sera and follicular fluid from mares previously determined as having antibodies to the zona pellucida were exposed to porcine ovarian oocytes before insemination with boar spermatozoa in vitro. There was a dramatic decline in the number of spermatozoa bound to zonae compared to treatments with sera and follicular fluid from mares negative for zona antibodies. These data suggest that antibodies reactive with the zona pellucida may be responsible for reduced or even complete infertility in some mares. In a group of 50 randomly selected mares tested for antizona antibodies, 2 pregnant mares were ...
Rathelot J, Canioni P, Bosc-Bierne I, Sarda L, Kamoun A, Kaptein R, Cozzone PJ.Porcine and equine colipases have been submitted to mild tryptic digestion. Proteolysis occurs at the Arg5-Gly6 bond with the loss of the N-terminal pentapeptide. Studies of native and trypsin-treated colipases by circular dichroism and laser chemically induced dynamic nuclear polarization indicate that proteolysis induces conformational changes in the region of the tyrosine cluster. Experiments in the presence of phospholipid provide further evidence showing that these residues are in or close to the region of the protein interacting with aggregated lipids. Kinetic studies of the reaction of ...
Schein E, Rehbein G, Voigt WP, Zweygarth E.The vertebrate development of Babesia equi from infected Hyalomma marginatum in Morocco was investigated in vitro and in vivo. It was demonstrated that the sporozoites of B. equi initiate a phase of exo-erythrocytic schizogony in lymphocytes both in vitro and in vivo. On the other hand, sporozoites did not invade erythrocytes in vitro. The complete vertebrate life cycle of B. equi was simulated in vitro, from the invasion of lymphocytes by sporozoites, to the development of macro- and microschizonts, the invasion of erythrocytes by merozoites, and the subsequent intra-erythrocytic schizogony. ...
Anderson LW, Banks KL.Equine macrophages were obtained from female Shetland ponies by injection of Escherichia coli lipopolysaccharide through the lactiferous ducts of the mammary gland. After 6 to 11 days, balanced salt solution was injected into the mammary gland to wash out accumulated cells. Harvested cells contained a mixture of macrophages, lymphocytes, and neutrophils, with the majority of the cells of mononuclear type. In culture, cells adherent after 24 hours were characterized as macrophages by morphologic features, nonspecific esterase staining, and by the presence of complement and immunoglobulin recept...
Robinson RA, Tucker PW, Dauenhauer SA, O'Callaghan DJ.Genomic DNA sequences of equine herpesvirus type 1 (EHV-1) have been cloned as BamHI and EcoRI restriction fragments into the plasmid pBR322 and propagated in Escherichia coli. With the exception of two EcoRI restriction fragments that reside in the S region of the viral genome, all of the cloned fragments demonstrated the same electrophoretic mobilities, restriction cleavage sites, and blot-hybridization patterns as did the parent fragments produced by BamHI or EcoRI digestion of virion DNA. The EcoRI J fragment and the BamHI E fragment of the L-region terminus were cloned after the addition ...
Hardy GW, Darbre A, Merrett M.3-Phosphoglycerate kinase was isolated from horse muscle and subjected to the action of cyanogen bromide. The resulting peptides were separated using gel filtration combined with either ion exchange chromatography on phosphocellulose in 6 M urea or high voltage paper electrophoresis. The sequence of the largest peptide, CB5, has been determined by a combination of automated and manual Edman degradation carried out on the intact peptide and derivatives obtained by proteolytic digestion. The isolation of two peptides derived from CB5 by cleavage of the bond between Asp109 and Pro110 facilitated ...
Doyle A, Owen LN.Sixteen cytotoxic drugs used in cancer chemotherapy in man were studied for cytopathic effect on equine fibrosarcoma, melanoma and normal equine lung cells in vitro. Three drugs, vincristine, melphalan and methotrexate, produced cytopathic effect
Côté GP, Smillie LB.Whereas skeletal muscle tropomyosin binds strongly to muscle F-actin in a buffer containing 30 mM KCl and 1-2 mM free Mg2+, equine platelet tropomyosin only binds stoichiometrically (1 tropomyosin molecule per 6 actin monomers) at higher Mg2+ concentrations (7-8 mM free Mg2+). At low free Mg2+ concentrations (1.5 mM) the binding of the platelet protein is only marginally increased by raising the KCl concentration to an optimal value (0.10-0.20 M). This weaker binding can be attributed to the relatively poor head-to-tail polymerization of platelet tropomyosin and its fewer actin-binding sites. ...
Stewart F, Allen WR.The role of equine chorionic gonadotrophin (CG, formerly termed Pregnant Mare serum Gonadotrophin, PMSG) in maintaining equine pregnancy was investigated by examining the effects of this hormone on the maternal ovaries during early gestation and relating these findings to the receptor binding activities of CG in vitro. Measurement of plasma progestagen profiles in mares and donkeys carrying horse, donkey, mule ( female horse X male donkey) and hinny (female donkey X male horse) conceptuses confirmed that CG induced several secondary ovulations and thus maintained maternal progestagen concentra...
Yoshimura T, Sogabe T, Aki K.Electron transfer between horse heart and Candida krusei cytochromes c in the free and phosvitin-bound states was examined by difference spectrum and stopped-flow methods. The difference spectra in the wavelength range of 540-560 nm demonstrated that electrons are exchangeable between the cytochromes c of the two species. The equilibrium constants of the electron transfer reaction for the free and phosvitin-bound forms, estimated from these difference spectra, were close to unity at 20 degrees C in 20 mM Tris-HCl buffer (pH 7.4). The electron transfer rate for free cytochrome c was (2-3).10(4)...
Carsana A, Furia A, Gallo A, Beintema JJ, Libonati M.1. Extensively glycosylated ribonucleases, like the enzymes from pig and horse pancreas, show a much higher activity on double-stranded RNAs than similarly charged, carbohydrate-free RNAases under stranded assay conditions (relatively high salt concentrations). Glycosylated pig and horse pancreas RNAases also show a larger destabilizing effect on double-stranded poly[d(A-T)] X poly[d(A-T)], than that displayed by bovine RNAase A under these conditions. Both activities show a similar dependence on the ionic strength of the medium. 2. A partial enzymic removal of the heterosaccharide side chains...
Rondeau M, Rouleau M.Using semen from bull, boar and stallion as well as different spectrophotometers, we established the calibration curves relating the optical density of a sperm sample to the sperm count obtained on the hemacytometer. The results show that, for a given spectrophotometer, the calibration curve is not characteristic of the animal species we studied. The differences in size of the spermatozoa are probably too small to account for the anticipated specificity of the calibration curve. Furthermore, the fact that different dilution rates must be used, because of the vastly different concentrations of ...
Orpin CG.Microscopic examination of horse caecum contents revealed vegetative growth of phycomycete fungi on particles of digesta, and uniflagellated cells similar to fungal zoospores in the liquid phase. Three morphologically distinct isolates of strictly anaerobic phycomycete fungi were obtained from the caecum contents and cultured in vitro. Two of the isolates were able to utilize a wide range of plant carbohydrates for growth, including alpha-cellulose, xylan and particulate starch, and extensively digested water-insoluble plant tissues.
Allen BV.A technique for automating equine differential leucocyte counts by analysis of volume distribution curves using the Coulter Channelyzer has been developed and evaluated. A comparison between the results obtained by this method and standard microscopic techniques showed good agreement in most cases. Blood samples can be analysed for both differential and total leucocyte counts at a rate of 25/h. For each sample an average 16,000 leucocytes are classified by the Channelyzer. The method of volume analysis is suitable for the precise counting of polymorphonuclear neutrophils, lymphocytes and eosin...
Kingma SE, Thibault ME, Betteridge KJ, Schlaf M, Gartley CJ, Chenier TS.Poor survival of cryopreservation by equine expanded blastocysts may involve low penetration of the embryonic capsule by cryoprotective agents (CPAs). This study characterized the permeation and accumulation rates of the CPAs ethylene glycol (EG) and glycerol (GLY) across isolated capsule in vitro, using a dual-chambered Valia-Chien permeation apparatus. Pieces of Days 14 to 18 ± 1 capsules separated media in the "donor" chamber containing either 1.5 M EG (n = 6), 0.74 M EG (n = 5), 0.87 M GLY (n = 7), or 0.15 M NaCl (saline, SAL) (n = 6), from the "recipient" chamber. Concentrations of CPA, ...
Page SW.The use of chloramphenicol in the horse is now prohibited as horses are classified as food-producing animals. However, chloramphenicol has until recently been widely available for oral, intramuscular or intravenous administration. A critical appraisal of the published literature on the use of chloramphenicol in the horse clearly demonstrates that there are sound pharmacokinetic and microbiological reasons for concluding that chloramphenicol is not an appropriate antibiotic for systemic use. The short half-life of chloramphenicol in the horse, together with the broad range of minimum inhibitory...
Lee JY, Kang TY, Lee YD, Shin TK.The binding specificities of various lectins, such as the Dolichos biflorus agglutinin (DBA), soybean agglutinin (SBA), and the Bandeiraea simplicifolia BS-1 (Isolectin B4), Triticum vulgaris (WGA), Arachis hypogaea (PNA), and Ulex europaeus (UEA-I) lectins, were studied in the vomeronasal organ of the horse. The microvilli of the vomeronasal sensory epithelium were positive for DBA, SBA, Isolectin B4, WGA, PNA, and UEA-I. The receptor cells showed intense reactivity for DBA and WGA. Lectins were not detected in the supporting cells or basal cells. The Jacobson's glands were positive for WGA a...
Morris DD, Moore JN.An experiment was designed to determine whether a change in the ability of macrophages to respond to lipopolysaccharides (LPS) of gram-negative bacteria was involved in the development of cross-reactive immunity to endotoxemia. The endotoxin-induced production of thromboxane A2(TxA2) and prostacyclin (PGI2) by peritoneal macrophages from horses which were hyperimmunized against the common core region of LPS were compared to those in unimmunized horses. Bacterins used for induction of core LPS immunity were prepared from the J-5 mutant of Escherichia coli 0111:B4, and the R 595 mutant of Salmon...
Ma L, Sang M, Zhang J, Zhang S.Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily and plays multifunctional roles in the immune system. In the present study, a homolog of TRAIL from the Mongolian horse (named ecTRAIL) was identified and characterized. The 870-bp open reading frame encodes a polypeptide of 289 amino acid residues with a predicted molecular weight of 33.47 kDa and pI of 8.47. The genomic structure of ecTRAIL shares a five-exon/six-intron arrangement similar to its orthologs. Multiple alignments show that ecTRAIL is a type II transmembrane protein with a t...
Thomas PG, Ball BA.To facilitate the study of interactions between equine spermatozoa and homologous oviduct epithelial cells, we developed an assay to count labelled spermatozoa bound to oviduct epithelial cell (OEC) monolayers and used the assay to compare the binding ability of spermatozoa from different stallions. Washed spermatozoa from three stallions were incubated with the fluorochrome Hoechst 33342 (5 micrograms/ml) for 1 min. Spermatozoa were then layered over confluent monolayers of oviduct epithelial cells in 2 cm2 culture wells. Coculture treatments comprised five concentrations of spermatozoa (10(5...
Kelley DE, Schnobrich MR, Gayer S, Scoggin C, Bradcamp E, Canisso IF.The objective of this study was to compare a commercially available leukocyte esterase strip test with endometrial cytology in diagnosing endometritis and establish a cutoff point, sensitivity, and specificity for the leukocyte esterase test (LET). Forty-six light breed mares presented for breeding management were enrolled in this study. Transrectal palpation and ultrasonography examinations were performed to determine when the mares were in estrus. Kalayjian endometrial swabs were used for culture, cytology, and the LET by using the cap to retrieve an endometrial scraping. Thirty-six mares ha...
Monet-Kuntz C, Guillou F, Fontaine I, Combarnous Y.Using a suspension of seminiferous tubule cells, we had previously shown that equine FSH is superactive in the male rat, i.e. that it exhibits a higher biological potency than expected from its binding activity. In this work we investigated equine FSH superactivity in rat, pig and sheep, by comparing in each species the equine FSH with the homologous FSH, both for their binding activities (in a radioreceptor assay using a testicular membrane fraction) and for their in vitro biological potencies (in a plasminogen activator assay using a Sertoli cell-enriched population cultured on plastic). In ...
Galey FD, Beasley VR, Schaeffer DJ, Davis LE.Prazosin, isoxsuprine, and nifedipine were screened for ability to reverse contraction of isolated equine digital vascular strips produced by epinephrine (Epi) in the presence of hydrocortisone (Hc) and an aqueous extract of black walnut (Juglans nigra) (BW). Two arteries and two veins from each of three horses for each drug (n = 9) were maintained in isolated tissue baths in Krebs' bicarbonate buffer with 95% oxygen at 37 degrees C. Six-point Epi concentration-response (C-R) curves were obtained for each vessel in the presence of Hc, BW, and the appropriate vehicle. This was repeated for each...
Camacho CA, Estradé MJ, Cazales N, Caballeros JE, Fiala-Rechsteiner SM, Neves AP, Mattos RC.This experiment aimed to verify if the proteins present in a 13 day conceptus induce changes in the equine endometrial ultra-structure, histology, and vascularization, two days after its infusion. Ten healthy cyclic mares were used. Once estrus was confirmed, mares were examined daily to detect ovulation (day 0). After ovulation, mares were examined daily until day seven by transrectal palpation and B-mode and Doppler ultrasonography. In this first cycle, intrauterine biopsies were collected at day seven after ovulation, constituting the Cyclic group (n = 10). In the second cycle, the same mar...
Knoll U, Strauhs P, Schusser G, Ungemach FR.Olsalazine sodium (Dipentum*) has been used therapeutically against inflammatory bowel disease in human medicine as an alternative to sulphasalazine over the past 20 years. Bacteria in the colon split this prodrug into two molecules of the locally effective 5-aminosalicylic acid (5-ASA). Considering the potential therapeutic use in equine colitis, the pharmacokinetics of olsalazine (OLZ) after single oral administration to six horses at a dosage of 30 mg/kg was investigated. Plasma concentrations of OLZ, 5-ASA, and its main metabolite N-acetyl-5-aminosalicylic acid (Ac-5-ASA) were analysed by ...
Spirito S, Campi S, Boquet M, Fernández H, Ferrari M.The aims of this study were to estimate the ability of the Feulgen reaction to identify equine sperm nuclei with different ploidy levels, to determine the frequency of haploid, diploid and polyploid sperm nuclei in the semen of fertile equines and to evaluate the relationship between the nuclear DNA content and the nuclear area. Determination of the ploidy level of Feulgen-stained spermatozoa using a scanning microspectrophotometer was very similar to the subjective estimations made with a light microscope. This indicates that the Feulgen reaction is a simple, inexpensive and reliable techniqu...
Ecot P, Vidament M, de Mornac A, Perigault K, Clément F, Palmer E.In the present study, the interactions among stallions, semen extenders and cooling treatments before stallion semen samples were frozen were studied. In Expt 1, the effects of four cooling treatments and three semen extenders were investigated (11 stallions x four split ejaculates), whereas in Expt 2, the effects of two semen extenders, two egg yolk concentrations and two glycerol concentrations were investigated (six stallions x five split ejaculates). Sperm motility after thawing was evaluated. In Expt 1, the extender x cooling treatment interaction was significant. Centrifugation and addit...
Wong JK, Tang FP, Wan TS.The study of the metabolism of drugs, in particular steroids, by both in vitro and in vivo methods has been carried out in the authors' laboratory for many years. For in vitro metabolic studies, the microsomal fraction isolated from horse liver is often used. However, the process of isolating liver microsomes is cumbersome and tedious. In addition, centrifugation at high speeds (over 100 000 g) may lead to loss of enzymes involved in phase I metabolism, which may account for the difference often observed between in vivo and in vitro results. We have therefore investigated the feasibility of us...
Alm H, Neumann H, Torner H, Tomek W, Wollenhaupt K, Kanitz W, Becker F.Equine oocytes were collected by follicle aspiration in vivo or by dissection of material obtained from an abattoir, and the ultrastructure, protein phosphorylation and mRNA status of the oocytes were evaluated. Electron microscopy studies indicated that the nucleus had a smooth membrane in oocytes with a compact cumulus, whereas the nuclear membrane was undulated in all other groups. Oocytes with compact cumuli had only a few microvilli, whereas those with expanded cumuli had more microvilli. There were only small numbers of cortical granules close to the oolemma in oocytes with compact cumul...
Pietra M, Guglielmini C, Forni M, Cinotti S.The viscosity of the mucus, its DNA concentration and the size range of the DNA were determined on tracheobronchial samples from 11 horses with lower airway diseases before and after incubation with recombinant human deoxyribonuclease (rhDNase). The horses were divided into two groups on the basis of the cytology of the samples: group A (five horses) with more than 60 per cent neutrophils and group B (six horses) with fewer than 50 per cent neutrophils. The mean mucus viscosity and DNA concentration in the preincubation samples were significantly higher in group A than in group B, and there wa...
Shirer HW, Orr JA, Loker JL.To determine if CO2-sensitive airway receptors are important in the control of breathing, CO2 was preferentially loaded into the respiratory airways in conscious ponies. The technique involved adding small amounts of 100% CO2 to either the latter one-third or latter two-thirds of the inspiratory air in an attempt to raise CO2 concentrations in the airway dead space independent of the arterial blood. Arterial blood gas tensions (PCO2 and PO2) and pH, as well as respiratory output (minute volume, tidal volume, and respiratory rate), were measured in a series of 20 experiments on 5 awake ponies. ...
Işık R.Lactoferrin (LTF), also called lactotransferrin, is an iron-binding protein and member of transferrin family, whereas β-LG is an important milk protein and belongs to the ligand-binding protein family of lipocalins and binds retinol. Beta-lactoglobulin (β-LG) is a major whey protein and it is a member of lipocalins family. β-LG is also known as a major allergen reason of cow milk protein allergy. Yet, no information has been reported about β-LG and LTF genes in donkeys. In this study, the genetic variation of β-LG and LTF genes were analyzed via DNA sequencing in 77 donkeys, which were in...
Gaskin JM, Neal FC, Rubin HL.Precipitin lines not associated with equine infectious anemia (EIA) were observed in routine agar gel immunodiffusion (AGID) testing for the infection. The serums which produced these lines were obtained from horses which had been given multiple vaccinations with commercially available cell culture-origin equine virus vaccines as part of a comprehensive herd health program. The lines formed against cell culture-derived, but not spleen-derived EIA viral antigens. Investigation revealed that bovine serum proteins in the vaccines induced precipitating antibodies which reacted with bovine serum pr...
Houghton E, Dumasia MC, Teale P, Smith SJ, Cox J, Marshall D, Gower DB.Stable isotope gas chromatography/mass spectrometry has been used successfully in the elucidation of structures of urinary steroid metabolites in the horse and in the identification of metabolites isolated from in vivo perfusion and in vitro incubation studies using equine tissue preparations. Deuterium-labeled steroids, testosterone, dehydroepiandrosterone, and 5-androstene-3 beta,17 beta-diol have been synthesized by base-catalyzed isotope exchange methods and the products characterized by gas chromatography/mass spectrometry. [16,16(-2)H2]Dehydroepiandrosterone (plus radiolabeled dehydroepi...
Törneke K, Larsson CI, Appelgren LE.Isoxsuprine is used in veterinary medicine as a vasodilating agent. The drug has been detected in the urine of horses up to 6 weeks after the cessation of administration. In the present study, the distribution pattern of 3H-isoxsuprine was investigated using whole body autoradiography in mice to find a possible site of retention. Melanin was the only place of retention identified. Additional in vitro studies showed an affinity of isoxsuprine to both melanin and keratin. The K(d) values were 0.02 mmol/l and 1 mmol/l, and the B(max) values were 0.2 micromol/mg and 2 micromol/mg, respectively. A ...
Morisset S, McClure SR, Hillberry BM, Fisher KE.To compare the in vitro holding power and associated microstructural damage of 2 large-animal centrally threaded positive-profile transfixation pins in the diaphysis of the equine third metacarpal bone. Methods: 25 pairs of adult equine cadaver metacarpal bones. Methods: Centrally threaded positive-profile transfixation pins of 2 different designs (ie, self-drilling, self-tapping [SDST] vs nonself-drilling, nonself-tapping [NDNT] transfixation pins) were inserted into the middiaphysis of adult equine metacarpal bones. Temperature of the hardware was measured during each step of insertion with ...
Moslemi S, Silberzahn P, Gaillard JL.Explants of equine full-term placenta have been shown to synthesize 19-norandrogens from labelled androgens. Steroid metabolites were purified by silica-gel column chromatography then analysed and quantified by c18-reverse-phase HPLC coupled to a radioactive flow detector. 19-Norandrostenedione was subsequently recrystallized to constant specific activity, providing unequivocal evidence of its synthesis by the equine placenta. 19-Norandrostenedione synthesis appeared to be localized in the microsomal fraction. Regardless of the substrate used, formation of 19-norandrogens was far weaker than t...
Martin-Pelaez S, Rabow Z, de la Fuente A, Draheim P, Loynachan A, Fiehn O, Meyers S, Lyman C, Dini P.Postmortem and pre-euthanasia oocyte retrieval provides the last opportunity to preserve the genetic material in mares. Pentobarbital (PB) is the most common euthanasia agent; however, its effect on the developmental competence of oocytes has not been determined. Here, we evaluated the concentration of PB in equine follicular fluid (FF) and investigated its effect on the developmental competence of oocytes using a bovine IVF model to overcome the low availability of equine oocytes. The concentration of PB was measured by gas-chromatography/mass-spectrometry in FF collected from mare ovaries im...
Belloli C, Arioli F, Beretta C, Madonna M.The contractile effects of the tachykinins eledoisin, substance P and neurokinin A and B were investigated in vitro on circular and longitudinal muscle strips from horse duodenum, ileum and colon. Circular smooth muscle of the small intestine was highly responsive, large intestine circular smooth muscle less so, while longitudinal muscle from all gut segments was much less sensitive. pD2 values and intrinsic activities on small intestine circular muscle indicated differences in receptor distribution between the duodenum and ileum: NK3 and a smaller number of NK2 receptors being present in the ...
Leonel EC, Bento-Silva V, Ambrozio KS, Luna HS, Costa e Silva EV, Zúccari CE.The aim of this study was to test the use of mechanical and mechanical-enzymatic methods, saline solution (SS), and PBS solution for the manipulation and isolation of mare ovarian preantral follicles (PAFs). The ovaries were subjected to mechanical isolation (mixer) alone or in association with enzymatic digestion (collagenase). Incubation times of 10 and 20 min were employed. In the first group, 4.1 ± 4.9 PAFs were harvested with the mechanical-enzymatic method vs 71.1 ± 19.2 with the mechanical procedure, showing a significant difference between methods; using SS and PBS, these number...
Mini-myoglobin (mini-HHMb) is a fragment of horse-heart myoglobin (HHMb) considered to be the prototype of the product encoded by the central exon of the HHMb gene. For this reason, mini-HHMb has been studied extensively showing that carbonylation and oxygenation properties of the ferrous form are similar to those of the full-length protein, while kinetics and thermodynamics of azide binding to the ferric form are significantly different from those of HHMb. To analyze the structure-function relationships in mini-HHMb and the role of conformational fluctuations in ligand accessibility, the mole...
Brinkmeyer-Langford C, Raudsepp T, Gustafson-Seabury A, Chowdhary BP.A total of 207 BAC clones containing 155 loci were isolated and arranged into a map of linearly ordered overlapping clones over the proximal part of horse chromosome 21 (ECA21), which corresponds to the proximal half of the short arm of human chromosome 19 (HSA19p) and part of HSA5. The clones form two contigs - each corresponding to the respective human chromosomes - that are estimated to be separated by a gap of approximately 200 kb. Of the 155 markers present in the two contigs, 141 (33 genes and 108 STS) were generated and mapped in this study. The BACs provide a 4-5x coverage of the regio...
Pinyopummin A, Mahasawangkul S, Kornkaewrat K, Rattanapirom S, Leartsang W, Kitkha S.The effects of seminal plasma (SP), derived from autologous, homologous and heterologous species (stallion, boar and dog) on chilled Asian elephant sperm quality, were determined. Semen was collected from eight males and samples with ≥30% motile spermatozoa were used in the study. Semen was diluted with Tris-glucose-egg yolk extender, supplemented with different SP types and preserved at 4°C for 48 hr. Experiment 1 (n = 31), showed that the presence of SP (autologous) helped to preserve sperm quality in terms of sperm motility and acrosome integrity (p < .05). Homologous SP did not ...
Vacchina V, Ionescu C, Oguey S, Lobinski R.A method was developed for the quantification of Zn-, Cu- and Mn-glycinates in supplemented feed samples. The coupling of capillary electrophoresis (CE) with ICP MS detection after purification of the extract by ultrafiltration was shown to be efficient for the quantitative recovery of glycinates. The method developed was then applied to evaluate the bioaccessibility of glycinates using a sequential enzymolysis approach. The data obtained indicated a strong bioaccessibility of each element (79-94%). A new complex was also found to be formed during the digestion process. Bioavailability was the...
