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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.
Mechanical properties of the isolated equine trachea.
Research in veterinary science    July 1, 1991   Volume 51, Issue 1 55-60 doi: 10.1016/0034-5288(91)90031-i
Art T, Lekeux P.In order to study the in vitro mechanical properties of the equine trachea submitted to the compressive pressures observed in vivo, the pressure-volume relationship was determined in intra- and extra-thoracic tracheal segments taken post mortem from 29 healthy horses (one to 15 years old; 352 to 651 kg). At the same time, the cross-sectional lumen area (X-SA) at the mid-point of the segment was measured using a slit-lamp transillumination and photographic measurement by endoscopy. The tracheal specific compliance (Cs) as well as the relative changes in X-SA and in the sagittal and transverse d...
In vitro responses of distal airways in horses with recurrent airway obstruction.
American journal of veterinary research    July 1, 1991   Volume 52, Issue 7 999-1003 
LeBlanc PH, Broadstone RV, Derksen FJ, Robinson NE.Distal airway segments (ID, 3 to 4 mm; length, 5 mm) from 2 groups of horses were isolated and suspended in tissue baths filled with Krebs solution, aerated with 5% CO2 in oxygen and maintained at 37 degrees C. Responses to exogenous acetylcholine, isoproterenol, or electrical field stimulation were compared. Control horses (n = 30) had no history of recurrent airway obstruction, whereas principal horses (n = 15) had recurrent airway obstruction and were studied during an acute episode of airway obstruction. Although the distal airways contracted in response to the cumulative half-logarithmic ...
Isolation of equine herpesvirus-1 mutants in the presence of (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine: demonstration of resistance in vitro and in vivo.
Antiviral research    July 1, 1991   Volume 16, Issue 1 29-39 doi: 10.1016/0166-3542(91)90056-w
Field HJ, Awan AR, de la Fuente R.The compound (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA) had been previously shown to be highly effective in treatment of EHV-1 in a murine model for the equine disease. This paper describes the isolation of a series of mutants resistant to the drug. Resistance was demonstrated in cell culture and one mutant was tested in a murine model. The resistant mutant was pathogenic for mice; infectious virus was recovered from respiratory tissues and blood at levels similar to the parental virus. However, the mutant showed a significant degree of resistance in vivo, thus proving the viru...
Regulation of mitogen- and TCGF-induced lymphocyte blastogenesis by prostaglandins and supernatant from equine embryos and endometrium.
Research in veterinary science    July 1, 1991   Volume 51, Issue 1 61-65 doi: 10.1016/0034-5288(91)90032-j
Watson ED, Zanecosky HG.Immunosuppressive substances which interfere with lymphocyte blastogenesis are released in vitro by embryos and endometrium from mares in early pregnancy. Immunosuppression was not evident when tissues were cultured in the presence of indomethacin (a prostaglandin-synthesis inhibitor). Various prostaglandins (PGs) were added to equine lymphocytes and lymphocyte proliferation was measured after the addition of concanavalin A (Con A) or phytohaemagglutinin A (PHA). PGE2 and PGF2 alpha inhibited Con A-induced blastogenesis down to final concentrations of 1.8 x 10(-9) M and 1.3 x 10(-6) M, respect...
Gonadotropin releasing hormone (GnRH) induced luteinizing hormone (LH) secretion from perifused equine pituitaries.
Domestic animal endocrinology    July 1, 1991   Volume 8, Issue 3 353-368 doi: 10.1016/0739-7240(91)90003-3
Pinaud MA, Roser JF, Dybdal N.In vitro responsiveness of the horse anterior pituitary (AP) gonadotropes to single and multiple GnRH challenges was examined. The pituitaries were collected from reproductively sound mares in estrus (n = 5) and diestrus (n = 5). Uniform 0.5 mm AP slices were subdivided using a 3 mm biopsy punch and then bisected for use in the perifusion chamber. Four bisected sections per chamber were perifused at 0.5 ml/min at 37 C for 560 min in Medium 199 saturated with 95% 0(2)/5% CO2. Ten minute fractions were collected after an initial 2 hr equilibration period. Four different treatment regimes of GnRH...
Components of electrogenic transport in unstimulated equine tracheal epithelium.
The American journal of physiology    June 1, 1991   Volume 260, Issue 6 Pt 1 L510-L515 doi: 10.1152/ajplung.1991.260.6.L510
Joris L, Quinton PM.Basic components of unstimulated electrolyte transport across equine tracheal mucosa were characterized. After the tissue was mounted in Ussing chambers, both current and tissue resistance gradually increased for approximately 60 min before reaching stable values. Thereafter, under open-circuit conditions, the tissue had a resistance of 250 +/- 14 omega.cm2, generated a transepithelial potential difference of -34 +/- 1.7 (SE) mV (referenced to the serosal side) and an equivalent short-circuit current (Ieqsc) of -149 +/- 10.2 microA/cm2. Even though 10(-5) M amiloride reduced the current by app...
Expression in Escherichia coli of a synthetic gene coding for horse heart myoglobin.
Protein engineering    June 1, 1991   Volume 4, Issue 5 585-592 doi: 10.1093/protein/4.5.585
Guillemette JG, Matsushima-Hibiya Y, Atkinson T, Smith M.A gene for expression of horse heart myoglobin in Escherichia coli has been constructed in one step from long synthetic oligonucleotides. The synthetic gene contains an efficient translation initiation signal and used codons that are commonly found in E. coli. Unique restriction sites are placed throughout the gene. It has been inserted in a phagemid vector and is expressed from the lac promoter in E. coli at high efficiency, the soluble heme protein representing approximately 10% of soluble protein. Two versions of horse heart myoglobin were produced with aspartic acid or asparagine at residu...
Altered ionic permeability in skeletal muscle from horses with hyperkalemic periodic paralysis.
The American journal of physiology    May 1, 1991   Volume 260, Issue 5 Pt 1 C926-C933 doi: 10.1152/ajpcell.1991.260.5.C926
Pickar JG, Spier SJ, Snyder JR, Carlsen RC.A recently described disorder in certain registered Quarter horses bears many clinical similarities to the muscle disease identified as hyperkalemic periodic paralysis (HPP) in humans. Pathological changes in membrane permeability or Na(+)-K+ pump activity have been proposed to produce the muscle depolarization and inexcitability that characterize the condition in humans. Biopsies of external intercostal muscle from normal and affected horses were used to determine whether alterations in either permeability and/or pump activity could be linked to the pathology in horses. Affected horse muscle ...
Titrimetric determination of muscle buffering capacity (beta mtitr) in biopsy samples.
Equine veterinary journal    May 1, 1991   Volume 23, Issue 3 193-197 doi: 10.1111/j.2042-3306.1991.tb02753.x
Marlin DJ, Harris RC.In vitro titration of muscle homogenates has been used to assess muscle buffering capacity (beta mtitr) in a variety of species. In the present study, factors likely to affect the estimation of beta mtitr were investigated. Also, values of beta mtitr from normal Thoroughbred horses are presented. A non-linear titration curve was obtained with addition of HCl to muscle homogenates. As a result, beta mtitr is expressed as the mumol H+ required to change the pH of 1g of dry muscle or wet muscle from 7.1 to 6.5. An effect of dilution on the initial pH was found below 40 mg wet muscle per ml homoge...
Circulating antagonist of luteinizing hormone in association with infertility in stallions.
Endocrinology    May 1, 1991   Volume 128, Issue 5 2497-2502 doi: 10.1210/endo-128-5-2497
Whitcomb RW, Schneyer AL, Roser JF, Hughes JP.Using a LH radioligand receptor assay (RRA) previously validated for use in serum and an equine monoclonal RIA, we have distinguished a subset of subfertile stallions with an elevated RRA/RIA ratio. After purification of the active moiety by anion exchange chromatography and immunoprecipitation with the equine LH (eLH) monoclonal antibody, RRA activity remained in the supernatant. This activity was also recognized by a polyclonal LH antibody (GDN 15) with wide cross-species recognition. This active fraction was further purified by gel filtration chromatography and shown to displace labeled eLH...
In vitro transport of cycloleucine by equine cecal mucosa.
American journal of veterinary research    April 1, 1991   Volume 52, Issue 4 539-542 
Freeman DE, Donawick WJ.Mucosa obtained from the cecum of healthy horses and incubated in vitro with 0.1 mM cycloleucine could accumulate this amino acid against an apparent concentration gradient after 60 and 120 minutes. Accumulation by the serosal (antiluminal) surface of the tissue was 3 times greater than accumulation by the mucosal (luminal) surface after 120 minutes (P less than 0.001). Cycloleucine accumulation was significantly reduced by Na deprivation after 60 minutes (P less than 0.05) and 120 minutes (P less than 0.01) and by anoxic conditions after 120 minutes (P less than 0.05). Transmucosal flux from ...
Corynebacterium pseudotuberculosis: in vitro susceptibility to 39 antimicrobial agents.
Veterinary microbiology    April 1, 1991   Volume 27, Issue 2 145-150 doi: 10.1016/0378-1135(91)90005-z
Judson R, Songer JG.The minimal inhibitory concentrations of 39 antimicrobial agents for 54 isolates of Corynebacterium pseudotuberculosis in vitro have been determined. The most active agents were penicillins, macrolides, tetracyclines, cephalosporins, lincomycin, chloramphenicol, and rifampicin. Most isolates were resistant to aminoglycosides, nitrofurans, polymyxins, nalidixic acid, and cycloheximide.
Effect of dietary alpha-linolenic acid on endotoxin-induced production of tumor necrosis factor by peritoneal macrophages in horses.
American journal of veterinary research    April 1, 1991   Volume 52, Issue 4 528-532 
Morris DD, Henry MM, Moore JN, Fischer JK.A study was conducted to determine whether dietary supplements with alpha-linolenic acid altered the ability of equine peritoneal macrophages to produce tumor necrosis factor (TNF) in response to endotoxin. Peritoneal macrophages were harvested from 6 healthy adult horses before and after the horses were fed a nutritionally balanced ration that contained 8% linseed oil as a source of alpha-linolenic acid. The macrophages were cultured in media containing no additives (control), endotoxin (0.5 to 50 ng/ml), or the calcium ionophore, A23187. Macrophage supernatants were collected after 6 and 24 ...
Equine infectious anemia virus and human immunodeficiency virus DNA synthesis in vitro: characterization of the endogenous reverse transcriptase reaction.
Journal of virology    April 1, 1991   Volume 65, Issue 4 1952-1959 doi: 10.1128/JVI.65.4.1952-1959.1991
Borroto-Esoda K, Boone LR.The endogenous reverse transcriptase reaction of equine infectious anemia virus (EIAV) has been studied, and conditions allowing synthesis of full-length minus-strand DNA have been determined. In contrast to results reported for other retroviruses, synthesis of EIAV full-length minus-strand DNA was not impaired by high concentrations of Nonidet P-40, a nonionic detergent used to make the virion envelope permeable. All components of the reaction were titrated for maximum synthesis of complete minus strands, and a time course under the standardized conditions was determined. Minor subgenomic ban...
Modulation of equine tracheal smooth muscle contractility by epithelial-derived and cyclooxygenase metabolites.
Respiration physiology    April 1, 1991   Volume 84, Issue 1 105-114 doi: 10.1016/0034-5687(91)90022-b
Tessier GJ, Lackner PA, O'Grady SM, Kannan MS.The role of epithelium in the modulation of contractile responses to electrical field stimulation (EFS), acetylcholine (ACh), and KCl were studied in vitro in strips of equine tracheal smooth muscle (TSM). EFS with 0.5 ms pulses of voltage (70 V) resulted in frequency dependent contractions of equine TSM that were sensitive to tetrodotoxin (TTX) and atropine. In TSM without epithelium, preincubation with indomethacin significantly potentiated contractile responses to EFS. The potentiating effect of indomethacin on EFS contractions was abolished by the addition of 3 nM prostaglandin E2 (PGE2). ...
Hemostatic studies in racing standardbred horses with exercise-induced pulmonary hemorrhage. Hemostatic parameters at rest and after moderate exercise. Johnstone IB, Viel L, Crane S, Whiting T.The purpose of this study was to determine whether a defect in hemostasis might be a factor in the etiology of exercise-induced pulmonary hemorrhage (EIPH). Hemostatic parameters were evaluated in 22 EIPH-positive and ten EIPH-negative racing horses while in a rested state. Nineteen EIPH-positive and ten EIPH-negative horses were further evaluated just before and immediately after a 15 min exercise period on a 260 m oval track. When EIPH-positive and EIPH-negative horses were compared at rest, there was no significant difference in any of the coagulation and fibrinolytic parameters studied. Th...
1H NMR resonance assignments in a paramagnetic heme protein by two-dimensional spectroscopy: heme resonances in equine met-azido myoglobin.
Biochemical and biophysical research communications    March 15, 1991   Volume 175, Issue 2 515-519 doi: 10.1016/0006-291x(91)91594-3
Peyton DH.Specific heme protons for the majority of resonances in the downfield resolved region of equine met-azido myoglobin have been assigned using solely the two-dimensional 1H NMR experiments NOESY and COSY. Metazido myoglobin provides a useful test case for the applicability of these techniques to paramagnetic proteins for the following reasons. First met-azido myoglobin is a mixed spin-state protein, with significantly shorter relaxation times and broadened lines relative to pure low-spin systems (eg., met-cyano myoglobin). Second, met-azido hemoglobin and met-azido myoglobin are important as mod...
Proliferation of chick embryo neuroblasts grown in the presence of horse serum requires exogenous transferrin.
Journal of neuroscience research    March 1, 1991   Volume 28, Issue 3 391-398 doi: 10.1002/jnr.490280311
Barakat-Walter I, Deloulme JC, Sensenbrenner M, Labourdette G.We have previously shown that neuroblasts from cerebral hemispheres of 6-day-old chick embryos are able to proliferate when grown in the presence of fetal calf serum. We report here that in the presence of horse serum alone the proliferative rate of neuroblasts is strongly reduced. A high proliferative rate is restored upon the addition of bovine transferrin and to a lesser extent with added FeSO4 or hemin. These findings suggest that the transferrin of horse serum cannot be used by chick neuroblasts in vitro, while bovine transferrin exogenously added is active in promoting cell proliferation...
Alterations of cellular immune response during intensive training of event horses.
Zentralblatt fur Veterinarmedizin. Reihe B. Journal of veterinary medicine. Series B    March 1, 1991   Volume 38, Issue 2 90-94 doi: 10.1111/j.1439-0450.1991.tb00850.x
Buschmann H, Baumann M.During strenuous exercise of horses that are prepared for international Three-Day-Events a significant decrease in the in vitro killing rate of phagocytosed yeast cells by the blood granulocytes has been observed. Other immunological parameters, such as the phorbolmyristate dependent chemiluminescence in granulocytes and the mitogenic stimulation of blood lymphocytes, remained unchanged.
Pathway of ultrasound waves in the equine third metacarpal bone.
Journal of biomedical engineering    March 1, 1991   Volume 13, Issue 2 113-118 doi: 10.1016/0141-5425(91)90057-e
Langton CM, Riggs CM, Evans GP.The velocity of ultrasound waves through bone has been used widely as a non-invasive method for assessing bone quality. Accurate measurement of velocity depends on accurate assessment of the distance travelled by the sound wave. It has been argued that the sonic pathway is deflected around the marrow cavity and so does not follow a straight line through the bone; therefore, correction factors have been developed to account for the extra distance travelled. This hypothesis was examined in vitro using sections from the equine third metacarpal bone. Two 1 MHz transducers used with the transmittin...
In vitro development of day-2 equine embryos co-cultured with oviductal explants or trophoblastic vesicles.
Theriogenology    March 1, 1991   Volume 35, Issue 3 669-682 doi: 10.1016/0093-691x(91)90462-m
Ball BA, Altschul M, Ellington JE.This study compared the in vitro development of Day-2 equine embryos co-cultured with either trophoblastic vesicles or oviductal explants. Embryos were collected surgically from the oviducts of pony mares 2 d after ovulation and assessed for stage of development. Culture medium was Ham's F12 and Dulbecco's Modified Eagle's Medium (50:50 v/v) in a humidified atmosphere of 5% CO(2) in air at 38.5 degrees C with either trophoblastic vesicles or oviductal explants. The quality score of embryos was assessed daily. After 4 d in culture, embryos were stained (Hoechst 33342) and evaluated with epifluo...
Characterization and mapping of melatonin receptors in the brain of three mammalian species: rabbit, horse and sheep. A comparative in vitro binding study.
Neuroendocrinology    March 1, 1991   Volume 53, Issue 3 214-221 doi: 10.1159/000125721
Stankov B, Cozzi B, Lucini V, Fumagalli P, Scaglione F, Fraschini F.Melatonin receptors were characterized in the brains of three mammals (rabbit, horse and sheep) by an in vitro binding technique, using 2-[125I]iodomelatonin as labelled ligand. Although binding sites for melatonin have been described recently in several vertebrate species (including the sheep), the rabbit and the horse have not been the subject of investigation so far. Apart from characterization, the present report describes receptor distribution in a number of brain regions, thus allowing for direct interspecies comparison under the same methodological conditions. 2-[125I]iodomelatonin labe...
1H and 119Sn magnetic resonance study of the SnIV protoporphyrin IX complex of equine myoglobin. Structure of the porphyrin-binding pocket.
The Journal of biological chemistry    February 25, 1991   Volume 266, Issue 6 3728-3733 
Deeb RS, Peyton DH.Tin protoporphyrin IX (SnPP) is being used in the treatment of hyperbilirubinemia. We have studied the SnPP complex with equine myoglobin (EqMb) by 1H and 119Sn nuclear magnetic resonance spectroscopy (NMR) as a general model for SnPP interaction with hemoproteins. The complex formed from SnPP and EqMb, SnPP.EqMb, was found to have essentially the same porphyrin-binding pocket as EqMbCO, including the same porphyrin orientation in the major form of EqMbCO. 119Sn NMR spectroscopy has been used to demonstrate that the proximal His93F8-metal coordination is likely to be intact in SnPP.EqMb. Minor...
Use of a computerized system for evaluation of equine spermatozoal motility.
American journal of veterinary research    February 1, 1991   Volume 52, Issue 2 224-230 
Varner DD, Vaughan SD, Johnson L.Three ejaculates from each of 3 stallions were used to evaluate a computerized system (Hamilton-Thorn motility analyzer; HTMA) for measuring equine spermatozoal motility. Variance components (ejaculate-within-stallion, chamber-within-ejaculate, and microscopic field-within-chamber) were determined for each stallion after diluting ejaculates to 25 x 10(6) spermatozoa/ml with a skim milk-glucose seminal extender. The HTMA was compared with frame-by-frame playback videomicrography (VIDEO) for determining: percentage of spermatozoal motility and spermatozoal number in microscopic fields; curviline...
Steroidogenesis by equine preovulatory follicles: relative roles of theca interna and granulosa cells.
Endocrinology    February 1, 1991   Volume 128, Issue 2 1159-1166 doi: 10.1210/endo-128-2-1159
Sirois J, Kimmich TL, Fortune JE.Estrous cycles in mares have several unique characteristics, including the presence of a long period of estrus and the absence of a typical LH surge. Like follicles of other species, equine preovulatory follicles are characterized by their ability to secrete large amounts of 17 beta-estradiol, but it is not clear which follicular cell type is responsible for estradiol synthesis in mares. To better understand the relative roles of theca interna and granulosa cells in follicular steroidogenesis, presumptive ovulatory follicles were obtained from mares during early estrus (first or second day of ...
Steroid 21-hydroxylase activity in equine ovarian follicles evidenced by isotope dilution-mass spectrometry.
The Journal of steroid biochemistry and molecular biology    February 1, 1991   Volume 38, Issue 2 165-172 doi: 10.1016/0960-0760(91)90122-l
Bijault C, Dehennin L.Steroid 21-hydroxylase activity of the microsome-enriched fraction of follicular linings from equine ovaries has been demonstrated by gas chromatography-mass spectrometry. The 21-hydroxylated metabolites were quantified by isotope dilution with deuterated analogues. The two most abundant potential substrates for follicular steroid 21-hydroxylase, progesterone (P) and 17-hydroxyprogesterone (17OHP), were converted respectively to 11-deoxycorticosterone (DOC) and 11-deoxycortisol with corresponding apparent specific activities of 308 and 24 pmol/mg protein/h and apparent Km values of 1.1 and 6.4...
[The effects of crude drugs using diuretic on horse kidney (Na+ + K+)-adenosine triphosphatase].
Yakugaku zasshi : Journal of the Pharmaceutical Society of Japan    February 1, 1991   Volume 111, Issue 2 138-145 doi: 10.1248/yakushi1947.111.2_138
Satoh K, Yasuda I, Nagai F, Ushiyama K, Akiyama K, Kano I.In the folk-medicine, several kinds of crude drugs are used as diuretics. Twenty three kinds of diuretic drugs were chosen, and examined for their effects on the horse kidney (Na+ + K+)-adenosine triphosphatase (ATPase), which is an intrinsic enzyme of the plasma membrane and responsible for the active transport of Na+ and K+ across the membrane. Twenty one out of twenty three kinds of ethanol extracts of diuretic drugs inhibited the kidney (Na+ + K+)-ATPase activity. The intensity of the inhibition of these drugs was compared by estimating the amounts of their ethanol extracts which inhibited...
Calmodulin-mediated adenylyl cyclase from equine sperm.
Methods in enzymology    January 11, 1991   Volume 195 91-110 doi: 10.1016/0076-6879(91)95157-f
Toscano WA, Gross MK.No abstract available
Isolation of horse IgG with protein A. Fernandes I, Takehara HA, Mota I.Horse immunoglobulins were obtained from normal serum defatted with dextran sulfate and precipitated with ammonium sulfate. Eight mg of this preparation was submitted to affinity chromatography with protein A-Sepharose CL-4B. Low temperature (4 degrees C) and a starting buffer at pH 8.0 were conditions required for all IgG subclasses to bind to protein A, even those with low affinity. The IgGs bound to protein A were eluted with glycine buffer at pH 2.8. The yield was about 90%. It is suggested that isolated IgG, instead of whole Igs, be used in serum therapy, reducing the amount of Igs and di...
Electrophoretic characterization of human, equine and bovine transferrins.
Comparative biochemistry and physiology. B, Comparative biochemistry    January 1, 1991   Volume 98, Issue 1 41-45 doi: 10.1016/0305-0491(91)90305-w
Penhallow RC, Mason AB, Woodworth RC.1. Human, bovine and equine transferrins have been characterized with respect to mol. wt, and behavior on urea-polyacrylamide gels, and isoelectric focussing gels. 2. As shown by SDS-polyacrylamide gel electrophoresis human transferrin has one major polypeptide whereas both bovine and equine transferrins have two polypeptides. 3. The transferrins show multiple banded patterns on urea-polyacrylamide and isoelectric focussing gels, particularly when iron saturated. The various forms are not resolved by neuraminidase treatment.