Laboratory methods in equine research encompass a variety of techniques and procedures used to analyze biological samples from horses to study health, disease, genetics, and physiology. These methods include hematological analyses, biochemical assays, molecular biology techniques, and microbiological cultures. Commonly utilized laboratory techniques involve blood tests for complete blood count (CBC) and serum chemistry, polymerase chain reaction (PCR) for genetic and infectious disease studies, and enzyme-linked immunosorbent assays (ELISA) for detecting specific proteins or antibodies. These methods provide valuable data that contribute to understanding equine health and disease mechanisms. This page compiles peer-reviewed research studies and scholarly articles that explore the application, development, and outcomes of laboratory methods in the context of equine research.
Barstow LE, Young RS, Yakali E, Sharp JJ, O'Brien JC, Berman PW, Harbury HA.Horse heart cytochrome c can be split with cyanogen bromide into a heme peptide (residues 1-65) and a nonheme peptide (residues 66-104). In a process involving (i) complex formation between the two fragments and (ii) restoration of the severed peptide linkage, a fully active cytochrome c preparation can be re-formed. Use has been made of this process to couple the heme peptide to peptide 66-104 synthesized by the Merrifield solid-phase procedure. The semisynthetic product formed in this manner is indistinguishable from reconstituted cytochrome c prepared with nonsynthetic peptide 66-104.
Dusek J.Various sets of horses were examined in view of the necessity of widening the range of biochemical substances for diagnostic purposes in the field of veterinary medicine. The aim of the investigations was to obtain basic information on fibrinogen level and its variability. The average value stated was 280 mg% s = 89, sx = 12, V% = 32). The fibrinogen level in horses of the pronounced oxidation type was lower than in those with reduced metabolism, the difference being connected with the speed of sedimentation of erythrocytes. Repeated examination of a part of the set of horses (n = 10) on three...
Drudge JH, Lyons ET.The critical test is the primary method used for the efficacy evaluation of drugs against the major internal parasites (bots, ascarids, large strongyles, small strongyles, and pinworms) of the horse. The critical test determines: (1) spectrum of activity, (2) effectiveness of removal, (3) pattern of discharge, and (4) physical condition of each species of these parasites. General characteristics of the major parasitisms of the horse are discussed briefly. Criteria of the critical test also are considered including: (1) number of tests, (2) strain variation and drug resistance, (3) selection of...
Jahrling PB, Beall JL.Hydroxylapatite column chromatography methods were developed to characterize selected alphavirus populations. Different conditions of pH and phosphate molarity were required to obtain satisfactory elution profiles and separations for Western equine encephalomyelitis virus strains, compared with Eastern equine encephalomyelitis virus and Semliki Forest virus strains. Raising the pH of the buffers effected earlier elutions of all viruses. Selection of phosphate gradients with more gentle slopes and adjustment to the proper pH effected better separations of virus subpopulations. Elution profiles ...
Dixon PM, Brown R.Equine blood containing different levels of methaemoglobin was stored under varying conditions and the methaemoglobin content was monitored during the storage period. Only under aerobic storage at 4 degrees C did the methaemoglobin content of all samples appear to remain stable.
Buening GM, Perryman LE, McGuire TC.Serum concentrations of immunoglobulin M (IgM) and immunoglobulin G (IgG) can be determined in the horse with a satisfactory degree of accuracy, using commercially available reagents. Selected lots of anti-human IgM can be used in precipitation tests to detect and quantitate equine IgM. Commercially available anti-equine IgG tended to overestimate the amount of IgG in single radial immunodiffusion tests. Even with these limitations, commercial reagents can be used to differentiate immunodeficiency disorders of foals, including combined immunodeficiency and failure of passive transfer of colost...
Dyson DA, Smith GR.When incorporated in solid medium at a concentration of 15 per cent, the defibrinated blood of certain horses strongly suppressed the growth of some, but not all, strains of Mycoplasma mycoides subsp mycoides so that many colonies failed to develop to a visible size. Blood from a single rabbit was tested and found to exert a similar effect. There was striking variation in the degree of inhibition produced by different samples of horse blood and, of five strains of the organism examined, the T1 vaccine strain was the most susceptible. The results suggested that the effect was not due to antibod...
Peterman BF, Morton RA.The apparent equilibrium constant and rate of oxidation was investigated for the reaction of cytochrome c with iron hexacyanide. It was found that if horse heart ferricytochrome c was exposed to ferricyanide (to oxidize traces of reduced protein) the cytochrome subsequently, even after extensive dialysis, had an apparent equilibrium constant different from that of electrodialyzed protein. The effect of ferricyanide ion apparently cannot be removed by ordinary dialysis. The ionic strength dependence of the apparent equilibrium constant and bimolecular oxidation rate constant was measured in the...
Kucera CJ, Beckenhauer WH.An inactivated, aluminum hydroxide adjuvant equine influenza vaccine was tested in horses and guinea pigs to determine the levels of antigen that would elicit maximum serological responses. Vaccine containing serial twofold increments of A/Equi-1/Prague and A/Equi-2/Miami strains of equine influenza virus was administered to random groupings of both types of test animals. The hemagglutination inhibition antibody response for each group was then measured. Results in horses and guinea pigs were compared to determine if the equine serological values could be related to a potency test in laborator...
Moore JN, Traver DS, Turner MF, White FJ, Huesgen JG, Butera TS.Peritoneal fluid from each of 15 clinically healthy horses and five horses with acute abdominal disease was evaluated for lactic acid concentration. The normal range was 2-7--13-4 mg/dl. Simultaneous blood and peritoneal fluid samples from healthy horses revealed consistently lower lactic acid concentrations in the peritoneal fluid than in the blood, whereas peritoneal fluid lactic acid levels were consistently greater than blood levels in the diseased horses. The diseased horses had highly significant (P less than 0-005) increases in both blood and peritoneal fluid lactic acid concentrations ...
Mathieu HP, Mathieu-Nast C, Vrignaud C.A rapid and low cost radioimmunologic procedure for progesterone assay in mare plasma is proposed. Radioimmunoassay is performed directly on 10 microliter of unextracted plasma. Free progesterone is adsorbed on dextran-charcoal, then the aqueous phase is decanted and extracted by 1 ml of scintillation fluid. Counting is performed directly on this two-phase system. Results are comparable to those obtained with radioimmunoassays using extracted plasma.
Nielsen KH.Using antisera specific for the heavy chain of human IgE and bovine reaginic immunoglobulin, the degree of cross-reaction amongst sera from pig, rat, rabbit, guinea pig, goat, cow, horse, dog, cat and human was tested. Antihuman IgE antiserum gave strong reactions with pig, rabbit, cow, goat and human sera (100% to 15.1%) and weak reactions with rat, guinea pig, horse, dog and cat sera (10.1% to 3.22%). Antibovine reagin antiserum produced a considerable amount of cross-reaction with sera from pig, rat, rabbit, goat, horse and human (43.6% to 20.1%) with limited reactions with guinea pig, dog ...
Kristensen F, Firth EC.Using agarose as a supporting matrix, electrophoresis was conducted on 50 serum samples and 20 cerebrospinal fluid samples from clinically normal horses (n = 50) of various ages and breeds. The technique was shown to be reliable. A positive correlation between age and gamma-globulin concentration was found in young horses. Features of the electrophoretograms of serum and cerebrospinal fluid samples are discussed, and a nomenclature based on Rf values is proposed.
Seybert DW, Moffat K, Gibson QH, Chang CK.Horse globin has been recombined with 2,4-dimethyldeuteroheme and 2,4-dibromodeuteroheme to yield the corresponding reconstituted hemoglobins, and the ligand binding reactions of these reconstituted hemoglobins have been examined in detail. Both hemoglobins exhibit relatively high n values, but 2,4-dimethyldeuterohemoglobin displays a consistently higher oxygen affinity than native hemoglobin, whereas the oxygen affinity of 2,4-dibromodeuterohemoglobin is consistently lower than that of native hemoglobin. The rate constants l’, and 1’4 for the binding of the first and fourth molecules of C...
Stewart F, Allen WR, Moor RM.Rat testicular radioreceptor assays specific for FSH and LH were used to determine the FSH:LH ratio of PMSG produced by horse, donkey, mule and hinny conceptuses. Measurements of FSH and LH activities in PMSG produced both in vivo and in vitro by the four types of conceptuses showed that the genotype of the foetus markedly influences the FSH:LH ratio of PMSG. The FSH:LH ratio of PMSG produced by the horse conceptus was around unity whereas the ratio of PMSG produced by the donkey conceptus was as low as 0-2. Furthermore, the hybrid mule and hinny conceptuses both produced PMSG with an FSH:LH r...
Walker D.Rectal examination is a reliable method of diagnosing pregnancy in the mare. Also, test kits are available for the simple quick detection of pregnant mare serum gonadotrophin. Nevertheless there is a considerable demand by practitioners for an independent laboratory service in equine pregnancy diagnosis, particularly during the gestational phase when placental gonadotrophin is concentrated in the blood. An initial attempt to provide a service by means of the agar gel diffusion test was disappointing and alternatives were sought. The primary requirements for an ideal alternative technique were ...
Fernley RT.1. Angiotensin I converting enzyme from horse plasma has been extensively purified and shown to be homogeneous by disc-gel electrophoresis. 2. The metal ion involved in the catalytic reaction of the enzyme has been identified for the first time as zinc by atomic absorption spectrometry. 3. A number of other physicochemical properties of the enzyme are described and compared with results obtained by other investigators. The molecular weight was determined by gel filtration to be 113 000 daltons. The pH maximum was found to be 7-4. The chloride activation of the enzyme appears to act by facilita...
Silvestri R.A macromethod and a semimicromethod were developed to measure erythrocyte acetylcholinesterase activity in cattle, sheep, goats, horses, dogs, and swine, and to measure plasma cholinesterase activity in horses, dogs, and swine. Comparison of the 2 methods with erythrocytes of sheep, cattle, goats, and horses indicated both methods gave similar results. They can be done in a shorter time and are more sensitive than Michel's method. Normal deltapH values per minutes, with standard deviations for blood cholinesterase activity of animals of different ages, sexes, breeds, and species, were: 0.76 +/...
Shahrabadi MS, Marusyk RG, Crawford TB.Sequential changes induced by an equine adenovirus in cultured fetal equine kidney cells were studied by electron microscopy. The first morphological change was the appearance of type I inclusions. These inclusions developed to type II inclusions which appeared as ring forms. Type III inclusions were formed within the central part of type II inclusions and finally filled up most of the nuclear space. As the infection proceeded, type IV inclusions which appeared as dense dark-staining spheres were formed at the center of the type III inclusions and also inside the cytoplasm. These dark-staining...
McGuire TC.Isolated equine immunoglobulin (Ig)G(T) antibodies to equine infectious anemia virus P26 antigen did not precipitate with antigen when the ratio of antibody to antigen was high. However, at lower ratios of antibody to antigen precipitation occurred. In addition, complement-fixation by IgG and P26 antigen was inhibited by high concentrations of IgG(T). The unusual reaction pattern noted with IgG(T) antibodies was still detectable by the immunodiffusion test for equine infectious anemia virus. In situations of nonprecipitability by IgG(T), the adjacent positive control line was inhibited, and th...
Rico AG, Braun JP, Benard P, El Hassan AA, Cazieux A.In the horse, gamma-glutamyl transferase (GGT) was found to be mainly located in the kidneys, liver and pancreas. As renal lesions are followed by a urinary escape of enzyme, it can be assumed that if there are raised serum enzyme levels then the source will be chiefly from the liver and pancreas. In the blood, GGT can be measured either in plasma or serum. Its mean level in 58 horses was 12 U/L. This level was not affected by moderate dilution or slight haemolysis and its activity was only slightly decreased by storage at--30 degrees C. The relative hepatic specificity of this enzyme and its ...
Malek G, Richard H, Beauchamp G, Laverty S.Focal bone microcracks with osteoclast recruitment and bone lysis, may reduce fracture resistance in racehorses. As current imaging does not detect all horses at risk for fracture, the discovery of novel serum biomarkers of bone resorption or osteoclast activity could potentially address this unmet clinical need. The biology of equine osteoclasts on their natural substrate, equine bone, has never been studied in vitro and may permit identification of specific biomarkers of their activity. Objective: (1) Establish osteoclast cultures on equine bone, (2) Measure biomarkers (tartrate resistant ac...
Yoshitomi MD, Kuramoto T, Hatazoe T, Mitsuda K, Smith H, Misumi K.Culture protocols need to yield 100 million equine synovial fluid (SF)-derived mesenchymal stromal cells (SF-MSCs) in around 3 weeks are needed, before these cells can be evaluated as agents of articular repair in clinical trials. Objective: To investigate mass culture of equine SF-MSC culture protocols using nonwoven polyethylene terephthalate (PET) fabrics for the potential to meet the targets for clinical trials. Methods: In vitro experiments. Methods: SF samples were collected from the carpal joints in thoroughbred racehorses (n = 21) undergoing arthroscopic surgery and cultured in 10%...
Kay PH, Dawkins RL, Bowling AT, Bernoco D.Plasma or serum samples from 12 Arabian and 181 standardbred horses have been typed using an immunofixation technique to determine electrophoretic polymorphism of equine third complement component (C3). Six distinctly different electrophoretic patterns of equine C3 have been recognized thus far. SDS PAGE analysis of equine C3/anti C3 complexes revealed that the submolecular structure comprised an alpha chain and beta chain of molecular weights approximately 118,000 and 63,000 daltons respectively. The molecular weights of the alpha and beta chains were similar in all electrophoretic variants t...
Kim JY, Kim SJ, Paeng KJ, Chung BC.A gas chromatographic-mass spectrometric (GC-MS) method for the determination of ketoprofen, a non-steroidal anti-inflammatory drug (NSAID), in horse urine by selected ion monitoring (SIM) mode is described. Urine samples (2 mL) were extracted by liquid-liquid extraction with diethyl ether. The residues were then evaporated, derivatized and injected into the GC-MS system. Validation of the GC-MS method in the SIM mode using flurbiprofen as the internal standard (IS) included linearity studies (10-10 000 ng/mL), recovery (95%) and limit of quantitation (LOQ) (10 ng/mL). The response was linear,...
Sweeney RW.Malassimilation should be suspected in horses with weight loss in spite of a good appetite. Malassimilation is usually confirmed with oral glucose or D-xylose absorption tests, whereas the oral lactose tolerance test can be used to evaluate lactase deficiency in foals. Once malassimilation is confirmed, other diagnostic tests such as abdominocentesis, rectal mucosal biopsy, or exploratory laparotomy with intestinal biopsies may determine the etiology of malassimilation.
Wormstrand A.An immunological gel-diffusion test for the diagnosis of pregnancy in the mare is described. 56 blood samples from 50 different mares were tested. Control tests were made both by the Ashheim-Zondek method and by clinical examination. The accuracy of the immunological method was 96.4 %. No false positive reactions were observed. It is recommended to draw the blood sample at approximately 45 days or more after the last service. The immunological method is simple, cheap and accurate and is recommended as a routine test for the diagnosis of pregnancy in mares.
Milne EM.Equine serum haptoglobin was separated by polyacrylamide gel isoelectric focusing and visualized by protein staining or Western blotting. Conventional protein staining revealed up to three bands in the pI range 4.17 to 4.44. The blotting technique, however, showed an anodal group of 8 to 10 bands with a pI range of 4.11 to 4.52 and a cathodal group of 4 to 6 bands with a range of 4.55 to 5.14. The blotting method revealed that equine haptoglobin migrates outside the prealbumin area, in contrast to previous reports.
Sivula NJ.Between 1984 and 1989, 33 horses were diagnosed with renosplenic entrapment of the large colon. Duration of colic, signalment, physical findings, and laboratory values were determined, and treatment methods were evaluated. Nonsurgical correction was attempted in 22 of the horses with suspected renosplenic entrapment of the large colon and was successful in 11 cases. Survival and complication rates also were determined. Nonsurgical correction is a viable alternative to immediate surgery for renosplenic entrapment of the large colon, if cases are selected properly.
Martens JG, Stephens KA, Kerchner LJ, Heck FC, Martens RJ.Plasma fibronectin concentrations were measured in clinically healthy mares and their neonatal foals, using a modified human fibronectin competitive enzyme-linked immunosorbent assay. Ranges of plasma fibronectin were established in clinically healthy horses, and the assay was reliable and reproducible. Plasma fibronectin concentrations were similar in mares and foals, both before and after colostrum ingestion.
May SA, Hooke RE, Lees P.The concentration of Percoll required for isolating equine peripheral blood mononuclear cells has been reinvestigated. A poor cell yield was obtained at the 60 per cent concentration already reported. It is recommended that workers specifically interested in high yields of mononuclear cells, for investigation of lymphocyte and monocyte functions, use a concentration of 65 per cent Percoll. However, workers wishing to isolate pure populations of equine neutrophils might consider a concentration of 70 per cent in the upper layer of Percoll used to retain the mononuclear cells.
Sánchez-Pacheco UA, Bahena-Mondragón BM, Hernández-Piedras FR, Soria-Osorio R, Meneses-Acosta A.The immunotherapy agents derived from horses are biological products that allow the neutralization of clinically relevant immunogens, such as the SARS-CoV-2 virus that causes COVID-19, or the neutralization of toxins present in the venoms of snakes, spiders, and other poisonous animals. Due to their importance, detecting adventitious viruses in equine hyperimmune serum (raw material in industrial processes) is a critical step to support the safety of products for human use, and, in consequence, it is a requirement for commercialization and distribution. The safety of the finished product is ba...
Feng YY, Yang H, Gu XT, Jiang HJ, Lu TH.In this paper, the interaction between Cu(II) ions and Fe-protoporphyrin in horse-heart myoglobin (FePP-Mb) was studied. As a result, some of the Fe(II) ions in FePP-Mb were found to be replaced by Cu(II) ions forming CuPP-Mb, by adding Cu(II) ions into the myoglobin solution. The interaction became stronger when adding more Cu(II) ions into the myoglobin solution. By studying the metal ions' interaction with myoglobin proteins as macromolecules and discussing the interaction mechanism, this work provides a theoretical basis for the further study of hazardous metal ions' interaction with the h...
Kuznetsova LP, Nikitina ER, Sochilina EE, Vasil'eva KA.The influence of some cationic detergents on the catalytic activity of the horse blood plasma cholinesterase in reaction of hydrolysis of alpha-naphthylacetate at different pH were investigated. It was shown, that in the absence of detergents in acid pH of the reaction medium the Km value increases, but V remain constant. In the range of pH from 8.5 to 5.0 in the presence of detergents the Km and V values are not practically changed. That is why the activation of cholinesterase hydrolysis of alpha-naphthylacetate in the presence of detergents is considerably higher than that of the neutral pH....
Seeger K, Thurow H, Haede W, Knapp E.A simple enzyme immunoassay (EIA) for the measurement of progesterone is described. Antibody against 11-OH-hemisuccinate-BSA is bound to polystyrene tubes. 11-OH-hemisuccinyl-beta-D-galactosidase is used as enzyme-coupled antigen and methylumbelliferyl-beta-D-galactoside as substrate. Concentrations down to 0.156 ng/ml plasm or amounts of 93 pg/tube are detectable. Probit analysis gave a linear relationship between log concentration and percentage of binding. A comparison of EIA and radioimmunoassay gave a correlation coefficient of 0.81. The assay is sufficiently sensitive to estimate progest...
Poole AW, Heath MF, Sage SO, Evans RJ.Equine platelets in platelet-rich plasma were incubated with the fluorescent indicator dye, Fura-2-AM (Fura-2-acetoxymethyl ester) and the degree of loading of the cells with the dye and the extent of hydrolysis of the ester was assessed by quantitative fluorimetry and by thin-layer chromatography respectively. Under these conditions the cells loaded poorly with Fura-2 to a concentration of 4 microM. The technique was validated by demonstrating adequate loading of human platelets with Fura-2, to a concentration of 250-300 microM, using the same method. The removal of plasma from the extracellu...
Joppich-Kuhn R, Luisi PL.The interaction between horse liver alcohol dehydrogenase and the oxidized and reduced forms of the 3-thionicotinamide--adenine dinucleotide coenzyme analogues (sNAD and sNADH) has been investigated by ultraviolet absorption, fluorescence and circular dichroism. The fluorescence of sNADH is enhanced when bound to the enzyme, and the protein fluorescence is quenched by both sNADH (60--65%) and sNAD (65%). The possible origin of the larger quenching produced by sNAD with respect to that of NAD is discussed. Coenzyme dissociation constants have been determined by monitoring the quenching of the p...
Evers P, Hoffmann B.This paper describes the use of hormone analysis in the diagnosis of adrenal cortex dysfunction in the dog, cat and horse. Analytical problems concerning the determination of corticosteroid levels are discussed and the pathology of adrenal dysfunction is briefly presented. The paper focuses on the problems in establishing physiological norms for adrenal function based on the established assays. Own experiences and other reported data are referred to.
Mugg PA, Hill A.The failure of N. gonorrhoeae to grow on isolation media was found to be due to inhibitory substances present in commercially available horse sera. Subsequent investigations indicated that the inhibitory action of the horse serum may have been due to antibodies to N. gonorrhoeae, H. influenzae, H. parainfluenzae and beta hemolytic streptococci. This experience highlights the need for media quality control programmes in laboratories which prepare microbiological culture media.
Delbeke FT, Teale P, Debackere M, Houghton E.A commercially available generic promazine ELISA kit is available which shows cross-reactivity for the tranquilizer chlorprothixene (CPT). The ELISA test readily detects the presence of CPT or its metabolites in equine urine for up to 24 h after the i.v. and i.m. administration of sub-therapeutic doses (4.5 mg) to three horses. Maximum concentrations (CPT equivalents) are obtained 2 h after i.v. dosing. No distinct concentration peak values are observed after i.m. administration. Following solid-phase extraction, confirmation of CPT and its metabolites by electron impact mass spectrometry afte...
Liau MY, Huang RJ, Chen SW.As the conventional hyperimmunization schedule in horses introduced by Tanaka could not produce enough neutralizing antibody against Naja naja atra venom, the mixture of Carboxymethyl cellulose (CMC)-Cobra venom incorporated with adjuvant was used for immunization. The neutralizing antibody produced (30 LD50) seemed to be increased but still not to reach the satisfactory level. By using CMC-Cobratoxin adjuvant mixture as an immunizing agent, highly potent antivenin (220 LD50) was obtained.
Hinrichs K, Schmidt AL, Memon MA, Selgrath JP, Ebert KM.Embryos were recovered from the uteri of mares 5 d after ovulation. Six embryos, all morulae, were placed singly in 200-ul droplets of Ham's F-12 with 10% fetal calf serum and cultured at 37 degrees C in a 5% CO(2) atmosphere. The embryos expanded to form blastocysts by the third day of culture. The blastocysts hatched from their zona pellucida, rather than the zona thinning and flaking off, as occurs in vivo. Hatching from the zona pellucida began on the third day of culture and was complete in five of six embryos by the sixth day. The embryonic capsule, normally present in equine embryos aft...
Schoene C, Nedderman AN, Houghton E.Little is known about the metabolism of 17 alpha-alkyl anabolic steroids in horses. In this study, the metabolism of 17 alpha-methyltestosterone is investigated by oral administration of a (1 + 1) mixture of the steroid and its deuteriated analogue. Both compounds were synthesized from dehydroisoandrosterone (DHA), using a Grignard reaction followed by an Oppenauer oxidation. Post-administration urine extracts were analysed by gas chromatography--mass spectrometry (GC-MS) using both electron impact (IE) and chemical ionization (CI). Interpretation of the data was facilitated by observation of ...
Cabañes FJ, Abarca L, Bragulat MR, Calvo MA.The ability of 17 strains of Epidermophyton to perforate hair in vitro using the Ajello & Georg's test procedure and a modification of Lu's method has been studied. Following the Ajello & Georg's test procedure only E. stockdaleae perforated hair. Sporadically some strains of E. floccosum perforated horse hair. We noted as well unusual perforations originated from inside to outside of the hair. By the other technique, all strains, excepting E. floccosum var. nigricans in child hair, perforated hair. E. floccosum showed these perforations later than E. stockdaleae.
Skok MV, Denisiuk PV, Komissarenko SV.Glutaraldehyde treatment does not change the absorption of cytochrome c either in the visible or in UV spectra. It brings about the formation of dimers, trimers and high-polymeric forms of cytochrome c and shifts the pI of all cytochrome c isoelectric fractions to more acid pH. Polymerization also results in changes of kinetic parameters of cytochrome c benzidine reaction increasing its affinity to 3,3-diaminobenzidine with a simultaneous decrease in the effectiveness of H2O2 binding. These biochemical changes can be related to immunochemical differences of native and glutaraldehyde-treated cy...
Blach EL, Amann RP, Bowen RA, Sawyer HR, Hermenet MJ.Transmission electron microscopy was used to confirm that a monoclonal antibody (F79.3E2; class IgG1 kappa) was specifically localized to an antigen in the acrosomal ground substance of stallion sperm. This antibody was used to develop and validate an indirect immunofluorescent procedure to evaluate integrity of the plasma-acrosomal membranes of stallion sperm. The concept was that primary monoclonal antibody would be "shielded" from its acrosomal antigen by an intact plasma membrane. Conversely, sperm with damaged plasma-acrosomal membranes would exhibit green acrosomal fluorescence when view...
Harasawa R, Higashi T.Viral DNA obtained from the equine adenovirus propagated in equine transitional cell carcinoma (ETCC) cells and in equine fetal dermis cells were compared by cleaving with isoschizomeric restriction enzymes, HpaII and MspI, and then electrophoresed in 1.4 per cent agarose gels. Differences between the HpaII and MspI cleavage patterns were evident in viral DNA obtained only from the equine adenovirus propagated in ETCC cells, suggesting site specific methylation at CpG sequences.
Stachel CS, Weik HO.Incubation of equine very low density lipoproteins with lipoprotein lipase isolated from horse postheparin plasma resulted in the formation of lipoproteins of a higher density. Lipoproteins isolated after incubation and plasma lipoproteins had a different chemical composition and triacylglycerol fatty acid pattern. In vitro-obtained low density lipoproteins contained substantially more phospholipids and triacylglycerols but significantly less cholesteryl esters than native low density lipoproteins. Comparing the triacylglycerol fatty acid pattern of plasma very low density lipoproteins and in ...
Michell AR, Taylor EA.In the presence of vanadate, the optimum pH of renal (Na+, K+)-ATPase in rats is reduced and lies in the range of intracellular pH. This explains the difference in optimum pH observed with ATP extracted from equine muscle. Removal of vanadate from such ATP (with noradrenaline) raises the optimum to the accepted range obtained with synthetic ATP. Changes in the sensitivity of the enzyme to potassium concentration contribute to the alterations in optimum pH. The optimum pH of Mg-ATPase is unaffected by vanadate. Since vanadate may be an intracellular regulator of (Na+, K+)-ATPase changes of opti...
Margalit R, Schejter A.The specific binding of cations to horse heart ferrocytochrome c has been studied, using the gel
filtration method. The cations investigated were: Mg2+, Co2+, cinchonine and proflavine. The stability
constants are in the range of 5-8 mM-1, and the number of binding sites per protein molecule are
1 to 2. The temperature dependence of the stability constant for the Mg2+-ferrocytochrome system
was measured. The thermodynamic parameters were found to be: dH&s = 4-12 kcal/mol, dG;,,
(25 "C) = -5.6 kcal/mol and AS&, = +57 calxmol-lx K-I.
Kay PH, Dawkins RL, Bowling AT, Bernoco D.A cDNA probe to the alpha subunit of the murine acetylcholine receptor was used to demonstrate restriction fragment length polymorphism in an acetylcholine receptor gene in the horse. Three different patterns of polymorphism have been observed with fragment sizes of 4.3 and 2.9 kilobases (kb) (pattern 1), 4.3 and 2.5 kb (pattern 2) and 4.3, 2.9 and 2.5 kb (pattern 1,2). Analysis of a three generation pedigree has suggested that patterns 1 and 2 represent two allelic forms of the gene encoding the alpha subunit of the acetylcholine receptor. These data provide a basis for the examination of the...
