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Topic:Biochemistry
The study of biochemistry in horses encompasses the chemical processes and substances that occur within equine organisms. This field investigates the molecular interactions and pathways that are fundamental to horse physiology, including metabolism, enzyme activity, and genetic expression. Key areas of interest include the examination of metabolic disorders, nutrient absorption, and the biochemical basis of muscle function and energy production. Researchers utilize biochemical analysis to understand health and disease mechanisms in horses, contributing to the development of diagnostic tools and therapeutic strategies. This page gathers peer-reviewed studies and scholarly articles that explore various biochemical processes and their implications for equine health and performance.
A subunit-sized butyrylcholinesterase present in high concentrations in pooled rabbit serum. A butyrylcholinesterase of mol.wt. approx. 83000 was observed in pooled rabbit serum. The enzyme was named monomeric butyrylcholinesterase to distinguish it from the larger oligomeric butyrylcholinesterase of horse and human serum whose subunits are the same size as the monomeric enzyme. The active-site concentration of monomeric butyrylcholinesterase in the pooled serum was 0.18mum, which is five times the concentration of butyrylcholinesterase in pooled horse serum. This was surprising, since the horse serum is regarded as a rich source of butyrylcholinesterase, whereas rabbit serum is not g...
Studies related to the metabolism of anabolic steroids in the horse: 19-nortestosterone. 1. The metabolism of 19-nortestosterone in a cross-bred horse has been studied using 14C-labelled material. 2. Two neutral metabolites isolated from urinary extracts by column chromatography were identified as isomers of 3-hydroxyestran-17-one and estrane-3,17-diol by g.l.c.-mass spectrometry. 3. The stereochemistry of the two metabolites has been investigated by comparison of the retention times of their trimethylsilyl derivatives with those of standard steroids of known configuration.
Staining of glycosaminoglycans in intervertebral disc cells. Disc material from horse, ox, sheep, pig, dog and cat was stained by the Alcian-blue-critical electrolyte concentration technique and with the standard and two-step periodic acid Schiff methods. The effects of pretreatment with hyaluronidase and with chondroitinase was also evaluated. There appears to be a small increase in total cellular glycosaminoglycan content with age in all species: cellular material of high molecular weight however only increases in aged animals. The degree of sulphation of cellular glycosaminoglycans does not vary with age or with position in the disc.
Circular dichroism of porcine, bovine, and equine pancreatic phospholipases A2 and their zymogens. Unusual conformations simulating helix content. Conformation of porcine, bovine, and equine pancreatic phospholipases A2 (EC 3.1.1.4) and their zymogens was studied by the circular dichroism (CD) probe in the far and near ultraviolet spectral zones.
All these phospholipases and their zymogens displayed CD curves suggesting the presence of moderate amounts of α-helical conformation. However, on the basis of known primary structure and recent X-ray structural analysis of prophospholipase A2 crystals (Drenth, J., Enzing, C.M., Kalk, K.H. and Vessies, J.C.A. (1976) Nature 264, 373–377), it has to be concluded that the positive CD band cen...
Studies on a number of erythrocytic enzymes and intermediate products of equine erythrocyte metabolism. The activities and concentrations of a number of erythrocytic enzymes and intermediate products of erythrocyte metabolism were determined in twenty-one normal standard-bred horses which were studied clinically and biochemically. These studies showed that equine anaerobic glycolysis is characterized by a biochemical pattern similar to that observed in human PK deficiency. The greater sensitivity of equine haemoglobin to oxidants is attributable either to low stability of GSH, which may be due either to the low activity of GR or that of 6PGD as observed in the studies. In addition, the saturatio...
Familial methaemoglobinaemia and haemolytic anaemia in the horse associated with decreased erythrocytic glutathione reductase and glutathione. A trotter mare with a history of poor performance was found to have methaemoglobinaemia and haemolytic anaemia associated with decreased erythrocyte glutathione reductase and glutathione levels. The mare's dam, which also had a history of poor performance, was subsequently found to be similarly affected.
Nucleolar fragmentation in cells infected with alphaviruses (39886). No abstract available
Semisynthetic cytochrome c. 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.
[Fibrinogen level in clinically healthy horses]. 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...
Effect of training on some metabolic changes associated with submaximal endurance exercise in the horse. The effects of prolonged cantering before and after a 10 week training programme were studied in 6 horses. Determinations were carried on on venous blood for packed cell volume, glucose, glycerol, free fatty acids, beta-hydroxybutyrate, 11-hydroxycorticosteroids, pH and pCO2. Exercise caused a slight increase in glucose, lactate and pH, a moderate rise in PCV, glycerol and free fatty acids, and a marked rise in 11-hydroxycorticosteroids. A decrease in venous pCO2 occurred and a slight but not significant decrease in beta-hydroxybutyrate. Training was found to cause no significant difference in...
Phenylalanine inhibited p-nitrophenyl phosphatase activity in the serum as an indication of intestinal cellular disruption in the horse. Examination of tissues obtained from thoroughbred horses showed that the 'intestinal' phosphatase activity could be differentiated from other phosphatases by analysis at a pH of 9-5 and inhibition with 15 mM L-phenylalanine. A simple method for the measurement of 'intestinal' phosphatase in heparinised plasma or serum is described. Application of the technique to serum or plasma from normal and diseased horses indicates that the increase in the activity of 'intestinal' phosphatase is associated with cases showing clinical, biochemical and haematological evidence of intestinal damage.
Chromatographic separations of alphavirus strains by hydroxylapatite. 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 ...
Phosphatase activity of placental extracts and pregnant mare’s plasma. Equine placental extracts show phosphatase activity with a pH optimum between 4.5 and 6. The enzyme shows heat stability to 45 degrees C and electrophoresis on cellulose acetate demonstrates the presence of two bands of activity. Histochemistry confirms the presence of phosphatase activity in the placental villi. Assay of plasma samples from pregnant mares showed no increase in phosphatase activity through pregnancy under conditions of test.
Effects of storage on the methaemoglobin content of equine blood. 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.
Identification of the receptor involved in adrenaline mediated sweating in the horse. Using adrenergic agonists and antagonists this study has demonstrated that adrenaline induced sweating is mediated via beta2-adrenoreceptors in the horse.
Equine cerebrospinal fluid: reference values of normal horses. Cerebrospinal fluid (CSF) samples were collected from the atlanto-occipital (AO) and lumbosacral (LS) subarachnoid spaces of 24 horses and 21 ponies that had no clinical evidence of neurologic disease. Depth of needle insertion, pressures, refractive index, rapid reagent strip test (protein, glucose, blood, pH) results, cell counts, content of protein, glucose, sodium, potassium, chloride, calcium, phosphorus, urea nitrogen, and cholesterol, and activities of creatine phosphokinase, aspartate transaminase, lactic dehydrogenase, and alkaline phosphatase were determined. The resulting clinical r...
The oxidation of ferrocytochrome c in nonbinding buffer. 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...
Direct radioimmunoassay of progesterone in mare plasma. 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.
Bovine reaginic antibody III. Cross-reaction of antihuman IgE and antibovine reaginic immunoglobulin antisera with sera from several species of mammals. 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 ...
Analysis of serum proteins and cerebrospinal fluid in clinically normal horses, using agarose electrophoresis. 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.
Nonsteroidal anti-inflammatory drugs: a review. New applications in hypersensitivity reactions of cattle and horses. Nonsteroidal anti-inflammatory drugs inhibit the biosynthesis of kinins and prostaglandins and stabilize leukocyte lysosomal membranes. Nonsteroidal anti-inflammatory drugs also weakly block the biosynthesis of histamine and serotonin, and pharmacologically antagonize kinins, prostaglandins and slow-reacting substance of anaphylaxis. Nonsteroidal anti-inflammatory drugs effectively control both cardiovascular and respiratory manifestations of hypersensitivity in cattle and horses. This, coupled with the contrasting lack of effectiveness of "antiamine" drugs, suggests that bio-amines such as hi...
The effect of training and detraining on muscle composition in the horse. 1. Percutaneous needle biopsies were obtained from six limb muscles in six horses before and during a training programme of 10 or 15 weeks designed to involve both aerobic and anaerobic work. In a subsequent detraining period, biopsies were also taken after 5 and 10 weeks. 2. Samples were analysed biochemically for enzyme activity of lactic dehydrogenase (LDH), creatine phosphokinase (CPK), aldolase (ALD), citrate synthase (CS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) and for glycogen content. Fibre typing was carried out histochemically before and 10 weeks after c...
