Hemoglobin is an iron-containing protein found in the red blood cells of horses, responsible for the transport of oxygen from the lungs to the tissues and the return of carbon dioxide from the tissues to the lungs. It plays a vital role in maintaining cellular respiration and energy metabolism. The structure and function of hemoglobin can be influenced by various factors, including genetics, age, and health status. Research into equine hemoglobin includes studies on its biochemical properties, the impact of different physiological and pathological conditions on its levels, and its importance in performance and endurance. This page compiles peer-reviewed research studies and scholarly articles that explore the characteristics, regulation, and clinical implications of hemoglobin in equine physiology and health.
Svendsen CK, Hjortkjaer RK, Hesselholt M.42 horses were examined. The physical signs with relation to circulatory insufficiency and the abdominal disease were registered following a two-phased examination procedure. Great prognostic value was found in the degree of circulatory insufficiency judged by pulse rate and character, filling of the jugular vein, skin temperature, colour of mucous membranes, capillary refill time, sweating, depression, skin turgor and degree of enophthalmus. In making a causal diagnosis the abdomen was examined for shape, tenderness, peristaltic sounds, gastric dilation by siphoning, abnormal rectal findings ...
Rifkind JM.The oxidation of horse hemoglobin by Cu(II) has been followed by the changes in the electron spin resonance spectra of copper. By stopped-flow and freeze-quenching techniques, it is shown that the second-order rate constant for the binding of Cu(II) to hemoglobin is greater than 5 X 10(5) mol-1 s-1 and the apparent first-order rate for the reduction of Cu(II) to Cu(I) is 0.051 s-1. It is also shown that the binding of Cu(II) to hemoglobin is followed by an alteration of the Cu(II) spectrum, decreasing the g values. This process has an apparent rate constant of 17 s-1 and presumably involves a ...
Verger C.We have shown previously that hemoglobin greatly stimulates chick embryo cell proliferation in Eagle's minimal essential medium supplemented with horse serum. In the present study we compared the effects of horse serum plus 10 micrometers hemoglobin to those of fetal bovine serum on subcultures of chick embryo cells serially propagated at high cell densities. The cells became elongated in the presence of fetal bovine serum and their rate of proliferation progressively decreased, whereas they became polygonal in the presence of horse serum plus hemoglobin and proliferated well in successive cel...
Willett K, Blackmore DJ.A method is described for the measurement of haptoglobin in equine serum using the peroxidase activity of the haemoglobin-haptoglobin complex. The problems of interference with Fe2+ and Fe3+ ions are described. Normal values for haptoglobin in 629 blood samples from thoroughbreds in training are presented showing a log normal distribution with a 5 per cent to 95 per cent range of 0.42 to 1.7 g/litre. There was no consistent alteration in haptoglobin concentration throughout the season in spite of a change in red cell size and total bilirubin concentration. It is concluded that the measurement ...
Rose RJ, Ilkiw JE, Martin IC.The effects of prolonged strenuous exercise on arterial and venous oxygen tension, carbon dioxide tension, pH, bicarbonate, standard bicarbonate, base excess, haemoglobin, packed cell volume and total plasma protein were studied in 36 horses during a 100 km endurance ride. There were significant changes in many parameters when pre-ride values were compared with both mid-ride and end of ride values. The prominent changes were the development of dehydration and a metabolic alkalosis. At the mid-ride sampling time those horses with higher heart rates had a greater degree of metabolic alkalosis th...
Sato T, Oda K, Kubo M.Hematological and biochemical parameters in five Thoroughbred foals during the first six months of life are reported. The samples were analyzed for red blood cell, packed cell volume, hemoglobin, platelet, white blood cell, absolute number for leukocytes, and erythrocyte fragility and serum calcium, inorganic phosphorus, sodium, potassium, chloride, magnesium, alkaline phosphatase, icterus index unit, bilirubin, blood urea nitrogen, nonprotein nitrogen, blood glucose, lacticdehydrogenase, glutamic pyruvic transaminase, glutamic oxalacetic transaminase, total protein, albumin, globulin, and A/G...
Ryder OA, Sparkes RS, Sparkes MC, Clegg JB.1. Through the use of isoelectric focusing and peptide analysis, the hemoglobins of Przewalski's horse. Equus przewalskii and the domestic horse, E. caballus have been compared. 2. Przewalski's horses have two separate alpha-globin chain polymorphisms similar to domestic horses. Each hemoglobin phenotype could be accurately determined by isoelectric focusing. 3. Confirmation of the electrofocusing hemoglobin determinations was made by comparison to amino acid composition analyses of purified tryptic peptides and by analysis of the rare hemoglobins phenotypes observed in a family of Norwegian t...
Alben JO, Bare GH.Infrared absorption spectra of the alpha-104 (G11) cysteine SH group have been observed for aqueous solutions of hemoglobin derivatives from humans, pigs, and horses. The center frequencies ((nu)SH) show ligand sensitive patterns that are similar for the three species, with (nu)SH (HbCO) <(nu)SH (HbO(2) ~ HbCN) < (nu)SH (Hb(+)) <<(nu)SH (deoxyHb) for human and pig hemoglobins. The alpha-104 SH group is most strongly H-bonded (smallest (nu)SH), has the greatest range of (nu)SH (Hb ? HbCO) in human hemoglobin, and is least strongly H-bonded and has the smallest range of (nu)SH (Hb ? HbCO) in hor...
Dollahite JW, Younger RL, Crookshank HR, Jones LP, Petersen HD.Lead acetate was fed to 4 groups of 2 horses each to study chronic lead intoxication. A 5th group of 3 horses was maintained as controls. The leas was fed in capsules, with the minimum dosage of 6.25 mg/kg/day of lead as lead acetate (group I). The dose was increased from group I through group IV in an approximate geometric series, with each group being given about 125% of the dose given the previous group. These doses were given for 105 days, a period designated as phase 1. Since clinical signs were not observed after 105 days, the doses were increased and fed for an additional 190 days (days...
Braunitzer G, Schrank B, Stangl A, Bauer C.The sequence analysis of llama (Lama glama, Camelidae) hemoglobin is described. The chains were separated, cleaved by trypsin as previously described, quantitatively characterized and sequenced in the sequenator. The llama hemoglobin differs from the human hemoglobin in that it has 25 different amino acids in the alpha chain and 24 different amino acids in the beta chain. The interaction between protein and phosphate is discussed. The earlier finding that the O2 affinity of the llama hemoglobin is dependent on its content of 2, 3-bisphosphoglycerate is interpreted here as a mutation of the 2, ...
Mirck MH, Franken P.Experimental infections using 600,000 infective larvae of Strongyloides westeri were carried out in seven worm-free Shetland ponies, four foals and thee yearlings. In the foals, the prepatent period varied from ten to fourteen days, the patent period ranging from forty-three to eighty-three days. Within approximately two months after infection, a decrease in the concentration of haemoglobin and an increase in the beta-globulin fraction of the protein pattern of the serum, practically coinciding with the maximum S. westeri faecal egg counts, were recorded. In the yearlings, the prepatent period...
Komárek J, Matousek V, Jadrný L.Blood parameters were studied in two groups of horses in the "Velká Pardubická" steeple-chase in 1974, 1975 and 1976. After the race, the levels of lactate showed a manifold increase; an increase was also ascertained in the levels of glucose, sodium, potassium, haemoglobin, in the haematocrit value and in the number of erythrocytes. The following parameters significantly dropped: the levels of acid-base balance - pH, base excess, bicarbonate levels. It was proved that the values of the same parameters in horses during training were incomparably lower. It is advisable to examine horses thorou...
Franken P, Schotman JH.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...
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.
Honstein RN, Monty DE.Field investigations were conducted under natural environmental conditions to determine the physiologic responses of rested, hydrated horses (Equus caballus) to the very hot, dry weather characteristic of the summer season in southern Arizona. The emphasis of the investigation was placed on those thermoregulatory mechanisms which are involved in the maintenance of homoiothermy. Rectal temperature of the horses studied remained relatively stable throughout the day, during both cool and hot weather seasons. However, when horses were exposed to hot summer temperatures, rectal temperature (heat st...
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...
Lykkeboe G, Schugaard H, Johansen K.Effects of training and exercise on blood respiratory properties were investigated in standard-bred race horses. Training caused an increase in the circulating O2 capacity at rest from 18.4 to 21.0 vol%, and in the O2 capacity during exercise from 24.9 to 30.3 vol%. An increase in the in vitro oxygen affinity [P50(PH 7.4, 37.9 degrees C)] of about 2 mm Hg correlated with a decrease in the red cell concentration of 2,3-diphosphoglycerate (DPG) from 6.35 mM-1-1(E), erythrocytes. Trained horses also showed an acute lowering of the red cell DPG concentration after maximal exercise. The physiologic...
Sakura JD, Rupley JA.Reaction of horse methemoglobin with O-methylisourea at pH 10.2 results in 95% conversion of lysine residues to homoarginine. Analysis of the chymotryptic peptides showed that no single ϵ-amino group was unreactive. Guanidination decreases the dependence of the sedimentation coefficient on hydrogen ion concentration in the range of pH 8 to 11 and did not affect the dependence on protein concentration at pH 7. These results support the conclusion that the lysine side chains involved in subunit contacts have sufficient freedom to accommodate the small changes in bulk and geometry associated wit...
Schroeder E, Wollmer A, Kubicki J, Ohlenbusch HD.The effect of proton concentration upon the subunit dissociation of horse methemoglobin has been investigated at two ionic strengths by light scattering photometry at 700 nm. Differential refractometry revealed a slight but systematic decrease of the specific refractive index increment with decreasing protein concentration for solutions in dialytic equilibrium with the solvent. In the pH range 4.8-7.2 the dissociation can be described by a simple equilibrium between tetramers and dimers. The dissociation constant Kd of the met derivative is found to be very similar to those of the O2- and CO-l...
Rifkind JM, Lauer LD, Chiang SC, Li NC.Oxidation studies of hemoglobin by Cu(II) indicate that for horse hemoglobin, up to a Cu(II)/heme molar ratio of 0.5, all of the Cu(II) added is used to rapidly oxidize the heme. On the other hand, most of the Cu(II) added to human hemoglobin at low Cu(II)/heme molar ratios is unable to oxidize the heme. Only at Cu(II)/heme molar ratios greater than 0.5 does the amount of oxidation per added Cu(II) approach that of horse hemoglobin. At the same time, binding studies indicate that human hemoglobin has an additional binding site involving one copper for every two hemes, which has a higher copper...
Smith HJ.A group of seven ponies naturally infected with large numbers of small strongyles and raised under conditions to minimize reinfection were treated periodically over a three year span with thiabendazole at the rate of 44 mg/kg body weight. Based on the absence of worm eggs in the feces following each treatment, thiabendazole removed the adult strongyles present with a new population subsequently developing by maturation of inhibited larvae. It took as many as four or five treatments to eliminate or reduce significantly the worm burdens present in the ponies under the conditions of this study. S...
Revington M.Eight hundred and sixteen blood samples were collected from horses at Sydney race tracks, 1 to 3 h before racing, and subjected to haematological analysis. Haemograms were also performed on 65 blood samples taken from horses at rest in their stalls. These were used as reference values of prerace and resting haemograms, respectively. The haemograms of 29 of the resting horses were compared with the haemograms of the same 29 horses the following day at the race track. Both samples were considered to be representative of their reference populations. In general, there was a significant increase fr...
Folin M, Gennari G, Jori G.The irradiation of horse and sperm-whale Fe” or Fez’ myoglobins with visible light
showed that axial ligands that render the heme diamagnetic (e.g. 02, CO or CN-) endow the
hemoproteins with a marked photosensitivity. In contrast, high-spin myoglobins are unaffected by
visible light. These findings appear to be of general validity for all hemo-proteins and are in agreement
with the involvment of the triplet state of the heme as the reactive intermediate. In all cases, the overall
photoprocess occurs within a very narrow spatial range, leading to specific modification of these
photoox...
Hammond JM, Lee WC, DeNicola DB, Roche J.Automated in-house diagnostic analyzers, most commonly used for hematologic and biochemical analysis, are typically calibrated, and then control materials are used to confirm the quality of results. Although this approach provides indirect knowledge that the system is performing correctly, it does not provide direct knowledge of system performance between control runs. Objective: The objectives of this study were to apply analysis of weighted moving averages to assess performance of hematology analyzers using animal patient samples from dogs, cats, and horses as they were analyzed and apply co...
Frabasile L, Amendola C, Buttafava M, Chincarini M, Contini D, Cozzi B, De Zani D, Guerri G, Lacerenza M, Minero M, Petrizzi L, Qiu L, Rabbogliatti V....Biosensors applied in veterinary medicine serve as a noninvasive method to determine the health status of animals and, indirectly, their level of welfare. Near infrared spectroscopy (NIRS) has been suggested as a technology with this application. This study presents preliminary time domain NIRS measurements of optical properties (absorption coefficient, reduced scattering coefficient, and differential pathlength factor) and hemodynamic parameters (concentration of oxygenated hemoglobin, deoxygenated hemoglobin, total hemoglobin, and tissue oxygen saturation) of tissue domestic animals, specif...
Rişvanlı A, Şen İ, Canuzakov K, Tülöbayev A, Taş A, Saklykov R, Ceylan N, Türkçapar Ü, Alimov U, Kazakbayeva A, Cunuşova A, Uulu NA....The aim of this study was to examine variations in stress, metabolic, and physiological parameters of horses used in the traditional equestrian team sport of Kök-Börü in relation to winning and losing outcomes. Methods: To accomplish this, blood samples were taken from horses on four different teams who participated in two separate games, both before and after game. These samples were used to measure levels of cortisol, ACTH, beta-endorphin, adrenaline, noradrenaline, triiodothyronine (T3), and thyroxine (T4) via species-specific commercial ELISA kits. The autoanalyzer tested biochemical an...
Souza LA, Hunka MM, Rezende Júnior SF, Silva CJFLD, Manso HECDCC, Simões J, Coelho CS, Fazio F, Aragona F, Manso Filho HC.The aim of this two-phase study was to evaluate the use of beet pulp concentrate (BPC) in athletic horses. On the first trial the effects of supplementation with 820g of BPC for 12 weeks were assessed and a crossover postprandial curves of blood biomarkers were determined in five adult Arabian mares. Differences were found in T-chol, HDL-chol, TPP and MCHC (p < 0.05). Postprandial curves varied among challenges (p < 0.05) for glucose, insulin, and hematocrit. These results confirmed that BPC supplementation led to changes in blood biomarkers, without inducing major metabolic disruption. Th...
Cheung HW, Wong KS, Cheng PCF, Tsang CYN, Farrington AF, Wan TSM, Ho ENM.Erythropoiesis-stimulating agents (ESAs) continue to be a significant threat to the integrity of human and equine sports. Besides conventional direct testing, monitoring the biomarkers associated with the effects of ESAs may provide a complementary approach via indirect detection to enhance doping control. In this study, we applied RNA-sequencing (RNA-seq) to discover blood RNA biomarkers in Thoroughbred horses after administration with a long-acting form of recombinant human erythropoietin (rhEPO), methoxy polyethylene glycol epoetin beta, Mircera®. A single subcutaneous administration of Mi...
Subhahar MB, Karakka Kal AK, Philip M, Muhammed Ajeebsanu M, Karatt TK, Perwad Z.Sickle cell disease, a debilitating genetic disorder affecting numerous newborns globally, has historically received limited attention in pharmaceutical research. However, recent years have witnessed a notable shift, with the Food and Drug Administration approving three innovative disease-modifying medications. Voxelotor, also known as GBT440, is a promising compound that effectively prevents sickling, providing a safe approach to alleviate chronic hemolytic anemia in sickle cell disease. It is a novel, orally bioavailable small molecule that inhibits hemoglobin S polymerization by enhancing o...
Arias-Esquivel AM, Moscoso E, Umaña D, Arguedas M, Solano D, Durán G, Gómez A, Gutiérrez JM, León G.The immunization and industrial bleeding of horses are essential stages for producing snake antivenoms. In Costa Rica, the traditional method involves stimulating the antibody response of horses by periodically injecting venoms, collecting hyperimmune plasma over three consecutive bleeding days, and repeating this process every eight weeks. While this method does not cause major physical or hematological issues in horses, the associated stress has not been evaluated. We compared this traditional method with an alternative method that involves injecting venoms, collecting hyperimmune plasma in ...
Sakura JD, Rupley JA.Reaction of horse methemoglobin with O-methylisourea at pH 10.2 results in 95% conversion of lysine residues to homoarginine. Analysis of the chymotryptic peptides showed that no single ϵ-amino group was unreactive. Guanidination decreases the dependence of the sedimentation coefficient on hydrogen ion concentration in the range of pH 8 to 11 and did not affect the dependence on protein concentration at pH 7. These results support the conclusion that the lysine side chains involved in subunit contacts have sufficient freedom to accommodate the small changes in bulk and geometry associated wit...
Pinkowski W, Mohr E, Krzywanek H.During training, in 10 trotters, blood samples from the vena jugularis were taken before and after a heat with 80% of maximum capability as well as in the recovery period. Lactic acid concentration and pH-value, haematocrit and haemoglobin content, as well as protein concentration and osmolality were measured. With the exception of protein concentration, the time course of the values during the recovery could be described by simple mathematical models (biexponential or exponential equations). Only in the case of blood lactate concentration, the basal value was not yet achieved 120 min after th...
Komárek J, Matousek V, Jadrný L.Blood parameters were studied in two groups of horses in the "Velká Pardubická" steeple-chase in 1974, 1975 and 1976. After the race, the levels of lactate showed a manifold increase; an increase was also ascertained in the levels of glucose, sodium, potassium, haemoglobin, in the haematocrit value and in the number of erythrocytes. The following parameters significantly dropped: the levels of acid-base balance - pH, base excess, bicarbonate levels. It was proved that the values of the same parameters in horses during training were incomparably lower. It is advisable to examine horses thorou...
Lewis IM, McLan JG.The levels of 2,3-diphosphoglycerate (2,3-DPG), which affects the transport of oxygen by haemoglobin, were examined in horse blood. Resting levels of erythrocyte 2,3-DPG were established in thoroughbred horses, and levels of 2,3-DPG together with haemoglobin levels, were examined in a variety of conditions. A negative correlation was observed between erythrocyte 2,3-DPG and haemoglobin levels. Mares had higher erythrocyte 2,3-DPG levels was observed during training, and this variation may have a significant effect on haemoglobin oxygen transport. Erythrocyte 2,3-DPG levels were not affected by...
Nappert G, Vrins A, Larivière N, Ochoa LN.The research paper looks at the accuracy and reproducibility of the Spencer hemoglobinometer, a device that rapidy determines equine hemoglobin concentration, particularly useful in emergency veterinary situations. Introduction of the […]
HOLTON FA.In 1941, Keilin & Mann described an optical method of studying the penetration of erythrocytes by bicarbonate ions and the intracellular activity of carbonic anhydrase. This method consists of converting the haemoglobin inside the cell to methaemoglobin and observing the transformation of the methaemoglobin from the acid to the alkaline form by the entering bicarbonate ions. During this work they noticed that this transformation did not occur if the methaemoglobin cells had been washed in acid phosphate and interpreted this as an effect on the permeability of the cells. Similar observations by...
Lindner A, Wahdati A, Sommer H.GSH-Px activity in blood and plasma of 269 horses was determined and interrelated to age, sex, and type of use or breed. Furthermore values in blood were related to hematocrit and hemoglobin contents. Trotters and riding horses had higher GSH-Px activities in plasma as well as in blood (0.83 +/- 0.22 and 0.79 +/- 0.23 U/ml plasma or 27.2 +/- 4.3 and 24.0 +/- 7.0 U/ml blood) than Thoroughbreds in training and yearlings (0.61 +/- 0.,14 and 0.56 +/- 0.16 U/ml plasma or 20.6 2 +/- 6.9 and 24.6 +/- 4.3 U/ml blood). 3 to 6 years old Thoroughbreds had higher GSH-Px-activities than 1 to 2 years old on...
HABEEB AF, SMITH DB.Horse globill and its conlponent polypeptide chains obtained by fractional
precipitation and column chroinatography have been ailalyzed for their con- stituent amino acids. The principal difference between the two chains is that
the valyl-leucyl chain is rich in serine and threonine and poor in glutamic acid
and tryptophan compared to the \-alyl-glutaininyl chain.