Erythrocytes, or red blood cells, are the most abundant cell type in the equine circulatory system and are responsible for transporting oxygen from the lungs to tissues throughout the body. They also facilitate the return of carbon dioxide from tissues to the lungs for exhalation. Equine erythrocytes are characterized by their biconcave disc shape, which enhances their flexibility and surface area for gas exchange. The lifespan of erythrocytes in horses is approximately 140-150 days, after which they are removed from circulation and broken down, primarily in the spleen. Variations in erythrocyte count, size, and morphology can indicate various health conditions, including anemia, dehydration, and certain metabolic disorders. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and clinical implications of erythrocytes in equine health.
Science (New York, N.Y.)March 3, 1972
Volume 175, Issue 4025 996-997 doi: 10.1126/science.175.4025.996
Gershon RK, Kondo K.Mice rendered tolerant to sheep red cells and then given normal thymocytes, made no antibody when immunized with these cells. When immunized with horse red blood cells, however, they made significant amounts of noncross-reacting antibody to sheep red blood cells. This suggests that antibody-making precursor cells (B cells) which are nontolerant but nonactivatable by specific antigen, may exist in tolerant hosts.
Anderson RS, Day NK, Good RA.Natural hemagglutinin activity against vertebrate erythrocytes is present in the hemolymph of the cockroach Blabarus craniifer. The hemagglutinin titer against rabbit erythrocytes is high, whereas sheep and horse red cells agglutinate weakly. Hemagglutinin activity was depressed by the complement inhibitor, cobra venom factor. Cockroach hemagglutinin is heat-labile; all activity is destroyed by heating at 56 C for 1 hr. A humoral factor similar to the complement component 3 proactivator is also present in cockroach hemolymph. The formation of the cobra venom factor-hemolymph "complex" is depen...
Barnett AL, Steel JD, Stewart GA.Free erythrocyte protoporphyrin was estimated in 166 Thoroughbred horses and the mean value was found to be 4o vg.Poo ml. packed cells. Signifi-cantly lower haemoglobin concentrations were found in 21 horses whose erythrocyte protoporphyrin concentration was 7o p.g.lioo ml. packed cells or greater.
Oki Y, Miura K.In the recent years, various red cell auto-antibodies have been determined in someanimal diseases, including autoimmune hemolytic anemia and systemic lupus erythe-matosus in dogs, ") Aleutian disease in minks, 8) and equine infectious anemia."?">In this report, the red cell auto-antibodies were examined for symptomatiCchanges, serological characteristics, and immunopathological roles in 20 horses infectedwith equine infectious anemia virus (Table l).Pathologic cold hemagglutiuain and warm hemagglutinin were identified in theplasma of artificially infected horses. The direct antiglobulin tests ...
Basrur PK, Kanagawa H, Podliachouk L.An intersex horse exhibiting cell types of different sex chromosome constitution was subjected to further studies in order to determine whether the house was a mosaic or a chimera. Cultures of gonadal tissue and peripheral blood revealed mainly 64/XX and 64/XY cells, the former predominating in both tissues. The frequency of drumstick-bearing poly-morphonuclear neutrophils in the intersex horse was similar to that noted in normal mares. Blood type analysis using 17 naturally occurring agglutinins and hemolysins revealed partial agglutinations with three antibodies for the factors of the A syst...
Srivastava SK, Beutler E.1. Erythrocytes from normal and glucose 6-phosphate dehydrogenase-deficient humans were subjected to hydrogen peroxide diffusion to oxidize the GSH. Studies were carried out in the presence and absence of chromate to inhibit glutathione reductase and with or without the addition of glucose. 2. The GSH content of erythrocytes from other species was oxidized by subjecting them to hydrogen peroxide diffusion in the presence of chromate and glucose. 3. Chromate (1.3mm) inhibited glutathione reductase by about 80%, whereas glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, hexokin...
Lee CL, Zandrew F, Davidsohn I.One hundred infectious mononucleosis and the same number of non-infectious mononucleosis sera were studied to evaluate the sensitivity and specificity of horse erythrocytes in the diagnosis of infectious mononucleosis. Titres of horse agglutinins in infectious mononucleosis sera ranged from 28 to 7,168 with a geometric mean of 550, whereas the corresponding sheep agglutinin titres ranged from less than 7 to 3,584, with a geometric mean of 126. Horse agglutinin titres of non-infectious mononucleosis sera ranged from less than 7 to 896, with a geometric mean of 59. Infectious mononucleosis sera ...
Reis KJ.A hemolytic assay was developed for the measurement of functional equine complement activity. The assay utilizes antibody sensitized chicken erythrocytes as the target cell and was specific for classical pathway (antibody dependent) complement activity. The assay was found to be reproducible and more sensitive than previous reports using other species of target cells. Total serum complement (CH50) values were determined for five mares and their foals and followed over a period of 3 months.
Medeiros LF, Medeiros LO, Berciano Sanjurjo MA.1. The metabolism in the erythrocytes of thoroughbred horses in a sequential study from umbilical cord to the 1st month was investigated. 2. Emphasis was put on hemolytic period at which: (a). PFK, GSH-Px and GSH play a significant role. (b). There is a lower glucose consumption determined by a decreased activity in several enzymatic steps. (c). Singularly high concentrations of 2-3DPG and ATP were detected. 3. It has been suggested that the metabolic adjustments were achieved by an increased activity of the hexose monophosphate shunt, G-3PD and AK.
Bowling AT, Nickel LS.Family data from Paso Fino horses support the existence of a new allele (Aabdf) in the A system of red cell alloantigens. Considering breeds throughout the world, the A system now consists of 13 alleles defined by reagents which serologically detect seven factors.
Schara M, Nemec M, Falnoga I, Kobal AB, Kveder M, Svetek J.The action of mercuric chloride and methyl mercuric chloride on the membrane lateral domain organization of bovine, equine, and canine erythrocytes was studied. Electron paramagnetic resonance (EPR) spectra of spin-labeled erythrocytes were analyzed with respect to their lateral domain structure. Continuous alteration of the membrane domain populations revealed that mercuric compounds affect the membrane via the evolution of toxic events in the cells.
FEGLER G.1. Volume p.c. of r.b.c., hæmoglobin concentration, relative viscosity of the plasma and blood, and the sedimentation rate of the r.b.c. have been estimated on 7 healthy horses.
2. Increase in the volume p.c. of r.b.c. was found in the excited or working horse. The concentration of r.b.c. in blood from the jugular vein in horses at rest is rather low in comparison with other animals.
3. Increase in the Hb. g. p.c./r.b.c. V. p.c. ratio was found in cases with the higher volume p.c. of r.b.c. with a significant correlation coefficient.
4. Apparent relative viscosity of horse blood at h...
Dart A, Perkins N, Dowling , Batterham T, Livingston C, Hodgson D.To evaluate the effects of three different doses of sodium pentosan polysulphate (PPS) on haematological and haemostatic variables in adult horses. Methods: Eight adult standardbred horses were used. All horses received a single injection of 0, 3, 6, and 10 mg/kg of PPS at the beginning of each treatment week for 4 weeks so that by the end of the study all horses had received all four doses of PPS. Blood samples were collected at 0, 1, 2, 3, 4, 6, 8, 12, 24, 48, and 168 h after each weekly injection of PPS. Variables measured were packed cell volume, haemoglobin, red blood cell count, mean cor...
Binev R, Valchev I, Nikolov J.Monitoring of changes in some blood laboratory parameters in 34 horses after ingesting freshly harvested maize that was to be used for ensiling, heavily contaminated with young Datura stramonium plants, is described. For a 7-day period the following parameters were monitored: haemoglobin content (HGB), red blood cell counts (RBC), white blood cell counts (WBC), haematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), differential white cell counts (DWC), erythrocyte sedimentation rate (ESR), protein fractions, aspa...
Garnier M, de Preville G, Pilardeau P, Boudia D.Internal sodium and lipoprotein composition of RBCs of nine mammalian species are measured. A significant correlation can be demonstrated between the erythrocyte mean sodium value of studied species and the membrane protein/lipid ratio (r = 0.80, alpha less than 0.01). Erythrocyte internal sodium can be correlated with membrane-free cholesterol but not with the phospholipid fractions.
Kumar S, Yokoyama N, Kim JY, Bork-Mimm S, Inoue N, Xuan X, Igarashi I, Sugimoto C.Theileria equi is a tick-transmitted intraerythrocytic protozoan parasite in equids. Equine merozoite antigen (EMA)-1 and EMA-2 of T. equi have been identified as immunodominant proteins co-expressed on the surface of extra-erythrocytic merozoites. Additionally, only the EMA-2 is shed into the cytoplasm of infected erythrocyte or inside the erythrocytic membrane during their early developmental stage. In this study, we initially performed West-Western blot analysis on Triton X-100-insoluble erythrocytic skeleton collected from a healthy horse, using a glutathione S-transferase (GST)-tagged rec...
Luther DG, Cox HU, Dimopoullos GT.Fatty acid composition of erythrocytes of healthy horses was determined. Three fatty acids (C16:0, C18:0, and C18:1) were found in approximately equal quantities and comprised 72.17% of the total. Nine other fatty acids were found in small amounts. Saturated fatty acids constituted 67.2% of the total. Marked variation was demonstrated in the occurrence and distribution of fatty acids in the sterol ester, triglyceride, phospholipid, and free fatty acid fractions.
Newman MJ, Beegle KH, Antczak DF.Monoclonal antibodies to equine lymphocyte antigens were produced, using normal peripheral blood lymphocytes as the immunogen and standard hybridoma techniques. Antibody producing hybridomas were detected by a solid-phase enzyme-linked immunosorbent assay. Antibodies produced by 6 cloned hybrids were characterized further by microlymphocytotoxicity, indirect immunofluorescence, and agglutination assays on peripheral blood lymphocytes, platelets, and erythrocytes. Reaction patterns on leukocytes indicated that these antibodies may recognize at least 3 different cell-surface antigens: (1) an ant...
Maget-Dana R, Michalski JC.A simple method for the isolation of hematoside NeuNG1-Lac-Cer from horse erythrocytes is described. An aliquot of the crude ganglioside fraction was labeled by tritiated sodium borohydride after mild periodate oxidation. The compounds obtained were used as radioactive tracers in column chromatography. Gangliosides were applied onto a silicic acid column and eluted stepwise by solvents of steadily increasing polarity. The major ganglioside, NeuNG1-Lac-Cer, was eluted in a high yield by the solvent mixture chloroform/methanol/water (60:35:8, v/v/v).
Windberger U, Ribitsch V, Resch KL, Losert U.There is little data on blood viscosity in different animals. Therefore a comparison was performed between five species by an in-vitro method using oscillatory flow. At shear rates from 1 to 150/sec the viscous and the elastic component of the complex blood viscosity was highest in pig, followed by horse, dog, ox, and sheep. Plasma viscosity and plasma density were similar in dog and sheep and were higher in ox. The differences in whole blood viscosity were obviously related to the variable interspecies hematocrit, and may also be influenced by different aggregation tendencies. Aggregation in ...
Amin TM, Sirs JA, Allen BV, Colles CM.A preliminary investigation has been undertaken of blood rheology in horses and ponies, its variation in navicular disease and the changes following treatment with warfarin. Erythrocyte flexibility, measured by a centrifuge packing technique, is higher in horses (30 per cent min-1) than in ponies (23.8 per cent min-1). There are corresponding differences in blood viscosity. The high erythrocyte flexibility in horses is caused by an unknown factor present in plasma. The erythrocyte flexibility in horses with navicular disease is even higher, at 38.5 per cent min-1. Treatment with warfarin reduc...
Moorthy AR, Spradbrow PB.Mycoplasmas were isolated from two of 43 nasal swabs taken from live horses, and from one of 28 tracheal swabs taken from slaughtered horses. The slaughtered horse that yielded mycoplasmas had no gross pathological changes in the respiratory tract, but the nasal isolations were made from horses with rhinitis. The three mycoplasmas could be distinguished by cultural characteristics, and probably they represent three different species.
Higgins AJ, Lees P, Taylor JB.In a two part cross-over experiment, acute inflammatory exudates were induced in 7 ponies by subcutaneous implantation of 3 sterile carrageenin-soaked polyester sponge strips. Treatment comprised a single therapeutic geenin-soaked polyester sponge strips. Treatment comprised a single therapeutic dose of 4.4 mg/kg phenylbutazone (PBZ) administered intravenously at the time of sponge implantation. Exudates were harvested at 6, 12 and 24 hours and examined for leukocyte and erythrocyte numbers using the improved Neubauer technique; for eicosanoids by radioimmunoassay and by high performance liqui...
Suwannachot P, Joosten BJ, Klarenbeek A, Hofma J, Enzerink E, van Weeren PR, Everts ME.To investigate the effects of moderate short-term training on K+ regulation in plasma and erythrocytes during exercise and on skeletal muscle Na+,K(+)-ATPase concentration in young adult and middle-aged horses. Methods: Four 4- to 6-year-old and four 10- to 16-year-old Dutch Warmblood horses. Methods: The horses underwent a 6-minute exercise trial before and after 12 days of training. Skeletal muscle Na+,K(+)-ATPase concentration was analyzed in gluteus medius and semitendinosus muscle specimens before and after the 12-day training period. Blood samples were collected before and immediately af...
Taylor FG, Cooke BJ.The fragility of erythrocytes is easily demonstrated by their ability to withstand osmotic swelling and lysis in solutions of increasingly hypotonic saline. In healthy animals a plot of percentage haemolysis against increasing hypotonicity produces a sigmoid curve. Using the same data a derivative curve calculated from haemolytic increments shows a normal distribution of fragility within samples. In enhanced fragility due to immune-mediated haemolytic anaemia, these profiles of haemolysis are markedly altered and the derivative curve becomes multiphasic, indicating the presence of subpopulatio...
Malikides N, Kessell A, Hodgson JL, Rose RJ, Hodgson DR.Evaluation of erythropoietic regeneration in horses is difficult unless serial bone marrow aspirates are performed. To investigate the acute and chronic erythropoietic regenerative response of equine bone marrow following acute removal or loss of blood, sequential bone marrow aspirates over 4 weeks were taken from the sternum of five horses from which 20 ml kg(-1)of blood had been removed. We found that the total number of erythroid cells counted (expressed as a percentage of the total number of erythroid and myeloid cells counted) expanded initially by 13.7 per cent within 3 days after blood ...
