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Topic:Species Comparison
Species comparison in horses involves examining the physiological, anatomical, and behavioral differences and similarities between horses and other animal species. This area of study can provide insights into the evolutionary adaptations and ecological roles of horses. Researchers often focus on aspects such as digestive systems, locomotion, sensory capabilities, and social structures to understand how horses have evolved to meet their environmental and survival needs. Comparative studies may also explore genetic differences and similarities, contributing to a broader understanding of species evolution and adaptation. This page aggregates peer-reviewed research and scholarly articles that analyze various aspects of species comparison involving horses, highlighting significant findings and methodologies used in the field.
Species of differences in postganglionic motor transmission to the retractor penis muscle. 1 Graded motor responses were elicited in isolated, desheathed, thin strips of dog, horse, pig and sheep retractor penis (RP) muscles by field stimulation with trains of 0.2 ms pulses at 10 hertz. These twitches were shown to be neurogenic in all four species, by their prompt extinction in tetrodotoxin.2 alpha-Adrenoceptor blocking drugs abolished the contractile response to noradrenaline and to tyramine in all four species.3 Motor transmission was wholly adrenergic in the horse as in the dog RP because phentolamine rapidly abolished the electrically induced twitches in both these species; but...
Some aspects of the pathogenesis and comparative pathology of toxoplasmosis. Some aspects of the pathogenesis and comparative pathology of toxoplasmosis are described. The general pattern of infection, with or without necrosis, and tissue cyst formation as it occurs in all species is dealt with. The wide pathological manifestations of toxoplasmosis as seen in sheep, cattle, pigs, horses, dogs, cats, chinchillas and man are reviewed.
Comparative study of blood coagulation tests in the horse and pony. The clotting times obtained with different assay procedures for routine coagulation tests were examined for horse and pony samples. The whole blood clotting time test and the activated coagulation test seemed to give similar results when both tests were done at 22 C. The results obtained for the activated partial thromboplastin time assay varied, depending on the commercial reagent used for the test. Consistent results were obtained for the one-stage prothrombin time assay with each reagent used.
Immunocytochemical demonstration of calcitonin-containing C-cells in the thyroid glands of different mammals. In the thyroid glands of the horse, pig, deer, mole, and rat, C-cells could be demonstrated by means of the immunocytochemical PAP-technique using rabbit antisera against human calcitonin. Only in ruminants, the cross-reaction between the intracellularly stored antigen and the antibodies used appeared to be incomplete.
[Comparative study of the muramidase (lysozyme) activity in the blood cells of laboratory and agricultural animals]. Comparative studies have been carried out on the blood of certain laboratory and farm animals and birds, whereby the activity of muramidase (lysozyme) is established in neutrophilic cells of mice, guinea pigs, rats, rabbits, dogs, hens, turkeys and geese and in the monocytes of rabbits and dogs. The percentage of cells with muramidase activity manifests species features. No cells with a presence of muramidase activity have been found in the perypheral blood of cattle, sheep, pigs, goats, horses and bullalos. Certain questions of a general biological aspect about the origin of muramidase in the...
The mini-pig as a model for penetration of penicillins. To be active, antimicrobials must reach the bacteria in the infectious foci in adequate concentrations. Direct measurements of levels in the various foci are difficult to perform, but a number of animal models with artificial extravascular foci have been developed. In many ways, the physiology of pigs resemble that of humans. Consequently, it was thought that pigs might also parallel humans in the handling of penicillins. General pharmacokinetics of ampicillin and flucloxacillin and the penetration of the substances to subcutaneously implanted teflon tistisue chambers were investigated. Ampici...
Male uterus in the donkey and horse. The anatomy and histology of the male uterus were studied in the donkey and the horse. In the former it was found complete and long, while in the latter it was incomplete or absent. Some variations met with are described. A new concept of "internal male hermaphroditism' is presented and two types are differentiated.
Proprioceptive innervation of the external cremaster muscle of some domestic mammals. The proprioceptive innervation of the external cremaster muscle of some domestic animals was studied. Muscle spindles and tendon organs with their well-known features were found, but this finding was uncommon and unexpected in the investigated animals. For this reason, we believe that there is no relationship between the presence of these proprioceptors and the cremasteric reflex.
Collateral flow resistance and time constants in dog and horse lungs. We studied collateral flow resistance in exsanguinated, excised lower lobes and accessory lobes of dog and horse lungs, respectively. A double lumen catheter obstructed a peripheral airway isolating a segment of the lobe. Oxygen flowed into the segment via a rotameter which measured flow (Vcoll) while the inner catheter recorded segment pressure (Ps). Gas delivered into the segment flowed out via collateral channels. Collateral flow resistance was calculated as (Ps - PL)/Vcoll, where PL = static transpulmonary pressure. Rcoll at PL = 20, 10, and 5 cm H2O averaged 0.24, 1.25, and 2.65 cmH2O.ml-...
Common and species-specific esterases of Equidae–IV. Horse of przewalski, onager and Zebra hartmannae. 1. Among several species of Equidae only E. przewalskii possesses a serum esterase identical with that of E. caballus. 2. The esterases of Hemionidae differ slightly from that of domestic horse by electrophoretic migration and by antigenic structure. 3. Zebras (grevyi, burchelli) appear devoid of this component but Z. hartmannae possesses an esterase of high enzymatic activity, differing notably from that of horse by electrophoretic and antigenic properties.
Comparative studies on blood serum alpha-L-fucosidases from several mammalian species. 1. Peripheral blood serum alpha-L-fucosidases have been studied from various mammalian species: Sus scropha var domestica L. (pig), Capra hircus L. (goat), Bos taurus L. (bull, races Morucha and Charolais), Equus caballus L. (horse) and Equus asinus L. (donkey). 2. Fluorimetric and spectrophotometric procedures were used for determination of alpha-L-fucosidases. 3. alpha-L-Fucosidases were more active towards fluorescent substrates than towards chromogenic substrates. 4. pH optima values of the enzymes are: (A) 5.5 for sera from all above-mentioned species when fluorescent substrates were empl...
Activity of adenosine deaminase and purine nucleoside phosphorylase in erythrocytes and lymphocytes of man, horse and cattle. 1. Activities of ADA and PNP were measured in erythrocytes and lymphocytes of man, horse and cattle. 2. In bovine hemolysates both enzyme activities are low when compared with activities in human hemolysates. In horse hemolysates both enzyme activities are virtually absent. 3. Enzyme activities are consistently lower (about 50%) in intact lymphocytes than in sonicated lymphocytes. This finding suggests that the uptake of nucleosides is rate-limiting for both enzymes in intact lymphocytes. 4. The activity of ADA in horse lymphocytes is comparable to that in lymphocytes of patients with severe c...
Ultrastructural observations suggesting merocrine secretion in the initial segment of the mammalian epididymis. Principal cells in the initial segment of the epididymis in horses, cattle, pigs, sheep, dogs, cats, and rabbits have an abundant, partly rough, endoplasmic reticulum and a large Golgi complex. Small vacuoles with opaque content seem to be formed by the Golgi complex and move to the cell apex, where they empty their contents into the lumen by a merocrine mechanism.
Vasculature of the equine and canine iris. Methyl methacrylic casts were prepared and tissue was freshly collected for histologic examination to compare the vascular supply and the structure of the vessels of the iris in the adult horse with those of the dog. In the horse, ciliary blood vessels divided in the iris and formed a complete major arterial circle of the iris. In the dog, the ciliary blood vessels divided in the ciliary body and, by means of recurrent branches, formed a complete arterial circle. From this circle, radial arteries extended toward the pupillary margin. The radial vessels in the horse were nearly straight and joi...
Immunological properties of two related fragments from human and equine growth hormones. The immunological properties of a synthetic human growth hormone fragment comprising the amino acids 73 through 128 and of the homologous natural horse growth fragment formed by amino acids 73 through 123, have been comparatively studied. Antisera obtained in rabbits inoculated with the native human hormone or with the fragments, were used. By hemagglutination experiments both fragments have the same reactivity toward the anti-human growth hormone serum, but complement fixation curves detect the existence of at least two populations of antibodies presumably originated against the sequence 73-1...
Horner’s syndrome in large animals. The sympathetic nervous innervation of the head was surgically transected in the horse, cow, sheep and goat. The site of transection was preganglionic in all 4 species and ganglionic-postganglionic in 2 additional horses. The Horner's syndrome, manifested as a result of the iatrogenic lesion, varied with the species. Ptosis was the most constant sign in all species. Unilateral sweating over the face and proximal neck, particularly at the base of the ear, was the most prominent feature in the horse. The cow revealed distension of vasculature and cutaneous heat of the pinna, and a reduced produc...
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 ...
A comparative study of the mechanical properties in aging alveolar wall. Alveolar wall from the lung of aging humans shows a progressive decrease in maximal extensibility, which should follow an increase in resting tissue length rather than a reduction in maximal length. An increase in resting tissue length is compatible with the change in lung volumes and reduction in elastic recoil that occurs with time. A model of the lung was used to compare the effects of a change in resting tissue length in diminishing elastic recoil with that of a reduction in the volume density of the elastic elements (emphysema). Such differentiation is important in selecting an animal tha...
Influence of foetal genotype on the follicle-stimulating hormone:luteinizing hormone ratio of pregnant mare serum gonadotrophin. 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...
New techniques to measure blood cholinesterase activity in domesticated animals. 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 +/...
