Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Plasma
Plasma is the liquid component of blood in horses, consisting primarily of water, electrolytes, proteins, and waste products. It serves as a transport medium for nutrients, hormones, and waste products throughout the body. Plasma also plays a role in maintaining blood pressure and volume, as well as serving as a reservoir for critical proteins involved in clotting and immune responses. Research on equine plasma often focuses on its composition, functions, and applications in veterinary medicine, such as transfusions and diagnostic testing. This page compiles peer-reviewed research studies and scholarly articles that explore the properties, functions, and clinical applications of plasma in equine health.
Effects of fat feeding and energy level on plasma metabolites and hormones in Shetland ponies. The aim of this study was to investigate the influence of a fat-supplemented diet compared with a carbohydrate diet on the lipid metabolism and the enteroinsular axis of Shetland ponies. The 'crossover' experiment was divided into two parts: in the first 10 weeks the diets comprised the correct number of calories according to requirements and in the following 10 weeks they were hypercaloric, in order to check the effect of a different energy content of the diets. Feeding the fat-enriched diet, independently of its energy content, led to a significant decrease in plasma triglycerides, associate...
Total weak acid concentration and effective dissociation constant of nonvolatile buffers in human plasma. The strong ion approach provides a quantitative physicochemical method for describing the mechanism for an acid-base disturbance. The approach requires species-specific values for the total concentration of plasma nonvolatile buffers (A(tot)) and the effective dissociation constant for plasma nonvolatile buffers (K(a)), but these values have not been determined for human plasma. Accordingly, the purpose of this study was to calculate accurate A(tot) and K(a) values using data obtained from in vitro strong ion titration and CO(2) tonometry. The calculated values for A(tot) (24.1 mmol/l) and K(a...
Systematic analysis of acid, neutral and basic drugs in horse plasma by combination of solid-phase extraction, non-aqueous partitioning and gas chromatography-mass spectrometry. A sample preparation method for mass chromatographic detection of doping drugs from horse plasma is described. Bond Elut Certify (1 g/6 ml) is used for the extraction of 4 ml of horse plasma. Fractionation is performed with 6 ml of CHCl3-Me2CO (8:2) and 5 ml of 1% TEA-MeOH according to its property. Simple and effective clean-up based on non-aqueous partitioning is adopted to remove co-eluted contaminants in both acid and basic fractions. Two kinds of 1-(N,N-diisopropylamino)-n-alkanes are co-injected with the sample into the GC-MS system for the calculation of the retention index. Total recov...
Enantiospecific pharmacokinetics of ketoprofen in plasma and synovial fluid of horses with acute synovitis. Pharmacokinetic parameters were established for enantiomers of the nonsteroidal anti-inflammatory drug (NSAID) ketoprofen (KTP) administered as the racemic mixture at a dose of 2.2 mg/kg and as separate enantiomers, each at a dose of 1.1 mg/kg to a group of six horses (five mares and one gelding). A four-period cross-over study in a LPS-induced model of acute synovitis was used. After administration of the racemic mixture S(+)KTP was the predominant enantiomer in plasma as well as in synovial fluid. Unidirectional inversion of R(-) to S(+)KTP was demonstrated but the inversion was less marked ...
Dietary protein restriction and fat supplementation diminish the acidogenic effect of exercise during repeated sprints in horses. A restricted protein diet supplemented with amino acids and fat may reduce the acidogenic effects of exercise. Twelve Arabian horses were assigned to a 2 x 2 factorial experiment: two fat levels: 0 or 10 g/100 g added corn oil and two crude protein levels: 7.5 g/100 g (supplemented with 0.5% L-lysine and 0.3% L-threonine) or 14.5 g/100 g. The experiment began with a 4-wk diet accommodation period followed by a standard exercise test consisting of six 1-minute sprints at 7 m/s. Horses were interval trained for 11 wk followed by another exercise test with sprints at 10 m/s. Blood samples were ta...
High fat intake lowers hepatic fatty acid synthesis and raises fatty acid oxidation in aerobic muscle in Shetland ponies. The metabolic effects of feeding soyabean oil instead of an isoenergetic amount of maize starch plus glucose were studied in ponies. Twelve adult Shetland ponies were given a control diet (15 g fat/kg DM) or a high-fat diet (118 g fat/kg DM) according to a parallel design. The diets were fed for 45 d. Plasma triacylglycerol (TAG) concentrations decreased by 55 % following fat supplementation. Fat feeding also reduced glycogen concentrations significantly by up to 65 % in masseter, gluteus and semitendinosus muscles (P < 0.05 and P < 0.01 and P < 0.01 respectively). The high-fat diet s...
Glucose-dependent insulinotropic polypeptide (GIP) and the enteroinsular axis in equines (Equus caballus). To investigate the enteroinsular axis (EIA) in equines oral (oGTT) and intravenous (i.v.GTT) glucose tolerance tests (5.6 and 1 mmol glucose/kg BW, respectively) were performed with healthy, normal weight large horses and Shetland ponies. Plasma was analysed for concentrations of glucose, glucose-dependent insulinotropic polypeptide (GIP) and insulin. In all equines plasma GIP concentrations only increased significantly when glucose was administered orally. The insulin glucose ratio (IGR) was significantly higher during the oGTT than during the i.v.GTT in both races. Basal plasma glucose level...
Effect of periovulatory prostaglandin F2alpha on pregnancy rates and luteal function in the mare. The objective of this study was to determine whether periovulatory treatments with PGF2alpha affects the development of the CL, and whether the treatment was detrimental to the establishment of pregnancy. Reproductively sound mares were assigned randomly to one of the following treatment groups during consecutive estrus cycles: 1. 3,000 IU hCG within 24 hours before artificial insemination and 500 microg cloprostenol (PGF2alpha analogue) on Days 0, 1, and 2 after ovulation (n=8), 2. 2 mL sterile water injection within 24 hours before artificial insemination and 500 microg cloprostenol on Days ...
Determination of oral dosage and pharmacokinetic analysis of flecainide in horses. To determine oral dosage and to evaluate the pharmacokinetics in horses of orally administered flecainide, an antiarrhythmic drug, the correlations between its plasma concentration and PR, QRS and QT intervals in equine electrocardiograms (ECG) were investigated. Six healthy horses were administered a randomly ordered dose of 4 or 6 mg/kg of flecainide acetate. The ECG was monitored (heart rate (HR), PR, QRS, and QT intervals) and blood was taken at timed intervals to measure the plasma flecainide concentrations pre- and post-administration. The maximum plasma concentration reached 1014+/-285 ...
Effects of caffeine on locomotor activity of horses: determination of the no-effect threshold. Caffeine is the legal stimulant consumed most extensively by the human world population and may be found eventually in the urine and/or blood of race horses. The fact that caffeine is in foods led us to determine the highest no-effect dose (HNED) of caffeine on the spontaneous locomotor activity of horses and then to quantify this substance in urine until it disappeared. We built two behavioural stalls equipped with juxtaposed photoelectric sensors that emit infrared beams that divide the stall into nine sectors in a 'tic-tac-toe' fashion. Each time a beam was interrupted by a leg of the horse...
Effect of number and diameter of follicles on plasma concentrations of inhibin and FSH in mares. The role of the number of follicles and circulating immunoreactive inhibin in the decrease in plasma FSH concentrations that occurs during development of a follicular wave was studied in mares. All follicles > or = 6 mm in diameter were ablated by ultrasound-guided transvaginal aspiration of follicular fluid on day 10 after ovulation. During the subsequent wave, all follicles, the three largest follicles (three follicle group), the largest follicle (single follicle group) or no follicles were retained and the remaining follicles were ablated before they reached > 10 mm in diameter (n = 1...
Postprandial arterial vasodilation in the equine distal thoracic limb. The effects of feeding on blood flow to the equine foot are poorly understood. In a temperature-controlled room, duplex Doppler ultrasonographic observations were made pre- and postprandially of the lateral proper palmar digital artery of 5 horses, randomly assigned to twice and 4 times daily feeding in an unbalanced 2 period crossover design. Arterial diameter and blood velocity were measured over 4 h and additional observations made of heart rate, blood pressure, total plasma protein, packed cell volume, plasma glucose and insulin. There was no effect of the feeding regimen on any variable. ...
Microvascular development and growth of uterine tissue during the estrous cycle in mares. To document uterine growth and microvascular development in the endometrium of uteri with differing degrees of fibrosis as well as uterine growth throughout the estrous cycle of mares. Methods: 30 mares. Methods: Uterine tissue was obtained during the breeding season from a slaughter facility. Stage of estrous cycle of the mares was assessed on the basis of ovarian structures and plasma progesterone concentrations. Endometrium was characterized by use of light microscopy, and blood vessel walls were marked by histochemical techniques. Microvascular development was evaluated by a computerized i...
Disposition, elimination, and bioavailability of phenytoin and its major metabolite in horses. To determine pharmacokinetics and excretion of phenytoin in horses. Methods: 6 adult horses. Methods: Using a crossover design, phenytoin was administered (8.8 mg/kg of body weight, IV and PO) to 6 horses to determine bioavailability (F). Phenytoin also was administered orally twice daily for 5 days to those same 6 horses to determine steady-state concentrations and excretion patterns. Blood and urine samples were collected for analysis. Results: Mean (+/- SD) elimination half-life following a single IV or PO administration was 12.6+/-2.8 and 13.9+/-6.3 hours, respectively, and was 11.2+/-4.0 ...
Effects of ovarian input on GnRH and LH secretion immediately postovulation in pony mares. The potential involvement of ovarian factors in regulating GnRH and LH postovulation was studied in ovarian intact (Group 1; n=3) and ovariectomized (OVX; Group 2; n=3) mares (OVX within 12 hr of ovulation). Blood samples were collected every 10 min for 6 hr from jugular vein (JV) and intercavernous sinus (ICS) during estrus and on Day 8 postovulation for LH and GnRH analysis. Additionally, JV samples were collected twice daily (12-hr intervals) for 30 days for LH and progesterone (P4) analysis. A significant treatment x day effect (P<0.0001) describes declining plasma LH concentrations in ...
Effect of hydroxyethyl starch infusion on colloid oncotic pressure in hypoproteinemic horses. To determine the effect of hydroxyethyl starch (HES) on colloid oncotic pressure (pi) during fluid resuscitation of hypoproteinemic horses and to evaluate the clinical usefulness of direct and indirect methods for determination of pi before and after infusion of a synthetic colloid. Methods: Prospective clinical study. Methods: 11 hypoproteinemic horses. Methods: Horses received IV infusions of 8 to 10 ml of a 6% solution of HES/kg (3.6 to 4.5 ml/lb) of body weight during fluid resuscitation. Blood samples were obtained for determination of plasma measured colloid oncotic pressure (pi meas) an...
Glycerol hyperhydration in resting horses. To determine whether administration of glycerol-containing solutions induces a state of transient hyperhydration in resting euhydrated horses, changes in plasma and urine constituents were measured in four horses for 1 h before and 5 h after nasogastric administration of each of four treatments (Experiment 1). Treatments were applied in a randomized fashion and included: (1) 1.0 g.kg(-)(1)glycerol in 8 L of water (G); (2) 8 L of water (W); (3) 8 L of 0.9% NaCl solution (S); and (4) 1.0 g.kg(-)(1)glycerol in 8 L of 0.9% NaCl solution (GS). In a subsequent study, voluntary water intake was measu...
[ACTH stimulation test for the determination of salivary cortisol and of cortisol responses as markers of the training status/fitness of warm-blooded sports horses]. Previous work (Marc et al., 2000) suggested that plasma cortisol responses to treadmill exercise or ACTH injection are a reliable marker for performance evaluation in warmblood horses. For practical purposes blood sample collections and treadmill exercise tests are somewhat troublesome and time consuming. The goal of this study was thus to evaluate the use of saliva for cortisol determination (by direct EIA) as a marker for performance and to investigate the reliability and repeatability of plasma cortisol responses to a single i.v. injection of ACTH (50 micrograms or 250 micrograms). Furtherm...
The effect of implanting gentamicin-impregnated polymethylmethacrylate beads in the tarsocrural joint of the horse. To determine the effect of intra-articular gentamicin-impregnated polymethylmethacrylate (PMMA) beads inserted in the equine tarsocrural joint on the synovial fluid, synovial lining, and cartilage, and to determine the peak and sustainable gentamicin concentrations in synovial fluid and plasma. Methods: Pharmacokinetic, cytologic, and histologic study of the effect of gentamicin-impregnated PMMA on normal equine tarsocrural joints. Methods: Five healthy adult horses. Methods: Gentamicin-impregnated PMMA bead strands (3 strands each of 40 beads, with each strand containing 100 mg gentamicin) we...
Effect of eltenac in horses with induced endotoxaemia. Ten horses were used in a crossover study to evaluate the effectiveness of eltenac against endotoxaemia. Eltenac (0.5 mg/kg bwt) or saline control was given i.v. then 15 min later, intravenous infusion of endotoxin was begun and continued for 120 min (total dose 100 ng/kg bwt). Horses were monitored for heart and respiratory rates, pulmonary and carotid arterial pressure and core body temperature. Blood was sampled at intervals for measurement of haematological variables and plasma concentrations of lactate, prostanoid metabolites, tumour necrosis factor (TNF) and stress hormones. In compariso...
Aggregation behavior and electrophoretic mobility of red blood cells in various mammalian species. Differences of red blood cell (RBC) aggregation among various mammalian species has been previously reported for whole blood, for RBC in autologous plasma, and for washed RBC re-suspended in polymer solutions. The latter observation implies the role of cellular factors, yet comparative studies of such factors are relatively limited. The present study thus investigated RBC aggregation and RBC electrophoretic mobility (EPM) for guinea pigs, rabbits, rats, humans and horses; RBC were re-suspended in isotonic 500 kDa dextran solutions for the EPM and aggregation measurements, with aggregation stud...
Pharmacokinetics of gentamicin in mares in late pregnancy and early lactation. The disposition of drugs may differ between pregnant and nonpregnant animals, necessitating a change in dosage. We hypothesized that volume of distribution or clearance may be different for aminoglycoside antibiotics in pregnant mares vs. nonpregnant lactating mares. To examine this hypothesis, we administered gentamicin sulfate to seven Thoroughbred and Quarterhorse mares on two occasions, followed by plasma drug gentamicin assay and pharmacokinetic analysis. The first dose was administered 1-4 weeks before parturition (mean weight 578 kg) and the second dose was administered in the period 1-...
Administration of ticarcillin in combination with clavulanic acid intravenously and intrauterinely to clinically normal oestrous mares. Ticarcillin and clavulanic acid (potassium clavulanate) were administered to normal oestrous mares intravenously (i.v.) at a dose of 50 and 1.67 mg/kg for ticarcillin and clavulanate, respectively. In a crossover design, the same drugs were administered intrauterine (i.u.) at a dose of 12.4 and 0.4 mg/kg for ticarcillin and clavulanate, respectively. The i.u. dose was administered in 100 mL of saline solution. Endometrial tissue biopsies and plasma samples were collected after drug administration for the determination of ticarcillin and clavulanate concentrations by high-pressure liquid chroma...
Role of exercise and ascorbate on plasma antioxidant capacity in thoroughbred race horses. During exercise, the oxygen consumption and the production of free radicals increase and can lead to oxidative stress with a deleterious effect on cellular structures involved in physical activity. To evaluate the oxidative stress produced by exercise and the role of ascorbate as an antioxidant, venous blood samples were obtained from 44 thoroughbred racehorses, before and after a 1000+/-200-m race at maximum velocity. Fourteen of these horses were treated intravenously with 5 g of ascorbate before running. Antioxidant capacity (PAOC), endogenous and exogenous ascorbate concentration, total an...
Effect of ration and exercise on plasma creatine kinase activity and lactate concentration in Thoroughbred horses with recurrent exertional rhabdomyolysis. To determine the effects of 3 rations (low grain, fat, high grain) on plasma creatine kinase (CK) activity and lactate concentration in Thoroughbred horses with recurrent exertional rhabdomyolysis (RER). Methods: 5 Thoroughbreds with RER and 3 healthy Thoroughbreds (control horses). Methods: Rations were formulated to meet (low-grain and fat rations) or exceed (high-grain ration) daily energy requirements. Each ration was fed to horses in a crossover design for 3 weeks. Horses were exercised on a treadmill Monday through Friday; maximum speed on Monday and Friday was 11 m/s (6% slope), on Tues...
Quantification of phenytoin and its metabolites in equine plasma and urine using high-performance liquid chromatography. A reliable and sensitive method for the extraction and quantification of phenytoin (5,5'-diphenylhydantoin), its major metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) and minor metabolite, 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) in horse urine and plasma is described. The method involves the use of solid-phase extraction (SPE), liquid-liquid extraction (LLE), enzyme hydrolysis (EH) and high-performance liquid chromatography (HPLC). The minor metabolite, 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) was not present in a reliably quantifiable concentration in all samples. The ...
Effect of dose and day of treatment on uterine response to oxytocin in mares. To determine the effect of dose and day of oxytocin treatment on intrauterine pressure, 6 normal mares were treated with 10 or 25 IU oxytocin 2 days before ovulation, on the day of ovulation and 2 days after ovulation. Intrauterine pressure (IUP) was measured using micro-tip-catheters (one placed intrauterine, a second and third serving as reference sensors in the vagina and external to the mare) and transmitted by telemetry for 30 min to establish a baseline before saline was administered, iv, and for an additional 30 min after saline administration. Oxytocin was then given, iv, and IUP was r...
Dehydration, stress, and water consumption of horses during long-distance commercial transport. The aim of this study was to characterize progressive dehydration, stress responses, and water consumption patterns of horses transported long distances in hot weather and to estimate recovery time after 30 h of transport. Thirty adult mares and geldings were deprived of access to feed and water for 6 h, blocked by age, sex, breed, and body condition score, and assigned to one of the following treatments: penned, offered water (Penned/Watered, n = 5); penned, no water (Penned, n = 5); transported, offered water (Transported/Watered, two groups of n = 5); or transported, no water (Transported, ...
Distribution of immunoglobulin isotypes and subisotypes in equine guttural pouch (auditory tube diverticulum). To clarify the functions of the equine guttural pouch, the distribution of various immunoglobulin isotypes and subisotypes in the guttural pouch mucosa were examined in healthy horses. IgGa was present in the mucosa of guttural pouch, mucosal lymph nodules and submucosal lymph nodules. IgM was scattered in the mucosal lymph nodules and in the germinal centers of the submucosal lymph nodules. IgGc was recognized only in the submucosal lymph nodules. These immunoglobulin isotypes and subisotypes were found in lymphocytes and plasma cells. On the other hand, IgA was detected in glandular epitheli...
