Equine serum lipids: lipid composition and electrophoretic mobility of equine serum lipoprotein fractions.

The serum lipoprotein fractions from 5 Morgan and 5 Thoroughbred horses were isolated by preparative ultracentrifugation, chemically analyzed for lipid composition, and studied by 2 methods of polyacrylamide gel electrophoresis to determine electrophoretic mobility. Breed differences were not seen in the relative percentages of the lipid classes found in the various fractions. Normally, horses, like most animals, carry the majority of their lipid in high-density lipoproteins. Electrophoretically, the only difference seen between breeds occurred on disc electrophoresis where the extra band, which is characteristic of lipoprotein profiles of Morgans, was found in the high-density lipoprotein fraction.     

The influence of anticoagulants on the measurement of total protein concentration in equine peritoneal fluid

The aim of this study was to evaluate the influence of two commonly used anticoagulants (K3EDTA and lithium heparin) on refractometric and spectrophotometric measurement of total protein (TP) concentration in equine peritoneal fluid samples. The influence of a commercial solution of K3EDTA, a solution of K3EDTA in distilled water and lithium heparin on the refractometric and spectrophotometric (biuret) quantification of TP content in peritoneal fluid samples was assessed. Total protein concentration measured by refractometry was consistently overestimated in samples with commercial K3EDTA. The solution of K3EDTA in distilled water only caused TP overestimation at high K3EDTA concentrations (>5 micromol/ml). By contrast, lithium heparin did not influence the refractometric values of TP. Neither anticoagulant modified TP values when measured by the biuret method. In conclusion, the use of K3EDTA as anticoagulant may result in a significant overestimation of TP values of peritoneal fluid samples measured by refractometry.     

Relationship of protein concentration and water content of equine serum and plasma samples

A highly significant correlation between the water content and protein concentration of equine serum and plasma samples was demonstrated over a wide range of concentrations. A close correlation was also observed between protein concentration as estimated by refractometry and as determined by the biuret procedure for equine serum and plasma samples.     

Effect of temperature,storage time,and sample type on sorbitol dehydrogenase activity in llama serum and plasma

Abstract: Serum and heparinized plasma samples were collected from 11 adult, clinically healthy llamas. Aliquots were assayed for sorbitol dehydrogenase (SDH) activity after storage at room temperature (20°C), 4°C, or −20°C for defined time intervals up to 1 week postcollection. Sorbitol dehydrogenase activity in all samples was within reference intervals for our laboratory. No difference was found between serum and plasma SDH activity when measured immediately (within 1 hour) after collection. Sorbitol dehydrogenase activity decreased to 79% of initial activity by 24 hours in serum stored at room temperature; plasma had 94% of initial SDH activity under the same conditions. Sorbitol dehydrogenase activity was stable in both plasma and serum stored for up to 1 week at 4°C or −20°C. With the exception of serum stored at 20°C for > 8 hours, in vitro stability of llama SDH was adequate for its use in diagnostic testing.     

Determination of concentration of hyaluronate in equine serum

Concentration of hyaluronate (HA) in equine serum was determined by a recently developed specific radioassay. The mean +/- SD HA concentration in equine serum was 288 +/- 145 micrograms/L, was age dependent, and varied widely between horses (range, 190 to 760 micrograms/L). Light or moderate exercise increased serum HA concentration from baseline values by 1.5- to 3-fold. In all horses, serum HA concentration returned to or below the original resting values 1 and 2 hours after exercise.     

Study of the effect of total serum protein and albumin concentrations on canine fructosamine concentration.

The relationship among serum fructosamine concentration and total serum protein and albumin concentrations were evaluated in healthy and sick dogs (diabetics and dogs with insulinoma were not included). Fructosamine was determined using a commercial colorimetric nitroblue tetrazolium method applied to the Technicon RA-500 (Bayer). Serum fructosamine concentration was not correlated to total protein in normoproteinemic (r = 0.03) and hyperproteinemic dogs (r = 0.29), but there was a high correlation (r = 0.73) in hypoproteinemic dogs. Similar comparison between serum fructosamine and albumin concentrations showed middle correlation (r = 0.49) in normoalbuminemic dogs and high degree of correlation (r = 0.67) in hypoalbuminemic dogs. These results showed the importance of recognizing serum glucose concentration as well as total serum protein and albumin concentrations in the assay of canine serum fructosamine concentration.     

Ethylenediaminetetraacetic acid (EDTA) anticoagulant affects the refractometric measurement of total protein concentration in equine synovial fluid

The objectives of this study were to (i) determine the effect of ethylenediaminetetraacetic acid (EDTA) concentration on the refractometric measurement of the total protein (TP) concentration of equine synovial fluid and (ii) assess the effect of time and temperature on the refractometric measurement of TP concentration. Synovial fluid was retrieved aseptically from horses presenting to Liphook Equine Hospital either (a) immediately after euthanasia or (b) from those requiring arthrocentesis as part of their clinical investigation. Samples were aliquoted into commercially available (i) plain tubes (0.5 mL; control) and (ii) EDTA tubes (at different volumes to obtain serial dilutions of EDTA:synovial fluid). TP concentration was measured by two independent observers using a calibrated hand-held refractometer. Samples from a separate group of horses were stored for 24 h at 4°C and 20°C before analysis to assess the effects of time and temperature. Results were compared using repeated measures ANOVA. TP concentration was significantly higher at all EDTA concentrations compared to control samples, with the greatest effect seen with higher concentrations (P<0.0001 for samples with ≥3.17 mg EDTA/mL). Storage time or temperature did not significantly affect TP concentration. Refractometric measurement of small volumes of synovial fluid in commercially available EDTA tubes leads to artificially elevated TP concentrations. Delays in sample analysis and alterations in storage conditions did not significantly affect TP concentration within the parameters studied. The magnitude of overestimation of synovial total protein concentration could result in misclassification of suspect synovial sepsis cases where EDTA tubes are used.     

Effect of storage conditions on prothrombin time, activated partial thromboplastin time and fibrinogen concentration on canine plasma samples

The present study was to assess the effect of storage conditions on prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen concentration in blood samples of healthy dogs. Thirty-five dogs of various breeds were included in the study. Citrated blood samples were obtained and plasma was divided into four aliquots to assess selected clotting parameters by means of a coagulometer. The first aliquot was analysed within 1 h after collection, while the remaining 3 were stored at 8℃ for 4, 8 and 24 h, respectively. One-way repeated measures analysis of variance documented a significant decreasing effect on PT at 24 h compared to 8 h and on fibrinogen concentration after 8 and 24 h compared to sampling time and at 4 and 24 h compared to 8 h post sampling. In conclusion, the results of this study indicate that only fibrinogen appears prone to significant decrease. In fact, aPTT is not substantially affected by refrigeration for at least 24 h post sampling and PT showed a statistical difference that does not necessary indicate biological significance as the results obtained were within reference intervals for the dog.