Effect of Different Storage Conditions on Platelet Aggregation in Horse

Abstract

Platelet aggregation is the most important event in the hemostatic process, but no information is available on the stability of samples for aggregation testing in horses. The aim of the present study was to evaluate the effect of different storage conditions on platelet aggregation in horses. The study was carried out on 58 healthy horses of varying breed and gender, ranging in age from 4 to 12 years. Citrated blood samples were collected from all the subjects by means of jugular venipuncture and were used for platelet aggregation measurements. Platelet-rich and platelet-poor plasma samples were prepared by centrifugation and divided into six different aliquots to assess the maximum degree of platelet aggregation and the initial velocity of platelet aggregation at the final concentrations of 1 and 0.5 μM of the aggregating agent. The first aliquot was analyzed within 1 hour after collection at room temperature (22°C), the second 6 hours after collection at 22°C, the third and fourth were refrigerated at 8°C for 6 and 24 hours, respectively, and the fifth and sixth were frozen at −20°C for 24 and 48 hours, respectively. With the help of an aggregometer, platelet responses were quantified, and one-way repeated measures analysis of variance was used to determine significant differences. Probability values of <.05 were considered to be statistically significant. Analysis of variance showed statistically significant differences on maximum degree of platelet aggregation and the initial velocity of platelet aggregation using adenosine diphosphate at final concentrations of 1 and 0.5 μM. The results of this study suggest that the storage of equine plasma for more than 6 hours at room temperature and at 8°C has a significant effect on platelet aggregation, and that the storage of plasma for 24 and 48 hours at −20°C alters platelet aggregation. In conclusion, storage conditions had a statistically significant effect on the parameters of platelet aggregation directly correlated to temperature.