Effect of sample handling on measurement of plasma glucose and blood lactate concentrations in horses before and after exercise.

This research investigates the effects of different blood collection methods and storage procedures on the measured concentrations of plasma glucose and blood lactate in horses. It was found that the choices of anticoagulant and temperature at which the samples are stored can significantly alter the results of these measurements.

Choice of Anticoagulant

• The study examined the impact of different anticoagulants – sodium fluoride/potassium oxalate and lithium heparin – on the measured plasma glucose concentrations in samples taken from resting horses and those taken post exercise.
• It showed that when the blood was preserved with sodium fluoride/potassium oxalate, the measured plasma glucose concentrations were significantly lower than when lithium heparin was used (6% lower in resting horses and 10% lower after exercise).
• In addition, it was observed that the erythrocyte volume in samples preserved with sodium fluoride/potassium oxalate was 15% less than that of samples preserved with lithium heparin. This suggests that water moves out of erythrocytes when mixed with sodium fluoride/potassium oxalate.

Effect of Storage Procedures

• The research further analyzed the effect of storage temperature on the measured blood lactate concentrations. For this, part of the blood sample was evaluated immediately after collection, while other parts were stored at 0 degrees Celsius and at 22 degrees Celsius for 30 and 60 minutes before evaluation.
• The study found no difference in the blood lactate concentrations of samples stored at 0 degrees Celsius, regardless of the duration of storage, indicating that low temperature generally prevents changes in lactate concentration.
• Contrastingly, blood lactate concentrations were significantly higher in samples kept at 22 degrees Celsius as compared to immediate evaluations and those stored at 0 degrees Celsius, suggesting that higher temperatures may lead to an increase in measured blood lactate concentrations.