The influence of anticoagulant, storage temperature and time on equine plasma lactate concentration.

The study investigates how the storage temperature, time, and type of anticoagulant used in the process can impact the lactate concentration in horse plasma. Using a thoroughbred gelding for the study, the researchers explored how blood samples might react under various conditions that reflected how they typically are stored and handled in the field in Australia.

Procedure

• The study was conducted on a trained thoroughbred gelding. Blood samples were taken through a catheter placed in the horse’s right jugular vein before and after exercise on a treadmill.
• The speed on the treadmill was gradually increased and the horse was made to run until it was unable to maintain pace. Blood samples were then collected immediately and in regular intervals up to 90 minutes post-exercise.
• The collected blood samples were treated with two different types of anticoagulants – lithium heparin and sodium fluoride and potassium oxalate (fluoride-oxalate) – and stored under three different temperature conditions – 4°C, around 20°C, and 31°C
• These samples were stored for different time periods of 2 hours, 24 hours, and 96 hours. These storage conditions and time periods resulted in 18 different treatment combinations for each blood collection.
• After the stipulated storage periods, plasma was separated from the blood samples and stored at -20°C until analysis.

Lactate Analysis

• The lactate levels in the samples were measured using a YSI 2700 Automated Lactate Analyzer. The samples were thawed at 4°C and analysed in randomly assigned batches.
• The analyzer was calibrated after every five samples using a standard solution provided by the manufacturer, ensuring the accuracy and consistency of the results.

Significance

• The findings from this study shed light on how blood samples should be processed, stored and handled to preserve the accuracy of lactate concentration measurements. This is particularly important as lactate concentration is used as an indicator of metabolic responses to exercise in horses, as well as the prognosis in cases of abdominal crisis in horses.