Uric acid responses to endurance racing and relationships with performance, plasma biochemistry and metabolic alterations.

This research article explores how uric acid in horses responds to endurance racing and how this relates to racing performance, blood chemistry and any changes in metabolism. The researchers found that uric acid increases after significant physical effort, and that this increase is greater in horses exhibiting metabolic changes and those that run faster. Uric acid may, therefore, be indicative of a horse’s metabolic response during endurance exercise.

Research Methodology

• The study was built around three assays or tests. In Assay 1, 24 horses underwent an endurance race of 121 km, while in Assay 2, 17 horses competed in a longer race of 164 km. Finally, Assay 3 involved 19 horses that were disqualified due to metabolic disorders during various endurance races.
• Blood samples were collected from all participating horses before and shortly after the end of the races. They were used to measure different biochemistry parameters, including creatinine kinase (CK), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), alkaline phosphatase (AP), uric acid (UA), creatinine (Cr), urea, lactate (La), and plasma proteins (PP).
• Additional factors such as gender, age, racing duration, average speed, and recovery time were also recorded and analyzed.
• The data from Assays 1 and 2 were divided into three groups to categorize the competitive time, average speed, and total recovery time.
• Changes between the groups were evaluated using statistical ANOVA and Fisher’s PLSD test. Pre-and post-exercise differences were assessed using Student’s paired t-test.
• Pearson correlation coefficient was used to examine the relationship between all variables and any increases in UA.

Findings

• The researchers found that even though the horses in Assay 1 ran at a higher average speed as compared to the horses in the Assay 2, there was no significant difference in their plasma biochemistry values.
• Faster racing horses demonstrated significantly higher uric acid levels when compared to slower or medium-paced ones. This was true for the horses in Assays 1 and 2.
• Horses that developed metabolic alterations during the race showed significantly higher uric acid, CK, and PP levels than those who completed the race without any metabolic issues.
• Uric acid levels were found to correlate significantly with CK levels in all three assays and with PP levels in Assays 1 and 3.

Conclusion

• The researchers concluded that uric acid levels rise after prolonged physical exertion in horses, with more prominent increases observed in those with metabolic changes and in faster runners.
• This rise in uric acid is directly related to CK levels, implying that uric acid could be a useful indicator for the metabolic response to endurance exercise in horses.