Effect of allopurinol on the formation of reactive oxygen species during intense exercise in the horse.

The research article investigates the impact of drug allopurinol on reactive oxygen species (ROS) formation during strenuous physical activity in horses. The study concludes that allopurinol reduces ROS formation, thereby decreasing oxidative stress.

Methodology

• The research was conducted on six horses with allopurinol administered in a cross-over study.
• The study’s main focus was assessing the role of xanthine oxidase (XO) activity in forming reactive oxygen species (ROS) during intense physical activities.
• The formation of ROS was assessed through various indicators, including the concentration of lipid hydroperoxide in the plasma, oxidized glutathione (GSSG) in red blood cell haemolysates, and the glutathione redox ratio (GRR).

Results

• During intense exercise, plasma lipid hydroperoxide concentration significantly increased, reaching its peak within a minute of exercise completion.
• Similarly, maximum levels of GSSG and GRR were noted 20 minutes post-exercise.
• Administration of allopurinol significantly lowered the post-exercise spikes in lipid hydroperoxides, GSSG, and the GRR.
• Allopurinol administration also led to a significant increase in hypoxanthine and xanthine levels in the plasma after exercise compared to control horses. However, uric acid levels remained unchanged.

Conclusion

• In the control group of horses, plasma uric acid concentration increased after exercise, reaching its maximum level 20 minutes post-exercise. This increase was significantly lower in horses administered with allopurinol.
• The results demonstrate that allopurinol’s inhibition of XO activity leads to a decrease in ROS formation during strenuous exercise, which subsequently reduces oxidative stress.