Comparison on plasma caesium kinetics in goats and horses with special emphasis on exercising horses.

This research investigates how moderate exercise influences the rate of caesium (Cs+) removal from the bloodstream in goats and horses. Detailed results indicate that exercise notably speeds up Cs+ removal, which when compared to potassium (K+), behaves differently under the same conditions.

Research Method

• The researchers administered a dosage of 5 micromol kg(-1) Cs+ intravenously to both goats and horses. They followed the plasma Cs+ concentration for 100 minutes in goats and 60 minutes in horses.
• The horses were categorized into two groups – one engaged in rest and the other in moderate exercise on a treadmill at a slope of 3 degrees and speed 5 m s(-1).

Results

• The decay of plasma Cs+ concentration was found to be multiphase exponential. It could initially be approximated with a two-phase curve.
• The initially high rate constant for Cs+ removal decreased from approximately 10 h(-1) to around 1 h(-1) in 40 minutes.
• Between 20 and 40 minutes after starting exercise, Cs+ removal from plasma increased by more than double. After exercise ceased, the rate returned to resting levels within 10 minutes.
• Contrarily, the plasma K+ concentration continued to decrease for at least 20 minutes after exercise had ended.

Conclusions

• Moderate exercise significantly increases the removal of Cs+ from the bloodstream. Post-exercise, this rate returns to resting levels within a span of 10 minutes.
• The accelerated Cs+ removal during exercise is likely due to the enhanced activity of Na+, K+-ATPase in active skeletal muscles.