Behavior of renin angiotensin aldosterone axis during pulling exercises in euhydrated and dehydrated horses.

This research study investigates how hydration levels prior to exercise can influence the hormonal response of horses during exercise, specifically looking at renin, angiotensin, and aldosterone hormone levels.

Methodology

• The researchers used horses as their experimental subjects which were divided into two groups: control group (11 horses) and dehydrated group (53 horses).
• Based on their respective body weights, the horses were further categorized into Class A (approximately 350 kg), Class B (351-450 kg), and Class C (approximately 451 kg).
• All the horses were made to run 60 meters, while pulling a carriage that is loaded with twice, 2.25 times, and 2.5 times their body weight, for A, B, and C categories respectively.
• The researchers collected blood samples from the horses at rest, after exercise, and during their recovery phase.
• These samples were examined to determine the concentrations of electrolytes, albumin, renin, angiotensin, and aldosterone levels.

Key Findings

• The hormone aldosterone was found to be higher among the dehydrated and control horses in category A compared to B and C.
• The blood samples of the dehydrated horses showed higher concentrations of albumin, Sodium (Na), Potassium (K), Chlorine (Cl), angiotensin, and aldosterone at most of the sampling times.
• The study revealed no noticeable variation in renin levels relative to the body weight category, hydration status and exercise.

Conclusion

• The primary conclusion from the research was that, in dehydrated horses, there was a significantly elevated response of aldosterone to exercise compared to euhydrated (properly hydrated) horses.
• This highlights the potential effect of dehydration on the physiological response to exercise in horses, underscoring the importance of adequate hydration before exertion.