Does routine exercise induce stress and in consequence serum amyloid A (SAA) response in purebred Arabian racehorses?

摘要

This study aimed to evaluate whether a stress response to exercise increases the serum amyloid-A (SAA) production in purebred Arabian race horses. Eleven healthy Arabian horses aged 3 to 5 years were examined. All the horses were subjected to the same effort test consisting in 1200m gallop at a speed typical for the daily training programme. Four venous blood samples were collected, namely: at rest (T0), immediately after the end of the exercise (T1), after 30 minutes of rest (T2), and after 24 hours from the first sampling (T3). Serum levels of ACTH, cortisol, and SAA were estimated by the ELISA method. To evaluate a relative intensity of exercise, the plasma lactate (LA) concentration and serum lactic dehydrogenase (LDH) activity were determined. The results obtained revealed that the type of exercise used caused a statistically significant short-term increase in the LA and LDH values. Similarly, the exercise induced a HPA axis response by a significant increase in ACTH and cortisol at T1 (P <= 0.01). Then, the LA and hormones concentrations decreased significantly over one of the post-training sampling periods (T2) (P <= 0.05 and P <= 0.01, respectively). No statistically significant differences were observed in the SAA serum level during the respective steps of the experiment (T0-T3). In conclusion, the exercise-induced stress clearly affected the HPA axis response in horses by transient raising the ACTH and cortisol concentration. In contrast, the routine training session did not promote significant changes in the SAA level in studied horses.