The effects of biomechanical stress on inflammatory and adaptative responses of articular tissues in athletic horses were investigated. Synovial fluid was collected from the metacarpophalangeal joints of athletic horses before exercise and 3, 6, 24 hours after exercise, and as well as from the control group (without exercise). Apoptosis/necrosis percentage, TNF-a and PGE2 were determined by annexin V/PI assay, bioassay (L929) and ELISA, respectively. The results showed that total leukocyte count was higher in the athletic group when is compared with the control group. Three hours after the exercise was done there were increases of cellular apoptosis (P>0.05) and necrosis (P<0.05) percentage, PGE2 concentration (P<0.05) and protein concentration (P<0.05), and the TNF-a level has dropped. The athletic group showed moderate level of joint inflammation after the strenuous exercise. This articular tissue response to biomechanical insult due to the exercise, with high intensity after 3 hours after training associated with normality after 24 hours, reveals the articular adaptation to physical stress in athletic horses.
Equine; joint; inflammation; exercise; flow cytometry
