Effects Of Short-Term Exercise Training On Platelet Function And Plasma Total Antioxidant Status

Abstract

Platelets are implicated in the pathophysiology of numerous conditions including coronary heart disease. Therefore, prevention of enhanced platelet activation is a major therapeutic strategy to prevent platet aggregation. At present, the effects of physical training on platelet function remains controversial with some studies reporting exercise-induced increases in platelet activation whereas other studies contend that exercise reduces platelet activation at rest and in response to intense exercise. PURPOSE The present study determined whether a short-term exercise training protocol is capable of increasing plasma total antioxidant status (TAS) and desensitising platelets. Importantly, we also examined the relationship between plasma TAS and platelet responsiveness. METHODS Adult male Sprague-Dawley ratswere randomly divided into short-term training and control groups. Rats in the short-term training group performed an exercise protocol consisting of three bouts of treadmill running on three consecutive days (30 min/day at 25 m/min). Blood samples were taken twenty-four hours following the last bout of exercise. ADP, collagen-induced maximal platelet an aggregation rates, and platelet ATP release were measured in whole blood. Plasma TAS were measured in plasma. RESULTS Compared with the control group, exercise trained rats had higher plasma TAS and lower ADP-induced platelet ATP release (p <0.05). A negative correlation was observed between plasma TAS and ADP-induced ATP release from platelets. Finally, the exercise training protocol did not elicit significant changes (p>0.05) in aggreagation response and collagen-induced ATP released. CONCLUSIONS We conclude that shortterm training enhances plasma antioxidant defenses. Nonetheless, our data suggest that exercise-induced improvements in plasma TAS cannot completely explain the observed exercise-induced changes in platelet activation.