Effect of Regular Training on Platelet Function in Untrained Thoroughbreds.

This research explores the effect of regular physical training on platelet function in previously untrained Thoroughbred horses. The study found that the first long-term training period tended to stimulate platelet hyperactivity after 30 days but also ultimately led to the reduction of negative impacts on platelet activation from acute efforts.

Introduction and Aim of the Study

• This investigation was designed to study the changes in platelet activation and initial modifications in platelet-related blood clotting in young, untrained Thoroughbred horses undergoing their first course of progressive sprint training.
• Knowledge about blood coagulation is crucial in sports studies since training significantly impacts blood’s coagulation physiology in both humans and horses.
• The research intended to enhance understanding about how regular training influences platelet function in these animals.

Methodology

• Twenty-nine young, untrained Thoroughbred racehorses in good health were monitored during their four-month sprint exercise training.
• Blood samples were taken once a month for five times in total, and platelet aggregation was analysed using light transmission aggregometry in response to three agonists: adenosine diphosphate (ADP), collagen, and calcium ionophore A23187.
• The platelet function was assessed using a platelet function analyzer, employing collagen/ADP and collagen/adrenaline cartridges.
• The research also measured Nitrite-nitrate plasma concentrations using a colorimetric assay to evaluate the bioavailability of nitric oxide in vivo.
• Moreover, gene expression analyses were carried out to further investigate platelet activation patterns.

Findings and Implications

• Principal findings indicated significant changes compared to T-30, illustrating an upsurge in platelet aggregation, and a shorter closure time of C-ADP cartridges, which suggested heightened platelet activity, returning to baseline after 90 days.
• Plasma Nitrite-nitrate levels also notably rose after the first 30 days of training as compared to the baseline, indicating increased nitric oxide bioavailability.
• These findings suggest that, regular physical training appears to induce higher platelet activity after 30 days in previously untrained Thoroughbreds, after which platelet activity returned to normal.
• Furthermore, it was found that regular exercise decreases the negative impacts of sudden strenuous efforts on platelet activation, an insight which has important implications for the training and health management of these racing horses.