[Effects of exhaustive exercise on coagulation state in rats]

Objective: To investigate the effects of one-time exhaustive exercise on coagulation state in rats and its mechanism. Methods: Forty-eight SD rats were randomly divided into control group and exhaustive exercise group, 24 rats in each group. Rats in exhaustive exercise group were trained with treadmill training for 25～50 min at a time on non-slope treadmill and the initial speed of 5 m/min was uniformly accelerated to 25 m/min until the rats exhausted. Thrombelastography (TEG) was used to monitor the coagulation function of rats after training. The ligation model of inferior vena cava (IVC) was established to evaluate thrombosis. The phosphatidylserine (PS) exposure and Ca²⁺ concentration were detected by flow cytometry. The production of FXa and thrombin was detected by microplate reader. The clotting time was measured by using coagulometer. Results: Compared with the control group, the blood of rats in the exhaustive exercise group exhibited hypercoagulable state. The probability of thrombus formation, weight, length and ratio in the exhaustive exercise group were significantly higher than those in the control group (P＜0.01). The levels of PS exposure and intracellular Ca²⁺ concentration of red blood cells (RBCs) and platelets in the exhaustive exercise group were increased significantly (P＜0.01). The blood clotting time of RBCs and platelets was shortened (P＜0.01), and the production of FXa and thrombin was increased significantly (P＜0.01) in the exhausted exercise group, and both were inhibited by lactadherin (Lact, P＜0.01). Conclusion: The blood of exhaustive exercise rats is in a hypercoagulable state and the risk of thrombosis is increased. The increased PS exposure of RBCs and platelets caused by exhaustive exercise may be an important mechanism of thrombosis.