Dynamic changes of cardiovascular regulating factors in rats after aerobic exhaustive exercise.

OBJECTIVE: To study the changes of cardiovascular regulating factors in rats during recovery of aerobic exhaustive exercise. METHODS: Sixty male Wistar rats were randomly divided into control group, 1 h-exercise group, 3 h-exercise group, exhausted group, 2 h-recovery group and 12 h-recovery group. The rats were killed at corresponding times for each group after an 8-week-long treadmill training, and the levels of NO, ET, ANP and TXB2 in plasma were measured in each group. RESULTS: NO/ET ratio of 1 h-exercise group was significantly higher than that in control group (P < 0.01), while it was significantly decreased in 3 h-exercise group and exhausted group (P < 0.05). ANP contents in rat plasma were significantly higher in 3 h-exercise group, exhausted group and 2 h-recovery group than that in control group (P < 0.05 or P < 0.01). The concentration of TXB2 in plasma was significantly increased in 3 h-exercise group, exhausted group and 2 h-recovery group (P < 0.05). CONCLUSION: Changes in cardiovascular regulating factors after exhaustive exercise may lead to deficiency of coronary circulation blood/oxygen supply, which may cause exercise-induced fatigue.