Effect of serotonin on cardiac output during exercise of different intensity

Aim. The paper aims to identify the effect of the serotonin 5-HT2 receptor agonist on cardiac output in rats during exercise of different intensity. Materials and methods. Two types of swimming training sessions were used (endurance training, speed training). Laboratory rats of different performance levels received the serotonin 5-HT2 receptor agonist, then changes in cardiac output were recorded. Results. There was a decrease in HR in older rats and in rats subjected to exercise, particularly that of endurance nature. The indices of stroke volume and minute volume increased with age and as a result of exercise. The results indicated that the younger the rat the more pronounced changes were found in cardiac output. Rats subjected to speed training had higher values of minute volume after the administration of the serotonin 5-HT2 receptor agonist. Conclusion. In rats, the chronotropic response of cardiac output to various doses of the serotonin 5-HT2 receptor agonist decreases with age, while inotropic response increases with age and as a result of exercise. Endurance training results in more pronounced changes in the cardiac pump function compared with speed training.