[Various aspects of serotonin metabolism in thyrotoxicosis].

Serotonin content in the blood and its main metabolite 5-hydroxyindolacetic acid concentration in the urine were studied in 65 patients suffering from thyrotoxicosis of different severity and duration. The serotonin level was significantly lower in comparison with that of the control group (36 healthy subjects) while the daily excretion of 5-hydroxyindolacetic acid with the urine in comparable groups had no considerable differences. On this basis it was concluded that serotonin metabolism is accelerated under conditions of thyroid hormone excess in the organism. Possible causes for serotonin insufficiency development in thyrotoxicosis are also discussed. The results obtained have shown the relationships between the blood serotonin content and 5-hydroxyindolacetic acid excretion with the urine in various groups depending on duration, severity of the disease and the course of the menstrual cycle development (in females), that is caused by some features of neuro-hormonal regulation in several groups examined.