A study of hormonal changes after balneotherapy of hot sulfate spring was performed at Sukawa Spa in Iwate prefecture. The nature of the hot spring reveals pH. 3.8 and 45°C acid alum vitriol water. The subjects of the study are 77 patients with psychosomatic disorders and 16 cases of young healthy male students those taking whole body bath for 10 or 15 minutes three or four times daily during 10 days as a balneotherapy. The several endocrinological substances were measured in blood samples or urinary specimen which were taken from the subjects before and after serial immersion therapy. According to this experimental comparative study, following results were obtained.
The basic level of serum 11-OHCS in morning fasting stages gradually decreased, but in the afternoon it showed markedly rising up in the and period of the therapy on the standpoint of circadian rhythm. Growth hormone revealed increasing value after serial bath in some cases whose complaints of the disease had been markedly improved. By means of TRH test, plasma TSH revealed no significant changing and serum T₃ decreased in basic secretion and reactive values, but mild elevation was observed in plasma prolactin. Urinary excretion dosage of adrenaline and noradrenaline usually increased after every immersion, but its basic daily secretary dosage were decreased contineously until finishing the therapy. Basic plasma gastrin level went down transiently during the therapy, but it recovered until the ending period of the therapy.
Consequently, it might be said that the serial immersion of the hot sulfate spring bath administers some impact to the human endocrine system and regulates a homeostatic situation at final stage of the balneotherapy.