Abstract
In 7 normostensive elderly persons aged 69-83 years and 5 normotensive juvenile persons aged 23-31 years, the heart rates, blood pressure and plasma catecholamines before and after a bathing for 10min. in the Harvard bath were followed up in the time course. Both the elderly group and the juvenile group showed a significant increase in the heart rate during a bathing at 42°C, and this change was significantly greater than that during a bathing at 38°C. Also, at both temperature, the juvenile group showed significantly greater changes than the elderly group.
Although both groups showed significant decreases in mean blood pressure during a bathing at both temperature, those degrees showed no difference due to water temperature and age. Also the elevation of mean blood pressure accompanying the leave from a bath was significant at 38°C in both groups.
The values of plasma norepinephrine decrease slightly during a bathing in both of the juvenile and elderly groups, and rose after leaving from the bath. Such variations showed significantly positive correlations with variations in mean blood pressure.
The decrease of blood pressure accompanying the bathing seemed to be accompanied with an inhibition of the sympathetic activity.
