Effects of Hot-Spring Bathing on Plasma Concentrations of Human Atrial Natriuretic Polypeptide, Antidiuretic Hormone, Aldosterone and Endothelin

Abstract

Effects of hot-spring bathing on plasma concentrations of diuresis-related hormones were examined. Four healthy males were asked to bath in either 47°C hot-spring water for 3 minutes (jikan-yu) or 42°C hot-spring water for 10 min. Plasma levels of human atrial natriuretic polypeptide (HANP), anti-diuretic hormone (ADH), aldosterone (ALD), and endothelin (ET) were measured at 0, 5, 15, and 30 minutes after the start of the immersion. A transient rise was found only in plasma HANP at 5 minutes in the 42°C bath, which may have been induced by the hydrostatic pressure. Plasma concentrations of ADH, ALD, and ET hormones showed no remarkable change.
These results suggest that a few minutes of hot-spring bathing may have little influence on the amount of these hormones secreted.