Endokrine Reaktionen im Saunabad. Die Stimulierung des atrionatriuretischen Faktors (ANF)

The atrial natriuretic factor (ANF) probably is of importance in the regulation of water and electrolyte homeostasis and of blood pressure. The present experimental investigation is supposed to study the influence of sauna bathing on ANF. We measured ANF-plasma levels of six healthy probands, who underwent two subsequent sauna exposures of fifteen minutes each. Already following the first heat exposure a significant rise in the ANF-concentration was observed; however, the subsequent thermic exposure showed only a small increase. In the recovery phase the blood levels returned to their original values rather rapidly. ANF-release responds sensitively to changes in atrial pressures. An explanation of the ANF-releasing mechanism during sauna exposure is difficult insofar as the known hemodynamic changes under hyperthermia do not lead to an increase in atrial pressure or volume.