AJP - Regulatory, Integrative and Comparative Physiology, Vol 259, Issue 5 931-R935, Copyright © 1990 by American Physiological Society
Circadian rhythm in recognition threshold of salt taste in healthy subjects
A. Fujimura, H. Kajiyama, T. Tateishi and A. Ebihara
Department of Clinical Pharmacology, Jichi Medical School, Tochigi, Japan.
The circadian rhythm in recognition threshold of salt taste was examined in
six healthy young subjects. Plasma aldosterone (PA) and cortisol
concentrations, plasma renin activity (PRA), salivary sodium concentration,
and salt recognition thresholds were measured every 3 h for a 24-h period.
The salt recognition threshold and salivary sodium concentration exhibited
similar circadian rhythms, with the lowest values recorded in the
afternoon. Positive correlations were observed between the recognition
threshold and salivary sodium (P less than 0.001) and between cortisol and
PA (P less than 0.001). There was no correlation between PRA and PA. A
negative correlation was observed between PA and salivary sodium
concentration (P less than 0.01). These data indicate that the recognition
threshold for salt taste has a circadian rhythm in young healthy subjects.
This rhythm appears to be related to daily variations in the plasma
aldosterone concentration and its subsequent effects on salivary sodium
concentration.
