Sodium loading raises urinary cortisol in man.
It has been suggested that cortisol secretion is modified by sodium intake. We therefore studied the pituitary-adrenal axis by measuring diurnal rhythms of ACTH and cortisol levels in serum of 10 normal control subjects after 4 days of low sodium diet (intake 40 mEq/day) and after 6 days of high sodium diet (intake 320 mEq/day). Urinary excretion of aldosterone-18-glucuronide and free cortisol were determined at the end of each diet. Urinary aldosterone excretion declined from 17.9 +/- 2.6 to 2.8 +/- 1.1 microgram/day and urinary cortisol increased from 26.2 +/- 6.2 to 36.8 +/- 13.8 micrograms/day during low and high sodium intake. In contrast, plasma ACTH and serum cortisol measured every two hours for a 24-h period were similar both during low and high sodium intake. The results suggest an altered handling of cortisol by the kidney during high salt intake.
D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000652:urine; D000328:Adult; D000450:Aldosterone / Q000031:analogs & derivatives / Q000652:urine; D002940:Circadian Rhythm; D004039:Diet, Sodium-Restricted; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000652:urine*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D008297:Male; D010913:Pituitary-Adrenal System / Q000502:physiology; D011188:Potassium / Q000652:urine; D012964:Sodium
C018447:aldosterone 18-glucuronide; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D012964:Sodium; D011188:Potassium; D006854:Hydrocortisone