The contribution of the zona fasciculata and glomerulosa to plasma 11-deoxycorticosterone levels in man.
Using a newly developed radioassay method, plasma 11-deoxycorticosterone (DOC) levels were studied in 6 human volunteers for diurnal variation and for response to ACTH, metyrapone, dexamethasone, and low or high dietary sodium. DOC reached its peak of 6.4 +/- 1.2 ng/100 ml at 8:00 AM, and its nadir of less than 1 ng/100 ml at midnight. Corresponding plasma cortisol values were 14.1 +/- 1.4 mug/100 ml and 5.9 +/- 1.3 mug/100 ml respectively. After intramuscular ACTH (Cortrosyn 0.25 mg), DOC rose to 28.7 +/- 1.8 ng/100 ml in 1 h. Dexamethasone treatment for 3 days reduced DOC to less than 1 ng/100 ml in all 6 subjects. Oral metyrapone for 24 h resulted in dramatically elevated DOC levels of 1568 +/- 183 ng/100 ml. High dietary sodium did not affect DOC levels which averaged 5.6 +/- 0.7 ng/100 ml. After 3 days of sodium restriction, DOC levels were unchanged at 4.8 +/- 0.5 ng/100 ml (P greater than 0.9) despite high plasma renin activity and elevated plasma and urinary aldosterone. Dexamethasone was then added, and the diet continued for a further 2 days. In contrast to the effect of dexamethasone during ad lib sodium intake, DOC was not suppressed but slightly elevated to 8.6 +/- 1.4 ng/100 ml (P = 0.01), whereas plasma aldosterone decreased from 32.9 +/- 1.5 to 22.1 +/- 2.1 ng/100 ml. Seven additional subjects underwent the same diet for 5 days without the addition of dexamethasone. There was no change in their DOC values. It is concluded that the zona fasciculata is the main source of DOC, but in the presence of dexamethasone a contribution from the zona glomerulosa during sodium depletion is uncovered.
D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000328:Adult; D000450:Aldosterone / Q000097:blood; D002940:Circadian Rhythm; D003345:Corticosterone / Q000031:analogs & derivatives* / Q000097:blood; D003864:Depression, Chemical; D003907:Dexamethasone / Q000494:pharmacology; D004032:Diet; D004039:Diet, Sodium-Restricted; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007668:Kidney / Q000502:physiology*; D008297:Male; D008797:Metyrapone / Q000494:pharmacology; D011863:Radioimmunoassay; D012083:Renin / Q000097:blood; D012965:Sodium Chloride / Q000494:pharmacology; D013268:Stimulation, Chemical
D012965:Sodium Chloride; D000450:Aldosterone; D003907:Dexamethasone; D000324:Adrenocorticotropic Hormone; D012083:Renin; D003345:Corticosterone; D006854:Hydrocortisone; D008797:Metyrapone