Human adrenal glands secrete vitamin C in response to adrenocorticotrophic hormone.
BACKGROUND
When vitamin C intake is from foods, fasting plasma concentrations do not exceed 80 micromol/L. We postulated that such tight control permits a paracrine function of vitamin C.


OBJECTIVE
The purpose of this study was to determine whether paracrine secretion of vitamin C from the adrenal glands occurs.


METHODS
During diagnostic evaluation of 26 patients with hyperaldosteronism, we administered adrenocorticotrophic hormone intravenously and measured vitamin C and cortisol in adrenal and peripheral veins.


RESULTS
Adrenal vein vitamin C concentrations increased in all cases and reached a peak of 176 +/- 71 micromol/L at 1-4 min, whereas the corresponding peripheral vein vitamin C concentrations were 35 +/- 15 micromol/L (P<0.0001). Mean adrenal vein vitamin C increased from 39 +/- 15 micromol/L at 0 min, rose to 162 +/- 101 micromol/L at 2 min, and returned to 55 +/- 16 micromol/L at 15 min. Adrenal vein vitamin C release preceded the release of adrenal vein cortisol, which increased from 1923 +/- 2806 nmol/L at 0 min to 27 191 +/- 16 161 nmol/L at 15 min (P<0.0001). Peripheral plasma cortisol increased from 250 +/- 119 nmol/L at 0 min to 506 +/- 189 nmol/L at 15 min (P<0.0001).


CONCLUSIONS
Adrenocorticotrophic hormone stimulation increases adrenal vein but not peripheral vein vitamin C concentrations. These data are the first in humans showing that hormone-regulated vitamin secretion occurs and that adrenal vitamin C paracrine secretion is part of the stress response. Tight control of peripheral vitamin C concentration is permissive of higher local concentrations that may have paracrine functions.
Padayatty
Sebastian J
SJ
Molecular and Clinical Nutrition Section, Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, National Institute of Child Health and Human Development, Bethesda, MD 20892-1372, USA.
Doppman
John L
JL
Chang
Richard
R
Wang
Yaohui
Y
Gill
John
J
Papanicolaou
Dimitris A
DA
Levine
Mark
M
D000311:Adrenal Glands / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D001205:Ascorbic Acid / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000502:physiology; D006929:Hyperaldosteronism / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
D000324:Adrenocorticotropic Hormone; D001205:Ascorbic Acid; D006854:Hydrocortisone