Human adrenal glands secrete vitamin C in response to adrenocorticotrophic hormone1,2,3,4,5

When vitamin C intake is from foods, fasting plasma concentrations do not exceed 80 ...mol/L. We postulated that such tight control permits a paracrine function of vitamin C. The purpose of this study was to determine whether paracrine secretion of vitamin C from the adrenal glands occurs. During diagnostic evaluation of 26 patients with hyperaldosteronism, we administered adrenocorticotrophic hormone intravenously and measured vitamin C and cortisol in adrenal and peripheral veins. Adrenal vein vitamin C concentrations increased in all cases and reached a peak of 176 ± 71 ...mol/L at 1-4 mm, whereas the corresponding peripheral vein vitamin C concentrations were 35 ± 15 ...mol/L (P < 0.000 1). Mean adrenal vein vitamin C increased from 39 ± 15 Rmol/L at 0 mm, rose to 162 ± 101 ...mol/L at 2 mm, and returned to 55 ± 16 ...mol/L at 15 mm. Adrenal vein vitamin C release preceded the release of adrenal vein cortisol, which increased from 1923 ± 2806 nmol/L at 0 mm to 27 191 ± 16 161 nmol/L at 15 mm (P < 0.000 1). Peripheral plasma cortisol increased from 250 ± 119 nmol/L at 0 mm to 506 ± 189 nmol/L at 15 mm (P < 0.0001). 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. (ProQuest-CSA LLC: ... denotes formulae/symbols omitted.)