Cosyntropin Acutely Regulates Pregnenolone Sulfate Production from the Human Adrenal In Vivo and in Vitro

Presentation Number: MON 381
Date of Presentation: April 3rd, 2017

Aya T. Nanba*1, Juilee Rege1, Richard J. Auchus1, James J. Shields1, William E. Rainey2 and Adina F. Turcu2
1University of Michigan, Ann Arbor, MI, 2The University of Michigan, Ann Arbor, MI

Abstract

Background: Dehydroepiandrosterone sulfate (DHEAS) is the most abundant steroid in human circulation, and ACTH is considered the major regulator of its synthesis. DHEAS has been used as a diagnostic tool for hypothalamic-pituitary-adrenal (HPA) axis disorders; however, little is known about the dynamics of other sulfated steroids in humans.

Objective: To define the relative human adrenal production of sulfated ∆5-steroids under basal and ACTH-stimulated conditions.

Methods: Liquid chromatograph-tandem mass spectrometry was used to quantify the unconjugated ∆5-steroids: Pregnenolone (Preg), 17-hydroxypregnenolone (17OHPreg) and dehydroepiandrosterone (DHEA) and the sulfated steroids: Preg sulfate (PregS), 17OHPreg sulfate (17OHPregS), DHEAS, and 5-Androstenediol-3-sulfate (AdiolS) in human adrenal vein (AV) samples (21 patients, 14 men, age 33-78 years) and in cultured human adrenal cells, both before and after cosyntropin stimulation. Human adrenal glands were obtained from deceased kidney donors. Adrenal cells were isolated and cultured to 60% confluence before treatment with cosyntropin (10 nM) for 18 h. Cell media were collected at baseline and 3, 6, 12, 24 and 48 h after treatment. To further understand the intra-adrenal production of sulfated steroids, we also measured these unconjugated and sulfated steroids in microdissected zona fasciculata (ZF) and zona reticularis (ZR) from 6 adrenal glands.

Results: Of the sulfated steroids, PregS had the greatest increase with cosyntropin (32-fold) in AV samples, while DHEAS only doubled. Interestingly, PregS attained concentrations as high as DHEAS in the AV after cosyntropin stimulation (AV DHEAS/PregS, 12.6 and 0.9, p<0.0001 and p=0.07, before and after cosyntropin stimulation, respectively). However, in the inferior vena cava (IVC), DHEAS remained the dominant conjugated steroid both before and after cosyntropin stimulation (IVC DHEAS/PregS 20 and 12, respectively, p<0.0001). PregS was the most abundant conjugated steroid produced by the adrenal cells both under basal and cosyntropin-stimulated conditions. Furthermore, PregS demonstrated the sharpest response to cosyntropin of the sulfated steroids (14- to 22-fold higher compared to unstimulated cells), while DHEAS responded only modestly (1.3- to 3.3-fold higher compared to unstimulated cells). Steroids analysis in isolated ZF and ZR showed similar amounts of PregS and 17OHPregS in both zones (p>0.99, p=0.7, respectively), while DHEAS was higher in ZR (p<0.05).

Conclusion: Taken together, these studies demonstrate that unlike DHEAS, PregS displays a more dynamic response to ACTH. PregS could serve as a useful biomarker for AV catheterization and for HPA axis dysfunction, as occurs in Cushing syndrome or adrenal insufficiency.

 

Nothing to Disclose: ATN, JR, RJA, JJS, WER, AFT