D4 cortisol

Reagents were from Sigma or Steraloids unless otherwise stated. D4-Cortisol (9,11,12,12-[²H]₄-cortisol) and D2-cortisone (1,2-[²H]₂-cortisone) were from Cambridge Isotope Laboratories and ¹³³Xenon from Nordion.

/ce:inf>-cortisol, D4-cortisol) and deuterated cortisone (1,2-[²H]₂-cortisone, D2-cortisone) were supplied by Cambridge Isotopes (Tewksbury, MA, USA). Mifepristone (RU486), canrenone, alfaxolone and deuterated canrenone (2,2,4,7,22,22-[²H]₆-canrenone, D6-canrenone) were supplied by Sigma Aldrich (St. Louis, MO, USA). Each of these steroids were weighed and dissolved in methanol (final concentration 1 mg/mL) and stored at −20 °C.

MPA, NET-A, LNG, GES, NES, NoMAC, DRSP, pregnenolone (Preg), Prog, 17OH-Preg, 17OH-Prog, 16OH-Prog, deoxycorticosterone (DOC), corticosterone (CORT), 11-dehydrocorticosterone (11-DHC), aldosterone (Ald), deoxycortisol, cortisol, cortisone, dehydroepiandrosterone (DHEA), A4, testosterone, forskolin (FSK) and trilostane, were obtained from Sigma–Aldrich, South Africa, while 11β-hydroxyandrostenedione (11OH-A4) was purchased from Steraloids, USA. All test compounds, as well as FSK, were prepared in dimethylsulfoxide (DMSO), and added to the culturing medium at a final concentration of 0.2% DMSO. The deuterated internal standards, d2-testosterone, d9-Prog, d9-17OH-Prog and d4-cortisol were purchased from Cambridge Isotope Laboratories (Maryland, USA).