In vivo evidence that human adrenal glands possess 11 beta-hydroxysteroid dehydrogenase activity

Blood samples were collected intraoperatorily from inferior vena cava (VC) and adrenal vein (AV) of 8 male and 9 female consenting adult patients undergoing unilateral nephrectomy with ipsilateral adrenalectomy for kidney cancer, and steroid-hormone concentrations were assayed by quantitative HPLC. Hormonal concentrations were significantly higher in AV than in VC (systemic) blood and did not display significant differences between males and females. Higher levels not only of the main glucocorticoids cortisol and corticosterone, but also of their inactive oxidized forms corticosterone and 11-dehydrocorticosterone (DH-B), respectively, were detected in AV than in VC blood. Highly significant inverse correlations between cortisol and cortisone, and corticosterone and DH-B concentrations were observed in AV, but not in VC blood. Moreover, in AV blood the concentration of the main cortisol precursor 11-deoxycortisol correlated inversely with those of both cortisone and DH-B. Taken together, these findings are in keeping with previous in vitro evidence that human adrenal glands possess 11beta-hydroxysteroid dehydrogenase activity, which is engaged in the inactivation of newly formed glucocorticoids and is probably negatively regulated by the local concentrations of non-11beta-hydroxylated steroid-hormone precursors.