Human adrenal cortex and aldosterone secreting adenomas express both 11 beta-hydroxysteroid dehydrogenase type 1 and type 2 genes

11\u3b2-Hydroxysteroid dehydrogenase type 1 and type 2 (11\u3b2HSD1 and 11\u3b2HSD2) isozymes catalize the conversion of inactive glucocorticoids (e.g. cortisone) to their active forms (e.g. cortisol) and vice versa, respectively. Reverse transcription-polymerase chain reaction allowed the detection of 11\u3b2HSD1 and 11\u3b2HSD2 mRNAs in the human adrenal cortex, liver, kidneys, as well as in six aldosterone-secreting adenomas. 11\u3b2HSD1 and 11\u3b2HSD2 activity, as evaluated by the capacity of the microsomal fraction to convert [3H]cortisone to [3H]cortisol and vice versa, was detected in both human adrenal cortex and aldosteronomas, although it was less elevated than in liver and kidneys. Aldosteronomas possessed more intense 11\u3b2HSD1 activity and less intense 11\u3b2HSD2 activity than the normal adrenal cortex. The hypothesis is advanced that the elevated local concentration of steroid-hormone intermediates occurring in aldosteronomas up-regulates 11\u3b2HSD1 and down-regulates 11\u3b2HSD2, thereby contributing to their enhanced steroidogenic function