Biosynthetic pathway of 19-noraldosterone in isolated rat glomerulosa cells

The biosynthetic pathway of 19-noraldosterone (19-noraldo) in isolated rat glomerulosa cells (GC) and fasciculata-reticular cells (FC) was studied by analyzing [14C]pregnenolone metabolism using HPLC and quantification by specific RIA. In GCs, 18,19-dihydroxycorticosterone was detected after 15 min incubation with [14C]pregnenolone, 18-hydroxy-19-norcorticosterone was detected after 30 min and 19-noraldo was detected after 45 min before the appearance of an aldosterone peak. These three mineralocorticoids were not detected in FCs. The results demonstrate that 19-noraldo is synthesized in GCs and then undergoes further metabolism.