Acth regulation of the adrenal cortex

Though significant advances in understanding ACTH regulation of the adrenal cortex have occurred, many questions concerning hormonal regulation of the adrenal cortical cell remain. Knowledge of the steroid biosynthetic pathway, the substrates, enzymes, co-factors, and subcellular compartmentalization involved provides a framework for understanding regulatory control of differentiated function in both health and disease. It is likely that precise regulatory control points and the mechanisms involved will shortly be forthcoming to complete many years of careful work by many investigators. Knowledge of regulation of growth and replication remains with a more incomplete framework. This aspect of hormonal regulation has assumed increasing importance in the broad area of growth control in normal and neoplastic cells. While it is clear that regulatory mechanisms involving cAMP are central to control of differentiated function and of growth, it is equally clear that ACTH regulation of growth is not directly correlated with activation of adenyl cyclase and elevated cAMP levels. Much additional work is needed to understand growth regulation and the ways in which this is deranged in the neoplastic state.