We propose to study key cellular events related to ACTH-action in rat adrenal cell suspensions derived from enzymic digestion of rat adrenals. These events involve 1) the binding of ACTH to plasma mem- brane receptors, 2) activation of adenyl cyclase and cyclic-AMP (CAMP) production, 3) activation of glycolysis and respiration by CAMP and 4) CAMP-initiated corticosteroidogenesis and release of corticosterone to the outside of the cell. The overall objective of our studies is to understand the biochemical events occuring at the cellular level during activation of rat adrenocortical cells by ACTH. Comparative studies are also planned with the adrenal cells derived from normal rats and the corticoid producing Snell adrenocortical carcinoma 494. Such studies may indicate important abnormalities in all or some of the aforementioned events in the carcinoma cells and lead to some understanding of the cause(s) of cancer of the adrenal cortex.