Cholesterol metabolism in the rat adrenal cortex: acute temporal changes following stress.

Adrenal and serum corticosterone concentrations, cholesterol association with adrenal cortical cytochrome P-450scc (the cytochrome P-450 catalyzing the conversion of cholesterol to pregnenolone), and adrenal cortical activities of cholesteryl ester hydrolase, acyl-CoA:cholesterol acyltransferase, and cholesterol side-chain cleavage have been determined at various times following stress in female rats. The paramount importance of cholesterol side-chain cleavage activation in the response to stress at the low point of the circadian rhythm is confirmed. At the high point of the circadian rhythm, there is evidence that the provision of free cholesterol for the cytochrome P-450scc enzyme system may also be controlled. The data support a coordinate action of ACTH and pro-gamma-melanotropin in controlling cholesterol metabolism in the adrenal cortex following stress.