Melatonin and corticosteroid response to metyrapone in patients with pituitary disease.

Melatonin secretion is dependent both on the environmental lighting and noradrenergic control and seems to be related to the ACTH-cortisol secretion. The aim of the present study was to further elucidate the relationship between ACTH-cortisol and melatonin. For this purpose we chose the Metyrapone test. The melatonin secretion was studied in 10 patients, and increased significantly in 8/10 during and in one after the Metyrapone administration. These results further support a relationship between melatonin and ACTH-cortisol secretion, possibly through a suprapituitary interaction.