Metyrapone: an agent for melatonin as well as ACTH and cortisol secretion.
The metyrapone-test was used to study the influence of pituitary-adrenal activity on the pineal function in man. We recorded in blood the circadian rhythmicity of melatonin, ACTH and cortisol and the excretion of melatonin, cortisol and Porter-Silber chromogens in urine before, during and after the administration of 750 mg metyrapone every 4 h during 24 h in two healthy volunteers and in two patients with asymptomatic, moderate hyperparathyroidism and a prolactin-secreting microadenoma, respectively. The present study confirmed our previous report on an increased excretion of melatonin per 24 h and per mmol creatinine during the administration of metyrapone. The excretory maximum preceded the maximal ACTH-adrenal response. Serum melatonin remained unchanged during the administration of metyrapone. A second finding was depressed serum melatonin the night after the test in the subjects with the most marked ACTH-cortisol response following the metyrapone-test indicating suppression of melatonin secretion when ACTH-cortisol secretions were increased. A third finding was a late increase in diuresis appearing the day after metyrapone-administration while glomerular filtration rates did not show significant alterations. Thus, it is shown that the metyrapone-induced cortisol inhibition stimulates both ACTH and melatonin secretion, while high ACTH and cortisol levels are accompanied by reduced S-melatonin levels.
Brismar
K
K
Werner
S
S
Thorén
M
M
Wetterberg
L
L
D015065:17-Hydroxycorticosteroids / Q000652:urine; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000328:Adult; D003404:Creatinine / Q000652:urine; D004231:Diuresis / Q000187:drug effects; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D008297:Male; D008550:Melatonin / Q000097:blood / Q000378:metabolism*; D008797:Metyrapone / Q000494:pharmacology*
D015065:17-Hydroxycorticosteroids; C004835:Porter Silber chromogens; D000324:Adrenocorticotropic Hormone; D003404:Creatinine; D008550:Melatonin; D006854:Hydrocortisone; D008797:Metyrapone