Extra-adrenal actions of metyrapone in man. Effects on plasma cortisol disappearance, growth hormone secretion and glucose metabolism

Extra-adrenal effects of high doses of oral metyrapone (6 g over 210 min) were investigated in 9 normal subjects. Plasma sugar increased markedly. Plasma cortisol fell dramatically from 12.3±1.7 µg/100 ml (mean± SEM) at 0 min to 6.6±1.1 µg/100 ml at 30 min and to 3.0±0.6 µg/100 ml at 60 min. The disappearance half-time of endogenous cortisol from plasma, calculated over the 0-30 min period, averaged 32 min (range 22-49 min). This acceleration in the disappearance of cortisol from plasma was confirmed by control studies with labeled cortisol performed in 3 subjects. These data strongly suggest an extra-adrenal action of metyrapone upon cortisol catabolism and/or utilization. A significant increase in plasma levels of immunoreactive human growth hormone (IRHGH) was observed in spite of concomitant hyperglycemia; the maximal increment over basal level averaged 10.4±2.5 ng/ml. There was a significant negative correlation between the cortisol disappearance half-time and the maximal IRHGH increment. It is suggested that the IRHGH release could be mediated through the plasma cortisol fall. © 1971 by The Endocrine Society.SCOPUS: ar.j