Quantitative estimation of 17alpha-hydroxypregn-4-ene-3,20-dione (17alphaOH-progesterone) in adrenal venous blood and adrenal glands.

1. A method is described for the accurate estimation of small quantities of 17alpha-hydroxypregn-4-ene-3,20-dione (17alphaOH-progesterone) in blood and adrenal glands.2. The dog adrenal was found to secrete 17alphaOH-progesterone under conditions of operative stress at a rate of 5-10 mug/g tissue/hr. This is similar to the secretion rate of aldosterone.3. The secretion of 17alphaOH-progesterone was decreased after hypophysectomy and increased in response to adrenocorticotrophic hormone (ACTH).4. The adrenal gland of the dog, the monkey and the guinea-pig was found to contain between 0.6 and 6 mug of 17alphaOH-progesterone/g tissue. The concentration was usually somewhat smaller than that of pregnenolone or progesterone and between 1 and 20% of the concentrations of the glucocorticoids.5. A comparison of adrenal steroid contents and secretion rates under conditions of stress indicates a rate of synthesis in the order of 30-40 n-moles of 17alphaOH-progesterone/g adrenal tissue/min.