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any of the adrenal cortical hormones, or ketosteroids, that has a ketone group attached to its seventeenth carbon atom. These hormones are commonly measured in the blood and urine to aid the diagnoses of Addison's disease, Cushing's syndrome, stress, and endocrine problems associated with precocious puberty, feminization in men, and excessive hair growth. Measured in patients in the morning, the normal concentration in plasma is less than 30 μg/dL, in the evening, less than 10 μg/dL. The normal amounts in the urine of men after 24-hour collection are 8 to 15 mg; in women, 6 to 11.5 mg; in children 12 to 15 years of age, 5 to 12 mg; and in children younger than 12 years of age, less than 5 mg. Levels of 17-ketosteroids increase 50% to 100% after an injection of ACTH.
One of a group of neutral steroids having a ketone group in carbon position 17. They are produced by the adrenal cortex and gonads and appear normally in the urine. Among them are androsterone, dehydroisoandrosterone, corticosterone, and 11-hydroxyisoandrosterone. A greater than normal or less than normal excretion in the urine is indicative of certain endocrine disorders such as adrenal adenomas or Cushing's syndrome.See: perhydrocyclopentanophenanthrene