Testosterone urinary excretion products

Overall, other adrenal androgens also show a progressive decrease in urinary excretion in both men and women. Thus, the mean 17-ketosteroid urine levels of elderly people are about 50% of those in young adults. This is primarily secondary to decreased dehydroepiandrosterone (DHEA) and androsterone production. In men, about one-third of the daily 17-ketosteroids are of testicular origen, the remainder being mainly from the adrenals. Androstenedione is a prehormone for testosterone. 

An estimate of the maximum daily production of testosterone of a normal adult male was made by the slow intravenous infusion of 11 mg. of testosterone-D and the isolation of labeled androsterone and etiocholano-lone from the urine during the period of administration, Calculations based on this conversion and this subject s normal urinary excretion of androsterone give a daily testosterone secretion of approximately 15 mg. as a maximal value. 

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