IN VIVOMETABOLISM OF NEUTRAL STEROID HORMONES*

FOR almost twenty years workers in the steroid field have had the objective of relating the tissue steroid hormones to specific urinary metabolites. To this end, studies on the metabolism of steroid hormones have been made by the following approaches: a) a search for steroid hormones from testes, adrenals, placentae and ovaries, b) a search for steroid compounds in urines from animals and human subjects, and c) a search for steroid hormone metabolites in urine after the administration of steroid hormones to human subjects. As a result of these studies, almost 100 naturally occurring steroids have been isolated from tissue and urinary sources and 7 neutral steroid hormones have been submitted to in vivo metabolic investigations. On the basis of new experimental data, particularly with respect to the metabolism of adrenocortical hormones and in the light of some of the earlier findings, it is now possible to make some tentative generalizations which aid in the understanding of the basic relationship between the tissue steroid hormones and their urinary metabolites in human subjects. These generalizations may also be important in understanding the changes in steroid metabolism that occur in such conditions as old age, stress, and disease.