ABSTRACT
Biological hydroxylation of steroids has been recognized for many years. Hydroxylation at a variety of carbon atoms in the steroid molecule plays a well-defined role in the biosynthesis of such important hormones as the adrenal corticosteroids. This chapter discusses some aspects of the biological hydroxylation of the estrogens and androgens, including a review of the relationship of various hydroxylation steps, to the biological importance of the steroid metabolites produced. It considers the effect of steroid substrate conjugation upon the activities of the hydroxylases. The chapter presents data from the author's laboratory along with available information published by other investigators. The C18 phenolic steroids may be hydroxylated at several molecular positions. The number and type of metabolites formed varies from one mammalian species to another. Catechol estrogens have not been quantitated in urine from nonpregnant humans; however, in pregnancy, the main steroid of this type is 2-hydroxyestrone.
