Immunochemical Methods for Adrenal and Gonadal Steroids

All adrenocortical and gonadal hormones are steroids. The term steroid is used to designate those compounds containing a four-ring structure, the cyclopentanoperhydrophenanthrene nucleus (Fig.1). It includes many naturally occurring higher alcohols called sterols, such as cholesterol, ergosterol, the glycosides of digitalis, and many other substances without alcoholic hydroxyl groups, such as estrogens and progesterone.