THE CONJUGATED 17-KETOSTEROIDS OF HUMAN URINE*

Abstract

IT IS generally recognized that the steroids of human urine are principally conjugated to sulfuric acid and to glucuronic acid. Although the urinary corticosteroids (such as the metabolites of cortisol and corticosterone) are for the most part quantitatively released from their water-soluble forms of conjugation by incubation with various preparations of β-glucuronidase (1), the urinary 17-ketosteroids are not. Only 40 to 65 per cent of the total 17-ketosteroids of normal urine are hydrolyzed by β-glucuronidase (2–5). We have directed our attention to the examination of the individual 17-ketosteroids released enzymatically from human urine. This has been accomplished by means of chromatography on paper followed by elution of the individual steroids and their quantitative measurement by the Zimmermann reaction. EXPERIMENTAL A. Varying amounts of β-glucuronidase¹ were added to 25-ml. portions of a pooled male urine specimen after adjusting to pH 5, and the urines incubated at 37° C. for forty-eight hours. The 17-ketosteroids were extracted with ether-chloroform (4:1) (6) and determined by the Wilson micro-modification of the Callow method (7). The results (Table 1) show that a minimum of 50 units of liver β-glucuronidase per ml. of urine was necessary for maximum release of 17-ketosteroids.