CONVERSION OF CORTISONE TO COMPOUND F

Abstract

In this Journal Burton, Keutmann, and Waterhouse (1) published data concerning excretion of corticosteroids in patients treated with cortisone. They concluded that cortisone is convertible into compound F in the human body and that an extra-adrenal mechanism is the most important one. In enzymatic studies we have confirmed these findings (2). After the incubation of cortisone with liver homogenates of rat, pork, and beef we demonstrated the presence of 17-hydroxycorticosterone (compound F) on paper chromatograms. The activity of rat liver in transforming cortisone to compound F varied from 10 to 80 per cent of the incubated cortisone; beef adrenals showed considerably less activity; rat kidneys and muscles gave negative results. The highest activity was in whole liver homogenates. After a differential centrifugation procedure microsomes, not mitochondria, were most active, whereas the supernatant fraction obtained at 105400 ×g demonstrated no activity. These data indicate that the enzyme system is associated with the structural elements of the liver cells. Diphosphopyridine nucleotide, ascorbic acid, citric acid, and oxygen stimulated the conversion. As2O3, NaCN, and nitrogen had the reverse effect.