Über die adrenale Steroid‐Biosynthese in vitro I. Umwandlung endogener und exogener Vorstufen im Nebennieren‐Homogenat des Rindes

The conditions of the adrenal steroid biosynthesis in vitro have been thouroughly studied, using beef adrenal cortex homogenate with endogenous and exogenous precursors. The preformed endogenous precursor has been identified with cholesterol. Its aerobic incubation produced a 10–30‐fold increase of the amount of originally present corticosteroids, such as cortisol, corticosterone, aldosterone, 18‐hydroxy‐corticosterone and 19‐hydroxy‐corticosterone. From a wide variety of exogenous precursors studied so far, corticosterone proved quantitatively to be the best precursor for aldosterone, whereas the pathway involves probably 18‐hydroxy‐corti‐costerone. The results suggest that the optimal conditions for the formation of aldosterone are different from those for other corticosteroids. The methods used are fully described.